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.

中文翻译：

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澳大利亚北部牛群的繁殖性能。1. 营养、繁殖和畜群健康管理实践和环境调查

在澳大利亚北部进行的一项大型观察性研究开始时，通过对牧群所有者/管理人员（n = 78）的调查，获取了有关合作进行畜群营养、繁殖和健康管理的实践和政策的数据，以确定和量化影响主要动物、管理群体和财产层面的风险因素对繁殖性能的衡量。本研究中的合作牛群被认为在地理、规模和所有权方面具有广泛的代表性北澳大利亚牛肉养殖企业。本文使用四大区域类别，对“摇钱树”项目中合作牛群的管理实践和营养条件进行了描述性总结。北部丘陵和北部森林地区的房产规模最大，是南部森林中最小的。与其他国家类型相比，北部森林中一岁公牛的预期平均年增长率要低 50 公斤以上，这似乎也与确定的生产系统和转产动物有关。尽管营养和环境挑战加剧，并且北部森林中的新管理者可能需要更多时间来深入了解牛和财产动态，但该地区的管理变革发生率最高。本研究中总结的营养信息强调了雨季的有效磷，如粪便水平与膳食能量的比例所示，可能会限制北部丘陵和北部森林的动物生产。在旱季，牧场消化率和蛋白质水平可能接近每个国家类型约 50% 奶牛的维持水平，并且对瘤胃可降解蛋白质的反应也可能出现在 50% 的资产上。尽管有这一发现，但观察到北部丘陵地区旱季补充剂的使用率较低，部分原因是基于泌乳状态和妊娠情况隔离奶牛的管理系统发生率高。在所有国家类型中，公牛与母牛的比例高于广泛管理情况下推荐的 2.5%，同时也观察到疫苗的使用有限以控制生殖丧失的传染性原因。这项研究的主要结论是干预措施对特定企业的适应存在显着差异，