Biological rhythms are repeating patterns that are driven by time-keeping mechanisms within the animal and are adaptive as they coordinate physiology and metabolism with the external environment. The dairy cow has a well recognised natural daily pattern of feed intake and milk synthesis, but regulation of these rhythms has not been well described in the literature or well considered in current dairy management. Recent discoveries have clearly described circadian time-keeping mechanisms in peripheral tissues that are responsive to the timing of food availability. Some management strategies on dairy farms may desynchronise the interactions between central and mammary circadian timekeepers, resulting in reduced milk yield and efficiency. Feeding a total mixed ration is commonly assumed to create constant ruminal conditions, but the large variation in the rate of feed intake across the day causes large fluctuations in rumen fermentation and absorbed nutrients. Milk composition also differs across the day due to both dynamics in nutrient absorption and biological regulation attempting to match milk yield and composition with calf requirements across the day. Recent work has shown that milk synthesis varies over the day and is modified by the timing of feed intake and nutrient absorption. These rhythms have also been shown to be affected by the timing of feed delivery. We expect that maximal milk yield and efficiency are achieved when we have more consistent rumen fermentation and match the timing of nutrient absorption and mammary capacity for milk synthesis. Managing feeding times provides the opportunity to modify feed intake across the day, but behavioural responses are complex. Appreciating the impact of circadian rhythms provides the foundation to develop nutrition and management strategies considering circadian dynamics of intake and milk synthesis and provides opportunities for new gains in cow efficiency, welfare, and health.

The pet-food industry is a significant and rapidly growing market, with global sales estimated at over US$100 billion in 2020. The market size for pet food was estimated at 22.9 million tonnes in 2020. The number of cats and dogs being fed commercial pet food is also on the rise, with an estimated 62% of cats and 68% of dogs being fed commercial pet food in the United States alone with an estimated value of A$2.3 billion in 2020. This represents a growth of 3.3% from the previous year, and the market is expected to continue growing with a forecast compound annual growth rate (CAGR) of 3.4% from 2021 to 2025. The demand for high-quality, specialised pet-food products has led to consistent year-on-year growth in the industry. With this, the increasing demand for commercial pet food on a global scale comes with growing sustainability challenges that must be addressed. In this paper, we will examine some of the opportunities for the use of black soldier fly larvae (BSFL) meal and oil in pet-food formulations to reduce the environmental impact of pet food and pet ownership and deliver nutritional and functional benefits to our pets.

Context: Climate and economic changes promote the encroachment of woody plants on marginal mountain pastures. In the Alps, the main woody invader is the nitrogen-fixing shrub Alnus viridis (green alder). Robust breeds of different ruminant species may perform well on these shrub-encroached pastures.Aims: To assess the effects of A. viridis encroachment levels of mountain pastures on the growth performance and carcass and meat characteristics of cattle and sheep.Methods: For 8–9 weeks, 22 15-month-old growing Dexter cattle and 20 7-month-old weaned Engadine sheep were grazed rotationally on pastures in a subalpine zone with four different levels of A. viridis encroachment (average: 0.8%, 28.7%, 50.3% and 67.8%). Following slaughter, the assessed carcass and meat characteristics (longissimus thoracis and biceps femoris) included physicochemical meat quality, muscle fibre typing, fatty acid profiling (intramuscular and perirenal fat) and the sensory properties of patties.Key results: The shrub encroachment levels had only minor effects on the animals. Interactions with the animal species influenced some sensory and fatty acid characteristics. The average daily gains were 201 g in the Dexter cattle and 104 g in the Engadine sheep. Both species achieved satisfactory carcass and meat quality and favourably low n-6/n-3 fatty acid ratios (0.63 and 0.68 in the intramuscular fat of the cattle and sheep, respectively). The meat from the Dexter cattle had a slightly higher cooking loss and shear force and a slightly lower proportion of fatty acids relevant to human health. Flavour appreciation was in favour of the burgers prepared from the beef.Conclusions: Both robust breeds were suitable for producing meat on extensive pastures with A. viridis encroachment of up to 70%. Based on indirect evidence, it seems that neither species consumed significant quantities of leaves or bark from the trees.Implications: Our study provides detailed information on rare robust breeds of two animal species in the context of meat production according to customer preferences. To better explain the differences between the two animal species, particularly in terms of fatty acid profiles, the role of the A. viridis understory needs to be clarified.

Context: Conversion of native vegetation to cropland is one of the most widespread anthropogenic landscape alterations, particularly in the Great Plains region of the United States. Mule deer occur throughout the Great Plains; however, it is the south-eastern edge of their geographical distribution, and few populations coincide with dense cropland. The rapidly depleting Ogallala Aquifer supplies irrigation to row-crops throughout the region, which will likely shift towards dryland agricultural practices in the near future.Aims: We sought to understand how cropland use influences morphology, body condition indices, reproductive output, and survival of free-ranging mule deer.Methods: We accumulated a multi-year, longitudinal dataset of movement and morphology for 146 mule deer in the Texas Panhandle. We linked seasonal cropland use with observed morphology, body condition metrics, and reproductive output via linear mixed-effect modelling and assessed the influence of cropland on annual survival by using Cox proportional hazard models.Key results: Mule deer that did not use cropland at any time during the year exhibited morphological and nutritional indices similar to those that did; except body-fat percentage being greater for mature (≥4-year-old) males that used cropland. Further, cropland use did not predict survival probability. Analyses of cropland use during seasons defined by life-stage showed context-dependent nutritional benefits. Use of cropland during winter following reproduction demonstrated an increase in young (≤3-year-old) male antler size and body mass and summer crop use increased body condition for all males. Female mule deer that utilised cropland before pregnancy had increased probability of successful reproduction, demonstrating a potential capital investment strategy in reproduction.Conclusions: Cropland does not limit morphology or survival of mule deer; however, additive use of row-crops can provide a nutritional buffer and enhanced reproductive output for individuals that choose to utilise it.Implications: Our study demonstrates important population-level interactions with the environment for a species near the extent of their geographical distribution. Conversion of row-crop farming from aquifer depletion or climate shifts may not diminish mule deer populations, but these changes may alter specific habitat-nutritional health relationships that can influence population performance and future conservation efforts.

The global goat meat sector is advancing and contributes to long-term food security, especially in meeting the protein demands of the growing human population in developing countries. Spanning all countries, Australia, is the largest exporter of goat meat, although it has negligible consumption. However, Australia does potentially have a secure future as an innovative, profitable, and resilient world leader in goat production, provided some challenges are addressed. These challenges facing the goat meat sector require suitable strategies and interventions for better profitability and acceptance of goat meat consumed in Australia and as an export product. Limited research on goat meat quality and the lack of an adequate grading system for goat meat quality are two of the major issues that need attention from the industry and researchers. Some of the most critical areas that need further research to enable growth of the goat meat industry are the influence of genetics and age of animals on meat quality, standardisation of the ageing period of various goat meat cuts, cooking innovations, consumer acceptance and sensory analysis of goat meat (both farmed and rangeland goats). This paper reviews the status of the goat meat sector and identifies the opportunities for the goat meat sector, particularly in Australia. In addition, we highlight several key issues requiring further research and interventions to enhance the growth of the goat meat industry.

Context: There are still comparatively few methods for the detection of drug residues in buffalo milk.Aims: This study aims to develop a method for the detection of drug residues in buffalo milk.Methods: In this study, we developed an analytical method for veterinary drug residues in buffalo milk using liquid chromatography–tandem mass spectrometry. The multi-residue method was established for the simultaneous identification and quantitation of eight common veterinary drugs, including metronidazole, salbutamol, atropine, trimethoprim, hydrocortisone, kitasamycin, roxithromycin and tylosin.Key results: The sample processing method for buffalo milk was compared and optimised. The precision, recovery and matrix effects of the method were validated. The precision and accuracy of all analytes ranged from 1.81% to 12.35% and 1.25% to 14.57%, respectively. The average recovery percentages varied between 93.59% and 114.57%, and the average matrix effect ranged from 87.12% to 103.76%. All eight analytes in buffalo milk exhibited stability under different treatment conditions.Conclusions: The developed method was successfully applied to laboratory analysis and routine sample analysis. The method was demonstrated to be rapid, sensitive and reliable for the rapid monitoring of veterinary drug residues in buffalo milk.Implications: The findings of this study contribute to the risk assessment of veterinary drug residues for preventing the human consumption of contaminated buffalo milk and its derivatives.

Precision nutrition regimes currently rely on the assumption that broilers will grow in a steady and predictable way on a daily basis, with the continuous deposition of nutrients into muscle or, in the case of laying hens, into an egg. However, it has been observed that this is not the case for egg production, with Ca requirements being aligned with eggshell formation. Recent research has suggested that muscle is also deposited at differing rates over a 24-h cycle. The circadian rhythm synchronises various biological processes to oscillate within a 24-h cycle. Thus, the cyclic nature of body systems should be explored, to determine whether consideration of the circadian rhythm is required for precision nutrition programs, achieving peak efficiency of performance and accurate nutrient requirement recommendations. Recent advances in nutrition have demonstrated the powerful effect of the circadian rhythm on human health and animal growth and production. Therefore, this review discusses recent circadian-rhythm research with relevance to poultry. Specific focus is given to the interaction of the circadian rhythm with diet and dietary nutrients, for the precision nutrition of poultry and optimising production.

Context: The Patagonian huemul, an endangered Odocoilinedeer, has an estimated 350–500 individuals remaining in Argentina. Today’s population size, representing a numerical reduction of >99% of original estimates, is fragmented into small groups along ~2000 km of Andean mountains. The species’ numbers were heavily reduced by past overexploitation and they disappeared in areas of high anthropogenic activity, predominantly the fertile valley bottoms.Aims: This research delineates the current potential distribution of Patagonian huemul by using climatic indicators, topographic and vegetational proxies, and anthropogenic pressure, to determine the relevance of the climatic envelope on current distribution.Methods: Occurrence records (latitude and longitude) were compiled (n = 159) by consulting the literature. Twenty environmental variables were used (WorldClim database) and two other representative environmental variables (normalised difference vegetation index (NDVI) and enhanced vegetation index (EVI)) were added to test their predictive power. We added the human footprint index (HFP) as a variable to control for model bias. Using the maximum entropy algorithm (MaxEnt), we modelled the species’ potential distribution. We designated the historical distribution as area M. Additionally, we calculated three areas of distribution: current, historical and potential. Finally, we calculated distributional retraction of the species and area lost per year.Key results: The model showed good predictive power (AUCTest = 0.764 ± 0.091). However, low values were obtained for AUCtrain and AUCprom for the different predictor scenarios. Although the model shows the interaction among several climatic, environmental, and topographic variables, the human footprint index (39.9%) was the variable that most influenced the current potential distribution of this species.Conclusion: Our model shows that most of Patagonia’s surface is climatically suitable for huemul. This suggests that the causes of distributional retraction are not related to limitations imposed by the climate envelope, but rather concur with recent research showing impact owing to the species’ behavioural response to anthropogenic activity.Implications: Current populations are small, fragmented, and confined to poor-quality sites. Although the species is currently found mainly within protected areas, management actions must be initiated that promote innovative strategies in unprotected areas, as well as high-value habitats, particularly as protected areas contain limited fertile lower-valley habitats.

It is clear that the societal role of meat is being challenged with ideological and simplified logic without substantiation from robust data-driven science. With this background, the international summit titled ‘The societal role of meat – what the science says’ was held in Dublin, Ireland, during October 2022, to provide evidence-based evaluations and the Dublin Declaration was signed by over 1000 scientists. In this paper, we provide a synopsis of the summit and then give context for evaluating the societal role of meat in Australia. The key themes of the summit were the essential roles of meat in (1) diet and health, (2) a sustainable environment and (3) society, economics and culture. Evidence clearly showed the role of meat as a nutrient-dense source of high-quality protein and micronutrients that can be safely consumed by humans. Further, the complementary role of livestock in agricultural systems was highlighted with both plant- and animal-based agriculture reliant on each other to maximise the efficient production of food. Thus, from both an Australian and world perspective, very little food considered to be human-edible is fed to livestock. The role of livestock in rural societies across the world was emphasised to underpin regional and national economies, with particular importance in those countries with developing economies to facilitate growing wealth to ‘step out’ of poverty and provide gender equality. Meat production, particularly from ruminants, is a critical part of Australian primary production and it is concluded that the Dublin Declaration is highly relevant to Australia. Finally, concern regarding future funding and organisation of research and extension is discussed. There is a need to continue funding highly collaborative programs that bring a broad range of disciplines together, in conjunction with undergraduate and postgraduate teaching to underpin the social license to operate for meat and livestock production.

Context: The accuracy of estimated breeding values (EBVs) is an important metric in genetic evaluation systems in Australia. With reduced costs for DNA genotyping due to advances in molecular technology, more and more animals have been genotyped for EBVs. The rapid increase in genotyped animals has grown beyond the capacity of the current genomic best linear unbiased prediction (GBLUP) method.Aims: This study aimed to implement and evaluate a new single-nucleotide polymorphism (SNP)–BLUP model for the computation of prediction error variances (PEVs) to accommodate the increasing number of genotyped animals in beef and sheep single-step genetic evaluations in Australia.Methods: First, the equivalence of PEV estimates obtained from both GBLUP and SNP-BLUP models was demonstrated. Second, the computing resources required by each model were compared. Third, within the SNP-BLUP model, the PEVs obtained from subsets of SNP were evaluated against those from the complete dataset. Fourth, the new model was tested in the Australian Merino sheep and Angus beef cattle datasets.Key results: The PEVs of genotyped animals calculated from the SNP–BLUP model were equivalent to the PEVs derived from the GBLUP model. The SNP–BLUP model used much less time than did the GBLUP model when the number of genotyped animals was larger than the number of SNPs. Within the SNP–BLUP model, the running time could be further reduced using a subset of SNPs makers, with high correlations (>0.97) observed between the PEVs obtained from the complete dataset and subsets. However, it is important to exercise caution when selecting the size of the subsets in the SNP–BLUP model, as reducing the subset size may result in an increase in the bias of the PEVs.Conclusions: The new SNP-BLUP model for PEV calculation for genotyped animals outperforms the current GBLUP model. A new accuracy program has been developed for the Australian genetic evaluation system which uses much less memory and time to compute accuracies.Implications: The new model has been implemented in routine sheep and beef genetic evaluation systems in Australia. This development ensures that the calculation of accuracies is sustainable, with increasing numbers of animals with genotypes.

Context: Fat colour is one of the most important economic traits in the marketing of beef. There are many factors that affect fat colour, such as breed, age, diet and gender. Fat colour is observed in different ranges of colours, including white, yellow and brown. The main issue with improving fat colour is that consumer preferences of fat colour vary across the globe. Therefore, investigating the metabolic mechanisms of fat colour may provide new biomarkers for phenotyping, so as to develop effective selection strategies to achieve the locally desired fat colour.Aims: This study aimed to perform a comparative metabolic analysis between white and yellow fat from crossbred cattle so as to identify potential biomarkers for the selection of fat colour and to better understand the metabolism of white and yellow fat depots.Methods: Carcass samples of subcutaneous fat were collected from crossbred cattle (Simmental × Mongolian cattle) and scored for fat colour. Liquid chromatography–mass spectrophotometry analysis of extracted metabolites from the subcutaneous fat of six animals with white fat and six animals with yellow fat was performed.Key results: The comparison between metabolites of white and yellow fat colour samples indicated that there were five categories of 235 significant metabolites, which included hydrocarbons, lipids and lipid-like molecules, organic acids and their derivatives, organic oxygen compounds and organoheterocyclic compounds. The principal-component analysis illustrated that yellow and white fat samples can be classified in groups; however, the metabolites of white fat samples showed greater variation than those in the yellow fat. In the white fat, there were 163 metabolites that had a higher relative abundance than in yellow fat and 72 that had a lower relative abundance than in yellow fat. 3-Hydroxyoctanoic acid, anethofuran, 9,10-DiHODE, furanoeremophilane, pregeijerene, N-glycolylneuraminic acid, and glycocholic acid were identified as the metabolites that differed the most in abundance between the white and yellow fat samples.Conclusions: This study has provided insights into the metabolic differences between white and yellow fat depots and identified key metabolites associated with beef fat colour.Implications: This study has provided potential biomarkers that may be useful for selection of beef fat colour in live animals.

Context: Feeding behaviour is an important tool for the early detection of diseases in dairy cows.Aims: The aim of this study was to evaluate whether the variation in time spent feeding in the prepartum and postpartum periods may be used to detect the occurrence of metritis and subclinical ketosis (SCK) before the onset of the clinical symptoms at the postpartum.Methods: The research was conducted in four electronic databases, including Scopus, Science Direct, Pubmed, and Web of Science. The inclusion criteria for citations were original research, evaluation of daily time spent feeding in dairy cows, and use of this indicator for early identification of metritis and/or SCK in dairy cows in the prepartum and postpartum periods. A random-effect meta-analysis (MA) was conducted for metritis with the time spent feeding means of control (healthy) and treated (sick) groups measured in the prepartum and postpartum periods. The analysis was conducted with the values of daily time spent feeding before and after calving in both groups.Key results: In total, 26 trials from six papers, involving 1037 dairy cows, were included in the statistical analysis. No data were obtained for SCK to conduct a MA, while for metritis, 16 trials from six papers (prepartum) and 10 trials from three papers (postpartum) were considered. The heterogeneity between studies on metritis was moderate (I2 = 57.5%) in the prepartum period and low (I2 = 10.0%) in the postpartum period. The mean difference feeding time for healthy and unhealthy animals was greater during postpartum (21.14 min/day, P < 0.001) than during prepartum (16.36 min/day, P < 0.001). Meta-regression analysis showed that number of daily milkings, sample size, and the place of running trial significantly influenced the time spent feeding by cows.Conclusion: On the basis of available and suitable scientific literature, time spent feeding is reduced at the prepartum and postpartum periods in dairy cows further affected by metritis.Implications: This study evidenced that feeding time might be incorporated into health-monitoring protocols for early detection of metritis in dairy cows.

Context: Coping with high levels of cold stress should be beneficial to survival of lambs, given the high mortality rate associated with severe winter storms. The Elsenburg Merino selection experiment involved divergent selection for reproduction. Phenotypic results comparing the positively selected H-Lines and negatively selected L-Lines suggested that cold-stress adaption could have contributed to the favourable genetic trends for survival of H-Line lambs. However, observing the genetic merit of better adapted animals depends on the presence of cold stress at the time of recording. A genotype by environment component (G × E) could, thus, be important when assessing survival/mortality phenotypes.Aim: This study proposed the genetic analysis of this possible G × E component and compared the H- and L-Lines in this regard.Methods: The sire model allowed the use of progeny phenotypes for neonatal mortality recorded during different levels of cold stress, and the possible G × E could be investigated through the reaction-norm approach. Genetic parameters were evaluated as random regression components by implementing a Gibbs sampling approach. A data set of 5723 individual lamb records was analysed as the progeny of 213 sires.Results: A modelled G × E component played an important role in mortality outcomes, with the mean estimate (and 95% confidence interval) for the slope () only marginally smaller than the corresponding estimate for the intercept (). The reaction-norm model showed a higher heritability (h2± posterior standard deviation) for mortality at 3 days of age during high cold-stress (0.22 ± 0.16 at ~1100 KJm−2h−1) than during mild (0.13 ± 0.10 at ~960 KJm−2h−1) conditions, suggesting a greater ability to discriminate between sires at increasing stress levels.Conclusions: Failure to account for this G × E component putatively contributes to the low h2 commonly reported for survival traits. The higher h2 at increased levels of cold stress could have played an important part in the higher survival of the H-Line progeny, who were better at coping with cold, wet and windy conditions.Implications: Larger studies representing a wider environmental trajectory are recommended. This should be very feasible since cold stress can be derived from commonly available weather-station data.

Context: It is common practice to manage red deer on highly digestible easily harvested forage during winter on New Zealand deer farms, particularly in areas that experience low or no pasture growth during this period. However, not all individuals within these production systems perform equally.Aims: To investigate foraging behaviour of young red deer and liveweight gain of young red deer and wapiti crossbred sire lines when offered two contrasting winter forage diets.Methods: One hundred and sixty-three rising 1-year-old female red deer and red deer wapiti crossbreds representing five red deer and two wapiti sires, were split into two management groups balanced by sire and liveweight and managed on either an easily harvested highly digestible diet (forage kale) or a harder-to-harvest more poorly digestible diet (pasture) for a 6-week period during winter. Foraging behaviour was monitored on 95 red deer yearlings by using GPS collars over a 2-week period. Liveweights were recorded at the start and end of the 6-week period.Key results: Progeny managed on the kale treatment exhibited an extended activity period during the dawn period and a suppressed activity period during the middle of the day. Progeny managed on the pasture treatment exhibited frequent shorter activity periods from dawn to dusk. Time spent foraging and the number of foraging bouts greater than 5 min in duration were different among progeny of different sires. These differences in behaviour did not affect liveweight gain. Liveweight gain over the 6-week trial period was significantly higher for progeny from one wapiti sire than for all red deer sire progeny while being managed on the kale diet (P < 0.001), but there were no differences among progeny on the pasture diet.Conclusion: Foraging behaviour varied considerably between sire lines and appeared to vary between forage type, but there were no correlations between behaviour and liveweight gain in this trial.Implications: Forage type offered to young red deer may alter their foraging behaviour. Offering an easier to harvest high digestible forage diet may increase liveweight gain of progeny that have a higher genetic potential to grow during the winter period.

Context: In grazed grassland, the per area output of animal-source products usually declines with decreasing stocking rates because of lower herbage utilisation efficiency. Consequently, nutrient export is larger with increased stocking intensity, which should decrease the productivity in the long term. However, little information is available on long-term productivity of extensive grasslands under varied stocking intensities receiving no input.Aims: The effect of stocking intensity was investigated in a long-term grazing trial over 16 years of production. We hypothesised that, despite minimal nutrient export under grazing, no reduction in productivity occurs over long-term periods, but expected an interaction between stocking intensity and year.Method: The net pasture productivity was determined in terms of animal performance assessed from Fleckvieh cows grazing in a randomised block design with three replicates in three different stocking intensities (moderate, lenient, and very lenient, corresponding to stocking rates of 1.1, 0.7, and 0.5 livestock unit/ha.year respectively), recorded from 2005 to 2020. Metabolisable energy in GJ/ha.year (MEtotal) provided by the pasture and the livestock unit grazing days/ha.year (LUGD, 1LU = 500 kg) were calculated on the basis of liveweight measurements.Key results: The interaction of year and treatment significantly affected LUGD (F = 16.85, d.f. = 30, P < 0.0001) and MEtotal (F = 12.81, d.f. = 30, P < 0.0001) and indicated a cyclic trajectory with increases and decreases in performance over the study years. Overall, the moderate stocking intensity led to and maintained significantly higher performance than did very lenient grazing of up to 60% and 55% in LUGD and MEtotal respectively. However, structural equation modelling indicated a negative temporal trend irrespective of stocking intensity.Conclusions: On the basis of existing data of herbage quality and botanical composition from the same experiment, this trend was likely to be a result of nutrient redistribution within pastures that probably changed the botanical composition and grass sward productivity in conjunction with drier years towards the end of this study period.Implications: This study showed that productivity in low-input grassland under continuous grazing declines over time irrespective of stocking intensity. Productivity decline in all treatments implies tradeoffs for farmers grazing at lower stocking intensities.

From racehorses to family pets, equine production and management is primarily pasture-based in New Zealand. Pasture-based equine production systems largely reflect the horse’s ecological niche and have a unique set of management and welfare challenges. This review examines the potential welfare issues related to the management of horses in New Zealand. The economic value of horses varies greatly depending on their usage, which covers a wide spectrum from pest species (e.g. feral horses) to production (e.g. racehorses) and companion animals (e.g. leisure and sport horses). The view of where the horse is positioned on this spectrum may cause differing welfare threats to horses, due to the economic considerations, which drive the majority of welfare and managemental decisions. The organisation, management, racing and wastage metrics of the Thoroughbred racehorse industry are well documented, and the benefits of the pasture-based system have become evident through less stressful weaning practices and opportunity for early exercise (which has been associated with longer careers and fewer musculoskeletal injuries). Identification of equine-welfare research priorities in New Zealand remains challenging, given the lack of vertical integration of many sectors of the equine industry resulting in fragmented and limited availability of data.

Context: Soil acidity constrains pasture productivity, limiting production from grazing animals. Lime application can ameliorate acidity, although the rate is increased when incorporated rather than surface applied. Soils in south-eastern Australia are generally highly erodible, containing valuable native grasses that might be lost if disturbed. Surface application is, therefore, the only option, but the extent to which lime can ameliorate acidity and increase pasture and animal production requires research.Aim: This 10-year experiment studied three rates of surface-applied lime, two of superphosphate (P) and two stocking rates (SR) on continuously grazed sheep on acidic soils. Two flocks were studied, one from May 1999 to December 2002, and the second from August 2005 to July 2008. We hypothesised that wool production and animal liveweight would increase as (1) lime rate increased, (2) P rate increased, and (3) peak animal productivity would occur under the combination of the highest rates of lime and P.Key results: The experiment coincided with the Millennium Drought reducing forage production, and slowing lime movement into the soil and consequent amelioration. During Flock 1, effective SR (dry sheep equivalents (DSE)/ha) of the low P, low SR and limed treatment became higher by 1 DSE/ha for 10 months during the final flock measurement months, as drought intensified. During Flock 2, effective SR of both high P, high SR and limed treatments were greater by 2 DSE/ha than non-limed counterpart for the first 9 months of 2006. Trends of higher animal production under lime became clearer with time, so were more apparent in Flock 2 than Flock 1, and at higher SR. High lime, high P and high SR had the greatest wool production. High P, low SR and nil lime was initially highly productive, but declined sharply when legumes disappeared, associated with soil aluminium toxicity. Lime maintained superior ground cover under drought, reducing the danger of sward death and soil erosion, demonstrating its sward preservation, sustainability and ecosystem service benefits.Implications: With the ever-increasing price of land, farmers must increase their land’s productivity. This trial demonstrated production and environmental benefits associated with acid soil amelioration through lime application.

Vitamin K (VK) has long been known for its essential role in blood coagulation. However, over the past decade, evidence has mounted for its intrinsic and essential roles in other functions within the body, including bone metabolism, calcification, brain development and glucose metabolism. Thus, VK should no longer be considered a single-function ‘haemostasis vitamin’, but rather as a ‘multi-function vitamin’. While current research has focused on its emerging role in human nutrition, the role that VK plays in other species such as the horse has not been well described, with most of our current understanding having been extrapolated from other species, especially rodents. This review assesses the current state of knowledge of VK as it pertains to human and animal nutrition, and, where data exist, its metabolism and nutrition in the horse is explored. Future research on the roles of VK as they pertain to horses, particularly extra-hepatic functions, is necessary. Such insight will allow a greater understanding of how VK is metabolised, facilitating the development of recommendations to assist in the health, growth, and longevity of horses.

Context: Fodder beet (FB) is a widely used winter feed in New Zealand’s southern regions due to its high yield, consistent quality, and environmental benefits. However, FB is low in crude protein, phosphorus and fibre, and a survey showed that many dairy farmers were concerned that feeding FB may have negative impacts on lifetime performance.Aim: To determine whether winter feeding FB or kale (Ka) to dairy cows, and then their heifer offspring at 1 and 2 years old, affects the heifer performance from birth until the end of their first lactation.Methods: In June–August 2017, pregnant dairy cows were fed FB or kale over winter and then 140 of the resultant heifer offspring were divided into four treatment groups at 9–11 months old according to their dam’s winter diet and offered either FB or kale, with pasture baleage. The groups were as follows (dam crop–heifer crop): FB–FB, FB–Ka, Ka–FB, Ka–Ka. The heifers’ subsequent performance (growth, stature, milk production, and reproduction) was measured to the end of their first lactation (May 2020), and blood mineral status was monitored from May 2018 to May 2019. This observational study has its limitations, but is useful for generating hypotheses to test in more controlled research.Key results: Heifers grazing FB in winter (June–August) 2018 had lower blood plasma urea and phosphate concentrations than did heifers grazing kale, despite similar dietary crude protein contents. Treatments had no effect on milk production. However, the heifer liveweights were affected and there was an indication of poorer reproductive performance. The FB–FB heifer treatment group had a lower average liveweight than the FB–Ka heifers from 1 to 2.8 years old.Conclusions: Although no impact on milk production for the first lactation was observed, the key results suggest possible negative impacts of feeding heifers FB during winter, particularly if their dam also wintered on FB.Implications: The combined effects of FB dam and heifer winter diets on lifetime productivity warrant further investigation to help develop sustainable FB feeding systems. When feeding FB, we recommend that farmers test their crops and supplements to ensure that sufficient nutrition, in particular protein and phosphorus are provided.

Context: Feed is the largest expense on a dairy farm, therefore improving feed efficiency is important. Recording dry-matter intake (DMI) is a prerequisite for calculating feed efficiency. Genetic variation of feed intake and feed efficiency varies across lactation stages and parities. DMI is an expensive and difficult-to-measure trait. This raises the question of which time periods during lactation would be most appropriate to measure DMI.Aims: The aim was to evaluate whether sequence variants selected from genome-wide association studies (GWAS) for DMI recorded at multiple lactation time periods and parities would increase the accuracy of genomic estimated breeding values (GEBVs) for DMI and residual feed intake (RFI).Methods: Data of 2274 overseas lactating cows were used for the GWAS to select sequence variants. GWAS was performed using the average of the DMI phenotypes in a 30-day window of six different time periods across the lactation. The most significant sequence variants were selected from the GWAS at each time period for either first or later parities. GEBVs for DMI and RFI in Australian lactating cows were estimated using BayesRC with 50 k single nucleotide polymorphisms (SNPs) and selected GWAS sequence variants.Key results: There were differences in DMI genomic correlations and heritabilities between first and later parities and within parity across lactation time periods. Compared with using 50 k single-nucleotide polymorphisms (SNPs) only, the accuracy of DMI GEBVs increased by up to 11% by using the 50 k SNPs plus the selected sequence variants. Compared with DMI, the increase in accuracy for RFI was lower (by 6%) likely because the sequence variants were selected from GWAS for DMI not RFI. The accuracies for DMI and RFI GEBVs were highest by using selected sequence variants from the DMI GWAS in the mid- to late-lactation periods in later parity.Conclusions: Our results showed that DMI phenotypes in late lactation time periods could capture more genetic variation and increase genomic prediction accuracy through the use of custom genotype panels in genomic selection.Implications: Collecting DMI at the optimal time period(s) of lactation may help develop more accurate and cost-effective breeding values for feed efficiency in dairy cattle.