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Context Smallholder beef farming in Lao People’s Democratic Republic (Laos) is constrained by poor reproductive performance, contributing to regional food insecurity. To address this, interventions were promoted in some rural communities by extension services to enhance cattle and buffalo nutrition, health, and reproductive husbandry. Aims This study assessed the impacts of these interventions on cattle and buffalo reproductive performance. Methods Knowledge, attitude and practice surveys were conducted on smallholder beef farmers in 2015 (n = 637) and 2018 (n = 226). With written records lacking on these farms, the survey relied on farmer recall of the number of calves born in the previous 12 months and the number of female cows (>12 months of age) present. The rate of these, calves/female cows, was used as an indicator of reproductive performance. Key results This proportion was higher in 2018 at a predicted mean 0.27 calves/cow compared with 2015 at 0.21 calves/cow (P < 0.001), suggesting a beneficial effect of interventions over time. Specifically, reproductive performance improved with increasing land dedicated to forages (P < 0.001) and increased farmer market-orientation (P = 0.006). Farmers who believed that selling sick large ruminants stopped the spread of disease had enhanced reproductive performance (P = 0.008). Although the practice of culling animals of low reproductive performance is desirable, in countries where foot-and-mouth disease is endemic, it is important to discourage practices that increase infectious disease transmission risk. Conclusion As reproductive knowledge interventions were not associated with reproductive performance, introducing interventions such as castration and weaning to consolidate reproductive knowledge is recommended as well as addressing challenges that limit forage adoption; and debunking misconceptions on effectiveness of biosecurity. Implications The use of evidence-based research helps inform the selection of interventions required to best enhance reproductive efficiency, potentially leading to improved reproductive performance of smallholder large ruminant systems in Laos and beyond.

Context Anthelmintic treatments are not widely adopted by smallholder farmers in Laos (Lao People’s Democratic Republic) to treat bovid Toxocara vitulorum, resulting in high calf morbidity and mortality. Aims Field trials were conducted to provide baseline efficacy data on an alternative, easy-to-use treatment by provision of fenbendazole-medicated molasses blocks (FMB) in situ. Methods Participating villages were randomly allocated to the following treatments: (1) conventional orally administered pyrantel, (2) access to FMB, (3) access to non-medicated molasses blocks (MB), and (4) no blocks (control). Faecal eggs per gram (EPG) and weight were monitored in cattle (n = 171) and buffalo calves (n = 44) under field conditions for 48–56 days. Key results In 2016, the MB treatment was associated with the fastest reduction in predicted average EPG at 2% per day, while FMB and pyrantel had an equivalent reduction of 1% per day, relative to the control (P = 0.062). Predicted average weight also differed significantly among treatments, with pyrantel and MB having the greatest average daily gain at 230 g and FMB at 200 g, which was higher than for control calves at 170 g (P = 0.002). In buffalo calves, treatment was not significantly associated with EPG or weight. The 2018 trial corroborated that FMB and MB treatments were associated with increased EPG reductions in cattle at 3% per day, relative to control calves (P = 0.007). Again, the MB treatment had the greatest predicted average daily gain at 200 g, compared with FMB calves at 160 g and control calves at 150 g (P = 0.005). Conclusions The field trials provided baseline evidence that FMB and MB have potential applications in reducing environmental contamination of T. vitulorum eggs and may improve calf growth in low-input systems. However, further testing ex situ is required to control for variability in calf weight and T. vitulorum burdens, so as to optimise anthelmintic doses, assess the addition of urea to the block formula and assess product marketability. Implications If successful, medicated nutrient blocks may be a simple method to reduce calf mortality and morbidity, enhancing the reproductive efficiency of large ruminant production in smallholder farms in developing countries.

We investigated the potential for automatic detection of subclinical mastitis (SCM) in pasture-based automatic milking systems. The objective of the study was to determine the ability of electrical conductivity (EC), together with relative changes in daily activity (activity) and daily rumination (rumination) recorded using heat and rumination–long-distance tags, to predict quarter-level SCM. Activity (arbitrary unit/day) and rumination (min/day) data were determined across 21 days using heat and rumination–long-distance tags for 170 cows. Cows were allocated into the following three groups: SCM (n = 32, EC ≥ 7.5 millisiemens/cm (mS/cm) in one or more quarters and a positive bacteriological culture in the corresponding quarter(s)); true-negative (TN, n = 9, EC ≥ 7.5 mS/cm and a negative culture in all four quarters); and apparently healthy (n = 129, no culture test and EC < 7.5 mS/cm). Group mean differences in activity and rumination were compared using Welch’s t-tests. Logistic mixed models were used to predict SCM by EC, activity and rumination changes before mastitis detection, including parity information between SCM and TN groups. Cow- and quarter-specific information were included as random effects, followed by model assessment by producing receiver operating-characteristic curve and area under the curve (AUC) value. In total, 287 quarters were used in the prediction model, including 143 quarters with a positive culture (Gram-positive; n = 131, Gram-negative; n = 6, mixed; n = 6) and 144 quarters with a negative culture. On average, SCM group had 4.65% greater (P < 0.01) activity and 9.89% greater (P < 0.001) rumination than did the TN group and 11.70% greater (P < 0.001) activity than did the apparently healthy group. A combined model with terms for EC, activity changes, rumination changes prior to detect SCM and parity had a better SCM prediction (AUC = 0.92) ability than did any of them separately (all AUC < 0.8). Hence, we conclude that EC in combination with activity and rumination information can improve the accuracy of prediction of quarter-level SCM.

The objective of the present study was to estimate genetic parameters and evaluate the genetic trends of 100-day milk yield (MY), fat percentage (FP) and protein percentage (PP) in three government dairy cattle farms in Thailand, located in the north and north-east of the country. The data consisted of records from 1745 first-lactation cows that calved between 1986 and 2015, which were the progeny of 287 sires and 1237 dams. Most of the animals were crossbred Holstein-Friesian with native or zebu animals. The total number of animals in the pedigree was 4753. Univariate and bivariate linear mixed models were used to estimate genetic parameters and breeding values by using ASReml-R. The fixed effects in the model were herd, year of calving, season of calving, breed group and the interaction between year and season of calving, and the random effects were animal and residual. All fixed effects had significant effects on the three traits, except breed group. The estimated heritabilities for MY, FP and PP were 0.242 ± 0.061, 0.066 ± 0.048 and 0.329 ± 0.072 respectively. The genetic correlation for MY and FP, MY and PP, and FP and PP were 0.219 ± 0.352, –0.271 ± 0.177 and 0.452 ± 0.255 respectively. The genetic trends based on estimated breeding values over year of birth did not show consistent improvement in all three traits, although there was a slight declining trend in MY in the later years.

During hot weather cows typically reduce feed intake and actively seek shade and water to reduce the metabolic stress on their bodies. This can have a negative impact on the occurrence of voluntary milking visits to an automatic milking system (AMS) operating with voluntary traffic, thus reducing milking frequency. Shade is known to be effective in alleviating heat stress in dairy cattle; however, the impact of providing shade at the milking facility of a pasture-based AMS on time taken to voluntarily enter a milking unit is unknown. A herd of ~300 lactating cows milked in a pasture-based AMS were divided into two groups during the summer of 2016. Each group spent 4 weeks in a SHADE (predominately shaded pre-milking yard) and a NO-SHADE (predominantly non-shaded pre-milking yard) treatment, with two periods in a crossover design. Cow respiration rates, time spent in pre- and post-milking areas, concentrate consumption and milk yield were recorded. On average, cows in the SHADE treatment were found to take longer to enter the milking unit than did cows in the NO-SHADE treatment (SHADE = 11.40 min, NO-SHADE = 8.70 min, P < 0.001). SHADE was also associated with lower average respiration rates (SHADE = 68 breaths per minute (bpm), NO-SHADE = 73 bpm, P < 0.001), increased concentrate consumption (SHADE = 6.50 kg/cow.day, NO-SHADE = 6.39 kg/cow.day, P = 0.03) and increased milk yield (SHADE = 11.44 kg/cow.milking, NO-SHADE = 10.95 kg/cow.milking, P < 0.001). Overall, SHADE made available to the cows pre-milking appeared to improve cow performance and comfort (as indicated by reduced respiration rates).

High inclusion concentrations of dietary calcium (Ca) from limestone may have detrimental effects on broiler performance, such as increased gastric pH and a reduction in phosphorus (P) and amino acid digestibility. To assess the potential for feeding diets with lower total Ca concentrations, the effect of a novel highly soluble source of calcium (HSC) on bird performance, nutrient digestibility and skeletal integrity of 1120 male Cobb-500 broilers was compared with that of limestone. Eight dietary treatments in a 2 × 2 × 2 factorial design consisted of two sources of Ca (limestone or HSC), two concentrations of Ca (6.0 or 7.7 g/kg in the starter and 4.0 or 5.7 g/kg in the grower), two phytase levels (0 or 500 FTU/kg). The effect of dietary treatments on growth performance and feed intake were measured from Day 1 to Day 40 and foot ash and leg health on Day 40. At the end of the starter period, in the absence of phytase, changing Ca source from limestone to HSC at 6.0 g/kg total Ca decreased both bodyweight gain and feed intake (P < 0.05). The addition of phytase to diets containing 6.0 g/kg total Ca provided by HSC increased bodyweight gain (P < 0.05), as well as increasing feed intake (P < 0.05). At the end of the grower period, diets supplemented with phytase increased bodyweight gain (P < 0.001), birds fed the higher Ca concentration were also observed to have an increased bodyweight gain (P < 0.001). Apparent ileal Ca digestibility significantly increased with the addition of phytase to diets containing 4.0 g/kg total Ca provided by HSC (P < 0.05), this was also observed for P digestibility. Replacement of limestone with HSC when fed in conjunction with phytase has the potential to be an effective strategy to improve broiler performance and bone mineralisation.

Mastitis adversely affects profit and animal welfare in the Australian dairy industry. Electrical conductivity (EC) is increasingly used to detect mastitis, but with variable results. The aim of the present study was to develop and evaluate a range of indexes and algorithms created from quarter-level EC data for the early detection of clinical mastitis at four different time windows (7 days, 14 days, 21 days, 27 days). Historical longitudinal data collected (4-week period) for 33 infected and 139 healthy quarters was used to compare the sensitivity (Se; target >80%), specificity (Sp; target >99%), accuracy (target >90%) and timing of ‘alert’ by three different approaches. These approaches involved the use of EC thresholds (range 7.5– 10 mS/cm), testing of over 250 indexes (created ad hoc), and a statistical process-control method. The indexes were developed by combining factors (and levels within each factor), such as conditional rolling average increase, percentage of variation, mean absolute deviation, mean error %; infected to non-infected ratio, all relative to the rolling average (3–9 data points) of either the affected quarter or the average of the four quarters. Using EC thresholds resulted in Se, Sp and accuracy ranging between 47% and 92%, 39% and 92% and 51% and 82% respectively (threshold 7.5 mS/cm performed best). The six highest performing indexes achieved Se, Sp and accuracy ranging between 68% and 84%, 60% and 85% and 56% and 81% respectively. The statistical process-control approach did not generate accurate predictions for early detection of clinical mastitis on the basis of EC data. Improved Sp was achieved when the time window before treatment was reduced regardless of the test approach. We concluded that EC alone cannot provide the accuracy required to detect infected quarters. Incorporating other information (e.g. milk yield, milk flow, number of incomplete milking) may increase accuracy of detection and ability to determine early onset of mastitis.

Milk production per cow has significantly increased over the last 50 years due to the strong genetic selection for increased milk production; associated with this increased production has been a decline in reproductive performance. As a result, superior-yielding cows that have failed to get into calf in a traditional 12-month calving system may be carried over and milked continuously for another 6 months instead of being culled. Studies indicate that cows are able to achieve lactations greater than 305 days and up to 670 days under pasture-based systems, with and without the use of supplementary feeds. Extended lactations of 16 months are most common and economically viable in Australian dairy systems. These findings indicate a potential role for extended lactation in countries such as Australia, where pasture-based dairy systems in which Holstein-Friesian dairy cows predominate. However, variation between cows in their milk yield profiles and the ability of cows to reach a planned dry-off date over an extended lactation occurs depending on the cow’s genetic strain, nutrition and environmental interactions, with certain strains of cow being better suited to extended lactation than others. The focus of this review is to examine the scope for genetic improvement as well as important considerations (non-genetic factors) when selecting suitable animals for extended lactation in pasture-based dairy systems, with an emphasis on Australian systems. These considerations include the impacts of cow strain, nutrition, milk production, and biological and economical costs associated with extended lactation. Methods for modelling extended lactation and estimating genetic parameters of lactation persistency, milk yield and component traits under extended lactation will be addressed and future directions for further research suggested.

The behaviour of Merino ewes during non-oestrus and oestrus were quantified using Global Navigation Satellite System (GNSS) tracking devices and direct visual observation. GNSS devices were attached to neck collars and deployed on mixed-age ewes (38 maiden and 40 experienced ewes) following hormonal oestrus synchronisation. The positional accuracy of the GNSS data was validated through a comparative study of GNSS estimates of each animal’s location compared with direct visual observations. Positional accuracy was estimated at 90–94%, for a 4-m and 6-m-buffer radius, respectively. Ewe speed of movement was calculated from the GNSS data and plotted against hour of the day to determine diurnal activity patterns during non-oestrus and oestrus days. Ewes showed increased speed of movement during the early morning of the anticipated day of oestrus compared with the non-oestrus day (P < 0.001). In addition, ewes that increased their speed of movement by 0.05 m/s received 1.4–28.4 times more mounts depending on the hour of the day (P = 0.02). Ewes also displayed an increased speed of movement in the period leading up to maximum sexual activity, defined as the hour in which ewes received the maximum number of mounts. Thereafter, ewe activity decreased. No difference in sexual activity was detected between maiden and experienced ewes. The present study has demonstrated a change in ewe diurnal activity at oestrus, suggesting the onset of sexual activity can be identified as a period of increased speed of movement followed by a return to ‘normal’ activity. The development of commercial remote autonomous monitoring technologies such as GNSS tracking to detect this change in behaviour could facilitate improved reproductive management of sheep in extensive systems.

Gilt progeny are born lighter, have lower weaning weights and require more medication throughout their life time than do sow progeny. Therefore, strategies to improve their post-weaning performance are of importance to pork producers. Dietary fatty acids have been shown to be potent modulators of physiological processes. Studies in other species have reported that dietary fatty acids affect in utero development, cognitive behaviour, immune system function, carcass composition as well as feed efficiency of offspring. However, little information is available that details their use in gilt progeny and when fed throughout their lifetime. In the present study, two experiments were conducted to investigate the effects of feeding three different types of fat to gilts and their progeny on the growth, body composition and performance post-weaning. Diets were enriched with either saturated fatty acids (SFA; tallow), or n-3 (fish-oil extracts) or n-6 (safflower oil) polyunsaturated fatty acids (PUFA) and were fed to gilts through gestation and to their progeny post-weaning. In Experiment 2, half of the female progeny from n-3 and n-6 PUFA litters were fed SFA post-weaning. For both studies, there was no significant difference in weaning bodyweights. However, in Experiment 1, pigs fed n-6 PUFA diets post-weaning were significantly lighter 7 days post-weaning than were pigs fed SFA- and n-3 PUFA-enriched diets. Despite feed intake of n-6 PUFA-fed pigs becoming comparable to that of the other groups during the finisher period, bodyweight for this group remained significantly lower than that of the other groups at the conclusion of the experiment. No effect of dietary fatty acid type on the carcass composition of finisher pigs, as determined by computed tomography, was found. The results of Experiment 2 showed that feeding pigs n-6 PUFA diets post-weaning through to slaughter significantly compromised their growth, being in agreement with those from Experiment 1. Feed consumption for this group was significantly less during the post-weaning and the finisher periods. However, pigs from n-6 PUFA litters that were fed SFA diets post-weaning showed no compromise in growth and performance and were comparable to pigs from the other treatment groups. During the grower and finisher periods, pigs fed n-6 PUFA diets had a significantly higher rate of mortality that was as much as 13 times that of pigs fed SFA diets. Pigs from n-6 PUFA litters that were fed SFA diets post-weaning were not affected in this manner. The results of the current study showed that feeding diets enriched with n-6 PUFA to pigs significantly compromised their growth and performance and that this fatty acid type may also have negative health effects with prolonged consumption. The data suggested that the type of fatty acid used in pig diets may be an important consideration for nutritionists when formulating diets to optimise post-weaning growth and performance.

The predation of sheep (Ovis aries) by wild and domestic dogs (Canis lupis) is a major issue in Australia, causing serious welfare issues to inflicted animals. The estimated cost of sheep and cattle production losses caused by wild dogs when combined with an extensive range of control measures, costs the Australian economy AU$66 million annually. Spatio-temporal data derived from global navigation satellite system (GNSS) devices were used to quantify the behavioural responses of two flocks of 15 Merino ewes ranging from 2 to 8 years old (average 4.5 years) during simulated dog predation events. Each sheep was fitted with a GNSS collar, and the behavioural responses of the sheep were video recorded during six trials (three per flock). The behavioural data collated from video recordings were then compared with the movement metrics derived from the GNSS collars. Derived metrics include the spatial distribution of flock members, speed of animal movement and specific behavioural changes including centripetal rotation (circling behaviour of the flock, with individual sheep seeking the centre). While the spatial distribution data did not appear to be specific enough to enable identification of a predation event, the velocity of sheep was higher (P < 0.001) during compared with before and after a simulated dog predation event. Centripetal rotation occurred in 80% of the simulated predation events during this study, and may provide a means for identifying predation. The spatio-temporal data from GNSS devices have potential as a research tool to assist in understanding sheep movement patterns during a dog attack. While further research and mathematical modelling of predation events is clearly required, the application of remote sensing technology has the potential to improve future livestock monitoring.

The objective of the present study is to investigate the reproduction, production and semen traits of the stress-negative Piétrain line of pigs in the north of Vietnam, as well as to identify various factors (halothane genotype, generation-origin, parity, sex and month of the year) acting on these traits. The experiment was carried out on a purebred nucleus on Dong Hiep farm, Haiphong province in Vietnam. The reproduction performances and the sperm quality measures were based on 12 sows and 5 boars imported from Belgium as well as on 29 sows and 14 boars born in Vietnam, while the production performances were recorded only from 251 animals born in Vietnam. No significant differences were observed between halothane genotypes of sows for reproduction traits (P > 0.0578). At the age of 7.5 months, bodyweight, backfat thickness and longissimus depth (7.5) of homozygous-dominant pigs were higher (P < 0.05) than in heterozygotes. Homozygous-dominant boars had higher total number of spermatozoa than heterozygote boars (P < 0.05); similarly, Vietnam boars also presented higher total number of spermatozoa values than Belgium boars (P < 0.001). Vietnam sows had longer duration of pregnancy, more piglets born alive and heavier litter weight of weaning than Belgium sows (P < 0.01). Bodyweight at birth, at weaning, at 2, 5.5 and 7.5 months of age increased from the first to third parity (P < 0.05). Gilts had more lean meat than intact boars (P < 0.01). Compared with observations made in temperate countries, the reproduction and production performances, sperm concentration and total number of spermatozoa of stress-negative Piétrain pigs were reduced, whereas lean meat percentage was not affected. This might be due to the different climate, although improving values for animals born in Vietnam might indicate adaptation of the animals and/or of the technicians with that breed. The results support the interest of the use of this new Piétrain line in tropical countries with ecological and climatic conditions similar to Vietnam.

Immune responsiveness, the ability of an organism to effectively respond immunologically following antigenic exposure, is an essential component of life history, as organisms require effective immune functionality in order to grow, survive and reproduce. However, immune status is also associated with concomitant trade-offs in these physiological functions. Herein we demonstrate the validation of phytohaemagglutinin (PHA) injection in saltwater crocodiles, Crocodylus porosus, to assess cellular immune responsiveness. Following injection of 2 mg mL–1 PHA into the hind toe webbing, we observed a peak swelling response 12 h after injection, with PHA inducing increased thickness compared with webs injected with phosphate-buffered saline (PBS) (F5,518 = 145.13, P

The adaptation success of inexperienced heifers to a pasture-based automated milking system (AMS) is likely to influence the viability and feasibility of the system. This study evaluated two heifer training programs designed to improve adaptation success to determine their impact on early lactation performance within a pasture-based AMS. The two training programs involved heifers calving in spring 2007 (S07) and autumn 2008 (A08) being managed as members of the milking herd for 2 weeks, starting 2 months before their expected calving date. In each calving season, heifers were randomised into two treatment groups with one being fed and teat sprayed (FTS) while visiting the milking stations, while the other group passed through (PT) the milking stations. Milk yield, milking frequency and waiting time were selected as indicators of early lactation performance within an AMS and were reported as values relative to those measured by their experienced herdmates (within calving season). Longer relative waiting times (hours spent in pre-milking area where experienced herdmates = 1.0; FTS: 1.36 vs PT: 1.95; P = 0.006) may have been one cause of the low relative milk production levels reported (range 0.49 S07PT–0.78 A08PT). The milking frequencies of the heifers were in line with their experienced herdmates (range 0.83 S07PT–1.10 A08PT). There were no significant differences between the two training programs, indicating that farmers could adopt either program and expect similar early lactation heifer performance. The choice of program would more likely be affected by AMS utilisation levels, costs of consumables (teat spray and concentrate feed) and any existing desire to feed concentrate to heifers during the training period.

Two quantitative trait loci (QTL) for mouse bodyweight have previously been reported on mouse chromosomes (MMU) 4 and 11 from crosses of a highly fecund and large mouse strain, Inbred Quackenbush-Swiss 5 (QSi5) and C57Bl/6J. QSi5 has now been crossed with CBA/CaH to produce 1128 F2 mice to confirm the existence and effect of these QTL. In total, 226 mice from the upper and lower deciles for bodyweight were genotyped using 12 microsatellite markers covering MMU4 and MMU11. Regression and maximum likelihood based interval mapping by either including all mice (ungenotyped mice were treated as having missing genotypes) or including only selectively genotyped mice in the analyses were used to estimate the positions and effects of the QTL. The results confirmed the existence and effects of both QTL. Although all methods estimated the same QTL positions, the QTL effects were overestimated compared with the estimates using a suggested method (maximum likelihood by including all mice in the analysis). However, the overestimated QTL effects could be mathematically corrected. Since the confidence intervals of both QTL are still too large for positional cloning, an advanced intercross line is being bred for finely mapping these bodyweight QTL.

Wild dogs and European red foxes are considered pest animals in Australia. Restraining devices to capture these wild canids are sometimes required by wildlife managers. However, the use of traps is controversial. This paper discusses the efficiency, selectivity and injuries inflicted by some leg-hold traps that are available in Australia for capturing wild canids. The trapping of feral cats with wild-canid traps is also briefly discussed. The most commonly used leg-hold trap in Australia is the toothed, steel-jawed, leg-hold trap. Alternative traps, including offset- and padded-jawed traps (similar to the Victor Soft Catch®), and steel-jawed traps that have been modified to incorporate padding and off-setting of jaws, were shown to be preferable. The alternative traps were as efficient and selective as toothed, steel-jawed traps, but were less injurious. The Treadle snare, although more likely to miss target animals, was also shown to be less injurious than unmodified, steel-jawed leg-hold traps. It is difficult to justify the continued use of unmodified, steel-jawed leg-hold traps for the capture of wild canids in Australia.