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Context: Australia is renowned for its climate variation, featuring years with drought and years with floods, which result in significant production and profit variability. Accordingly, to maximise profitability, dryland farming systems need to be dynamically managed in response to unfolding weather conditions. Aims: The aim of this study is to identify and quantify optimal tactical livestock management for different weather-years. Methods: This study employed a whole-farm optimisation model to analyse a representative mixed enterprise farm located in the Great Southern region of Western Australia. Using this model, we investigated the economic significance of five key livestock management tactics. These included timing of sheep sales, pasture-area adjustments, rotational grazing, crop grazing and sheep nutrition adjustments. Key results: The results showed that, on the modelled dryland mixed-enterprise farm in the Great Southern region of Western Australia, short-term adjustments to the overall farm strategy in response to unfolding weather conditions increased expected profit by approximately 16%. Each tactic boosted profit by between A$7704 and A$53,171. However, we outline several complexities that farmers must consider when implementing tactics. Conclusions: The financial gains from short-term tactical management highlighted their importance and farmers' need to develop and apply those skills. The tactical skills promote business resilience and adaptability in the face of climate uncertainties. Implications: The study highlighted the economic value of dynamic livestock management in response to climate variations, offering farmers in the Great Southern region the means to underpin profitable and sustainable farm practices. Under Australia's renowned climate variation, it is profitable for farmer to implement short-term tactical management adjustments in response to the unfolding weather conditions. This paper has identified and quantified optimal tactical livestock management for different weather-years for a mixed-farming system in the Great Southern region of Western Australia. [ABSTRACT FROM AUTHOR]

The measurement and prediction of pasture intake in extensive grazing systems, typical of northern Australia, remain elusive after 50 years of research. The aim of this paper is to review research conducted over the past 50 years, highlight advances in understanding, discuss remaining challenges and consider future developments with digital technologies. While the fundamental components of voluntary intake are well understood, their measurement is difficult, particularly in extensive grazing systems, which has limited the development of predictive models that adequately address the interplay of factors influencing intake from the bite to the landscape scale. Ongoing research by the authors is used as an example to highlight the potential application of digital technologies to overcome limitations in measurement and prediction. Digital technologies offer the opportunity for monitoring factors that control voluntary pasture intake at scale and under commercial conditions. However, our ability to ground-truth novel indices of intake remains limited without ongoing development of physical methods. This will limit the accuracy and precision of predictive models incorporating digital technologies that can be applied to the extensive grazing conditions of northern Australia. The advent of precision livestock management for extensive cattle production is essential if the industry is to remain viable in the future where production is transparent, ethically sound and environmentally defensible as well as profitable. Feed intake is fundamental to animal performance and efficiency. Yet, for the cattle industry of northern Australia, our understanding of pasture intake is limited. While much is known about the components of feed intake, it remains difficult to integrate this knowledge into a dynamic and responsive estimation of voluntary intake under typical grazing conditions. This paper reviews the state of understanding, highlights gaps in knowledge and discusses the potential impact of digital technologies that will offer new solutions to old challenges. [ABSTRACT FROM AUTHOR]

This perspective paper provides industry leaders, researchers and policy developers strategic approaches to ensure that the welfare of dairy cattle is protected at the same time as the industry increases its resilience to climate change. Farm systems and practices will evolve in response to the direct impacts of climate change and/or from responses to climate change, such as mitigation strategies to reduce dairy's greenhouse-gas (GHG) emissions. The five domains framework (nutrition, physical environment, health, behaviour, mental state) was used to assess the potential impacts on animal welfare and strategies to minimise these impacts are outlined. Given that the future climate cannot be certain these approaches can be applied under a range of emissions pathways to (1) ensure that the effects of GHG mitigations on animal welfare are considered during their development, (2) engage with end users and the public to ensure solutions to the effects of climate change and weather variability are accepted by consumers and communities, (3) identify and measure the areas where improved animal health can contribute to reducing GHG emissions from dairy production, (4) ensure those supporting farmers to develop and manage their farm systems understand what constitutes a good quality of life for dairy cattle, (5) ensure effective surveillance of animal disease and monitoring of welfare outcomes and farm-system performance in response to climate change and GHG mitigations. Overall, these strategies require a multidisciplinary co-development approach to ensure that the welfare of dairy cattle is protected at the same time as the industry increases its resilience to the wider impacts of a changing climate. [ABSTRACT FROM AUTHOR]

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. The societal role of meat is being challenged with ideological and simplified logic without substantiation from robust data driven science. The international summit titled 'The societal role of meat – what the science says' was held to provide evidence-based evaluations and the Dublin Declaration. A synopsis of the summit is described and the societal role of meat in Australia is evaluated under the themes of meat for (1) diet and health, (2) a sustainable environment and (3) society, economics and culture. [ABSTRACT FROM AUTHOR]

A population-based epidemiological study was conducted between 2007 and 2011 and involved 78 northern Australian commercial beef-breeding herds and in excess of 56 000 cattle concurrently monitored. Cow reproductive performance was described from the biannual assessment of fetal age and lactation status. Both novel and well established measures of performance were used within four broad country types and included the following: percentage of lactating cows pregnant within 4 months of calving; percentage of cows pregnant within an approximate 12-month reproductive cycle (annual pregnancy); fetal and calf loss between confirmed pregnancy and weaning; percentage of cows contributing a calf at weaning and percentage of non-pregnant females retained for re-mating. The results from the present study described the variation in reproductive performance of commercial beef herds across northern Australia and defined typical and achievable levels of performance. The results from the study suggest that a weaning rate of 66% is a more realistic target level of performance for the Northern Forest, while weaning rates of at least 75–80% are realistic for other country types. Female-cattle performance was much lower in the Northern Forest than in the other country types. In absolute terms, there were 15–20% fewer surviving mated cows contributing a calf at weaning in an annual production year and ~4% more missing pregnant cows, which was associated with the ~20% higher retention of non-pregnant cows for re-mating. The reproductive performance of herds varied substantially among and within country types, with a 20–30% variation in reproduction rates and 5–15% variation in fetal and calf loss for half of the herds in all regions. Further analyses were performed and identified the major causes of this variation and are reported in subsequent papers within this series. The results from the present study appear to suggest that substantial opportunities to increase the reproductive performance of northern beef herds exist, providing that the causes of this variation are able to be identified and alleviated. An observational population-based epidemiological study was conducted in commercial northern Australian beef-breeding herds to describe reproductive performance and to quantify the prevalence and impact of the major risk factors. The present paper describes the monitored reproductive performance of ~56 000 cows managed on 78 commercial beef-breeding properties in a tropical region. Reproductive performance varied markedly both within and among country types. The proportion of females weaning a calf annually was much lower in the Northern Forest than in the other country types. [ABSTRACT FROM AUTHOR]

Data concerning the practices and policies of collaborating properties for nutritional, breeding and health management of herds were captured by survey of herd owners/managers (n = 78) at the commencement of a large observational study conducted across northern Australia to identify and quantify the effect of major animal-, management group- and property-level risk factors on measures of reproductive performance. The cooperating herds in this study were considered to be broadly representative of north Australian beef breeding enterprises in terms of geography, size and ownership. Using four broad regional categories, this paper presents descriptive summaries of the management practices and nutritional conditions of cooperating herds in what was known as the Cash Cow project. Property sizes were largest within the Northern Downs and Northern Forest, and smallest within the Southern Forest. The expected average annual growth of yearling steers was >50 kg less in the Northern Forest, compared with the other country types, which also appeared to be associated with the identified production system and turnoff animal. Despite the exacerbated nutrition and environmental challenges and likely increased time required for new managers within the Northern Forest to attain an in depth understanding of the cattle and property dynamics, this region had the greatest incidence of management changes. The nutritional information summarised in this study highlights that available phosphorus during the wet season, as indicated by faecal levels in proportion to dietary energy, was likely to limit animal production within the Northern Downs and Northern Forest. During the dry season, pasture digestibilty and protein levels were likely to be approaching maintenance for cows on ~50% of properties in each country type and that responses to rumen degradable protein were also likely on 50% of properties. Despite this finding, low use of dry season supplements was observed for the Northern Downs, which was partially explained by the high incidence of the management systems based on segregating cows on lactation status and pregnancy. In all country types, the ratio of bulls to cows was higher than the 2.5% recommended for extensively managed situations, while limited use of vaccines to control infectious causes of reproductive loss was also observed. The major conclusion of this study is that there was marked variation in the adaption of interventions to specific businesses, indicating considerable opportunity exists for further adaptation in the region. A large epidemiological study known as the Cash Cow project was conducted in commercial beef breeding herds across northern Australia between 2007 and 2011 with the aim of determining and quantifying the effect of management, nutritional and environmental factors on reproductive outcomes. This paper describes results from survey questionnaires examining their nutritional, breeding and herd health management practices and policies completed by herd managers/owners of participating properties at the commencement of the study. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Context: A significant opportunity remains to further increase the supply of premium sheepmeat products to Australia's customers, which requires a more rapid rebuilding of the national sheep flock. To help meet this challenge, developing relevant information for sheep producers to assist them to achieve a profitable flock-rebuilding outcome is viewed as highly desirable. Aims: (1) Develop flock-rebuild scenarios that track inventory, cashflow, profit and loss, and the overall balance sheet over a 5-year projection. (2) Model the impact on flock-rebuilding pathways of exposure to variation in supplementary-feed costs, purchase of stock and price received for sale animals and flock structure. (3) Model variation in benefits and costs for a range of production zones, enterprise types and flock-age profiles. Methods: Fourteen flock-rebuilding pathways were assessed for up to nine flock types, using a spreadsheet model that tracked inventory, cashflow, profit and loss, and the overall balance sheet over 5 years. Key results: The top four pathways for profitability and capacity to rapidly rebuild flock numbers include retention of more older ewes, purchasing young ewes, purchasing older ewes (mostly 5–6-year olds) in Merino and Merino-cross flock types only and joining ewe lambs in Maternal and Cleanskin flock types only. These pathways were not sensitive to variation in the cost of supplementary feed, stock prices or flock structure, although joining Merino ewe lambs became one of the top four pathways when feed costs were lower. Conclusions and implications: The well established practices of retaining ewes for longer and purchasing ewes, especially young ewes, have the most potential to both rapidly and profitably rebuild flock numbers. However, joining ewe lambs, particularly in Maternal and Cleanskin flocks, can also profitably contribute to rapid flock rebuilding. While reducing reproductive wastage or increasing reproductive potential were mostly profitable, they could not rapidly rebuild flock numbers. In contrast, accelerated lambing systems can rapidly rebuild flock numbers, but are only marginally profitable. The outlook for Australia's sheepmeat industry is very positive, with a significant opportunity available to further increase the supply of premium sheepmeat products to customers, by more rapidly rebuilding the national flock. This paper presents the findings of a study focussed on providing the confidence and material to sheep producers to choose optimal pathways to rebuild their flocks. At least 6 of the 14 alternatives investigated were deemed suitable for commercial use and not sensitive to variations in supplementary-feed costs, stock-purchasing and -sale prices. [ABSTRACT FROM AUTHOR]

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. The accuracy of estimated breeding values is routinely provided to breeders as part of genetic evaluations in Australia. A new method to approximate accuracies using genomic information has been developed and is presented in this paper. The new model has been implemented in Australia's routine sheep and beef genetic evaluation systems. This development ensures that the calculation of accuracies is sustainable with increasing numbers of animals with genotypes. [ABSTRACT FROM AUTHOR]

Context: The performance of commercial beef-breeding herds in northern Australia is highly variable. Identifying and understanding the major factors that influence this is critical in determining which management interventions should be implemented to best manage these factors. Aims: This study aimed to describe the occurrence and magnitude of the risk factors identified as being strongly associated with one or more measures of cow performance in northern Australia. Methods: A prospective epidemiological study was conducted in a cross-section of commercial beef-breeding herds in northern Australia, to determine and quantify the major associations of up to 83 candidate herd management, nutritional and environmental risk factors with cow performance. Descriptive analyses of significant risk factors were conducted. Key results: Unfavourable levels of risk factors were observed for all country types and across three cow-age groups. However, generally, adverse property-level nutritional, environmental and management risk factors had a higher incidence in the Northern Forest, which was associated with significantly lower performance of heifers and cows. This was reflected in generally lower body condition of heifers and cows in this country type. Although the performance of heifers and cows was generally higher in the Southern Forest, the irregular incidence of adverse risk factors contributed to the observed quite variable performance. Conclusions: The factors significantly affecting the performance of cows in the major beef-breeding regions of northern Australia are described. These factors were additively more adverse in the Northern Forest. Implications: In this study, the necessary understanding of the factors most likely to be affecting the performance beef cows in this environment has been described. This is required to make appropriate decisions about management interventions to control these factors. A large epidemiological study known as the Cash Cow project was conducted in commercial beef breeding herds across northern Australia between 2007 and 2011, with the aim of determining and quantifying the effect of management, nutritional and environmental factors on cow performance. This paper describes the occurrence and magnitude of the factors shown to significantly affect cow performance. [ABSTRACT FROM AUTHOR]

Context: High and variable fetal and calf loss in beef herds occurs across northern Australia. Reasons for the majority of these losses, a major cost to the industry, have remained unknown. Aims: The research question was, which of the 58 region-, property-, management group-, and animal-level risk factors measured are associated with pregnant females failing to wean their calf? Methods: An epidemiological study measured fetal and calf loss (consistently expressed as % points) between confirmed pregnancy and weaning and the major associated risk factors using a selected population from 55 commercial beef breeding herds representing 23 166 pregnancies in the mostly dry tropical environment of northern Australia. Key results: Median fetal and calf loss was 9.5% with large variation. Achievable levels appeared to be <10% for Northern Forest herds, and <5% for Southern Forest, Central Forest and Northern Downs herds. The risk factors most strongly associated with fetal and calf loss were low-fertility country type interacting with phosphorus inadequacy (up to 10% increase), low body condition score interacting with phosphorus inadequacy (up to 8% increase), tall cows (up to 4% increase), and high temperature–humidity index around calving interacting with country type (up to 7% increase). These are nutritional and environmental risk factors and had the combined highest individual effect and frequency. Other risk factors associated with fetal and calf loss included first-lactation cows, which interacted with mustering around calving (up to 9% increase), having not reared a calf in the previous year interacting with cow age (up to 8% increase), low mustering efficiency (up to 9% increase), perceived predation by wild dogs (4–5% increase), high prevalence of Campylobacter fetus sp. venerealis antibodies (7% increase), recent infection with bovine viral diarrhoea virus (9% increase), and inadequate dry-season protein (4% increase). Conclusions: The combined effects of environmental, nutritional and management risk factors on fetal and calf loss in northern Australia were large and additive and were much greater, collectively up to 30–40%, and more consistent than that due to either endemic infectious diseases or animal factors. Implications: Opportunity for remedial action is high and, for the effect of non-infectious risk factors, should target milk delivery to neonatal calves. An observational study was conducted in commercial beef breeding herds in northern Australia to determine and quantify the major associations among herd management, nutritional and environmental factors and individual cow attributes and measures of reproductive performance. This paper presents the findings of the study designed to identify risk factors associated with reproductive losses between confirmed pregnancy and weaning. [ABSTRACT FROM AUTHOR]

Context: There are multiple reports of high annual cow mortality rates in northern Australia, but no reports clearly indicating the overall rates and the impact of primary risk factors. Aims: The research aimed to determine which measured region-, property-, management group- and animal-level risk factors are associated with missing pregnant females. Methods: Risk factors for the annual rate of pregnant-cow mortality were investigated in an epidemiological study using outcomes for 21 554 cows from 52 beef herds in 2009 and 2010 in four primary country types within the mostly-dry tropical north Australian environment. Modelling of 2001–2011 Australian beef-herd statistics was used to corroborate and further quantify findings. Key results: In the epidemiological study, the overall predicted annual mean incidence of missing pregnant cows, a surrogate for mortality, was 10.9%, including lost tags and unrecorded cow movement that were estimated to constitute up to 9% missing cows. Risk factors associated with higher pregnant-cow mortality were as follows: not having follow-up rainfall more than 30 days after the first wet-season storms (4 percentage point increase); <2 t/ha of available pasture biomass in the early dry season (2–6 percentage point increase); pasture dry-season biomass <2 t/ha interacting with less than moderate mid-dry-season body condition score (3–10 percentage point increase); and, calving between April and September (non-significant trend for a 1–2 percentage point increase). Feed-quality measures did not affect mortality rate. Population modelling of Australian beef herd statistics suggested an average annual cow mortality rate in the Northern Forest region of ~7% compared with 2% in more nutritionally endowed regions. Conclusions: The major risk factor for cow mortality is under-nutrition, related either to generally-low soil fertility, seasonally-dry conditions, or management that exposes animals to poor nutrition. Annual mortality of pregnant cows appears 6–9 percentage points higher in the low-fertility Northern Forest region than elsewhere. Implications: Beef cow mortality is a major business cost in northern Australia. The efficacy of targeted management to achieve high cow performance was demonstrated by losses in a third of studied businesses in the Northern Forest being kept to the same or lower levels as median loss in endowed regions. An epidemiological study was conducted in commercial beef-breeding herds in northern Australia to determine and quantify the major associations between measures of performance and risk factors for herd management, nutritional, environmental and individual cow attributes. This paper presents the findings from the study using 21 554 pregnant cows in 52 herds that determined the major risk factors associated with those that went missing. This was supported by an analysis to calculate mortality rates using contemporary statistical data for the Australian beef herd. [ABSTRACT FROM AUTHOR]

Context: Sound reproductive efficiency is a key determinant for the overall productivity and profitability of a beef breeding business. Failure of a cow to conceive results in either culling or the cost of carrying non-pregnant animals. Aims: This study aimed to determine and quantify the major factors associated with non-pregnancy in commercial beef breeding herds of northern Australia. Methods: A prospective population-based epidemiological study of the likelihood of non-pregnancy in cows after an annual mating in northern Australian beef breeding cows used data from 73 herds from four broad country types and 62 323 animal years; approximately 80 property-, management-group- and cow-level risk factors were considered. A multivariable model building process was employed to scrutinise the resulting dataset, so as to identify what herd management practices, nutritional, environmental, and individual cow factors were associated with non-pregnancy and estimate their magnitude of effect. Key results: Non-pregnancy was disproportionately high in the Northern Forest (32.1%), compared with the Northern Downs, Central Forest and Southern Forest where it was 17.1%, 16.0% and 13.2% respectively. Time of expected calving had the largest impact on occurrence of non-pregnancy. Parity also had a significant influence, with first-lactation cows typically having 5–12% higher non-pregnancy than did mature cows. Non-pregnancy decreased with an increasing body condition score at the branding/weaning muster for lactating cows. The difference in non-pregnancy when comparing availability of wet-season pasture phosphorus content and digestibility of pasture during the dry season was 13.2 and 10.2 percentage points respectively. Conclusions: This study demonstrated the substantial impact environment, herd management practices, nutrition and disease factors can have on the reproductive performance of females. Implications: To optimise the efficiency of females (through reducing the occurrence of non-pregnancy) under commercial conditions in northern Australia, production systems should support beef herds calving early in the production year, being in at least moderate body condition and having access to more digestible pastures that address the nutritional requirements for both protein and phosphorus. This indicates focus for management, especially in the Northern Forest where the likelihood of non-pregnancy was highest. A large epidemiological study of annual pregnancy rate was conducted in commercial beef cattle breeding herds in northern Australia. The effect on non-pregnancy of the major herd management, nutritional and environmental risk factors and individual cow factors was determined and quantified. This paper presents the findings of the study designed to determine the major predictors of cows not achieving pregnancy. [ABSTRACT FROM AUTHOR]

Context: Sound reproductive efficiency is a key determinant for the overall productivity of a beef breeding business. For beef breeding herds to obtain high levels of reproductive productivity, breeding females need to efficiently become pregnant while lactating. Aims: This study aimed to determine and quantify the major factors associated with lactating cows becoming pregnant within 4 months of calving (P4M) in commercial beef breeding herds of northern Australia. Methods: A prospective epidemiological study was conducted using 78 commercial northern Australian beef breeding herds and involved 78 000 cattle that were monitored for 3–4 years. A multivariable model-building process was employed to scrutinise the resulting dataset to identify what herd-management practices, and nutritional, environmental and individual cow factors were major determinants of lactating cows becoming pregnant within 4 months of calving (P4M) and to estimate their magnitudes of effect. Key results: Overall, 41.6% of cows per production year were successful for P4M. Country type was strongly associated with 65.4%, 57.5%, 61.8% and 16.4% P4M for the Southern Forest, Central Forest, Northern Downs, and Northern Forest respectively. Between-year variability ranged between 3.3 and 11.7 percentage points. Cows calving in December–January (61%) had a substantially higher occurrence of P4M than did cows calving between July and September (15%). The difference in P4M when comparing availability of wet-season pasture protein and phosphorus was 12.7 and 20.3 percentage points respectively. Modelling of the impact of group seroprevalence and management group prevalence of recent infection with several infectious diseases was estimated, with a large negative association between group bovine viral diarrhoea seroprevalence and P4M suggested. Conclusions: This study further demonstrated the substantial impact that environment, herd management practices, nutrition and disease factors can have on the reproductive performance of females. Implications: To optimise the performance of females (through increasing the occurrence of cows contributing calves in consecutive years) under commercial conditions in northern Australia, herd managers should focus on maximising the proportion of cows within a herd calving at the desired time of the year, ensuring that any nutritional deficiencies and herd health issues are managed, and that cows are managed such that they are of good body condition score at the time of calving. An observational study was conducted in commercial beef breeding herds in northern Australia to determine and quantify the major associations between herd management, and nutritional, environmental and individual cow factors and measures of reproductive performance. This paper presents the findings of the study designed to determine the major predictors of lactating cows becoming pregnant within 4 months of calving. [ABSTRACT FROM AUTHOR]

Context: High international demand for goat meat and high prices for goat in Australia have resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of Rangeland goats within these developing managed production systems. Aims: The aim of these experiments was to determine the response to supplements and the metabolisable energy requirements for maintenance and liveweight gain of young entire male Rangeland goats. Methods: Dose–response relationships to various supplements were established in two experiments with young entire male Rangeland goats. In Experiment 1, 54 goats were allocated to rolled-wheat grain, rolled-sorghum grain, or lucerne pellet supplements offered from 0 (control) to 24 g dry matter/kg liveweight.day. In Experiment 2, 24 goats were allocated to a commercial starch-based pellet offered from 0 (control) to ad libitum. In both experiments, goats were held in individual pens and offered their daily supplement allowances with ad libitum access to Mitchell grass hay and drinking water for 70 days. Key results: Total intake (30 to 32 g dry matter/kg liveweight.day) increased in a linear fashion with an increasing intake of all supplements. Maximum intake of rolled-wheat, rolled-sorghum, lucerne pellets and the commercial starch-based pellet supplements ranged from 18 to 22 g dry matter/kg liveweight.day. Unsupplemented goats lost liveweight (−20 to −32 g/day), while supplemented goats gained liveweight (0 to 126 g/day) in a linear fashion with an increasing supplement and metabolisable energy intake for all supplements, with the highest response in goats supplemented with the commercial starch-based pellets. Estimated metabolisable energy requirements to maintain liveweight (372 kJ/kg liveweight0.75.day) and for liveweight gain (35 kJ/g) of the goats were the same in both experiments. Conclusion: Liveweight gain increased in a linear fashion with metabolisable energy intake, with the maximum rates of liveweight gain occurring when starch-based supplement intake was approximately 20 g dry matter/kg liveweight.day. Implications: Supplementation with starch-based rations will increase liveweight gain and decrease age at turn-off of young entire male Rangeland goats; however, the local availability and cost of these supplements need to be considered. High prices for goats in Australia due to high international demand has resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of goats within these managed production systems. The present paper demonstrates that the highest rates of liveweight gain of young male Rangeland goats is when they are offered a high energy supplement. [ABSTRACT FROM AUTHOR]

Sheep stocking rate influences farm profit significantly; however determining the optimal stocking rate is a difficult task. In this paper, we address this challenge through three main steps. First, we review the definition of stocking rate; second, we examine prior research relevant to the review topic and highlight the factors that need to be considered when determining the optimal stocking rate; and third, we make recommendations for improvements in research on establishing the optimal sheep stocking rate. Inconsistency in the definition of stocking rate can lead to miscommunication among researchers, advisers and farmers. If 10 dry sheep equivalents (DSE)/ha is optimal for one flock, it may not be optimal for another flock because the DSE measure does not fully capture the nuances of different patterns of nutritional requirements among sheep classes and feed availabilities and their respective prices and costs. The optimal stocking rate occurs when the marginal economic benefit of an additional animal equals its marginal cost. Determining this point requires an understanding of the quantity and quality of feed available throughout the year, the optimal liveweight profile throughout the year, the impact of seasonal variation, the impact of labour availability, the cost of alternative feeds, prices of livestock and livestock products, the risk preferences of the farmer, and any emission policies relating to greenhouse gases. Farmers tend to use their own judgement to set their stocking rates, with the aim of maximising utility. However, the complexities listed make it a challenging task. Thus, researchers have used various simulation and programming models to aid decision-making over optimal stocking rates, but most farmers continue to rely on their own personal judgement. Moreover, often a focus of this modelling is for sheep systems in eastern Australia. Generalising this research across Australia is difficult due to differences in climatic conditions and markets across Australia. Often farmers are unaware of the profits they are foregoing when choosing either an overly conservative or excessive stocking rate. Our research has shown that foregone income of up to AUD50 per hectare can occur when a stocking rate 30% below or above the optimum is selected. Thus, despite the complexities that underpin the stocking rate decision, we believe that there are potential rewards from further research on the optimisation of stocking rates. [ABSTRACT FROM AUTHOR]

Dairy cows in Australia and New Zealand are generally kept outdoors, making them susceptible to weather variability and in particular heat stress. In this paper, we review (1) exploiting genetic variability to improve heat tolerance, (2) genotype by environment interactions, i.e. suitability of high merit cows to weather variability and (3) how novel phenotyping and genomics can help improve heat tolerance. Selection for heat tolerance is a permanent and cumulative strategy and especially useful in grazing situations where management practices, such as cooling mechanisms, are sometimes impractical. Australia was the first country in the world to release breeding values for heat tolerance in dairy cattle nationally in 2017. The breeding value captures genetic variation in the reduction of milk production traits with rising temperature and humidity. The breeding values have been validated in independent studies (in Victoria, Australia, and California, USA), showing that thermotolerant cows maintain a lower core body temperature under hot and humid conditions. Genotype by environment interactions for traits sensitive to heat is only a concern for farms in very extreme conditions and therefore affect only a small proportion of individuals (those in the extreme 5th percentile). Heat tolerance is a complex trait in that in addition to milk traits, health and fertility may also be affected. Next-generation heat tolerance breeding values may include sensor device information in addition to changes in milk composition, or other measurable biomarkers. This is especially useful when measured in genotyped female populations. Research into novel ways of measuring heat tolerance could transform the way we select for this trait and capture more of the complexity of this trait. To be successful in this area, multi-disciplinary collaboration among animal scientists is likely to facilitate this goal. Combining genomics, traditional and novel measures of heat tolerance with intermediate metabolic biomarkers and prioritised genetic variants could be a way to capture the complexity of thermotolerance in future heat tolerance breeding values. Finally, selecting cows that are resilient to variability in weather is feasible and heat tolerance is a good example of this. Dairy cows are susceptible to weather variability and in particular heat stress because of the metabolic load associated with lactation. Australian genomic breeding values for heat tolerance have been available for breeding decisions since 2017 and have been validated in independent studies. Technological advances, such as sensor devices and novel biomarkers that are measurable in female genomic reference populations will pave the way for the next-generation heat tolerance breeding values. [ABSTRACT FROM AUTHOR]

As the sophistication of genomic technologies increases and their cost continues to decrease, they are becoming routine tools in livestock breeding programs and production systems. The convergence of electronic measurement systems, cloud-based computing and fast internet enable the use of powerful decision support to help automate and manage livestock production, animal welfare and quality control. The complexity of livestock production systems, combined with the challenges of producing top-quality discretionary products for consumers, means that no single organisation has the range of expertise to support coordinated development of innovation in the relevant supply chains. Collaboration between a broad spectrum of scientists and industry partners is essential to ensure well integrated input to the design and implementation of programs to deliver improvements in efficiency, quality and profit. The need for collaboration among researchers, among research organisations and with end-users has never been more important. Collaboration brings together the skills needed to manage complex problems and enables the sharing of facilities and scarce resources within Australia and internationally. However, the most important component of effective collaboration is the early engagement of end-users to contribute to the design of programs of innovation, to ensure that investment is well targeted and that there is ownership of the problem as well as the solutions delivered through research. Although the potential benefits of effective collaboration are clear, it often takes more than logic to get individuals and organisations to work together. There needs to be a significant financial incentive combined with strong industry leadership and agreed common goals. Allocating resources to establish these foundations for effective collaboration should precede any major research and development funding initiative. The present paper argues that the new face of animal science in Australia should be structured around coordinated programs of research and development, on the basis of effective collaboration. Research leading to significant change in agricultural practice almost always involves collaboration between teams of researchers and multiple end-users as well as sharing resources across multiple organisations. Although benefits and efficiencies are easily recognised, effective multi-institutional teamwork is often difficult to achieve. The present paper draws on experience from the Sheep CRC, over a period of nearly 20 years, where collaboration among an increasing number of participants contributed to many significant changes in the Australian sheep industry. [ABSTRACT FROM AUTHOR]

Litter management is important when rearing meat chickens because litter conditions can affect production as well as chicken health and wellbeing. An industry survey was conducted to gather information from Australian meat chicken growers and integrators about their litter management practices, providing an opportunity to share their knowledge, experiences and perceptions about litter re-use and litter turning. This information was essential for researchers investigating litter management practices because it provided a better understanding about litter preparation and shed configuration to ensure that representative and timely data could be collected. Eighty-four survey responses were received from all major growing regions across Australia. The survey closely reflected the proportions of conventional and free-range production systems of Australian chicken meat industry, with approximately 21% of survey responses representing free range and 80% representing conventional barn housing. Concerning litter management practices, the survey showed that litter re-use is limited (32% of responses), but litter turning is a widespread practice (89% of responses). Litter turning is used to reduce the occurrence of caked litter and to keep litter 'working'. Maintaining 'dry and friable' litter has been shown to reduce the risk of health issues and allows chickens to display behaviours, such as dustbathing, which are believed to be associated with improved welfare. Comments from the survey indicated that litter turning alone does not achieve dry and friable litter, and that proactive ventilation, heater and drinker management are essential. Growers also explained that litter turning is not without its challenges, and can potentially contribute to spikes of dust, ammonia and/or odour. They also expressed concerns relating to operating machinery in poultry houses, particularly when there is high liveweight density. When growers were asked about litter re-use, several reported that it has benefits in reducing production costs and improving moisture holding capacity, but concerns were also expressed about risks relating to ammonia, litter beetle control and disease transmission. Researchers will be able to use these survey results to gain an insight into practices, perceptions, constraints, and challenges relating to the Australian chicken meat industry and ensure that future research relating to litter management reflects local conditions and practices. Litter management is important in meat chicken production because good litter contributes to good productivity, health and wellbeing. Many different practices are used to manage litter, and they can lead to different outcomes. This paper summarises the responses of a survey that allowed growers and integrators in the Australian chicken meat industry to share their litter management practices and experiences. This survey will provide researchers with a deeper understanding of industry practices and conditions and will enable them to tailor their studies to reflect these. [ABSTRACT FROM AUTHOR]

The symposium 'Recent Advances in Animal Nutrition – Australia' (RA) was instigated at the University of New England (UNE) in the early 1970s. In the 1950s and 1960s, under the visionary leadership of Professor G. L. (Bill) McClymont, a talented group of young biochemists and nutritionists was recruited to become the Department of Biochemistry and Nutrition at UNE and quickly developed a strong reputation for nutritional research on ruminant and monogastric animals. Its members were keen to share their findings with relevant industry representatives and to learn about the major industry challenges. The idea for RA emerged ~1970 when Drs Robin Cumming and David Farrell saw the opportunity for regular RA schools, bringing invited experts from Australia or overseas to interact with UNE staff, post-graduate students and representatives of the monogastric and ruminant livestock industries. The first RA school was probably held in 1974. Aided by flexible working arrangements at UNE, David Farrell was able to champion further RA meetings that were held successfully about every 2 years. However, ~1990, the federal Education Minister John Dawkins began a process of amalgamating Australian higher-education institutions that produced detrimental administrative and financial ramifications for UNE and drained staff morale. After the 1993 meeting, Professor David Farrell left UNE, followed soon afterwards by Professor Ron Leng. The future of RA was at a crossroads; its funding and organisation needed overhauling to enable it to survive. A second, more formal phase of RA meetings (13 in all; 1995–2021), was instigated within a newly formed Department of Animal Science at UNE. The meetings became more formalised and even more financially dependent on industry support and sponsorship; meetings were planned by larger organising committees. Soon, papers were being formally refereed and the scope for provocative speculation of the type promoted at earlier meetings was somewhat curtailed in favour of scientific rigour. Organisers experimented with changed meeting dates, formats and venues at UNE, cumulating with a contentious decision to hold this meeting away from UNE. Despite its challenges, RA has grown in stature over 47 years from the small, informal schools of the early 1970s, to become Australia's leading animal nutrition symposium. 'Recent Advances in Animal Nutrition – Australia' has grown in stature over half a century to become Australia's leading nutrition symposium. This history describes how the first 'nutrition school' was conceived at the University of New England, Armidale (UNE), in the early 1970s, and covers the 25 biennial meetings held at UNE; it pays homage to the many organisers, invited speakers and attendees who have focussed on finding innovative solutions to industry-relevant problems, thereby ensuring the symposium's long-term success. [ABSTRACT FROM AUTHOR]

Context: Dual-purpose wheat (Triticum aestivum L.) and canola (Brassica napus L.) crops have been extensively researched for grazing in Australian farming systems, with a focus on grazing by sheep. In some regions, dual-purpose crops have been grazed by cattle, but there have been reports of animal health problems. Aims: This paper sought to collate all known experiments conducted throughout Australia of cattle grazing dual-purpose crops, in order to evaluate grazing management options for cattle on dual-purpose crops that result in high growth rates and good animal health outcomes. Methods: There were six experiments. In Expts 1–3, cattle were grazed on wheat crops with and without available mineral supplementation of NaCl and MgO in a 1:1 ratio. In Expt 3, lime was also added to the mineral mix. In Expts 4 and 5, dual-purpose crops were grazed in combination with annual pastures to determine whether strategic use of dual-purpose crops could increase whole farm livestock productivity. In Expt 6, cattle were introduced to dual-purpose canola with different periods of adaptation (0, 4 and 7 days). Liveweight gain was monitored regularly to assess differences between adaptation treatments. Key results: Liveweight gain was increased by 0–27% when cattle grazing high quality, dual-purpose wheat were provided with mineral supplement. Cattle had an initial lag in growth rate when introduced to dual-purpose canola for grazing and this was not affected by the adaptation strategy used. Cattle that experienced a shorter adaptation period achieved higher weight gains more quickly. After the lag phase, average daily gain (ADG) was ≥2 kg/head.day, with an ADG over the entire grazing period for all treatments of 1.75 kg/head.day. The effect on the farm system was determined by extending the length of the grazing period on the dual-purpose crops. Grazing periods of shorter duration did not increase overall liveweight gains compared with grazing only pasture, whereas extending the period of dual-purpose crop grazing resulted in increased cattle weights. Conclusions: Cattle benefit from the addition of mineral supplements when grazing a dual-purpose wheat crop, with a response similar to that previously demonstrated in sheep. Cattle can safely graze dual-purpose canola and achieve high ADG. Inclusion of dual-purpose crops can improve overall cattle performance in the farming system. Implications: The potential area for production of dual-purpose crops within the Australian mixed farming zone is large and there may be insufficient livestock numbers within the zone to utilise the potential forage production. Cattle from other regions could be introduced during autumn and winter to realise this large forage potential during a period that is commonly a feed deficit on grazing-only properties. Estimates suggest that up to two million young cattle could be supported for 60 days, increasing liveweight by 90 kg/head. Beef cattle grazing dual-purpose crops on mixed farms can achieve high liveweight gains during periods of pasture deficit. Use of dual-purpose crops for beef production offers significant opportunity for the southern Australian beef industry. Growth rates of young cattle can be improved by appropriate mineral supplementation and livestock management. [ABSTRACT FROM AUTHOR]

Livestock producers are facing increasing pressure to reduce the environmental and animal-welfare impacts of production, while also managing the challenge of an increasingly variable climate and diminishing resources. This perspective paper highlights the role for animal scientists to contribute to the sustainability of future livestock systems. We argue the need for a broader, more inclusive and more integrated concept of animal science, better connections among scientists, producers, consumers and policy makers, and more support for the next generation of animal scientists. Animal scientists have an important role to play in providing the evidence to support the social licence of livestock production and inform decisions made by policy makers and consumers regarding the production and consumption of livestock products. Animal scientists can also assist producers to adapt to social, environmental and political challenges that affect their livelihoods and the way they farm. Traditionally, animal science has focussed on species- and discipline-specific areas of research such as ruminant nutrition, genetics or reproductive physiology. While this fundamental research remains essential to understand the underlying biology of livestock production and improve production efficiency, it needs to be better integrated into research applied at and beyond the herd or flock level. Systems thinkers who can apply this knowledge across farm, regional and national scales also have an important role in providing information to key decision makers, from farmers to national government. Better engagement with the social and economic sciences can inform how animal scientists and extension services interact with producers to understand constraints to production as well as adoption of new technology and co-develop evidence-based solutions. Underlying this, the demographics of those who study and work in animal science are changing. Australian animal industries require the best and brightest minds to overcome future challenges and engaging these students as the new face of Australian animal science is an essential step towards sustainable future livestock systems. Livestock production is facing new challenges from consumers and operating environments, and, so, the role of animal science must also change to adequately solve these complex problems. The increasingly diverse next generation of animal science graduates has less traditional career pathways and links to primary industries, and will require new methods of mentoring and professional development to support the needs of livestock producers. Integrating other disciplines and systems approaches with species- and discipline-specific science will be essential to ensuring a sustainable future for livestock production in Australia. [ABSTRACT FROM AUTHOR]

Context: Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim: The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates <4 ewes/ha. Methods: Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of <4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results: In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P < 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions: The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications: These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival. Improving lamb survival has the potential to increase profit to the Australian sheep industry by AU$1 billion per year. Our national research demonstrated that reducing mob size at lambing will improve lamb survival. These findings will contribute to current guidelines for managing lambing ewes to improve lamb survival across Australia. [ABSTRACT FROM AUTHOR]

The present paper addresses turning knowledge into practical benefit; acknowledging a critical emphasis of the career of John L. Black. Average efficiency of pasture use by beef enterprises in southern Australia is historically ~35%. Two projects established in 2002 showed that the efficiency of pasture use could approach 90% and the conservative rates observed were due to a low adoption of existing knowledge and the perceived risks from intensification. A risk-control management system, 'More Beef from Pastures', was developed from these projects, to identify management practices that had the largest impacts on productivity and profitability, the variables that needed to be measured and the upper and lower limits for those measurements to optimise enterprise performance. The principles from that system were incorporated into a productivity and economic spreadsheet model for a beef enterprise near Blayney on the Central Tablelands of New South Wales. The present paper reports the effects on productivity and profitability of several management scenarios, including current practice with 180 breeding cows and progeny sold in the second year after birth; buying and selling steers; making silage; or combinations of steers and silage, to maintain pasture availability between 1200 and 2600 kg DM/ha. Simulations were conducted for rainfall and growth of a phalaris-subterranean clover pasture predicted for the Blayney climate by the Sustainable Grazing Systems model for the Years 2000-2011. The simulations covered eight consecutive years from 2002 to 2009, when mean pasture growth was only 70% of the average. Results from the simulations for current practice were similar to those observed for the enterprise. The simulations showed the importance on profitability of utilising excess pasture in years of high pasture growth. The highest average profitability across years resulted from the scenario involving purchase and sale of steers, but year-to-year fluctuations were large and significant capital was required. The silage and steer-silage scenarios were intermediate in profitability, and depended on initial silage reserves and numbers of breeding cows. The exercise demonstrated that a simple spreadsheet model based on principles of animal nutrition, pasture management and economics was needed to fully evaluate alternative management strategies for practical benefit on existing beef enterprises. [ABSTRACT FROM AUTHOR]

Australian seedstock cattle breeders have expressed concerns that while there has been genetic improvement in feedlot and abattoir performance of cows, it could have led to a decline in maternal productivity, especially under variable nutritional conditions. This paper describes a substantial project with two components designed to address these issues. The first sub-project was to monitor bodyweight and composition of 7760 young Angus and Hereford cows as they experience variable physiological states (pregnancy and lactation) and seasons. This was conducted on large numbers in seedstock herds. The second sub-project was to monitor more regularly bodyweight, body composition, and calf rearing performance of 500 Angus cows that are genetically divergent for either fat or residual feed intake at two research centres. This also included two levels of nutrition and recording of weekly feed intake of small groups of cows for at least three parities to allow reporting of genotype × nutrition effects on maternal productivity and efficiency. Results from the project are reported in a series of papers with each one having a defined focus. [ABSTRACT FROM AUTHOR]

Dairy feeding systems in Australia and New Zealand have seen an increase in the use of mixed rations to manage variability in climate and market conditions and enable a certain degree of resilience in the operating environment. In this review, resilience was defined as the ability of the farm system to respond to challenges, optimise productivity and profitability for a given set of circumstances, and persist over time. Specific attributes of a dairy system that contribute to resilience were considered as flexibility, consistency, adaptation, sustainability and profitability. A flexible forage base that uses water efficient forage species provides a consistent supply of nutrients from home-grown forages across the year and is a key driver of resilience. Consistent milk production from purchased concentrates adds value to the forage base and will ensure that the system is profitable in the long term. Appropriate investment in infrastructure and careful management of debt has a positive impact on technical and financial efficiency and improves overall economic performance and resilience of the system. Nutrients, feed wastage, cow comfort and welfare were also identified as key areas to focus on for improved sustainability. Future research investigating the interaction between forages and concentrates, and the subsequent milk production response will be important for the future resilience of mixed ration systems. Adaptive management at a tactical and strategic level across several technical areas will further underpin the resilience of a mixed ration dairy system, and minimise the impact of climate and price variability. This will have flow on benefits to animal welfare and resource sustainability, which will have a positive impact of the public perception of these systems within the Australian and New Zealand dairy industries. The use of mixed ration feeding systems in Australia and New Zealand has increased in the past decade in response to variable climate and market conditions and to enable dairy businesses to be more resilient. This paper reviews the attributes contributing to resilience, namely flexibility, consistency, adaptation, sustainability and profitability with a particular focus on the forage base, milk production responses, the production : cost base and resource management. Potential areas for future work to maintain the resilience of mixed ration systems are also considered. [ABSTRACT FROM AUTHOR]

The Australasian dairy industry is facing the dual challenges of increasing productivity, while also reducing its emissions of the greenhouse gases (GHG) methane and nitrous oxide. Following the COP21 Paris Agreement, all sectors of the economy will be expected to contribute to GHG abatement. Enteric methane is the major source of GHG emissions from dairy production systems (>70%), followed by nitrous oxide (13%) and methane (12%) from animal waste, with nitrogen (N)-fertiliser use contributing ~3.5% of total on-farm non-carbon dioxide equivalent (non-CO2e) emissions. Research on reducing methane emissions from dairy cattle has focussed on feeding dietary supplements (e.g. tannins, dietary oils and wheat), rumen modification (e.g. vaccine, inhibitors), breeding and animal management. Research on reducing nitrous oxide emissions has focussed on improving N fertiliser efficiency and reducing urinary N loss. Profitable options for significant abatement on farm are still limited, with the industry focusing instead on improving production efficiency, while reducing emission intensity (t CO2e/t product). Absolute emission reduction will become an imperative as the world moves towards carbon neutrality by 2050 and, thus, a priority for research. However, even with implementation of best-practice abatement, it is likely that some residual emissions will remain in the foreseeable future. The soil organic carbon content of dairy soils under well fertilised, high-rainfall or irrigated permanent pastures are already high, therefore limiting the potential for further soil carbon sequestration as an offset against these residual emissions. The Australasian dairy industry will, therefore, also need to consider how these residual emissions will be offset through carbon sequestration mainly in trees and, to a more limited extent, increasing soil organic carbon. The Australasian dairy industry is facing the challenge of increasing productivity while also reducing greenhouse gas (GHG) emissions. This paper reviews the most promising technologies, concluding that substantial GHG abatement is possible, but the industry will need to consider further offsets in trees to achieve carbon-neutral dairy farming in Australia and New Zealand. [ABSTRACT FROM AUTHOR]

As farmers continue to face increasingly uncertain and often rapidly changing conditions related to markets, climate or the policy environment, people involved in agricultural research, development and extension (RD&E) are also challenged to consider how their work can contribute to supporting farmer resilience. Research from the social sciences conducted in the past decade has focussed on adaptability or adaptive capacity as a key attribute for individuals and groups to possess for managing resilience. It is, therefore, timely to ask the following: do current ways of doing and organising RD&E in the dairy sector in New Zealand and Australia contribute to supporting farm adaptability? This paper reports on results from an examination of case studies of challenges to resilience in the dairy sector in Australia and New Zealand (i.e. dairy farm conversion, climate-change adaptation, consent to farm) and the contribution of dairy RD&E in enhancing resilience of farmers, their farms and the broader industry. Drawing on concepts from resilience studies and considering an empowerment perspective, the analysis of these cases suggest that, currently, agricultural RD&E supports adaptability in general, but varies in the strength of its presence and level of activity in the areas known to enhance adaptability. This analysis is used to generate principles for dairy scientists and others in the RD&E system to consider in (1) research designs, (2) engaging different farmers in research and (3) presenting research results differently. This represents a significant shift for the science and advisory communities to move to methods that acknowledge uncertainty and facilitate learning. This paper describes how farmers can be empowered to meet increasing challenges of changing conditions related to markets, climate or the policy environment through better organised agricultural research, development and extension (RD&E). It reports on three case studies in the Australian and New Zealand dairy sector to reveal that, currently, RD&E supports adaptability of farmers in general, but varies in the strength of its presence and level of activity in the areas known to enhance adaptability. It identifies key principles for dairy scientists and others in the RD&E systems to consider in research design, engaging farmers in research and presenting research results differently to farmers. [ABSTRACT FROM AUTHOR]

Seedstock breeders’ perspectives on topics associated with maternal productivity in beef cattle were investigated through the use of qualitative in-depth semi-structured interviews. Given the complexity of maternal productivity, it is possible that some issues may not be fully captured by recording performance and data analysis. This paper discusses theory emerging from content analysis of interview data on management and genetic factors affecting maternal productivity as detailed by seedstock breeders in southern Australia. Overall, 24 interviews were conducted as part of an intensive field-work component with seedstock breeders involved with the Cooperative Research Centre for Beef Genetic Technologies’ Maternal Productivity Project. Qualitative content analysis of interview data revealed a considerable divergence in attitudes to cow management with regards to grazing management, body condition fluctuation and the utilisation of body fat reserves. Specifically, production systems diverged on the basis of animal management characterised by either ‘controlled’ or ‘variable input’ feeding strategies. Variation in management approach was associated with different perspectives on the perceived importance of selecting for production traits including growth, beef yield and milk compared with selection for perceived resilience traits including increased subcutaneous fat. The results demonstrated that among seedstock breeders targeting similar end markets, substantial variation in animal selection and management exists and this requires further characterisation to ensure breeding programs and animal management are optimal. [ABSTRACT FROM AUTHOR]

Meat production has come under increasing scrutiny from consumers and citizens who feel that certain practices are unethical and negatively affect farm-animal welfare. Animal welfare can be viewed as both a scientific and social concept, and purchasing products with animal welfare claims can be considered an act of ‘ethical consumption’. The present paper reviews research that examines consumer attitudes to animal welfare and highlights tensions between consumer and citizen attitudes and behaviours, and assumptions that are made within these studies. We present our own research into motivations to purchase free-range eggs as an example of research that attempts to unpack these assumptions, in particular, that such purchases are made out of concern for animal welfare. We present a further example of our own research that attempts to identify how attitudes to meat production are socially constructed. We conclude with recommended strategies to engage the broader community in discussions about animal production, so as to improve industry–community communication about farm-animal welfare in meat-production industries. [ABSTRACT FROM AUTHOR]

The growing Asian middle class, the proliferation of export markets and a more discerning domestic consumer base are creating new opportunities and challenges for the Australian pork industry. To fully capitalise on these opportunities and face these new challenges, the right questions need to be asked by the Australian pork industry.Weneed to know not only what our consumers want, but who our consumers are. The present paper aims to demonstrate that novel approaches to investigate consumer attitudes will be required, and it cannot be assumed that current productions systems, products and marketing strategies are optimal for the changing environment and the creation of new premium market opportunities. With new markets and new products come new consumers; identifying who those consumers are, the networks they operate within as food consumers, and what influences their purchasing decisions are the key to their adopting Australian pork as premium produce in a new global market. [ABSTRACT FROM AUTHOR]

About 60% of the gross value of Australia’s agriculture (AU$49 billion) is produced from the 85 million ha of temperate grasslands of southern Australia. A large part of this production comes from grazing livestock in the high-rainfall zone (HRZ) where 40% of the area has been retained as native and naturalised pastures, located in variable landscapes. These native pastures have seen a decline in productivity and increasing environmental problems, such as erosion, due to a loss of productive perennial species over recent decades. Grazing management systems have been advocated to not only balance the quality and quantity of forage with the nutritional demands of grazing animals, but also to manage the degradation caused by grazing. There has been an evolution of grazing management research through national projects from Temperate Pasture Sustainability Key Program to Sustainable Grazing Systems and then EverGraze, which has shifted from a focus on small plots and fixed stocking rates, to large-plot and farmlet experiments that include landscape variability and flexible grazing systems that more closely resemble commercial practice. These experiments generate reliable plant and animal response data that can be used to validate system models needed to assess the spatial and temporal challenges of grassland management. The present paper introduces the research conducted at the Orange proof site as part of the national EverGraze program. The research investigated the interactions between landscape variability and grazing method (1-, 4- and 20-paddock grazing management treatments) with flexible stocking rates. The following three key questions were addressed: (1) does increasing the number of paddocks and implementing rotational grazing result in a higher stocking rate, higher per hectare production and better economic outcomes; (2) which is the most appropriate combination of grazing method and stocking rate to achieve a higher and more stable perennial component to improve production and environmental benefits in different parts of the landscape; and (3) can landscape variability be identified, mapped and effectively managed on HRZ native grassland properties? This special edition of Animal Production Science answers these questions and provides recommendations for managing HRZ native pastures. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of ruminal mechanical stimulating brushes (RMS brush) on rumen fermentation and plasma oxidative stress and subsequent milk production in early lactation dairy cattle in the Australian spring and summer. Two hundred pasture-fed Holstein, Jersey, and Holstein × Jersey multiparous cows were enrolled into Control (no treatment; n = 103) or RMS brush (n = 97) groups in a randomised controlled trial at 26 ± 15 days before calving. The RMS brush group had three brushes/cow administered orally. Each RMS brush consisted of synthetic polymer bristles held in place with a metal component and was enclosed in a paper capsule that dissolved after insertion. Milk yield (MY), bodyweight, and weather data were recorded daily for the first 30 weeks of lactation. Stomach tube rumen fluid samples and plasma were collected monthly for the first 3 months of lactation from a minimum subset of 14 cows from each group. A total of 182 cows calved successfully and 34 cows were removed during the first 30 weeks of lactation. There was no difference in survival between the groups (hazard ratio = 0.952, confidence interval = 0.481-1.88). Rumen, plasma oxidative stress, and milk production measures were not affected by group or the interaction between group and time, with the exception of a mean increase of 304 μM of biological antioxidant potential in the RMS brush cows. The mean temperature humidity index for the first 30 weeks of lactation was <72; hence, effects on heat stress could not be evaluated. Maximum and minimum temperature and THI over the first 30 weeks of lactation were not correlated with MY and bodyweight for either group on time series cross correlation. Positive correlations occurred for the Controls at lag 0 and negative correlations for both groups at lags of 3 and 4 weeks between MY and relative humidity at 1500 hours. There appeared to be no effect of RMS on mitigation of temperature humidity index within the range studied. There did not appear to be negative impacts of the RMS brushes. [ABSTRACT FROM AUTHOR]

The Australian dairy industry relies primarily on pasture for its feed supply. However, the variability in climate affects plant growth, leading to uncertainty in dryland pasture supply. This paper models the impact of climate variability on pasture production and examines the potential of two pasture-based dairy feeding systems: (1) to experience winter deficits: (2) to carry forward the conserved pasture surpluses as silage for future use; and (3) to conserve pasture surpluses as hay. The two dairy feeding systems examined were a traditional perennial ryegrass-based feeding system (ryegrass max. - RM) and a system that incorporated double cropping into the perennial ryegrass pasture base (complementary forage - CF). The conditional probability of the RM and CF systems to generate pasture deficits in winter were 94% and 96%, respectively. Both systems could carry forward the surplus silage into the following lactation almost once in every 4-5 years with the RM system performing slightly better than the CF system. The proportions of the grain-based concentrates fed in the two systems were 25% and 27% for the RM and CF systems, respectively. This study suggests that double-cropping systems have the potential to provide high-quality feed to support the feed gaps when pasture is not available due to increased variability in climatic conditions. [ABSTRACT FROM AUTHOR]