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Aims: To assess whether a whole-herd lameness score on a New Zealand dairy farm in spring could predict lameness prevalence on the same farm in summer (and vice versa) and whether a single-herd lameness score could be used to determine whether herd lameness prevalence was < 5% in both spring and summer. Methods: Prevalence data (proportion of the herd with lameness score ≥ 2 and with score 3; 0–3 scale) from a study where 120 dairy farms across New Zealand were scored in spring and in the following summer were analysed using limits-of-agreement analysis. In addition, farms were categorised as having either acceptable welfare (lameness prevalence < 5% in both spring and summer) or not (lameness prevalence ≥ 5% in either spring or summer or both). The accuracy and specificity of a single, whole-herd lameness score at identifying herds with acceptable welfare were then calculated. Results: The limits-of-agreement analysis suggests that 95% of the time, the prevalence of lameness in summer would be expected to be between 0.23 and 4.3 times that of the prevalence in spring. The specificity and accuracy of identifying a farm as acceptable on both occasions from a single observation were, respectively, 74% and 92% in spring, and 59% and 87% in summer. Conclusions: A single, one-off, whole-herd lameness score does not accurately predict future lameness prevalence. Similarly, acceptable status (lameness prevalence < 5%) in one season is not sufficiently specific to be used to predict welfare status in subsequent seasons. Clinical relevance: Whole-herd lameness scoring should be used principally as a means of detecting lame cows for treatment. A single whole-herd lameness score by an independent assessor should not be used to determine a herd's welfare status. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effect of preservation by addition of yoghurt starter, potassium sorbate and citric acid on counts of aerobic bacteria, Lactobacillus spp., Streptococcus thermophilus and coliforms, Brix percentage, pH, protein, fat and anhydrous lactose concentrations at 0, 7 and 14 days after collection for colostrum stored at ambient temperature. Method: Approximately 2 L of first milking colostrum was collected from 10 farms in the Waikato region. Following mixing, it was split into five 400-mL sub-samples and allocated randomly to a control (two sub-samples), or treatment with yoghurt, potassium sorbate, or citric acid preservative. Throughout the trial samples remained in the laboratory at ambient temperature with the lids slightly ajar, and were stirred daily for 15–30 seconds using a sterile spatula. Sub-samples were tested on Days 0, 7 and 14. On Days 0 and 14 aerobic bacteria (by aerobic plate count (APC)), Lactobacillus spp., coliforms and Streptococcus thermophilus counts, pH, Brix percentage, protein, fat and anhydrous lactose were measured. On Day 7 only bacterial counts were completed. The data were analysed using non-parametric clustered bootstrap sampling to estimate the effect of treatment, time, and their interaction on the outcome variables. Results: Compared to control samples, on Day 7 the APC for potassium sorbate (1.0 (90% CI = 0.6–1.6) × 108 cfu/mL) was approximately seven-fold lower than for yoghurt (7.3 (90% CI = 4.1–11) × 108 cfu/mL), and approximately three-fold lower than citric acid (3.2 (90% CI = 0.2–4.3) × 108 cfu/mL) remaining low to Day 14. All preservatives reduced coliform growth compared to control samples at Day 7 but growth was lower for potassium sorbate than the other preservatives. For Lactobacillus spp., at Day 7, samples with yoghurt preservative had greater counts than the other two preservatives. Potassium sorbate reduced growth of S. thermophilus compared to the other treatments, especially at Day 7, with 7–10 times fewer S. thermophilus per mL compared to the other three groups. All groups showed an obvious acidification over time, with very little variation within days and treatment groups. There was no evidence for change in fat or protein percentage over time regardless of treatment. Conclusion and clinical relevance: Aerobic and coliform bacteria proliferate extensively in unpreserved colostrum. All preservatives decreased coliform counts compared to un-preserved colostrum, but potassium sorbate was more effective at decreasing both coliforms and aerobic bacteria than either yoghurt or citric acid. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effect of injection of trace mineral supplement (TMS) 14–28 days before calving on white blood cell count (WBCC) and function, serum antioxidant capacity (SAC) and reactive oxygen species (ROS) in pasture-fed cattle after calving. Methods: On each of two South Island, seasonally calving, pastoral dairy farms,1 month before dry-off, a random sample of 150 multiparous cows predicted to calve within 7 days of the herd's planned start of calving (PSC) were stratified on individual somatic cell count, age, breed and expected calving date. On each farm, 14–24 days before PSC, 60 selected cows were randomly assigned for TMS (Zn, Mn, Se, Cu) injection, and 60 were controls. All 240 cows were contemporaneously injected with hydroxocobalamin, and controls with Se. Blood samples were collected pre-injection and 3, 12 and 40 days after calving. Phagocytic activity, count and proportion of neutrophils, lymphocytes and monocytes, WBCC, ROS, SAC were measured. Plasma concentrations of Se, Cu and glutathione peroxidase (GPx) were monitored from a random subset of animals. Differences attributable to TMS were estimated using mixed-multivariable Bayesian analysis, expressed as mean and highest density interval (HDI). Results: Three and 40 days after calving, TMS-treated cows had 0.36 (90% HDI = 0.00–0.77) x 109 and 0.25 (90% HDI = 0.00–0.55) x 109 fewer neutrophils/L. Neutrophils comprised 6 (90% HDI = 0–11)% and 4 (90% HDI = 0–8)% less of the WBCC, and the neutrophil count was 14 (90% HDI = 0–27)% and 9 (90% HDI = 0–18)% less than controls. However, 3 days after calving, there were 7 (95% HDI = 2–12)% more cells phagocytosing and 2,900 (95% HDI = 2,600–3,200) more bacteria ingested/cell. Twelve and 40 days after calving, TMS-treated cows had 0.65 (95% HDI = 0.17–1.17) x 109 and 0.28 (95% HDI = 0.00–0.59) x 109 more lymphocytes/L. Lymphocytes comprised 10 (95% HDI = 3–18)% and 5 (95% HDI = 0–9)% more of the WBCC, and the lymphocyte count was 30 (95% HDI = 11–51)% and 9 (95% HDI = 0–9)% more than controls. There were no meaningful differences in ROS, SAC, ROS/SAC, other white blood cells, or WBCC. Plasma Cu, Se and GPx concentrations were above recommended thresholds. Conclusions: Pre-calving TMS injection was associated with differences in white blood cell population and function that may reduce the risk of disease. Abbreviations: BHOB: Beta-hydroxybutyrate; GPx: Glutathione peroxidase; HDI: Highest density interval; MESF: Molecules of equivalent soluble fluorophore; OSi: Oxidative stress index; PSC: Planned start of calving; ROPE: Region of probable equivalence; ROS: Reactive oxygen species; SAC: Serum antioxidant capacity; THI: Temperature humidity index; TMS: Trace mineral supplement; WAIC: Widely applicable information criterion; WBCC: White blood cell count. [ABSTRACT FROM AUTHOR]

To identify farm-level risk factors for dairy cow lameness, and to describe lameness treatment protocols used on New Zealand dairy farms. One hundred and nineteen farms from eight veterinary clinics within the major dairying regions of New Zealand were randomly enrolled into a cross-sectional lameness prevalence study. Each farmer completed a questionnaire on lameness risk factors and lameness treatment and management. Trained observers lameness scored cattle on two occasions, between October–December (spring, coinciding with peak lactation for most farms) and between January–March (summer, late lactation for most farms). A four-point (0–3) scoring system was used to assess lameness, with animals with a lameness score (LS) ≥2 defined as lame. At each visit, all lactating animals were scored including animals that had previously been identified lame by the farmer. Associations between the farmer-reported risk factors and lameness were determined using mixed logistic regression models in a Bayesian framework, with farm and score event as random effects. A lameness prevalence of 3.5% (2,113/59,631) was reported at the first LS event, and 3.3% (1,861/55,929) at the second LS event. There was a median prevalence of 2.8% (min 0, max 17.0%) from the 119 farms. Most farmers (90/117; 77%) relied on informal identification by farm staff to identify lame animals. On 65% (75/116) of farms, there was no external provider of lame cow treatments, with the farmer carrying out all lame cow treatments. Most farmers had no formal training (69/112; 62%). Animals from farms that used concrete stand-off pads during periods of inclement weather had 1.45 times the odds of lameness compared to animals on farms that did not use concrete stand-off pads (95% equal-tailed credible interval 1.07–1.88). Animals from farms that reported peak lameness incidence from January to June or all year-round, had 0.64 times odds of lameness compared to animals from farms that reported peak lameness incidence from July to December (95% equal-tailed credible interval 0.47–0.88). Lameness prevalence was low amongst the enrolled farms. Use of concrete stand-off pads and timing of peak lameness incidence were associated with odds of lameness. Veterinarians should be encouraging farmers to have formal lameness identification protocols and lameness management plans in place. There is ample opportunity to provide training to farmers for lame cow treatment. Management of cows on stand-off pads should consider the likely impact on lameness. [ABSTRACT FROM AUTHOR]

To undertake a survey of the prevalence of tail deviations, trauma and shortening on a representative selection of New Zealand dairy farms, and to assess whether sampling based on milking order could be used instead of random sampling across the herd to estimate prevalence. This was a cross-sectional observational study, with 200 randomly selected farms enrolled across nine regions of New Zealand via selected veterinary practices (one/region). Veterinary clinics enrolled 20–25 farms each depending on region, with 1–2 trained technicians scoring per region. All cows (n = 92,348) present at a milking or pregnancy testing event were tail scored using a modified version of the New Zealand Veterinary Association Industry Scoring System. Palpated lesions were recorded as deviated (i.e. non-linear deformity), shortened (tail shorter than normal) or traumatic (all other lesions). The location of lesions was defined by dividing the tail into three equal zones: upper, middle and lower. A cow could have more than one lesion type and location, and/or multiple lesions of the same type, but for the prevalence calculation, only the presence or absence of a particular lesion was assessed. Prevalence of tail damage calculated using whole herd scoring was compared to random sampling across the herd and sampling from the front and back of the milking order. Bootstrap sampling with replacement was used to generate the sampling distributions across seven sample sizes ranging from 40–435 cows. When scoring all cows, the median prevalence for deviation was 9.5 (min 0.9, max 40.3)%; trauma 0.9 (min 0, max 10.7)%, and shortening was 4.5 (min 1.3, max 10.8)%. Deviation and trauma prevalence varied between regions; the median prevalence of deviations ranged from 6% in the West Coast to 13% in Waikato, and the median prevalence of all tail damage from 7% in the West Coast to 29% in Southland. Sampling based on milking order was less precise than random sampling across the herd. With the latter and using 157 cows, 95% of prevalence estimates were within 5% of the whole herd estimate, but sampling based on milking order needed > 300 cows to achieve the same precision. The proportion of cows identified as having damaged tails was consistent with recent reports from New Zealand and Ireland, but at 11.5%, the proportion of cows with trauma or deviation is below acceptable standards. An industry-wide programme is needed to reduce the proportion of affected cows. [ABSTRACT FROM AUTHOR]

To investigate the effect of parenteral vitamin B12 supplementation on the growth rate of dairy heifer calves over the summer and autumn on seven farms from the Central Plateau of New Zealand, an area historically associated with low cobalt levels in grazing pasture. This was a controlled clinical trial conducted on a convenience sample of seven farms with young female calves randomly assigned to three vitamin B12 treatment groups and followed through a grazing season. Two treatment groups received either monthly SC injections of a short-acting (SA) B12 formulation or 3-monthly injections of a long-acting (LA) B12 formulation and the third group received no treatment (NT). No additional parenteral vitamin B12 was given; however, all calves received additional cobalt (0.04–0.4 mg Co/kg liveweight) in the mineralised anthelmintic drenches given orally every month. Liveweight was recorded in December/January and at the end of the trial in May/June/July depending on farm. Pasture cobalt concentrations (mg/kg DM) were measured every month using 500-g herbage samples from 100-m transects in the area about to be grazed by the trial groups. There was evidence for a difference in growth rate between groups with mean final weight of 228 (95% CI = 212–243) kg for the LA groups, 224 (95% CI = 209–239) kg for the SA groups and 226 (95% CI = 211–241) kg for the NT groups respectively, (global p-value = 0.014). Calves given SA vitamin B12 were 3.77 (95% CI = 0.71–6.82) kg lighter than calves given LA vitamin B12 (p = 0.011). There was no evidence for a change in pasture cobalt concentrations (p = 0.32). The results of this trial raise the question as to whether the routine use of vitamin B12 supplementation in young cattle from areas traditionally thought to be cobalt deficient is necessary, and further raise the possibility that vitamin B12 supplementation by repeated injection of SA products may negatively impact growth rates. [ABSTRACT FROM AUTHOR]

To evaluate, in a pasture-based dairy herd, the response to a three-time point hoof trimming regime on lameness incidence and time from calving to observation of an elevated locomotion score (LS). This study was conducted on a 940-cow spring-calving herd in New Zealand's North Island between May 2018 and May 2019. Cows (n = 250) were randomly allocated to the hoof trimming group, with the remainder assigned to the non-trim cohort. One trained professional hoof trimmer used the five-step Dutch method to trim the hind feet of the trimming group. Throughout the subsequent production season, the whole herd was locomotion-scored fortnightly using the 4-point (0–3) Dairy NZ lameness score. Kaplan–Meier survival curves were used to assess the univariable effect of trimming on the interval between calving and first LS of ≥ 2 and first LS ≥ 1. A multivariable Cox proportional hazards regression was used to further evaluate the effect of trimming on time to elevated LS. Mean lameness (LS ≥ 2) prevalence was 2.6%, with 30% of cows having ≥ 4 observations during the study period when at least one LS was ≥ 2. For LS ≥ 1, mean prevalence was 40%, with 98.6% of cows having ≥ 4 observations during the study period when at least one LS was ≥ 1 during lactation. Hoof trimming had no apparent effect on the incidence of clinical lameness (LS ≥ 2) (trimmed vs. non-trimmed: 33.2% vs. 28.8%, respectively), but for LS ≥ 1, there was a small decrease in the incidence of LS ≥ 1 (trimmed vs. non-trimmed: 96.9% vs. 99.3%, respectively). The hazard of a cow having a first observed LS ≥ 2 in the control group was 0.87 (95% CI = 0.66–1.14) times that of the trimmed group; however, the hazard of a cow having a first LS ≥ 1 was 1.60 (95% CI = 1.37–1.88) times higher in the control than in the trimmed group. On this farm, prophylactic hoof trimming had no clinically relevant impact on the incidence of clinical lameness and was not associated with clinically beneficial reductions in time to first observed LS ≥ 2. This may be because claw horn imbalance was not pronounced on this farm, with 53% of cows needing no trim on either hind limb on the first trimming occasion. Further research on the response to prophylactic trimming in pasture-based dairy cattle is required. [ABSTRACT FROM AUTHOR]

To describe the time in days for lame dairy cows to recover after diagnosis and treatment of claw horn lameness, and to investigate whether cure rates differed between farms. Five dairy farms in the Waikato region were conveniently enrolled into a descriptive epidemiological study. Three of these farms had dairy cattle enrolled over two consecutive seasons, while two farms enrolled for one year. Lame cattle diagnosed by the farmers were enrolled into the study if they had a lameness score (LS ≥ 2 on a 0–3 scale) and claw horn lesions. All enrolled animals were treated by a single veterinarian following a consistent methodology, and subsequently assessed for LS at a median frequency of 4 days from enrolment until they were sound (LS = 0). The times (days) taken for animals to become sound and non-lame (LS < 2) were reported for all animals, and Kaplan–Meier survival curves used to present the results. A Cox-proportional hazard model was used to assess if the hazard of soundness was associated with farm, age, breed, lesion, number of limbs involved, and LS at enrolment. A total of 241 lame cattle with claw horn lesions were enrolled across the five farms. White line disease was the predominant pain-causing lesion in 225 (93%) animals, and blocks were applied to 205 (85%) of enrolled animals. The overall median days from enrolment to becoming sound was 18 (95% CI = 14–21) days, and 7 (95% CI = 7–8) days to become non-lame. A difference in the hazards of lameness cure between farms was identified (p = 0.007), with median days to lameness cure between farms ranging from 11 to 21 days. No associations were identified between age, breed, limb, or LS at enrolment on the lameness cure rates. Treatment of claw horn lameness following industry-standard guidelines in dairy cattle on five New Zealand dairy farms resulted in rapid cure, although cure rates differed between farms. Following industry best-practice lameness treatment guidelines, including frequent use of blocks, can result in rapid lameness cure rates in New Zealand dairy cows. This study also suggests that management of lame cattle on pasture can positively benefit their welfare and recovery times. The reported cure rates provide veterinarians with benchmarks on the length of time after which a lame animal should be re-examined, and in the investigation of poor treatment response rates at the herd level. [ABSTRACT FROM AUTHOR]

To compare the retention by New Zealand dairy cows kept at pasture in a lame cow group, of three hoof block products commonly used in the remediation of lameness. Sixty-seven farmer-presented Friesian and Friesian x Jersey dairy cows from a single herd in the Manawatū region (New Zealand) suffering from unilateral hind limb lameness attributable to a claw horn lesion (CHL) were randomly allocated to one of three treatments: foam block (FB), plastic shoe (PS) and a standard wooden block (WB). Blocks were applied to the contralateral healthy claw and checked daily by the farm staff (present/not present) and date of loss was recorded. Blocks were reassessed on Day 14 and Day 28 and then removed unless further elevation was indicated. Daily walking distances were calculated using a farm map and measurement software. Statistical analyses included a linear marginal model for distance walked until block loss and a Cox regression model for the relative hazard of a block being lost. Random allocation meant that differences between products in proportion used on left or right hind foot or lateral or medial claw were small. Mean distance walked/cow/day on farm tracks whilst the block was present was 0.32 (min 0.12, max 0.45) km/day; no biologically important difference between products in the mean distance walked was identified. Compared to PS, cows in the WB group were five times more likely to lose the block (HR = 4.8 (95% CI = 1.8–12.4)), while cows in the FB group were 9.5 times more likely to lose the block (HR = 9.5 (95% CI = 3.6–24.4)). In this study, PS were retained for much longer than either FB or WB. As cows were managed in a lame cow group for the study duration, walking distances were low and did not impact on the risk of block loss. More data are needed to define ideal block retention time. In cows with CHL the choice of block could be based on the type of lesion present and the expected re-epithelisation times. [ABSTRACT FROM AUTHOR]

To design a monitoring strategy that could be applied to regular veterinary visits to dairy farms to assess the prevalence and association between health conditions (uterine disease, hyperketonaemia and suboptimal body condition score) when diagnosed and treated at 1–7 days post-calving (DPC) and then re-examined at 28–35 DPC. This study evaluated data from 187 high-yielding dairy cows (21 primiparous, 166 multiparous) on one South Australian dairy farm on two occasions; Visit A which was 1–7 DPC and Visit B which was 28–35 DPC. On each visit, the nature of vaginal discharge, concentration of beta-hydroxybutyrate (BOH) in blood and BCS were recorded and assigned a clinical score. This was converted to a categorical outcome denoting the presence or absence of an abnormal health event, namely metritis or endometritis, hyperketonaemia (BOH concentration ≥1.2 mm/L) and suboptimal body condition score (>0.5 from optimum score). Cows with uterine disease or hyperketonaemia at either visit were treated. The prevalence of abnormal health events at each visit was determined and the association between the prevalence of disease at Visit A and Visit B (following appropriate treatment at Visit A) was measured using regression analysis. The prevalence of abnormal vaginal discharge, hyperketonaemia and suboptimal BCS at Visits A and B were 26%, 7%, 35% and 25%,16%, 33% respectively. A higher proportion of primiparous cows (Visit A: 0.86 (95% CI = 0.70–1.00); Visit B: 0.95 (95% CI = 0.86–1.00)) were found to have suboptimal BCS at both visits compared to multiparous cows (Visit A: 0.28 (95% CI = 0.20–0.35); Visit B: 0.24 (95% CI = 0.17–0.32)). A higher prevalence of hyperketonaemia at Visit B for multiparous compared to primiparous cows (19 (95% CI = 12–25)% vs. 0 (95% CI = 0–17) respectively) was identified. An increase in clinical discharge score at Visit A increased the odds of purulent vaginal discharge at Visit B (OR = 1.77 (95% CI = 1.31–2.40)). Failing to calve at target BCS was strongly associated with cows missing target BCS at Visit B (OR = 5.77 (95% CI = 2.35–13.11)) and for every unit increase in BCS at Visit A, BCS at Visit B increased by 0.40 (95% CI = 0.26–0.53). This study describes a pilot monitoring strategy for clinical parameters indicative of post-partum disease at 1–7 and 28–35 DPC. Determining the herd prevalence of these conditions will enable tracking of herd disease status over time. Abbreviations: BCS: Body condition score; BOH: Beta-hydroxybutyrate; DPC: Days post-calving; NEFA: Non-esterified fatty acids; SCHK: Subclinical hyperketonaemia [ABSTRACT FROM AUTHOR]

To assess whether adding glutamate dehydrogenase (GDH) activity measurements to measurements of gamma-glutamyl transferase (GGT) activity appreciably increases the accuracy of diagnosis of subclinical facial eczema (FE) in cattle. As part of a larger study on the impact of FE on productivity, GGT and GDH activities were measured in serum samples collected from 426 cattle from one dairy farm in the Taranaki region in April 2018. Bayesian latent class analysis was then used to estimate herd prevalence of subclinical FE as well as the specificity and sensitivity of the activity in serum of GGT or GDH alone, and of GGT and GDH activities combined, as diagnostic tests for subclinical FE. The latent class analysis estimated the true prevalence of subclinical FE in the study population as 47.5 (95% probability interval (PI) = 38.3–55.3)%. There was no evidence of any clinically relevant difference between GGT and GDH activities as predictors of subclinical FE; the difference between the areas under the receiver operating characteristic curves for the two measures was 0.005 (95% PI = –0.02 to –0.03). Using the two tests in parallel, with a threshold of 50 IU/L for GGT and 225 IU/L for GDH resulted in specificity and sensitivity of >95%, markedly increasing the accuracy of diagnosis of subclinical FE compared to using GGT or GDH alone at any threshold In this herd, combining the two tests resulted in a clinically relevant improvement in the accuracy of diagnosis of subclinical FE compared to using either test alone, which if used at the individual level will result in fewer cattle being assigned the wrong FE status. This will also apply at the herd level, with combined testing producing fewer false-positive herd test results than using one enzyme alone. This is particularly important for monitoring the efficacy of FE control measures when the expectation should be that the proportion of cattle with FE is very low. [ABSTRACT FROM AUTHOR]

To investigate the relationship between Zn concentrations in serum and those in milk or faeces, and to assess the ability of the Zn concentrations in milk, serum and faeces to predict intake of ZnO in dairy cattle. Seventy cows from one commercial farm in the Waikato region of New Zealand received one of seven dose rates (0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 g/100 kg bodyweight (BW)) of ZnO given by oral drench, every morning, for 7 consecutive days. Every afternoon, milk and blood samples were collected from all cows. Free-catch faecal samples were collected during the afternoon milking on 3 days throughout the trial. Linear mixed models were used to assess the relationship between the concentration of Zn in serum and that in milk, and in faeces, respectively, and the relationship between dose rate of ZnO and concentrations of Zn in serum, faeces and milk, respectively. Receiver operating characteristic curve analysis was used to determine the ability of the Zn concentration in serum, milk and faeces to predict that a cow had been treated with a dose of ZnO ≥2.5 g/100 kg, the industry-recommended dose rate needed to protect against facial eczema. A 1-µmol/L increase in Zn concentration in milk was associated with a 0.14 (95% CI = 0.11–0.17) µmol/L increase in Zn concentration in serum. Zn concentration in faeces was scaled by its SD; a 1 SD increase was associated with a 1.83 (95% CI = 0.54–3.12) µmol/L increase in zinc concentration in serum. Zn concentrations in serum and faeces increased with increasing dose rates of ZnO. No differences in Zn concentrations in milk were noted between animals dosed with 1.5–3.5 g ZnO/100 kg BW, inclusive. At the optimal threshold of Zn concentration in serum to predict protective ZnO intake (22 µmol/L), the sensitivity was 0.76 (95% CI = 0.69–0.82) and specificity 0.85 (95% CI = 0.80–0.89). For the concentration of Zn in faeces, the optimal threshold was 17.36 mmol/kg, with a corresponding sensitivity of 0.84 (95% CI = 0.84–0.85) and specificity of 0.85 (95% CI = 0.73–0.94). At the optimal threshold for the Zn concentration in milk (76.6 µmol/L), the sensitivity was lower than the other two sample types at 0.59 (95% CI = 0.52–0.67), but with a similar specificity of 0.84 (95% CI = 0.79–0.88). The concentration of Zn in milk shows promise as an initial screening test to identify dairy farms that do not provide adequate zinc to provide protection against FE. [ABSTRACT FROM AUTHOR]

To determine the association between production of milk solids (MS) and liver damage from facial eczema (FE) in dairy cattle during autumn and to determine the most practical cut-off for serum gamma-glutamyl transferase (GGT) activity in predicting production loss. Farm history and Pithomyces chartarum spore counts identified herds likely to be affected by raised GGT activity in serum during autumn 2018 or 2019. In these herds, a pilot blood sample from 30 cattle was collected, followed by a full herd blood test within 2 weeks if in those 30 cattle one or more had GGT activities >300 IU/L. Individual MS production was measured within −5 – +12 days of a full herd blood test. Information about feeding Brassica spp. was collected from the farmer. Pooled sera from 10 randomly selected cattle from 10/11 farms with GGT >40 IU/L were tested for anti-Fasciola antibodies. The association of liver damage and production of MS was analysed using mixed linear regression. Potential risk factors included farm, cow age, MS at last herd test before the likely FE risk period, breed of cow and GGT activity. Subsequently, GGT activity thresholds, from 40–400 IU/L, were used to indicate varying severities of liver damage. For each threshold, a mixed linear model using herd test data produced estimated marginal mean differences in MS production for cows above or below threshold. The prevalence of animals above threshold was multiplied by the per cow loss to obtain the reduction in MS/day/100 cows for each cut-off. The prevalence of animals with GGT activities > 40 IU/L ranged between farms from 11% (45/488) to 96% (139/145), and GGT activities for individual cows ranged from 3 – 6001 IU/L. From the model, an increase of 100 IU/L in GGT activity was associated with a decrease of 0.011 (95% CI = 0.010–0.012) kg MS/cow/day. A GGT activity threshold of 40 IU/L identified the largest association with MS production of 6.14 kg MS/day/100 cows. No evidence of significant liver fluke or brassica toxicosis was found. Liver damage was most likely caused by sporidesmin toxicity and was associated with substantial linear reduction in MS., When assessing the impact liver damage has on herd milk production, threshold and prevalence of animals exceeding threshold should be considered by the practitioner in assessing economically significant facial eczema. [ABSTRACT FROM AUTHOR]

To measure the prevalence of gross pathological damage in the livers of dairy cows at slaughter in the North Island of New Zealand in 2018 and 2019 and to determine, using Bayesian latent class analysis, the specificity and sensitivity of gross liver pathology score (GLS) as a method for detecting moderate to severe facial eczema (FE) at processing plants. Meat inspectors at four processing plants located in the Northland, Waikato, Bay of Plenty and Taranaki regions of New Zealand graded all dairy cattle livers on particular days in April and May of 2018 and 2019 using a gross liver pathology score (GLS) from 0–5 (0 = no damage, 1= fatty liver, 2 = cholangitis and early cirrhosis, 3 = cirrhosis, 4 = extensive cirrhosis, 5 = regeneration). Forty livers from each grade were selected for histopathology. Sections from the apical margin of the right and the left lobes were scored using a histology biliary score (HBS; scored from 1–16) based on the classical histological lesions of FE focussing on changes that differentiate FE from fasciolosis. Mean HBS was collapsed into scores 2–6 (no and mild damage) and score 7–12 (moderate and severe) and GLS was collapsed into grades 0–2 (no or mild damage) and grades 3–5 (moderate, severe and chronic damage). A Bayesian latent class model was developed to estimate sensitivity and specificity of HBS and GLS. The diagnostic target was moderate or severe, gross and/or histological changes in the liver consistent with FE. A total of 2,899 dairy cow livers were graded at the four plants over the two study periods. There were 700/2,899 (24.1%) livers with at least some form of gross pathology damage (GLS≥1) and 130/2,899 (4.5%) livers with moderate, severe or chronic gross pathology damage (GLS≥3). The estimates (posterior median) for the sensitivity and specificity of GLS to liver damage were 0.844 (95% credible interval (CrI) = 0.757–0.905) and 0.932 (95% CrI = 0.866–0.973) respectively. Estimates for HBS were 0.834 (95% CrI = 0.765–0.892) and 0.778 (95% CrI = 0.707–0.854), respectively. GLS is a useful means of estimating liver damage consistent with FE at slaughter. Increased use of liver scoring at slaughter could be useful for monitoring the likely impacts of FE at the country and regional levels. [ABSTRACT FROM AUTHOR]

Case history: Two commercial pasture-based farms within the North Canterbury district of New Zealand were feeding fodder beet (Beta vulgaris vulgaris L.) as a large proportion of the diet to cows during the dry period. On each farm 25 multiparous cows were blood sampled up to six times from 28 days before, to 21 days after calving (Day 0). Plasma samples were analysed for concentrations of β-hydroxybutyrate (BHBA), non-esterified fatty acid (NEFA), Ca, Mg and P, and aspartate aminotransferase (AST) activity. The first sampling visit was performed when cows were being fed their maximum intake of fodder beet. Clinical findings: The mean body condition score (BCS) of cows on Farm 1 was 5.4 (95% CI = 5.3–5.6) and on Farm 2, 5.4 (95% CI = 5.3–5.6) at first sampling. Mean concentrations of BHBA increased between Days −15 and Day −8 then decreased postpartum on Day 2 before increasing again on Day 21. On Farm 2, concentrations remained low (<1.2 mmol/L) on all days of sampling. Mean concentrations of NEFA in plasma remained low during the periparturient period on Farm 1, then increased on Day 2. On Farm 2, concentrations were elevated above 0.3 mmol/L between Days −28 and −17 then decreased on Day −10, before increasing on Day 2. Mean concentrations of Ca, Mg and P were higher than threshold values on both farms prepartum. However on Day 2, there were 8/23 (35%) cows on Farm 1 and 6/23 (26%) cows on Farm 2 with concentrations of Ca in plasma <2.0 mmol/L, and 10/23 (44%) cows on Farm 1 and 8/23 (35%) cows on Farm 2 with concentrations of P in plasma <1.3 mmol/L. Mean AST activities remained relatively constant and below 130 IU/L on both farms at all sampling times. Clinical relevance: On both farms, post-partum hypocalcaemia and hypophosphataemia were common after calving despite differing fodder beet feeding and mineral supplementation regimes. There was more variation in energy status, especially prior to calving. More research is required on factors affecting mineral and energy status in dry cows fed fodder beet. [ABSTRACT FROM AUTHOR]

Aims: To evaluate agreement between the concentration of Zn in serum from samples collected from cattle and sheep into standard collection tubes for serum and from samples collected into tubes developed for trace element measurement. Methods: Eighty-eight animals (78 cattle and 10 sheep) on eight farms had paired blood samples collected into standard serum and trace element vacutainers. The paired samples were submitted the same day to the laboratory to be tested for the concentration of Zn in serum using atomic absorption spectrophotometry. The agreement between the paired results was then assessed using limits of agreement analysis. On one farm an additional 10 pairs of samples was taken from the same animals; this second set of paired samples was refrigerated for 48 hours prior to laboratory submission to identify the impact of delaying submission on the apparent concentration of Zn in serum. Results: The limits of agreement analysis found no evidence of a systematic difference between Zn concentrations in serum collected into standard serum tubes and into trace element tubes as neither the intercept nor the slope on the mean-difference plot were significantly different from zero. The SD of the difference between results increased as the concentration of Zn increased, so at the lowest Zn concentration reported in this study (6.9 μmol/L) the limits of agreement were ±1.07 μmol/L, while at the highest (23.5 μmol/L) they were ±3.39 μmol/L. Refrigerating the sample (as whole blood) for 48 hours prior to submission increased the apparent concentration of Zn in serum in both standard serum tubes and trace element tubes by 1.3 μmol/L (95% CI = 0.75–1.85). Conclusions: There was no evidence that the concentration of Zn in serum from standard serum tubes were artificially elevated. In contrast, delaying sample submission by 48 hours did elevate Zn concentrations. Clinical relevance: While these data apply only to the batch of vacutainers used in this study, there is unlikely to be much between batch variation in the potential for contamination. Thus these results suggest that monitoring zinc status in ruminants, by measuring the concentration of Zn in serum from samples collected into standard serum tubes does not result in clinically relevant alterations in Zn concentration compared to using specific trace element tubes. However delaying submission to the laboratory may result in significantly elevated concentrations of Zn in serum so should be avoided. [ABSTRACT FROM AUTHOR]

Aims To compare wound healing 7 days after cautery disbudding of dairy calves treated immediately after disbudding with a traditional antimicrobial spray (OXY) or with a topical anaesthetic gel containing cetrimide, adrenaline and two local anaesthetics, lignocaine and bupivacaine (TA). Method Eighty-one female dairy calves between 6–8 weeks of age were disbudded using a standard cautery disbudding protocol (sedation, cornual block, and analgesia), with complete removal of the horn bud. After disbudding, the wound on the right and left horn buds within each animal were randomly allocated to receive either OXY or TA. One week after disbudding, wounds were visually assessed for the presence of exudate, necrotic tissue, crust, or granulation tissue which were each assigned a grade from 1–3, where 1 = no evidence, 2 = moderate presence; and 3 = marked presence. Results At 7 days after disbudding, the prevalence of wounds with exudate or necrotic tissue was very low, and independent of treatment. The odds of a disbudding wound treated with TA being scored as having granulation tissue and was 5.2 (95% CI = 1.72–15.7) times that of a wound treated with OXY. Conversely, the odds of wounds treated with TA being scored as having crusts was 0.18 (95% CI = 0.06–0.57) that of a wound treated with OXY. No sign of infection was seen in any calves. Conclusion and clinical relevance The greater prevalence of granulation tissue and reduction in crusting in disbudding wounds treated with topical anaesthetic gel compared to those treated with the antimicrobial spray suggests that use of the topical anaesthetic gel may speed wound healing compared to using antimicrobial spray. This should be further tested in a larger study undertaken over a longer period. [ABSTRACT FROM AUTHOR]

Aim: To estimate, ex vivo, the torque required to cause vertebral dislocation of cattle tails. Methods: Five tails from dairy cows, severed at the junction between the sacrum and the first caudal vertebra, were sourced from a slaughterhouse. Within 2 hours of slaughter, the severed end of each tail was clamped in a vice and a steel collar was placed halfway along the tail. A torque wrench was attached to the steel collar, which was then rotated to produce an audible and palpable vertebral dislocation, and the torque at the time of the break was recorded. Results: The maximum torque required to break a tail was 20 Nm, the minimum was 9.8 Nm, and the uncertainty was 4.9 Nm. Conclusion: The torque required to break a cow's tail is unlikely to be applied accidentally if cattle are handled following recommended best practice. Thus if cattle on a farm can be shown to have broken tails due to manipulation by farm staff, cattle handling is not meeting the recommended best practice of the New Zealand Dairy Cattle Code of Welfare. [ABSTRACT FROM AUTHOR]

In New Zealand, the recommended intake of Se for dairy cattle (0.03 mg/kg dry matter (DM)) is lower than in the United Kingdom and Australia (0.1 and 0.04 mg/kg DM, respectively), and much lower than in the United States of America (0.3 mg/kg DM). Advisors in New Zealand often suggest that New Zealand intake recommendations are far too low and that recommendations from the United States of America should be used. This has created confusion as farmers are given very different advice depending on which recommendations their advisor uses. In this review, we assess whether the published evidence supports the existing dietary requirements and associated Se status thresholds, or if change is required. We focus particularly on the evidence-base in cattle fed a primarily pasture-based diet, as it is critical that dietary recommendations are derived from data created using cows fed similar diets. Accordingly, we also consider whether the increased use of fodder crops, especially during the dry period, is likely to have altered the Se requirements of dairy cows in New Zealand. We report that the science behind the dietary requirements for Se is robust, being supported by factorial models validated using New Zealand data, and on-farm experimental studies. Published nutritional data suggest that the increased use of fodder crops is unlikely to have altered the dietary balance of pro- and antioxidant factors in New Zealand dairy cows in a way that would meaningfully affect Se requirements. However, the lack of specific data on the vitamin E and fatty acid content of the crops being fed in New Zealand means that more information is needed to confirm this conclusion. In general, the existing New Zealand recommendations for Se-status thresholds are supported, although studies are still lacking to properly characterise the upper threshold of the marginal range. Nevertheless many studies in New Zealand, of herds with marginal or low adequate Se status (using New Zealand recommendations), have failed to show an effect of Se supplementation on milk production, intramammary infection or reproductive performance, so it is highly unlikely that the upper threshold of the range is much higher than the current recommendation. Proponents of the hypothesis that Se intakes in New Zealand dairy cattle should be increased by at least 10 times the current recommendations are therefore not using the evidence base correctly. [ABSTRACT FROM AUTHOR]

The aim of this review is to critically assess the test characteristics and practicality of published data on direct and indirect tests for diagnosing failure of transfer of passive immunity (FPT) in dairy calves in New Zealand, to provide recommendations for veterinary practitioners, and to examine the recommended sample size for assessing herd-level prevalence of FPT and the confidence in the results obtained. The definition of FPT is based on measurement of concentrations of IgG in serum of neonatal calves after colostrum intake. The gold standard method for measurement of concentrations of IgG is radial immunodiffusion. However its cost, requirements for laboratory equipment, and the time taken to obtain results have meant that alternative tests have been developed. The turbidimetric immunoassay and ELISA also directly measure concentrations of IgG. Indirect tests include measurement of concentrations of total proteins (TP) in the laboratory or using a refractometer, γ-glutamyl transferase (GGT) activity, and the zinc sulfate turbidity (ZST) test. Of the indirect tests, measurement of concentrations of TP in the laboratory or using a refractometer combine high specificity and sensitivity with a consistent association with concentrations of IgG in calves between 1–7 days of age. Using a refractometer is less accurate than direct measurement in a laboratory, but is still a suitable test if low cost and speed are important. Although GGT activity is strongly associated with concentrations of IgG in serum, the relationship varies with time after birth. Therefore the target thresholds change with time, increasing error compared to the measurement of concentrations of TP in serum. Similarly, factors other than total concentrations of IgG have a significant effect on the association with ZST test, complicating interpretation. Thus, when direct measurement of concentrations of IgG is not feasible, the recommendation is that concentrations of TP in serum should be used as the diagnostic test for diagnosis of FPT, providing calves are not dehydrated. Using a sample size of 12 calves is suitable for estimating whether the herd-level prevalence of FPT is <20% or >20%, if there are no calves or >5 calves diagnosed with FPT, respectively, but is limited in diagnostic confidence when 1–4 calves test positive. Diagnostic interpretation can be significantly improved if tests of FPT are used alongside information on the likely risk of FPT on the tested farm. [ABSTRACT FROM AUTHOR]

Aims: To compare the effect of a topically applied anaesthetic to no pain relief or meloxicam on the behavioural responses, pain sensitivity and weight gain of calves following disbudding with or without sedation. Methods: A total of 364, 2–6 week-old calves from three commercial farms were systematically allocated to one of six treatment groups. All calves received a cornual nerve block prior to disbudding, with half restrained in a crate and half sedated with xylazine. Within these groups one third received no further treatment (control), one third were treated with meloxicam >10 minutes prior to disbudding and one third received a topical anaesthetic applied to the horn bud wounds following disbudding. The frequency of ear flicks, head shakes, head scratches and pain sensitivity of the wound were recorded on up to eight occasions over 24 hours after disbudding. Calves were weighed before, and 7 and 28 days after, disbudding to determine average daily weight gain (ADG). Results: Compared to calves in the crate-control group, all other groups had reduced ear flicks at all times following disbudding (p < 0.01). Treatment with meloxicam and topical anaesthesia in addition to sedation reduced head scratches compared to calves in the crate-control group (p ≤ 0.013). At 22 hours after disbudding head shakes were reduced in sedated calves treated with topical anaesthetic compared to calves in the crate-control group (p < 0.001). Pain sensitivity was lower in all sedated calves than unsedated calves (p < 0.001). The ADG between Days 0–7 was 0.14 (95% CI = 0.015–0.274) kg/day greater in sedated calves treated with meloxicam than calves in the crate-control group (p = 0.03), and the ADG between Days 0–28 tended to be 0.06 (95% CI=−0.01–0.13) kg/day greater in sedated calves treated with topical anaesthetic than calves in the crate-control group (p = 0.09). Conclusion and clinical relevance: Sedation of calves for disbudding reduced the pain experienced in the following 24 hours. There was a benefit to providing calves with topical anaesthetic following disbudding on behavioural responses and pain sensitivity, which was similar to that of treating calves with meloxicam. [ABSTRACT FROM AUTHOR]

Aims: To monitor the effect of using long-acting Zn boluses on the Zn status of a group of South American camelids, using measurements of concentrations of Zn in faeces and serum. Methods: As part of a facial eczema (FE) prevention programme, 15 camelids were treated with long-acting Zn boluses designed for preventing FE in sheep. Based on bodyweight, 13 alpacas (Vicugna pacos) received two boluses (26.4 g Zn/bolus) and two llamas (Lama glama) received three boluses. In order to monitor Zn status, measurements were made of concentrations of Zn in serum and faeces immediately prior to bolus treatment (Week 0) and 4, 6, 8 and 10 weeks later. Gamma glutamyl transferase (GGT) activity in serum was measured at Weeks 0 and 8. Results: Two alpacas regurgitated the boluses; in one case the animal was quickly re-treated but this was not possible in the second animal. Mean concentrations of Zn in faeces were higher at all time points compared to Week 0 (p < 0.001). Peak concentrations were measured at Week 8, and concentrations >120 mg/kg fresh weight (FW), suggested as being protective in calves, were only measured in all (13/13) treated camelids at Week 6. Mean concentrations of Zn in serum differed between weeks of sampling but changes were not consistent, and concentrations did not exceed 18 μmol/L following treatment. There was no evidence of a natural sporidesmin challenge during the study period and activity of GGT in serum of all animals was <45 IU/L. Conclusions: Treatment with Zn boluses significantly increased concentrations of Zn in faeces but not in serum, but peak concentrations in faeces were only detected 8 weeks after treatment. Clinical Relevance: The delay in achieving concentrations of Zn in faeces which were associated with protection against FE in calves, combined with the difficulties of administering boluses to camelids, means that we do not believe that Zn boluses should be used as the primary method for preventing FE in camelids. We recommend that FE prevention in camelids should focus on minimising spore production in pasture through the use of fungicides, grazing management and alternative forages, with boluses only used when it is thought that these methods are unlikely to provide sufficient protection against FE. Such use should always be under the guidance of a veterinarian and monitoring of serum GGT activity should be used to ensure that FE control is being achieved. [ABSTRACT FROM AUTHOR]

Aims: To assess the inter-observer agreement for detecting bovine digital dermatitis (BDD) lesions in digital colour photographs of the hind feet of cows, which had been taken while the animals were standing to be milked, between two trained observers. Methods: Thirty-six photographs were selected from a total of 184 photographs held by the first author (R1), who had classified them as negative (n=11) or positive (n=25) for BDD. They were delivered to a technician (R2) who had previously visually inspected cattle for BDD lesions, and who then recorded the photographs as being either BDD-positive or BDD-negative. The percentage agreement between R1 and R2, and two other inter-observer agreement statistics, Cohen's κ and Gwet's first-order chance correction agreement coefficient (AC1), were calculated. The cumulative membership probabilities of Cohen's κ and Gwet's AC1 were then calculated for different benchmark ranges of κ. Results: The percentage agreement between R1 and R2 was 33/36 (92%), Cohen's κ was 0.80 (95% CI=0.57-1.0) and Gwet's AC1 was 0.86 (95% CI=0.69-1.0). Based on the cumulative membership probabilities for Gwet's AC1, there was 75% probability that the two observers had almost perfect agreement (κ≥0.81). For both Cohen's κ and Gwet's AC1, there was >95% probability that the two observers had at least substantial agreement (κ≥0.61). Conclusions: The two trained observers had at least substantial agreement in identifying from a digital photograph as to whether BDD lesions were present or absent. Therefore results from the two could be used interchangeably. Clinical Relevance: Visual assessment for BDD lesions in the milking parlour can be subjective. However a high agreement between these two trained BDD inspectors means BDD prevalence reported from different regions in New Zealand by these two can be directly compared. [ABSTRACT FROM AUTHOR]

Case History: A group of 39, 19-22-month-old Friesian bulls were administered an ivermectin/closantel anthelmintic via intended S/C injection in the ischiorectal fossa on 15 June 2017 (Day 0). Over the next 50 days, 22 affected bulls presented various degrees of anorexia, abdominal pain and urine dribbling. Seventeen bulls were examined by transrectal ultrasonography which revealed urinary bladder distension in all 17, and peritoneal fluid accumulation in some. Overall, eight bulls died or were subjected to euthanasia. On-farm postmortem examination of three bulls revealed urinary bladder rupture. Clinical Findings: On Day 50 one affected live bull was admitted to Massey University for further investigation. This bull continuously dribbled urine and had an overtly distended urinary bladder as determined by rectal palpation and ultrasonography. Pathological Findings: Postmortem examination of this bull revealed a markedly distended urinary bladder, massive subcapsular and pericapsular renal oedema with retroperitoneal fluid accumulation, minimal hydronephrosis and no evidence of mechanical urinary outflow obstruction. The right ischiorectal fossa contained multifocal areas of tissue fibrosis that extended into areas innervated by the distal cutaneous branch of the pudendal nerve and the pelvic nerve. Histopathological changes consisted of extensive fibrosis, myonecrosis and neurodegeneration, and evidence of granulation tissue and inflammation at the putative injection site and in surrounding tissues. Diagnosis: A local inflammatory reaction at the presumed injection site together with localised peripheral neurodegeneration and myelopathy may have led to detrusor-sphincter dyssynergia causing urine retention. Clinical Relevance: These cases of urine retention and bladder rupture in cattle were of putative iatrogenic origin. Veterinarians should be aware of this rare complication after S/C injections in the ischiorectal fossa. [ABSTRACT FROM AUTHOR]

AIM: To determine the impact of sodium molybdate treatment, given weekly, on concentrations of Cu in liver, activity of liver enzymes, and weight gain over 4 weeks, in yearling bulls with elevated concentrations of Cu in liver. METHODS: The study was carried on two commercial grazing farms in the Otago region of New Zealand in yearling Friesian bulls (n=150 on Farm A and n=49 on Farm B) with mean concentration of Cu in liver >3,000 µmol/kg fresh weight. On Day 0, all animals were weighed and half were systematically allocated to treatment with sodium molybdate (3 mg/kg liveweight on Farm A and 7 mg/kg liveweight on Farm B); the remainder received no treatment (Control). Sodium molybdate was given as a drench weekly for 4 weeks and all animals were weighed again on Day 28. Ten animals on each farm (five from each treatment group) were systematically selected for blood sampling and liver biopsies on Days 0 and 28. Samples were analysed for concentrations of Cu in plasma, vitamin B12 in serum, activities of γ-glutamyl transferase, aspartate aminotransferase and glutamate dehydrogenase in serum, and concentrations of Cu and vitamin B12 in liver. Separate multivariable linear models were used to compare the change in outcome variables between Days 0 and 28 between bulls that had been drenched with sodium molybdate or not. RESULTS: On Farm A, mean concentrations of Cu in liver on Day 28, as a percentage of concentrations on Day 0, for the control group was 55 (95% CI=40-73)% and for the treatment group was 73 (95% CI=43-111)%. On Farm B, the equivalent mean for the control group was 75 (95% CI=42-131)% and for the treatment group was 85 (95% CI=38-134)%. The multivariable linear models indicated that the changes in concentrations of Cu in liver, activities of liver enzymes and weight gain between Days 0 and 28 did not differ between the bulls treated or not with sodium molybdate (p>0.18). CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with sodium molybdate in one bolus at weekly intervals for 4 weeks did not affect concentrations of Cu in liver, activity of liver enzymes or weight gain in animals with high concentrations of Cu liver on two farms. [ABSTRACT FROM AUTHOR]

AIMS: To gather information on management practices and farmer attitudes to management of cows and calves during the immediate post-partum period on dairy farms in New Zealand, and to assess these practices for associations with concentrations of total protein (TP) in serum of calves 1-8 days-old. METHOD: Between July and September 2015 blood samples were collected from calves aged between 24 hours and 7 days, from dairy farms (n=105) in nine areas in New Zealand, on three occasions throughout the calving period. Concentrations of TP were determined in all serum samples. At each visit technicians collected 1 L of the pooled colostrum that was intended for feeding to newborn calves that day. These samples were assessed for Brix, coliform and total bacterial counts. After the last sampling visit, the calf rearer or farm manager were asked to complete a questionnaire describing calf and colostrum management practices on the farm. Potential farm-level variables associated with concentrations of TP in serum of sampled calves were identified using univariable and multivariable linear mixed models. RESULTS: Mean concentration of TP in serum of calves across all farms was 59.8 (95% CI=59.4-60.2) g/L, and was associated with region and herd size in the final multivariable model. Concentrations of TP were lower in calves from farms in Otago (56.2 (95% CI=53.4-58.9) g/L) and Southland (56.9 (95% CI=54.1-59.7) g/L) compared to calves on farms in the Far North (62.6 (95% CI=59.8-65.3) g/L), and were lower in calves from farms with a herd size >600 (58.3 (95% CI=56.7-59.8) g/L) than ≤600 (61.3 (95% CI=60.1-62.5) g/L) cows. After accounting for fixed effects, farm accounted for only 8.4% of the unexplained variation. There was no association between any of the measures of colostrum quality and concentrations of TP in serum (p>0.2). CONCLUSION AND CLINICAL RELEVANCE: Very few herd-level variables were associated with concentrations of TP in serum. Risk factors that have been shown to be of importance in previous studies outside New Zealand were not identified as important in the current study. It is possible that, in the situation where calves are kept at pasture with their dams for prolonged periods, variables which influence how well a cow can feed its calf in the first 12-24 hours have a larger influence on concentrations of TP in serum than the collection and management of calves once they reach the rearing shed. [ABSTRACT FROM AUTHOR]

AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving. METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000 cells/mL at the first herd test after calving. RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000 cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000 cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30). CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis. [ABSTRACT FROM AUTHOR]

AIMTo determine the prevalence of failure of passive transfer (FPT) in dairy calves in New Zealand and to assess a range of potential calf-level risk factors for their association with FPT. METHODBetween July and September 2015, 107 dairy farms in nine regions across New Zealand were visited on three occasions: before 20% of cows had calved, when ∼50% of cows had calved, and when the last 10–20% of cows were calving. Farms were randomly selected from the client list of participating veterinary practices. On each farm, blood samples were collected from 10–20 calves between 24 hours and 8 days old and concentrations of total protein (TP) in serum determined. Calf identification, date of birth, dam’s age and breed, details of colostrum feeding and the farmer’s health assessment of the calf on arrival at the calf rearing facility were recorded. Concentrations of TP in serum ≤52 g/L were used to define FPT. RESULTSOf 3,819 calves sampled, 1,263 (33 (95% CI=31.6–34.6)%) were diagnosed with FPT, and the prevalence within farms ranged from 5–83%. Calf-level risk factors that were associated with increased odds of FPT were increasing age of dam (OR=1.12; 95% CI=1.08–1.16), calves recorded as unhealthy compared to healthy upon arrival at the calf rearing facility (OR=2.59; 95% CI=1.60–4.19), calves sampled on farms in Otago (OR=2.85; 95% CI=1.42–5.74) and Southland (OR 2.31; 95% CI=1.15–4.67) compared to the Far North, and calves sampled in the middle compared to the early calving period (OR=1.24; 95% CI=1.03–1.51). CONCLUSIONOn the farms visited FPT was diagnosed in one third of dairy calves. Calf-level risk factors for FPT included age of dam, health status of calf, region, and time of the calving period. Further investigations are required to establish why these are associated with increased odds of FPT. CLINICAL RELEVANCEThese results provide a baseline for benchmarking, which, alongside the reported calf-level risk factors, can be used by veterinarians to improve colostrum management. [ABSTRACT FROM AUTHOR]

Objective The aim of this research was to study the roles of the day 0 energy balance and gonadotrophin-releasing hormone ( GnRH) and progesterone levels on dominant follicle ( DF) and corpus luteum ( CL) development during the first 7 days of a gonadotrophin-prostaglandin-gonadotrophin ( GPG) + progesterone ( P4) program in anoestrous dairy cows. Methods Cows (n = 81) were allocated to one of the three treatments: (1) GPG + P4 (days 0 and 9, 100 µg GnRH; day 0-7, intravaginal P4 device; day 7, 500 µg PGF2α); (2) GPG (as for treatment 1 but excluding the P4 device) and (3) prostaglandin + GnRH + P4 (as for treatment 1, but excluding day 0 GnRH). DF and CL size, plasma concentrations of insulin, insulin-like growth factor-I ( IGF-I) and non-esterified fatty acid ( NEFA) were measured on days 0 and 7. Results The proportion of cows with a CL on day 7 was significantly different between groups ( GPG: 78%, GPG+ P4: 69%, PGF2α + GnRH + P4: 42%, P = 0.02). The CL volume on day 7 was significantly associated with treatment, treatment by time postpartum and plasma concentrations of insulin, IGF-I and NEFA. Conclusion In cows without a CL present on day 0 of an oestrus synchronisation program, removal of the day 0 GnRH treatment led to reduced CL development; however, no effect of adding progesterone was found. In contrast, in cows with a CL present on day 0 inclusion of a progesterone device led to a higher CL volume, but removal of the first GnRH injection had no effect. Response to the treatment was affected by plasma concentrations of insulin, IGF-I and NEFA. [ABSTRACT FROM AUTHOR]

AIMSTo examine the agreement between spore counts of Pithomyces chartarum measured in a single aliquot of wash water with counts from multiple aliquots from the same 60 g pasture sample, and between spore counts measured in an individual 60 g pasture sample with counts from three 60 g pasture samples selected from the same 200 g paddock sample. MATERIALS AND METHODSFour Waikato dairy farms were visited once weekly from early January to late May 2013. One paddock, with 40 sampling sites, was selected per farm. At each visit, ∼200 g of pasture was collected per site. Spore counting was undertaken using a standard method, except that three separate 60 g pasture samples per 200 g paddock sample was counted; and for each 60 g pasture sample, spores were counted in 10 aliquots of wash water. The relationship between the results of a single aliquot and 6–10 aliquots of wash water from the same 60 g grass sample were assessed by calculating 95% prediction intervals. Limits of agreement analysis was used to assess the agreement between counts from one, two or three aliquots per 60 g pasture sample compared with 10 aliquots, and between counts from one and three 60 g pasture samples from the same 200 g paddock sample. RESULTSComparing spore counts from individual aliquots with multiple aliquots resulted in large prediction intervals and 95% limits of agreement, which increased with increasing spore count. For an individual aliquot count of 2 spores, the 95% prediction interval for the count from 10 aliquots was 3–49 spores, and for an individual count of 10 spores the 95% prediction interval was 28–222 spores. Increasing the number of aliquots counted improved agreement. For a total count of 10 spores measured in 10 aliquots, the 95% limits of agreement, based on a single aliquot, were 2–50 spores, and for three aliquots were 5–20 spores. The agreement in spore counts measured in one compared with three 60 g pasture samples was moderate and also decreased with increasing spore count; the 95% limits of agreement were 4–14.5 for a mean spore count of 10. CONCLUSIONS AND CLINICAL RELEVANCEMeasuring the spore counts of three aliquots of wash water per 60 g grass sample improved repeatability, and should be used as the standard technique, particularly when determining whether to start or finish facial eczema control programmes. [ABSTRACT FROM PUBLISHER]

Background: ‪In this study, the factors related to the functional limitation were studied simultaneously using structural equation modeling. Material and methods: 1‪201 people aged 50 years and older were selected for this study using a stratified random sampling method from health centers of Bukan city in the northwest of Iran, in 2017. Trained interviewers collected information on demographic characteristics, socio-economic status, physical activity, history of falling/ fear of falling, visual and hearing condition, associated illnesses, social support, cognition, depression, assessed functional limitation and mobility of study participants. The structural equation modeling was used to analyze the data. Results: T‪he participants’ mean age was 59.2 ±7.97 yrs, of whom 61% were women. The result showed that the proposed conceptual model fitted well CFI (0.97), RMSEA (0.04), SRMR (0.06). Age (β = -0.45, p < 0.001), gender (β = -4.55, p = 0.004), and economic status (β = -3.57, p < 0.001), physical activity (β = -10.35, p = 0.025) and socio-psychological activity (β = -1.59, p < 0.001) negatively, and the variables of educational level (β = 2.34, p = 0.016), marital status (β = 5.43, p = 0.003), cognitive function (β = 0.66, p = 0.001), living environment (ground floor: β = 16.62, p < 0.001), duplex:(β = 5.19, p = 0.055), positively predicted the mobility limitation. Conclusions: ‪In this study, a range of socio-demographic factors, cognitive function, and living environment were identified as significant predictors of mobility limitation.

AIM: To evaluate the level of agreement of three indirect testing methods with concentrations of IgG in serum, and to determine their test characteristics for diagnosing failure of passive transfer (FPT), in dairy calves in New Zealand. METHODS: From 17 July to 30 November 2015, 471 blood samples were collected from dairy calves aged 0–8 days, from 19 different commercial dairy farms in the Waikato region of New Zealand. All serum samples were tested for concentrations of IgG and total protein (TP), and gamma-glutamyl transferase (GGT) activity, and 138 samples were tested using a digital Brix refractometer. The diagnostic tests were assessed for level of agreement with concentrations of IgG using Bland-Altman plots. FPT was defined as concentration of IgG ≤10.0 g/L and receiver operating characteristic curve analysis was used to determine optimal cut-points for correctly predicting FPT. The test characteristics for TP, GGT and Brix for predicting FPT were determined using the optimal cut-points. The effect of age on the relationship between test results and concentrations of IgG was also assessed. RESULTS: Based on the limits of agreement plots, the agreement with concentrations of IgG was greatest for concentrations of TP, followed by Brix, with the lowest being GGT activity. There was an interaction between age at sampling and the association between concentrations of IgG and GGT activity (p<0.001); in calves 5–8 days of age there was a greater increase in concentrations of IgG associated with a unit increase in GGT activity than in calves <5 days of age. The optimal cut-points for diagnosis of FPT were 52 g/L for concentrations of TP, 8.8% for Brix, 250 IU/L for GGT activity in calves <5 days old, and 210 IU/L for GGT activity in calves 5–8 days old. Accuracy for predicting FPT was greatest for TP (0.95), followed by GGT in calves <5 days old (0.94) and Brix (0.92). Specificities were high for all three tests, however sensitivity varied greatly. CONCLUSION: Measurement of concentrations of TP in serum was the most accurate alternative to measuring concentrations of IgG for diagnosing FPT in non-dehydrated calves. CLINICAL RELEVANCE: Veterinary practitioners in New Zealand now have confidence in using a test that is more accurate and practical than GGT and considerably cheaper than IgG to screen for FPT. [ABSTRACT FROM AUTHOR]

AIMS: To describe and evaluate the current practices used to manage and prevent facial eczema (FE) in North Island dairy herds, and determine the within-herd prevalence of cows with elevated activities of gamma glutamyl transferase (GGT), and with concentrations of Zn in serum <18 μmol/L. METHODS: Between January and May 2014, 105 herd managers from throughout the North Island of New Zealand were invited to participate in the study when regional spore counts forPithomyces chartarumstarted to rise towards 30,000 spores/g pasture. Managers selected 10 representative cattle that were weighed and blood-sampled by the herd veterinarian. Blood samples were analysed for concentrations of Zn in serum and GGT activity. Pasture samples were also collected and submitted for spore count estimation. Finally a survey of farm management practices relating to prevention of FE was completed by the herd manager. A mixed-effects logistic regression model was used to determine associations between herd-level and cow-level explanatory variables and the probability of a cow having a concentration of Zn in serum <18 µmol/L. RESULTS: Of the 1,071 cows tested, 79 (7.3 (95% CI=5.8–9.0)%) had GGT activity in serum >300 IU/L, and 35/106 (33 (95% CI=24.2–42.8)%) herds had ≥1 of the 10 cows sampled with GGT activity >300 IU/L. Of the 911 cows that were being treated with Zn, concentrations of Zn were between 18–35 μmol/L in 398 (43.6 (95% CI=40.4–46.9)%) cows, were >35 μmol/L in 32 (3.5 (95% CI=2.4–4.1)%) cows, and <18 μmol/L in 479 (52.6 (95% CI=49.3–55.9)%) cows. After adjusting for the confounding effect of region, the odds of a cow having concentrations of Zn in serum <18 μmol/L were 5.5 (95% CI=1.1–29) times greater for cows supplemented with zinc in water compared with those supplemented by drenching. Of the 105 herd managers, 103 (98%) stated that they had access to regional spore count data, but only 35/105 (33%) reported that they measured spore counts on their own farm. Overall, 98/105 (93%) managers reported that they had some form of FE management programme in place. Fungicides were used on their own or in combination with zinc treatments in 10 herds, ZnSO4in water troughs was used in 68 herds, oral drenching with ZnO in nine herds, and ZnO supplied in-feed in 26 herds. Estimated daily dose rates of zinc were less than that required to treat a 400 kg cow on 42/68 farms that administered ZnSO4in the water or ZnO as a drench. CONCLUSION AND CLINICAL RELEVANCE: This study has shown that FE management on dairy farms in the North Island of New Zealand could be substantially improved. It is likely that improved FE management would occur if herd managers were provided with more feedback on the success (or otherwise) of their FE management programmes. [ABSTRACT FROM PUBLISHER]

AIMS: To determine whether the application of lime or nitrogen to pasture affected the spore counts ofPithomyces chartarum. MATERIALS AND METHODS: The lime application studies were undertaken on a spring-calving, pasture-based, commercial dairy farm near Te Awamutu, New Zealand. On 6 November 2012, five randomly selected paddocks were split into three equal sections. In two of the sections, lime was applied at either 1.5 or 2.5 t/ha, and the central section was left as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. Starting in January 2013, five other randomly selected paddocks were monitored for spore counts. On 20 March 2013 the average spore counts in three paddocks were >100,000 spores/g of pasture. These paddocks were then divided into three equal sections and lime was applied as described above. Spore counting in each section continued weekly until 15 May 2013. The nitrogen application study was carried out on three commercial dairy farms near Te Awamutu, New Zealand. Two randomly selected paddocks on each farm were divided into three equal sections and, on 20 December 2012, nitrogen in the form of urea was applied at either 50 or 80 kg urea/ha to two of the sections; the central section remained as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. RESULTS: Following pre-summer lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.26). Similarly following autumn lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.11). Following nitrogen application median spore counts remained <20,000 spores/g pasture throughout the trial period and there was no effect of treatment on spore counts over time (p>0.49). CONCLUSION: This study found that application of lime before the risk period for facial eczema, in November, application of lime after a spore count rise, in March, or urea application in December did not affect changes in number of spores produced byP. chartarum. CLINICAL RELEVANCE: This study does not support previous suggestions that fertilising pasture with lime or urea could alter the spore counts ofP. chartarum. Fertiliser use does not provide an alternative to, or support, conventional methods of facial eczema control such as zinc prophylaxis or treatment of pasture with fungicides. [ABSTRACT FROM PUBLISHER]

A set of 18 × 0.5 ha paddocks at the DairyNZ research farm in Hamilton made up from three replicates of six sward mixes had pasture collected weekly from 31 January 2012 to 9 May 2012 and spore counts ofPithomyces chartarumwere determined. Low diversity (LD) meant that the paddock was sown with a single grass species (tall fescue, high sugar cultivar, ryegrass) and white clover. High diversity (HD) meant that the paddock was sown with a single grass species and white clover plus prairie grass, chicory, plantain and lucerne. The study aims were to assess the benefit of diversity and sward type in the control of facial eczema. There was no difference in spore counts over time between high diversity and low diversity pastures (P = 0.43). Both tall fescue paddocks (LD and HD) showed a lower spore count over time in comparison with low diversity ryegrass (P = 0.055 and 0.05). [ABSTRACT FROM AUTHOR]

AIM: To assess the effect of sedation and local anaesthesia (LA) at disbudding, and the addition of meloxicam or ketoprofen treatment, on weight gain in dairy calves following disbudding. METHODS: Friesian-Jersey cross calves, from four dairy farms, were enrolled when 3-6 weeks old. All calves (n=271) were disbudded by veterinary personnel and randomly assigned to six groups: 136 were disbudded without sedation or LA, of which 31 received 20 mg meloxicam S/C and 75 received 150 mg ketoprofen I/M. A further 135 were disbudded with sedation (0.25 mg/kg xylazine I/M) and LA, of which 30 also received meloxicam and 75 received ketoprofen. Calves were weighed 3 days before, and 15 and 30 days after, disbudding (Day 0). Daily weight gain was analysed using mixed models and ANOVA. RESULTS: Complete results were obtained from 263 calves. From Day −3 to Day 15, the growth rate of calves disbudded without pain relief (0.53 (95% CI=0.47-0.60) kg/day) was less that of calves disbudded with some form of pain relief (0.65 (95% CI=0.62-0.68) kg/d; p=0.004). There was no difference between the effect of meloxicam or ketoprofen (p=1.00). An interaction between use of sedation and LA and additional non-steroidal anti-inflammatory drugs (NSAID) meant that NSAID treatment did not increase growth rates in calves disbudded with sedation and LA but did increase growth rates for calves disbudded without pain relief (p<0.05). From Day 16 to Day 30 there was no effect of NSAID treatment on growth rate, but calves receiving LA and sedation grew faster (0.74 (95% CI=0.69-0.80) kg/day) than calves disbudded without LA and sedation (0.66 (95% CI=0.61-0.71) kg/day; p=0.018). From Day −3 to Day 30, calves disbudded with sedation and LA grew faster (0.71 (95%CI=0.64-0.77) kg/day) than calves disbudded without sedation and LA (0.60 (95% CI=0.55-0.65) kg/day; p=0.011). However, addition of NSAID to sedation and LA made no further difference to growth rates (p=0.69). CONCLUSIONS: Dairy calves disbudded with no pain relief had slower growth rates than calves receiving pain relief. From Day 15 to 30 calves given no pain relief, or NSAID alone, grew more slowly than those receiving sedation and LA at disbudding. The addition of NSAID treatment to sedation and LA did not further increase growth rates. CLINICAL RELEVANCE: This study adds to the evidence that pain management when disbudding is beneficial for calf productivity as well as calf welfare. [ABSTRACT FROM AUTHOR]

AIMS: To investigate the effect of targeted resynchronisation of cows treated for non-observed oestrus before the planned start of mating (PSM), that were not detected in oestrus or pregnant 23 days after treatment (phantom cows), on the proportion pregnant at 42 days after PSM and the end of mating. METHODS: Farm staff from eight herds in two regions of the South Island of New Zealand identified 1,819 cows not showing oestrus by 10 days before PSM. These cows were treated with intravaginal progesterone for 7 days, and I/M gonadorelin 10 days and 1 day before PSM. Three days before PSM they were injected with cloprostenol and equine chorionic gonadotrophin, with fixed time artificial insemination (FTAI) at PSM. By 23 days after PSM, 1,218 cows had not returned to oestrus. Of these, 161 cows confirmed not pregnant by transrectal ultrasonography were randomly assigned to no treatment (control group; n=74) or were resynchronised 25 days after PSM using the same treatment programme as above, with FTAI 35 days after PSM (n=87). All cows that returned to oestrus were artificially inseminated until 42 days after PSM, when natural mating was used. All cows were examined using transrectal ultrasonography 80 to 90 days after PSM to confirm conception dates. RESULTS: Of the 1,819 anoestrous cows treated before PSM, 526 (29 (95% CI=23.1-34.0)%) had not been observed in oestrus by 23 days after PSM and had not conceived, so were diagnosed as phantoms cows. For resynchronised cows, 42/87 (48 (95% CI=37.8-58.8)%) were pregnant by 42 days after PSM compared to 21/74 (28 (95% CI=18.1-38.7)%) control cows (p=0.009). At the end of mating 58/87 (67 (95% CI=56.6-76.7)%) cows in the resynchronised group were pregnant and 46/74 (62 (95% CI=50.9-73.2)%) in the control group (p=0.554). The hazard of conception from 21 to 42 days after PSM was 1.9 (95% CI=1.07-3.12) times greater for resynchronised than control cows (p=0.026). CONCLUSION: In cows not observed in oestrus and treated before PSM, resynchronisation increased the proportion pregnant by 42 days after PSM. CLINICAL RELEVANCE: The benefit of resynchronisation depends on the number of anoestrous cows before PSM and the number of phantom cows after PSM. However at the herd-level it is likely that providing advice to reduce the known risk factors for cows not being observed in oestrus before the PSM may well be more cost effective than identifying and treating a sub-population of phantom cows. [ABSTRACT FROM AUTHOR]

AIMS: To assess, in dairy cows between 60–160 days of gestation, whether the agreement between actual gestational age and that predicted by placentome size could be improved by using individual placentome measurements rather than a single average, and to identify how increasing the number of placentomes measured improved the prediction. METHODS: Data were obtained from 58 cows examined using transrectal ultrasonography every 10 days between 60–130 days, and every 15 days between 130–160 days of gestation. For each cow, four to six placentomes in each of the pregnant and non-pregnant horns were examined from the region of the uterus near to the cervix. A mixed-effects model, which included cow as a random effect, and a simple linear regression which ignored within-cow correlation, were fitted to the data. Inverse regression was used to compare the 95% prediction bands obtained for estimating gestational age using the means of three, five or eight placentome measurements. RESULTS: The fit of the mixed effects model was better than a simple linear regression (p<0.001) but the fitted lines from the two models were very similar. Using the simple regression model, for a mean placentome length of 15 mm estimated gestational age was 100 days, with 95% CI of 68–131 days for measurement of three placentomes, and 80–120 days for eight placentomes. CONCLUSIONS: The agreement between placentome size and gestational age was improved by increasing the number of placentomes measured. Direct comparison of these CI with those for other published fetal measures was not possible as similar prediction bands have not previously been calculated for fetal measures; however one study reported a residual SD which had been calculated using size measurements as the predictor variable and age as the response variable. Using these data 95% CI were calculated to be ±9 days for crown-rump length and ±25 days for uterine diameter. These are likely to be an underestimate of the true CI and do not take account of the increase in variance of the difference between predicted and actual gestational age as gestational age increases. CLINICAL RELEVANCE: Placentome measurement may be useful for estimating fetal age in late gestation. Further research is required to better establish the agreement between gestational age and the fetal measurements which are currently used to estimate fetal age. [ABSTRACT FROM PUBLISHER]

AIMS: To assess the feasibility of applying animal-based welfare assessments developed for use in Europe on New Zealand dairy farms; in particular, to identify measures which could be evaluated during a single visit at milking time alongside whole herd locomotion scoring. METHODS: A protocol for animal welfare assessment, developed in the United Kingdom (UK), was evaluated. Measures that were suitable for use on pasture-based dairy farms in New Zealand were then assessed for practicability on 59 farms across New Zealand, during and immediately after milking, alongside whole herd locomotion scoring. Where data were collected the results were compared to those from a UK study of 53 dairy farms. RESULTS: Thirteen observations of the physical condition of cows were considered suitable for measurement, excluding observations related to hock lesions as they are rarely observed on pasture-based farms. Five of these measures were not assessed as there was not time to do so during milking alongside whole herd locomotion scoring. Thus, the prevalence of dirty flanks, hind limbs and udders, dull coat, thick hairy coat, significant hair loss, very fat cows (body condition score (BCS) ≥7 on 1–10 scale) and very thin cows (BCS≤3), were recorded. Three measures of behaviour were considered suitable for measurement on-farm, but only locomotion score was practicable and was measured. Farmer-estimates for the incidence of mastitis, lameness, sudden death, milk fever and other diseases were also obtained.Overall, dirty flanks, dirty udders and estimated milk fever incidence were more prevalent in this study than in the UK. The prevalence of thin and fat cows, lame cows and estimated mastitis incidence were much lower in the present study than on UK farms. CONCLUSIONS AND CLINICAL RELEVANCE: Animal-based assessments can be used on dairy farms in New Zealand, but need to be modified from those developed for housed cows.Welfare on these farms was generally good compared to those in the UK, but these results need to be confirmed on more farms using a wider range of assessments than proved practicable in this study. [ABSTRACT FROM PUBLISHER]

AIM: To assess the effect of combining an internal teat sealant (ITS) and a long-acting cephalonium-based dry cow therapy (DCT) on the prevalence of cows with a somatic cell count (SCC) >150,000 cells/mL 60–80 days after calving, and the incidence of clinical mastitis diagnosed by farm staff in the first 100 days after calving. METHODS: Cows from a spring-calving, pasture-based, dairy farm in the South Canterbury region of New Zealand were randomly allocated to receive cephalonium DCT (n=289) or cephalonium and internal teat sealant (n=304) at the end of lactation. Cows were inspected twice daily by farm staff during the dry period and following calving for signs of mastitis. Individual SCC were determined from herd tests conducted in the previous lactation and following calving. Logistic regression models were used to determine relationships with the prevalence of cows with a SCC >150,000 cells/mL after calving, and survival analysis was used to model time to the first case of clinical mastitis following calving at the cow and quarter level. RESULTS: The OR for a cow with a SCC >150,000 cells/mL after calving, including age and individual SCC in the preceding lactation in the model, was 0.53 (95% CI=0.32–0.89) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.017). At the cow level, including age and preceding SCC in the model, the hazard ratio for diagnosis of clinical mastitis by farm staff in the first 100 days of lactation was 0.60 (95% CI=0.39–0.98) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.04). At the quarter level, the hazard ratio for diagnosis of clinical mastitis, with age included in the model, was 0.41 (95% CI=0.23–0.74) for the combination therapy compared to cephalonium alone (p<0.001). CONCLUSIONS: The combination of internal teat sealant and cephalonium DCT was more effective than cephalonium alone at reducing clinical mastitis diagnosed by farm staff in the 100 days after calving, and the prevalence of cows with a SCC >150,000 cells/mL 60–80 days after calving. CLINICAL RELEVANCE: This study adds to the evidence that the prevention of intra mammary infections throughout the dry period and up to calving by using combination therapy is important in reducing the incidence of farmer-diagnosed clinical mastitis and prevalence of cows with a SCC >150,000 cells/mL 60–80 days after calving. [ABSTRACT FROM PUBLISHER]

AIM: To evaluate the conception rate to fixed-time artificial insemination (FTAI) of two oestrus synchronisation programmes in dairy heifers on eight farms over 2 years. METHODS: The study was conducted in 2008 and 2010 on eight farms near Palmerston North, New Zealand. Nulliparous Friesian and Friesian×Jersey heifers (13–15 months of age) were randomly allocated to one of two oestrus synchronisation programmes. Group 1 (GPG+P4; n=330), received gonadotrophin-releasing hormone (GnRH) I/M on Day 0, a progesterone (P4)-releasing intravaginal device from Days 0–7, prostaglandin F2α(PGF) I/M on Day 7 and a second dose of GnRH at the time of FTAI on Day 9. The second group (P4+PGF; n=343) received a P4-releasing intravaginal device from Days 0–7, PGF on Day 6 and FTAI on Day 9. Pregnancy was diagnosed from Days 42–52 by transrectal ultrasonography. RESULTS: The overall conception rate was 52.4% and 54.8% for the GPG+P4 and P4+PGF groups, respectively. The odds of conception for the two treatments were not different (OR=0.90; 95% CI=0.67–1.23), nor was there any difference between groups in different years (p=0.58). Farm affected conception rate (p=0.002), but there was no interaction with treatment (p=0.92) . CONCLUSIONS: This study has shown that an alternative synchronisation programme can produce similar results in terms of conception rate to the GPG+P4 treatment, currently commonly used in heifers. More research is required to establish whether other modifications to the GPG+P4 programme can produce similar results at lower costs, and to identify and quantify farm factors which affect the economic benefit of heifer synchronisation. CLINICAL RELEVANCE: This study indicated that synchronising heifers with P4 and PGF resulted in conception rates equivalent to those resulting from a GPG+P4 treatment, but with reduced drug costs. However, because heifers in the GPG+P4 group received the second GnRH injection at the time of AI, they needed only three yardings as opposed to the four required for the heifers treated with P4 and PGF. Thus, the choice of programme for an individual farm will depend on that farm's circumstances, in particular the cost of yarding the heifers. [ABSTRACT FROM PUBLISHER]

AIM: To assess the effect of analgesia at disbudding on weight gain and milk intake of dairy calves. METHODS: Four disbudding protocols were used on 3- to 6-week-old Friesian-Jersey calves. Farm staff disbudded 101 calves without sedation or local analgesia, of which 51 received 20 mg meloxicam S/C. Veterinary staff disbudded 101 calves with sedation and local analgesia, of which 51 also received 20 mg meloxicam S/C. Calves were weighed before disbudding, 15 and 30 days later, and individual milk consumption was recorded for 11 days. Daily weight gain and milk consumption were analysed using mixed models and ANOVA. RESULTS: From disbudding (Day 0) to Day 15 farmer-disbudded calves receiving meloxicam grew faster (0.65 kg/day) than calves without meloxicam (0.55 kg/day; p=0.011), but an interaction between operator and meloxicam treatment (p=0.056) meant that meloxicam treatment did not increase growth rates in veterinary-disbudded calves (0.63vs. 0.64 kg/day; p=0.872). From Days 16–30 there was no significant effect of meloxicam on growth rate, but veterinarian-disbudded calves grew faster (0.76 kg/day) than farmer-disbudded calves (0.66 kg/day; p=0.034). Overall, for the first 30 days after disbudding, if meloxicam was not used’, veterinarian-disbudded calves grew faster than farmer-disbudded calves (p=0.002). However if meloxicam was used at disbudding there was no difference in growth rate between veterinarian- and farmer-disbudded calves (p=0.878). Mean cumulative milk consumption for the 11 days after disbudding was greater for calves disbudded by veterinary staff than by farm staff (p<0.001), but there was no effect of meloxicam treatment (p=0.618) and no interaction with operator (p=0.86) on cumulative milk consumption. CONCLUSIONS: Three to 6-week-old dairy calves disbudded by farm staff with no analgesia grew significantly slower over the next 15 days than farmer-disbudded calves given meloxicam, and slower over the next 30 days than veterinarian-disbudded calves given xylazine and lignocaine. However addition of meloxicam to the latter protocol had no effect on growth rate. Milk intake was significantly higher for 11 days for veterinarian- compared with farmer-disbudded calves. CLINICAL RELEVANCE: This study adds to the evidence that analgesia during disbudding is beneficial for calf productivity as well as calf welfare. [ABSTRACT FROM PUBLISHER]

AIM: The aim of this study was to evaluate, under farm conditions, the use of a teat sealant in addition to whole herd dry cow antibiotic therapy on the risk of clinical mastitis in dairy cattle at pasture, and to evaluate the impact of dry period length on that risk and the impact of the teat sealant on that risk. METHODS: Dairy cows in three herds which used routine whole herd antibiotic therapy were randomly assigned to receive either treatment with an internal teat sealant (n=322) or no additional treatment (n=313) at drying-off between March and May 2010. All clinical mastitis cases during the dry period and to the end of the subsequent lactation were recorded by farm staff; factors affecting risk of clinical mastitis were then analysed using a Cox proportional hazards model. RESULTS: Median duration of the dry period was 112 days with >25% of cows having a dry period >130 days. The incidence risk of mastitis during lactation for cows treated with teat sealant was 9.9 (95% CI=6.9–13.7) cases per 100 cows compared with 17.9 (95% CI=13.8–22.6) cases per 100 cows for cows treated with antibiotic alone. The addition of a teat sealant to dry cow antibiotic therapy decreased the risk of clinical mastitis only in the first 33 days after calving (Hazard risk 0.24 (95% CI=0.12–0.48)). Length of dry period did not significantly affect the risk of clinical mastitis, or the effect of adding teat sealant to dry cow antibiotic therapy on the risk of clinical mastitis. CONCLUSIONS: In these herds where, based on the mastitis history, whole herd antibiotic therapy had been recommended, the use of a teat sealant significantly reduced the risk of clinical mastitis. This effect was limited to the first 33 days after calving; subsequently there was no significant effect of treatment. There was no effect of dry period length on risk of clinical mastitis, nor any significant interaction with treatment. CLINICAL RELEVANCE: Combination therapy with teat sealant and antibiotic was effective under New Zealand conditions in herds using whole herd antibiotic treatment at drying off. Teat sealant reduced risk of clinical mastitis in cattle with dry periods substantially longer than 100 days, and there was no evidence that this effect changed as dry period length increased. [ABSTRACT FROM PUBLISHER]

AIM: The aim of this study was to estimate whether fetal age could be accurately estimated using placentome size. METHODS: Fifty-eight cows with confirmed conception dates in two herds were used for the study. The length of the long axis and cross-sectional area of placentomes close to the cervix were measured once every 10 days between approximately 60–130 days of gestation and once every 15 days between 130–160 days of gestation. Four to six placentomes were measured using transrectal ultrasonography in each uterine horn. A linear mixed model was used to establish the factors that were significantly associated with log mean placentome length and to create an equation to predict gestational age from mean placentome length. Limits of agreement analysis was then used to evaluate whether the predictions were sufficiently accurate for mean placentome length to be used, in practice, as a method of determining gestational age. RESULTS: Only age of gestation (p<0.001) and uterine horn (p=0.048) were found to have a significant effect on log mean placentome length. From the three models used to predict gestational age the one that used log mean placentome length of all placentomes, adjusting for the effect of horn, had the smallest 95% limits of agreement; ±33 days. That is, predicted gestational age had a 95% chance of being between 33 days greater and 33.7 days less than actual age. This is approximately twice that reported in studies using measurement of fetal size. CONCLUSIONS: Measurement of placentomes near to the cervix using transrectal ultrasonography was easily achieved. There was a significant association between placentome size and gestational age, but between-cow variation in placentome size and growth resulted in poor agreement between placentome size and gestational age. CLINICAL RELEVANCE: Although placentomes can be easily visualised during diagnosis of pregnancy using transrectal ultrasonography, mean placentome size should not be used to estimate gestational age. [ABSTRACT FROM PUBLISHER]

The article discusses a study which validated the use of a portable ultrasound machine for monitoring sole thickness in 24 dairy cows in New Zealand. The researchers investigated the agreement between ultrasound and electronic calliper measurement of distance from the external to the internal sole surface and the distance from the external sole surface to the distal phalanx (DP). The accuracy of the DP measurement method for monitoring mean sole thickness in a group of animals is also cited.

The article discusses a study of an outbreak of lameness in a group of peripartal heifers on a spring calving dairy farm in the Manawatu region of New Zealand at the start of the 2010-2011 season. Results of ultrasonography confirmed that the cause of lameness was thin soles, which developed as a result of a prolonged exposure to wet concrete on the feed pad.

Contents This study investigated the effects on embryo growth and survival rate of feeding heavily-fertilised spring grass, containing high levels of quickly-degradable nitrogen, to pregnant cows. Forty-eight lactating Holstein cows between 2 and 8 weeks pregnant were turned-out, after a one-week transition period onto high- or low-nitrate pasture and fed a high- or low-concentrate supplement. Cows grazing the High nitrate pasture had significantly higher milk and plasma urea concentrations than cows grazing the Control pasture, while cows which were fed less concentrate had a notably higher plasma ammonia. However, there was no evidence that an increased quickly-degradable nitrogen (QDN) intake from pasture affected embryo survival or growth from 20 days onwards. This suggests that the impact of turnout on fertility mainly affects ovulation, fertilisation and/or the early embryo. [ABSTRACT FROM AUTHOR]

Forty-seven pregnant uteri were collected from an abattoir at eight chronological stages of gestation. Assessments were made of placentome number, weight, length shape and ratio of foetal to maternal tissue by weight. The study showed that there was a great variation in number, size, weight and shape of placentomes. There was no significant change in the total number of placentomes during gestation. Both mean weight and length increased significantly during gestation, but there was a significant change in the relationship between the two as gestation progressed. There was no correlation between the number of placentomes and the mean weight or length of the placentomes. The development of the placenta in the non-pregnant horn was significantly different from that of the pregnant horn, with fewer, smaller, lighter placentomes. However, there was no evidence that placentome development in the non-pregnant horn was affected by placentome development in the pregnant horn. The proportion of the placentome that was maternal tissue increased during gestation, but there was no significant effect of placentome number, or individual placentome weight or length on this proportion. Two placentome shapes were identified, but no effect on foeto-maternal proportion or relationship between shape and total placentome number or weight was identified. [ABSTRACT FROM AUTHOR]

AIM: To compare the variation in rectal temperature measurement by digital, mercury and ethanol thermometers in cattle, horses and sheep. METHODS: Seven different makes of thermometer (four digital, two mercury, and one ethanol; (n=27) were tested individually in a calibrated water bath to identify whether there was an effect of thermometer make on recorded temperature. In addition, rectal temperatures of four cattle, four sheep and four horses were recorded using the same thermometers, by seven persons, with each person being assigned to one thermometer make. RESULTS: In the water bath test, mean temperature was affected by thermometer make (p<0.001) and ranged from 38.0°C for the Digital Large Animal thermometer to 38.3°C, which was recorded by the Rapid Digital thermometer and the three makes of capillary thermometer. There was an interaction between species and make of thermometer (p<0.001). In sheep, the lowest mean temperature was recorded using the Capillary Small Animal thermometer (39.2°C) and the highest using the alcohol thermometer (mean 40.4°C). In cows and horses, the highest mean temperatures were recorded by the alcohol thermometer (38.6 and 38.9°C, respectively), and the lowest by the Rapid Digital thermometer (37.7 and 36.3°C, respectively). Over all species, the Rapid Digital (mean difference 0.89 (95% CI=0.71–1.08)°C) and Genia Digiflash (mean difference 0.61 (95% CI=0.42–0.81)°C) both recorded lower temperatures than the reference thermometer (Capillary Small Animal). The alcohol thermometer recorded higher temperatures than all other thermometers (mean difference 0.55 (95% CI=0.35–0.74)°C compared with reference). There were differences in variance between thermometer types (p<0.001), with the Rapid Digital having the highest (SD 1.47) and the Capillary Small Animal the lowest (SD 0.53). CONCLUSIONS: Make of thermometer can influence rectal temperature measurements. In this study, digital thermometers generally recorded lower temperatures than mercury thermometers and had the highest variance. If digital thermometers are to be recommended for use in livestock, particularly in cattle and horses, robust data are needed showing that the specific make is reliable. [ABSTRACT FROM PUBLISHER]