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Introduction: Reducing antibiotic use in production animal systems is one strategy which may help to limit the development of antimicrobial resistance. To reduce antimicrobial use in food‐producing animals, it is important to first understand how antibiotics are used on farm and what barriers exist to decreasing their use. In dairy production systems, mastitis is one of the most common reasons for administering antimicrobials. Therefore, it is important to understand the motivations and behaviours of dairy farmers in relation to the diagnosis, treatment and prevention of mastitis. Materials and methods: In this study, we interviewed a sample of dairy farmers and dairy industry professionals from the major dairying regions of eastern Australia regarding their current practices used to diagnose, treat, and control subclinical and clinical mastitis. Inductive thematic analysis was used to code interview transcripts and identify the recurrent themes. Results: Four overarching themes were identified: (1) the challenges associated with the detection and diagnosis of clinical mastitis, including with laboratory culture, (2) the motivations behind treatment decisions for different cases, (3) decisions around dry cow therapy and the role of herd recording, and (4) concerns regarding the development of antimicrobial resistance. Discussion: This study identifies several challenges which may limit the ability of Australian dairy farmers to reduce antimicrobial use on farm, such as the need for rapid and reliable diagnostic tests capable of identifying the pathogenic causes of mastitis and the difficulties associated with conducting herd recording for the implementation of selective dry cow therapy. Industry professionals were concerned that farmers were not using individual cow records to aid in treatment decisions, which could result in unnecessary antimicrobial use. The results of this study can act as the basis for future research aimed at assessing these issues across the broader Australian dairy industry. [ABSTRACT FROM AUTHOR]

Antimicrobial use (AMU) in the food chain is a potential driver of antimicrobial resistance. Despite Australia's strong regulation of AMU limited to veterinary prescriptions, a proportion of empirical antimicrobial treatments are administered by dairy farmers to manage common cattle health problems. This cross‐sectional survey identified key influences on AMU by dairy cattle farmers within New South Wales, Australia, to detect opportunities for antimicrobial stewardship (AMS) engagement. The study identified existing relationships, resources and attitudes of the dairy farmers that could be optimised for on‐farm AMS strategies. Farmers were most highly influenced by veterinary advice and clinical signs of the animal followed by the withholding period and the potential for antimicrobial resistance development. Farmers' high confidence regarding their own knowledge of antimicrobials (>90%), their high regard for veterinary advice (>90%) and high rate of veterinary health care plan use (69%) provides a strong framework to build the profile and practice of AMS on dairy farms. Positive engagement by dairy farmers (survey response of 20%), was achieved by working with the NSW Food Authority. Despite respondents reporting low reliance on formal (government and commercial) organisations for information about AMU, their engagement demonstrates an opportunity for groups with unparalleled access to dairy farmers to drive AMS. An association between frequent use of veterinary advice and respondents keeping ceftiofur on‐farm requires further investigation. Quantitative and qualitative analysis of on‐farm resources, decision‐making, and practices is required to understand how practices relate to veterinary advice and accepted standards of appropriate AMU on dairy farms. [ABSTRACT FROM AUTHOR]

Breed structures of Australian dairy herds over time were described for a large subset of milk‐recording herds. The focus for this study was to describe the use of crossbreeding by dairy farmers, specifically proportions of herds using crossbreeding, whether they were using two‐breed or three‐breed crossbreeding systems, and how herd‐breed structures changed over time. The most common breed structure in Australian milk‐recording herds between 2000 and 2013 was two‐breed crossbreeding (39% of herd‐years). The next most common breed structure was purebred (35%). Over the period studied, the proportion of herds that were purebred decreased, while the proportion of herds that were crossbreeding increased (particularly three‐breed crossbreeding herds). Herd‐breed structures and changes over time varied with region and with the herd's calving system. There were also considerable changes in breed structure within herds, including herds changing breed structure before reverting back to their original breed structure. These results indicate that breed structures in milk‐recording dairy herds in Australia are dynamic, and that farmers have commonly employed crossbreeding strategies. [ABSTRACT FROM AUTHOR]

The dairy industry provides an important contribution to the Australian economy, but its productivity relies on grass pastures that suffer significant damage from invertebrate pests. Managing these pests remains a challenge as information on their abundance and impact is only available for a handful of taxa in a few Australian dairy regions. In this study, we undertook an extensive survey of above‐ and below‐ground pest communities across seven dairy regions in south‐eastern Australia by repeatedly sampling 57 paddocks in 2017 and 2018. We then applied energetic models to estimate the amount of metabolisable energy produced by pastures that are potentially consumed by pests. Our survey indicates that dairy farmers encounter a similar composition of above‐ground pests in most sampled regions, with a few pests, especially Sminthurus viridis (lucerne flea) and Rhopalosiphum padi (bird cherry‐oat aphid), dominating pest communities. Below‐ground pests were more variable between regions and are more likely to require region‐specific control strategies. Our energetic modelling suggests that pests consume a threefold greater percentage of metabolisable energy produced by pastures during autumn than spring. S. viridis and R. padi were among the most economically important pests across all regions and seasons, while other pests, including several species of scarabs and the small pointed snail, Prietocella barbara, were predicted to be particularly damaging in specific regions. Together, our field survey and energetic modelling provide baseline information to assist dairy farmers manage invertebrate pests and help guide future research in the Australian dairy industry. [ABSTRACT FROM AUTHOR]

Context. A high level of acceptance and use of breeding indices by farmers and breeding companies that target a National breeding objective is an effective strategy to achieve high rates of genetic gain. Indices require maintenance to ensure that they reflect current economic and genetic trends and farmer preferences. Often, indices are tested on an average herd on the basis of, for example, milk composition and calving pattern. However, this strategy does not differentiate the impact on breeds. Australian dairy farmers routinely make breeding decisions by using the balanced performance index (BPI) or the health weighted index, published by DataGene. Aims. The aim of the present study was to test new selection indices on the most popular breeds to better understand the genetic progress that each breed is expected to make. Existing economic models were updated to reflect changing trends in input costs and milk income. Consultative processes identified opportunities to improve alignment between farmer preferences and Australia's National Breeding Objective. In response, more than 20 selection index options were developed and options were discussed with industry. Methods. Indices were evaluated on three breeds in the following three ways: (1) expected response to selection from the use of each index, (2) index and trait correlations, and (3) relative trait emphasis. Key results. Farmer trait preferences varied by breed and this information was considered in the development of economic weights. The updated BPI has primary emphasis on production traits (44% in Holstein, 49% in Reds), secondary emphasis on health and fertility (35% in Holstein, 29% in Reds), tertiary emphasis on type, workability and feed saved. The equivalent index for Jerseys is similar, but following stakeholder feedback to multiple tests, it was decided to remove emphasis on the feed saved estimated breeding values, so that the percentage emphasis on trait groups in Jerseys is 51% production, 32% health and fertility and the remainder on type and workability. Implications. Understanding trait preferences and testing indices on different breeds can change the decisions that are made during index development. Conclusions. Developing a better understanding of the differences among breeds had a positive impact on farmer engagement and resulted in a modified BPI for the Jersey breed. [ABSTRACT FROM AUTHOR]

Aims: The study investigated critical biosecurity control points and dairy farmers' motivations towards biosecurity practices among selected dairy farmers across Australia. Methods: A questionnaire template was administered via an online survey. A three-stage process was used to develop the questionnaire by pooling of potential questions, selection and reduction of the questions to fit an 8–10 min survey. Key results: A total of 55 responses were obtained. Mixed species rearing was practiced on 69% of the farms, with a majority keeping either sheep or beef cattle within the same property as dairy cattle. Approximately half of the farms (49%) did not provide formal training to new staff on aspects of animal health, as well as not conducting bull breeding soundness. Most of the farms (98%) required staff to use personal protective equipment, such as overalls and gumboots, but only a few of the farms (34%) had designated areas to clean footwear and a system for recording visitors (17%). Record keeping pertaining to animal health, maintenance of good fences and use of vendor declaration forms was practiced in a majority of the farms. The practice of quarantining new stock before mixing with other stock was practiced in only 45% of the farms. Monthly herd health visits by a veterinarian were utilised by 55% of the farms. Multivariable analysis showed positive significant associations between mixed species rearing with the practice of regular pest control (P = 0.004) and use of footbaths (P = 0.024) and no biosecurity plan (P = 0.025). Furthermore, a positive significant association was also recorded on the presence of a biosecurity plan and the presence of a designated area to clean footwear (P = 0.002) and no regular deworming (P = 0.024). Animal and human health reasons were the main motivators for implementing and maintaining 'best practice' biosecurity practices, whereas government regulation was the lowest motivator. Conclusions: It is concluded that the biosecurity practices were variable, and animal and human health reasons were the primary motivators for instituting biosecurity practices. Implications: There is a need to continue educating farmers on the importance of biosecurity practices. Farm biosecurity refers to all measures geared towards the prevention of disease occurrences in farm animals. The study assessed important biosecurity aspects and motivations for implementing such measures within dairy farms in Australia. The study demonstrated that the biosecurity practices were variable and unstandardized, and animal and human health reasons were the main motivators for such programs. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study was to investigate farmers' perception of lameness in comparison to the estimated prevalence of lameness in NSW pasture‐based dairies to evaluate farmers' perceptions and approaches to detection, treatment and prevention of lameness. Methods: Across‐sectional study was conducted on 62 pasture‐based dairy farms across NSW, Australia. The prevalence of lameness in these farms was estimated using locomotion scoring (1–4 scale). A survey was also conducted, using a questionnaire and face‐to‐face interview, to explore farmers' perceived prevalence of lameness and approaches to treatment and prevention. Results: The prevalence of lameness estimated by farmers was 3.7 times less (mean: 5%; range 0% to 26%) than that determined by locomotion scoring (mean: 19.1%; range 5.0%–44.5%). Approaches to treatment included antimicrobial therapy, hoof inspection with or without application of wooden blocks. In 28% of the farms, the lame cows were managed by farmers or farm staff with no official training in treatment of lame cows. The mean interval from detection of lameness to examination of the affected hoof was almost 55 hours (range 2–720 hours). A very low percentage of farms kept lameness records or implemented lameness preventive strategies such as footbaths and prophylactic foot trimming. Conclusions: Farmers and farm managers were found to underestimate the prevalence of lameness which could be due to the low level of awareness and can contribute to subsequent lack of implementation of prophylactic procedures and preventive management strategies for lameness. These findings accentuate the need to improve farmers' ability to detect lame cows and to emphasise the importance of recording in order to facilitate the management of lameness in dairy herds. [ABSTRACT FROM AUTHOR]

Genotype-by-environment interaction (G×E) is commonly observed in perennial ryegrass species and significantly impacts dry matter yield (DMY) performance across environments. Variation in DMY of perennial ryegrass cultivars and their distinct responses to different environments directly influence the profitability of the Australian dairy industry. In this study, we implemented a separate two-way factor analytic strategy to fit multi-environment-multi-harvest data collected from 18 trials spanning 14 years to account for the G×E effects across complex pasture environments in south-eastern Australia to achieve accurate DMY predictions. Three mega-environments were identified, and the seasonal and environmental DMYs of 126 cultivars or breeding lines (defined by a combination of varieties and endophytes) were predicted. Statistical differences in DMY performance and crossover G×E effects in cultivar rankings were observed among the three mega-environments. Several high-yielding cultivars specific to each mega-environment were also identified. The analysis demonstrated the importance of accounting for G×E effects when predicting the DMY of perennial ryegrass and highlighted the potential for identifying high-yielding cultivars specific to mega-environments. The research rationalizes implementing an appropriate independent pasture trialling system to generate necessary data for the dairy industry and could further facilitate dairy farmers to select suitable cultivars based on their specific environments and perennial ryegrass breeders when accounting for the genetic relationship of cultivars. • G×E impacts perennial ryegrass cultivar rankings and breeding strategies. • Factor analytic model is a robust tool for analysing G×E. • Analysing G×E provides accurate DMY prediction and facilitates identifying high-yielding cultivars. • Identified 3 mega-environments and predicted DMYs for 126 cultivars. • Appling an independent trialling system is necessary to identify environmental-specific cultivars. [ABSTRACT FROM AUTHOR]

Objectives: To describe colostrum management practices carried out in northern Victorian dairy herds and to identify weaknesses in these areas that may affect calf health and welfare by comparing the results with the current industry recommendations Methods: A questionnaire to obtain information about colostrum management and calf‐rearing practices was sent to commercial dairy farming clients of Rochester Veterinary Practice between June and September 2013. The questionnaire consisted of a general herd overview and colostrum harvesting practices. Results: The response rate was 39% (58/150). Many dairy producers were not meeting the current industry recommendations in the following areas: (1) time of removal calf from the dam, (2) relying on calf suckling colostrum from the dam to achieve adequate passive transfer, (3) failing to supplement calves with colostrum, (4) feeding inadequate volumes of colostrum, (5) delayed colostrum harvesting, (6) pooling of colostrum, (7) failing to objectively assess colostrum quality or relying on visual assessment and (8) storing colostrum for a prolonged periods of time at ambient temperatures. Conclusion: The results from this survey highlight the need for greater awareness of industry standards for colostrum management and feeding hygiene. [ABSTRACT FROM AUTHOR]

Concerns about water scarcity and consequent environmental impacts are driving major structural adjustment in the Australian irrigated dairy industry. This has resulted in government policy initiatives including water licence buybacks and grant schemes to improve water use efficiency. One consequence is the loss of many small farms and the development of larger technologically efficient farms with altered access to irrigation water. In farm families, who dominate the dairy industry, livelihood strategies, labour demands and the boundaries between traditional female and male spheres of labour are changing. We present findings from an Australian Research Council funded project examining the impacts of these changes on dairy families in the Murray Dairy region. We note that reshaped livelihood strategies and increased labour demands are further entrenching traditional gender relations and that labour is being re-allocated in highly gendered ways. We note a 'farmer-manager' role is evolving amongst male dairy farmers and a critical but less public role comprising significant input to labour tasks is evident amongst women on larger farms. Drawing on interviews with couples, most of whom were interviewed separately, we examine how gendered livelihood strategies are being reshaped at the same time as the significant contributions of women are being obscured. [ABSTRACT FROM AUTHOR]