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Simple Summary: Forage chicory is one of the common herbs that has been posited as a complementary species to the traditional ryegrass/white clover mix in pasture-based systems, presenting the benefits of improved mineral nutrition and high nutritive feed during late spring and summer when there is a deficit. This work synthesised data from 15 unique research publications, examining the effect of chicory on milk production and milk fatty acid composition. The results reveal that the effect of chicory on milk production differed as a function of control forage type. Chicory inclusion into the diet of lactating dairy cattle increased milk yield and solids (milk fat + protein) when compared with cows grazing grass-based swards but was similar when compared with cows grazing other forages such as legumes. The increases in milk production when chicory was compared with grasses were associated with concomitant increases in dry matter and metabolisable energy intakes. Moreover, the milk that cows on chicory produced was higher in Omega-3 fatty acids such as alpha linolenic acid, which improve its nutritional quality. In traditional ryegrass/white clover (Lolium perenne L./Trifolium repens L.) pastoral systems, forage herbs such as chicory (Cichorium intybus L.) present an opportunity to fill feed deficits during late spring and summer. Although multiple research publications have evaluated the efficacy of chicory for enhancing milk production and milk fatty acid (FA) profile, no publication has quantitatively synthesised the body of research. This systematic review and meta-analysis examined the effect of chicory on milk production and composition, as well as on the milk fatty acid composition of dairy cattle. A total of 29 comparisons from 15 unique research publications involving 597 dairy cattle were used to develop a dataset for analysis. Three-level random-effect and robust variance estimator models were used to account for the hierarchical structure of the data and the dependency of effect sizes within publications. Chicory inclusion increased milk yield when compared to grass-based diets {weighted mean difference (WMD) = 1.07 (95% CI 0.54–1.60) kg/cow/d, p < 0.001}, but it provided a similar milk yield when compared to other forages such as legumes and herbs {dicots; WMD = −0.30, (95% CI −89–0.29) kg/cow/day, p = 0.312}. Increases in milk yield were congruent with differences in DM intake (p = 0.09) and ME intakes (p = 0.003), being similar in chicory-fed and dicot-fed cows but higher than grass-fed cows. Chicory feeding's effect on milk solids was twice as high during mid lactation {154 days in milk; WMD = 0.13, (95% 0.081–0.175) kg/cow/day, p < 0.001} as during late lactation {219 days in milk; WMD = 0.06, (95% 0.003–0.13) kg/cow/day, p = 0.041}. In line with milk yield, greater and more significant effect sizes were found for alpha linolenic acid {ALA; WMD = 0.20 (95% CI 0.06–0.35) g/100 g FA, p = 0.011} when chicory was compared to grass species only. Comparing chicory with dicots suggests that chicory inclusion did not impact ALA concentrations {WMD = 0.001 (95% CI −0.02–0.2) g/100 g FA, p = 0.99}. There were no differences in conjugated linoleic acid concentration in the milk of cows fed chicory or control diets. The study provides empirical evidence of chicory's efficacy for improved milk production and milk fatty acid composition. [ABSTRACT FROM AUTHOR]

Simple Summary: Behavioral patterns of grazing lambs associated with sickness were evaluated using a model of infusion with the endotoxin lipopolysaccharide (LPS), which can lead to subclinical symptoms of disease. Acceleration sensors are validated to have the potential to identify behavioral patterns of farm animals, which can indicate a deterioration in health. However, there is limited research on automatic identification of sickness behavior of grazing lambs. In the present study, the commercial ear-mounted CowManager SensOor (Agis, Harmelen, The Netherlands) was used to detect the changes in behavioral patterns of grazing lambs and showed promising potential for accurately identifying the sickness behavior of grazing lambs. Acute disease of grazing animals can lead to alterations in behavioral patterns. Relatively recent advances in accelerometer technology have resulted in commercial products, which can be used to remotely detect changes in animals' behavior, the pattern and extent of which may provide an indicator of disease challenge and animal health status. The objective of this study was to determine if changes in behavior during use of a lipopolysaccharide (LPS) challenge model can be detected using ear-mounted accelerometers in grazing lambs. LPS infusion elevated rectal temperatures from 39.31 °C to 39.95 °C, indicating successful establishment of an acute fever response for comparison with groups (p < 0.001). For each of the five recorded behaviors, time spent eating, ruminating, not active, active, and highly active, the accelerometers were able to detect an effect of LPS challenge. Compared with the control, there were significant effects of LPS infusion by hour interaction on durations of eating (−6.71 min/h, p < 0.001), inactive behavior (+16.00 min/h, p < 0.001), active behavior (−8.39 min/h, p < 0.001), and highly active behavior (−2.90 min/h, p < 0.001) with a trend for rumination time (−1.41 min/h, p = 0.075) in lambs after a single LPS infusion. Results suggest that current sensors have the capability to correctly identify behaviors of grazing lambs, raising the possibility of detecting changes in animals' health status. [ABSTRACT FROM AUTHOR]

The effect of defoliation frequency and severity on FA and nutrient composition of forage chicory (Cichorium intybus L.) before and after vernalisation were compared. Before vernalisation, the FA and nutrient components exhibited little variation with defoliation frequency and severity irrespective of the time of day. After vernalisation, total FA more than halved compared with pre vernalisation levels (52.2 versus 19.2 mg/g DM). Concentrations of total FA and polyunsaturated FA: linoleic and linolenic declined by 63%, 50%, and 74%, respectively. Furthermore, extending the defoliation frequency from 300 to 600 growing degree-days after vernalisation caused a decline of 28% of linoleic, 40% of linolenic and 33% of total FA concentrations. Diurnal fluctuations were detected for linoleic and oleic acids after vernalisation (P < 0.01). In terms of nutrient composition, vernalisation decreased CP, digestibility and ME, while fibre contents increased. Between morning and afternoon, there were general declines in CP and fibre contents as well as increases in soluble sugars the herbage regardless of vernalisation. Overall, the feeding value and the concentration of FA were greater on chicory herbage managed under shorter regrowth intervals than that under longer regrowth intervals, which is likely to favour animal production and the concentration of the desirable FA in ruminant products. [ABSTRACT FROM AUTHOR]

Context: Plantain has shown promise as a forage that can mitigate nitrogen (N) losses from farm systems, although adoption and regulation requires knowledge of the minimum amount of forage area or diet quantity to observe an effect. Aims: A grazing study was conducted to evaluate the effect of offering increasing proportions of spatially adjacent plantain (PL) and perennial ryegrass–white clover (PRGWC) on milk production and N utilisation of dairy cows. Methods: Forty-eight late lactating cows blocked into replicated (n = 3) groups of four cows were randomly allocated to one of the following four forage treatments based on percentage area of plantain: 0%, 15%, 30%, or 60%. Cows were allocated 25 kg DM/cow.day of forage above ground level daily on the basis of metabolisable energy requirements. Dry matter intake was estimated from the difference between pre- and post-grazing pasture mass, using a calibrated electronic rising-plate meter. Milk production was measured as yield and milk solids, while N use was estimated from total milk N excretion and spot subsamples of blood, urine and faeces. Key results: Offering cows spatially adjacent strips of PL increased apparent dry matter intake compared with PRGWC pasture alone (16.4 vs 15.1 kg DM/cow.day, P = 0.027) and apparent metabolisable energy intake (203 vs 188 MJ/kg.cow.day, P < 0.001). Milk yield (16.1 kg/cow.day), milk solids production (1.6 kg/cow.day) and fat concentration (5.69%) were unaffected by the proportion of plantain in the diet. PL offered at 60% of the area increased milk protein concentration compared with PRGWC (4.65 vs 4.36%, P < 0.01). There was no treatment effect on total apparent N intake (563 g N/cow.day), N excretion in milk (113 g N/cow.day) and N-utilisation efficiency (20 g milk N/100 g N consumed). However, total milk urea, blood urea and urine urea N concentrations declined with increasing plantain in the diet, reflecting an influence on urea metabolism. Conclusions: Offering plantain to grazing dairy cows did not improve milk yield or N-use efficiency, but influenced urea metabolism. Implications: Sowing plantain in spatially separate strips within perennial ryegrass–white clover pastures is a useful option to achieve target levels of plantain in the diet and, in conjunction with other mitigation strategies, can be used to improve the sustainability of pastoral dairy farming. Pastures that reduce the dairy nitrogen impact on the environment and increase milk production are desirable. Plantain is such pasture; however, limited knowledge on its inclusion rates in diets to make such a difference has not been generated. Including 15–60% plantain in dairy pastures reduced nitrogen in urine and maintained milk production similarly to ryegrass white clover. The implications of these results indicate that dairy farms may maintain milk production and emit less harmful nitrogen into water sources. [ABSTRACT FROM AUTHOR]

Nitrogen (N) leaching losses from grazed pasture systems pose a risk to the environment with mitigation strategies urgently required to achieve regulatory limits. There has been increased interest in alternative forages to manipulate excretion of urinary-N of livestock. This review summarises research on key forage attributes which affect the pattern of urine-N excretion. The literature showed an opportunity to alter both N concentration and moisture concentration of forages to reduce urine patch N loading. Complementary mitigations of extending the grazing rotation and reducing fertiliser were tested in simulations in addition to a diuresis effect on nitrate leaching in pastoral dairy systems. Findings suggested that forage species alone could not substantially reduce (by more than 20%) nitrate leaching. Combining all forage, management and systems-based solutions led to the greatest reductions in nitrate leaching, 59 and 31% for Waikato and Canterbury. Nonetheless, reductions in N loss came at the expense of pasture productivity which will likely affect profitability and farmer adoption of this suite of solutions in the absence of other drivers. The role of plant secondary metabolites in microbial dynamics has implications on N recycling in soil and rumen environments and this was identified as an area for further research. [ABSTRACT FROM AUTHOR]

Eight perennial ryegrass cultivars (representing the variations in ploidy, heading date and water‐soluble carbohydrates concentration) were investigated for morphology and nutritive value at three phenological stages: pre‐heading vegetative, reproductive and post‐flowering vegetative stages. Chemical compositions and digestibility of morphological components (lamina, pseudostem and reproductive stem) from each perennial ryegrass cultivar were analysed in a split‐plot design. At the vegetative stages, perennial ryegrass cultivars differed significantly in the proportions of lamina and pseudostem. Tetraploid cultivars, Base and Bealey, always had the greatest lamina proportion (51.8% and 53.2% at the pre‐heading and post‐flowering vegetative stages respectively). At the reproductive stage, the emergence of seed heads diminished the differences in morphology among cultivars. Perennial ryegrass cultivars also had distinct nutritive value throughout three phenological stages. The high‐sugar cultivar, AberMagic, had high WSC concentrations (276, 227 and 90 g/kg DM at the pre‐heading vegetative, reproductive and post‐flowering vegetative stages respectively); the intermediate‐heading cultivars, Kamo and Commando, generally had a lower organic matter digestibility in dry matter than the late‐heading cultivars at the pre‐heading vegetative (70.7% vs. 74.4%) and reproductive stage (63.9% vs. 68.2%). However, although the morphological components were different in nutritive value consistently, the differences in morphology did not account for the variation in nutritive value among perennial ryegrass cultivars. [ABSTRACT FROM AUTHOR]

Climate change is anticipated to lead to an increase in the occurrence and intensity of drought and fluctuations in insect cycles that will challenge modern pasture systems. Feeding by root aphids such as Aploneura lentisci Pass. can be a significant challenge to pastures. These below-ground living aphids are commonly found in New Zealand and Australia, feeding year-round on the roots of graminaceous plants such as perennial ryegrass (Lolium perenne L.). Some strains of the fungal endophyte Epichloë festucae var. lolii in perennial ryegrass can provide protection against root aphids and greater resilience under drought, contributing to higher persistency and growth than endophyte-free plants. However, the interaction between insect pressure and drought is not understood. This study examined the effect of drought on root aphid populations and plant performance in perennial ryegrass plants relative to endophyte status (±) and endophyte strain (AR37, NZCT) in a glasshouse experiment. Plants were cloned across the drought and well-watered treatments, and half of the plants were inoculated with root aphids, whilst half of the plants were treated with insecticide. Endophyte infection with strain NZCT and AR37 reduced root aphid numbers. Aphid populations were significantly higher in drought-stressed than in well-watered plants in both endophyte-infected and endophyte-free treatments. Under drought conditions, root aphid populations were increased 4-fold in NZCT and 8-fold in AR37 and endophyte-free plants in comparison with their well-watered counterparts. Root aphids reduced shoot dry weight by 16% in drought-exposed and 26% in well-watered plants in comparison with their insecticide-treated counterparts whilst reducing root biomass by 49%. Our results suggest that root aphids are likely able to exploit the higher availability of amino acids in the plant sap of drought-exposed plants. This study provides evidence that climate change-mediated impacts of root aphids could reduce production in perennial ryegrass-dominant pastures. However, field trials would be necessary to determine whether this effect is seen in situ, where numerous additional factors will be operating at the same time. [ABSTRACT FROM AUTHOR]

This experiment aimed to characterise the concentration of secondary compounds aucubin, catalpol and acteoside in plantain (Plantago lanceolata) herbage and determine if harvesting at different times or nitrogen (N) fertiliser inputs alter concentrations. Herbage of plantain was harvested each season over two years from plots fertilised at 180 or 450 kg N/ha/yr. At each harvest date, samples were taken in at 0700 h and 1600 h. The concentration of secondary compounds in plantain herbage was greatest for acteoside (range 1.77-36.0 mg/g DM), intermediate for aucubin (range 0.566-5.85 mg/g DM) and lowest for catalpol (<0.390 mg/g DM). Compound concentrations were unaffected by N fertiliser and showed limited diurnal fluctuation. There was a strong seasonal effect on all secondary compounds with peaks in concentration occurring in spring for aucubin and acteoside. This experiment suggests environmental factors other than soil N fertility and diurnal patterns influence the concentration of secondary compounds in plantain. [ABSTRACT FROM AUTHOR]

Highlights • Cows on a round-stone stand-off pad achieve acceptable time of lying down per day. • Frequency of lying is lower than normal when cows are on stone surface. • Sand surface in an uncovered stand-off system results in dirty cows. • Woodchip and carpet surfaces equally meet animal welfare standards. • Woodchip surface requires less maintenance than carpet. Abstract The objective of this study was to investigate the effect of stand-off surface type on cow lying behaviour, cleanliness and lameness. One hundred and sixty Friesian × Jersey crossbreed, pregnant non-lactating dairy cows were blocked into five groups of 32 cows and randomly assigned to one of five treatments. Treatments consisted of cows grazing fodder beet in situ and remaining in the paddock with no stand-off (control), or grazing fodder beet in situ and spending 16 h on a stand-off pad with either a woodchip, round-stones (40–60 mm), sand, or geotextile 'carpet' surface. Lying duration, monitored by AfiAct electronic pedometers (Afimilk, Kibbutz Afikim, Israel), showed cows on stone spent significantly more (P < 0.001) time lying (9.5 h) than cows on woodchip (8.4 h), control (8.1 h), and sand (7.6 h), but similar to those on carpet (8.8 h). However, there were fewer (P < 0.001) lying bouts (4.6 bouts/d) and longer (P < 0.001) bout duration (137 min/bout) for cows on stone than other treatments (average 7 bouts/day and 85 min/bout), which may suggest that cows found standing and sitting on the stone surface uncomfortable. As measured by a cleanliness score, cows on the sand surface were less (P < 0.001) clean than cows on other surfaces. Lameness, which was determined by visual scoring, revealed only moderate cases of lameness which tended (P = 0.059) to be more prevalent for cows on stone (11.3%) or sand (12.5%), compared with lowest in woodchip (4.0%) or carpet (4.7%), and intermediate in the control treatment (8.8%). The data indicate that sand and the size of stone used are less suitable surfaces than woodchip or carpet for an uncovered winter stand-off pad to meet minimum requirements of animal comfort and welfare. While both the woodchip and carpet surfaces equally met animal welfare standards, the woodchip required less maintenance. [ABSTRACT FROM AUTHOR]

Irrigated, diverse pastures were managed under normal (grazed to 3.5 cm) or lax (grazed to 5 cm allowing ryegrass seed head development) grazing intensity, with or without mowing (to 3.5 cm), in spring. On the subsequent grazing rotation in summer, an experiment was conducted to investigate the carry-over effects of previous management on herbage regrowth and milk production. Nine groups of three Friesian × Jersey dairy cows each were randomly allocated to three replicates of three treatments: normal grazing (Norm); previously lax managed pastures (Lax); previously lax managed pastures that were pre-graze mown (Mow). Herbage in Mow treatments had a higher ME (p < 0.05) than Lax and Norm (11.7, 11.3 and 11.4 MJ ME/kg DM, respectively). There was no difference in dry matter intake (18 ± 0.30 kg DM/cow/d) or MS production (1.85 ± 0.02 kg MS/cow/d) among treatments. Results of this study indicated that milk production was not altered by grazing management. [ABSTRACT FROM AUTHOR]

The effects of 50% or 100% of a herbage diet of plantain on milk production and urinary nitrogen (N) concentration were measured in two experiments for late (autumn 2015) and early (spring 2015) lactation dairy cows. Three groups of 12 mixed age Friesian × Jersey dairy cows were offered a perennial ryegrass-white clover pasture, or pure plantain or 50% perennial ryegrass-white clover and 50% pure plantain by ground area (50–50 pasture–plantain). Urine N concentration was lower in both experiments (P< .001) for plantain (2.4 and 2.2 g N/L) and 50–50 pasture–plantain (3.6 and 3.4 g N/L) than pasture (5.4 and 4.7 g N/L). Cows on plantain or 50–50 pasture-plantain produced at least as much milk as those on pasture in both experiments. Plantain may offer environmental benefits to dairy systems by reducing the N concentration of urine deposited on the soil from grazing cows. [ABSTRACT FROM PUBLISHER]

Simple Summary: Incorporating forage plantain into the diet of grazing dairy cows has the potential to reduce nitrogen (N) losses from pastoral systems. One of the key mechanisms for reduced N loss from plantain-fed cows is through increased urine volume and diluted urine N concentration, which increases the % of urine N used for plant growth. The aim of this study was to determine whether lower proportions of plantain in the diet would be effective in achieving changes in urination. The results showed that compared to cows grazing traditional perennial ryegrass and white clover pastures, cows with 25% plantain in their apparent dietary intake increased urine volume and urination frequency and reduced urine N% in the morning. When dietary plantain was less than 20%, there was only a small effect on increased urine volume, though morning urine N% was reduced. Ensuring more than 20% plantain in the diet has the potential to reduce N leaching risk via reduced urinary N load from grazing dairy cows. The objective of this study was to determine the effect of grazing plantain-based pastures on urine volume, urination frequency, and urinary nitrogen (UN) concentration of dairy cows under a typical pastoral dairy practice offering approximately 25% supplemented feeds. The experiment was a completely randomised design with three pasture treatments (perennial ryegrass–white clover (RGWC); RGWC + low plantain rate (PLL); and RGWC + high plantain rate (PLH)), five replicate plots, and repeated in two sequential grazing periods. Forty-five lactating Friesian × Jersey cows were randomly assigned into three groups of 15 animals each to graze over six days in adaptation paddocks and three days in experimental plots. Urine flow sensors were used to measure urine volume and urinary frequency, while spot urine sampling was conducted to determine nitrogen (N) concentration in cow urine. The results showed that including 25% plantain in the diet (PLH) increased daily urine volume by 44% and the daily number of urinations by 28%, compared to grazing the RGWC pasture. In addition, N concentration in cow urine was decreased by 18 and 29% when the diet contained 18% and 25% plantain, respectively. In conclusion, under a typical dairy farm practice, incorporating plantain into the RGWC pasture with the proportion of 25% plantain in the diet can increase the number of urine patches and reduce the concentration of N in the urine, thereby providing the opportunity to decrease N leaching from pastoral systems. [ABSTRACT FROM AUTHOR]

High yielding crops such as maize (Zea mays L.) and fodder beet (FB; Beta vulgaris L), are commonly used to extend lactation and increase animal productivity from pastoral dairy systems. Financial modelling to compare costs and benefits of different crops is useful for decision making, but such modelling often fails to account for potential animal health risks which can be associated with feeding supplements. A multi-component, whole-farm modelling approach was used to predict milk solids (MS, milk fat + protein) production and the economic farm surplus (EFS: operating surplus – adjustments) between 2016 and 2018 for an irrigated farm in Canterbury (South Island) and a non-irrigated farm in the Waikato (North Island), of New Zealand. The financial risk of the dairy business was measured using the ratio between mean return on assets (ROA) minus an assumed 5% risk-free ROA, and the standard deviation of ROA was calculated from 300 combinations of climate, milk, and feed price, land appreciation, and interest rate. Four scenarios of autumn and spring supplementation of pasture were considered at each geographical location; imported maize silage (Base), a crop of maize silage grown on the milking platform (MSC; area used to produce milk), a crop of FB grown on the milking platform (FBC), and a FB crop with an outbreak of acute (1% stock fatality) and subacute ruminal acidosis (5% decline of feed intake) across the entire herd (FBAC). The MSC scenario improved EFS by 5.8% compared with Base in both the irrigated and the dryland system. The predicted response to MSC reflected greater milk production, lower feed expenses, and shorter crop rotation, compared with either Base, FBC, or FBAC. While FBC increased EFS by 4.8% compared with Base under irrigation, EFS was similar to Base under dryland conditions ($2711 and $2759/ha, respectively). The limited advantage of growing FB under dryland conditions reflect reduced herbage supply due to the extended crop duration of FB compared with maize silage. Model predictions suggest that FBAC will increase the financial risk by reducing milk production and EFS by 6.5% (irrigated) and 7.1% (dryland) compared with Base. In the absence of any adverse health risks, farm performance from the FBC scenario was comparable to that of MSC under irrigated conditions. However, in dryland conditions, and when the potential economic cost of acute and sub-acute ruminal acidosis is considered, there is little advantage to growing FB on the milking platform. • There is limited economic advantage to growing fodder beet to support lactation. • Risk exposure to fodder beet crop increased under dryland conditions. • System response to crop inclusion is dependent on commodities market and climate. • Profitability of fodder beet crop was reduced by ruminal acidosis. • Maize silage lowers cow health risk and is a competitive alternative to fodder beet. [ABSTRACT FROM AUTHOR]

Future development pathways for irrigated dairy farms in Canterbury operating under stricter nitrogen (N) loss limits were compared in two farmlets over four years. One represented the traditional pathway of intensification via higher inputs of N fertiliser and supplementary feed ('higher input-high efficiency', HI-HE), while the other represented a lower input pathway using half the amount of N fertiliser and one quarter the amount of supplementary feed ('lower input-high efficiency', LI-HE). The stocking rate of both systems was matched to feed supply to achieve high utilisation (∼90%) of the pasture grown. Mean total annual N surplus and estimated nitrate-N leaching were lower in LI-HE than HI-HE, by 46% and 25% respectively. Milk production was lower for LI-HE (1,700 kg versus 2,240 kg milk fat + protein per ha/year). Estimated profit was the same for both systems at a milk price of $6.46/kg fat + protein, below which LI-HE was more profitable than HI-HE and vice-versa. Compared with the benchmark high-performing Lincoln University Demonstration Dairy Farm (LUDF) through the same period, LI-HE was 2% less profitable, but estimated N leaching was ∼30% lower. Subsequent adoption of the LI-HE system by LUDF demonstrated that the system is scalable, and profitable. [ABSTRACT FROM AUTHOR]

Labeling systems for niche market food products is becoming increasingly important to address consumers' expectations. Yak meat is 'green' product from natural extensive rangeland on Qinghai-Tibetan plateau. A trace technique is essential for consumers to know the origin of yak meat. In the current study, mineral fingerprints were investigated for their potential to classify yak meat according to geographical origin. The concentration of more than 50 mineral contents in 24 yak meat samples from three regions on Qinghai-Tibetan plateau were analyzed by ICP-MS. Multivariate statistical analyses were used to identify the most relevant indicators of origin. Seven elements (Na, As, Ni, Se, Rb, Cd and Ti) were selected for further routine analyses based on the significant origin differences (P<0.05). The three minerals (Se, Rb, Ti) were selected by statistics analysis and established discriminant model for yak meat traceability. Linear discriminate analysis gave an overall correct classification rate of 91.7% and cross-validation rate of 87.5%. These results demonstrate the usefulness of multi-element fingerprints as indicators for authenticating the geographical origin of yak meat. [ABSTRACT FROM AUTHOR]

Simple Summary: Fodder beet (FB) is widely used in grazing dairy systems of New Zealand to support early- and late-lactation milk production, however, the large fraction of water-soluble carbohydrate present in FB bulbs presents a risk of subacute and acute ruminal acidosis. Despite widespread use of FB across New Zealand, the incidence of ruminal acidosis using industry-recommended methods of feeding FB has not been investigated. This study analyzed the time-dependent changes to rumen fermentation, apparent dry matter intake, milk production, milk composition and plasma amino acid concentration of grazing dairy cows supplemented with moderate amounts (40% of dry matter intake) of FB during early lactation. Our findings indicate that incidence of subacute ruminal acidosis due to FB is greater than currently realized, as 25% of cows developed severe subacute ruminal acidosis following transition to target FB allocation (40% of daily intake). Across all cows, FB reduced rumen pH, feed conversion efficiency and was not advantageous to milk production. These results suggest methods for adapting cows to a diet containing FB require further evaluation to reduce the risk of subacute ruminal acidosis (SARA) experienced by individuals within the herd. In a cross-over design, eight rumen cannulated dairy cows were used to explore the industry-recommended method for dietary transition to fodder beet (FB: Beta vulgaris L.) on changes to rumen fermentation and pH, milk production, dry matter intake (DMI) and the risk of subacute ruminal acidosis (SARA) during early lactation. Cows were split into two groups and individually allocated a ryegrass (Lolium Perenne L.) and white clover (Trifolium repens L.) diet (HO) or the same herbage supplemented with 6 kg DM/cow of harvested fodder beet bulbs (FBH). Dietary adaptation occurred over 20 days consisting of: stage 1: gradual transition to target FB intake (days 1–12, +0.5 kg DM of FB/d); stage 2: acclimatization (days 13–17) and stage 3: post-adaption sampling (days 18–20). Response variables were analyzed as a factorial arrangement of diet and stage of adaption using a combination of ANOVA and generalized linear mixed modelling. Dietary proportion of FB represented 22, (stage 1), 32 (stage 2) and 38% (stage 3) of daily DMI. One cow during each period developed SARA from FB and the duration of low pH increased with FBH compared to the HO treatment (p < 0.01). Rumen concentrations of lactic and butyric acid increased with FBH but concentrations of acetate, propionate and total volatile fatty acids (VFA) declined by 9.3% at day 20, compared to the HO treatment (p < 0.01). Treatments did not affect milk production but total DMI with supplemented cows increased during the final stage of adaptation and feed conversion efficiency (FCE kg milk/kg DM) declined with the FBH treatment. The occurrence of SARA in 25% of animals fed FB suggest it is a high-risk supplement to animal health and further evaluation of industry-recommended methods for feeding FB at the individual- and herd-scale are needed. [ABSTRACT FROM AUTHOR]