Lessire Françoise, Moula Nassim, Hornick Jean-Luc, Dufrasne Isabelle
Centre des Technologies Agronomiques de Strée, rue de la Charmille, 4577 Strée, Belgium.
Department of Veterinary Management of Animal Resources, Faculty of Veterinary Medicine, Fundamental and Applied Research for Animal and Health (FARAH), University of Liège, 4000 Liège, Belgium.
Animals (Basel). 2020 May 25;10(5):913. doi: 10.3390/ani10050913.
More dairy farms (up to more than one in four in some countries) are equipped with automatic milking systems (AMS) worldwide. Because of the positive impacts of grazing, e.g., on animal welfare or on production costs, numerous researchers have published papers on the combination of AMS with grazing. However, pasture-based AMS usually causes a reduction in milking frequency (MF) compared to indoors systems. The objectives of this meta-analysis were to review publications on the impacts of pasture-based AMS on MF and mitigation strategies. First, data from 43 selected studies were gathered in a dataset including 14 parameters, and on which a Principal Component Analysis (PCA) was performed, leading to the description of four clusters summarizing different management practices. Multiple pairwise comparisons were performed to determine the relationship between the highlighted parameters of MF on milk yield (MY). From these different analyses, the relationship between MF and MY was confirmed, the systems, i.e., Clusters 1 and 2, that experienced the lowest MF also demonstrated the lowest MY/cow per day. In these clusters, grazed grass was an essential component of the cow's diet and low feeding costs compensated MY reduction. The management options described in Clusters 3 and 4 allowed maintenance of MF and MY by complementing the cows' diets with concentrates or partial mixed ration supplied at the AMS feeding bin or provided at barn. The chosen management options were closely linked to the geographical origin of the papers indicating that other factors (e.g., climatic conditions or available grasslands) could be decisional key points for AMS management strategies.
全球范围内，越来越多的奶牛场（在一些国家，比例高达四分之一以上）配备了自动挤奶系统（AMS）。由于放牧具有积极影响，例如对动物福利或生产成本方面，众多研究人员发表了关于AMS与放牧相结合的论文。然而，与室内系统相比，基于牧场的AMS通常会导致挤奶频率（MF）降低。本荟萃分析的目的是回顾关于基于牧场的AMS对MF的影响及缓解策略的相关出版物。首先，从43项选定研究中收集的数据形成了一个包含14个参数的数据集，并在此数据集上进行了主成分分析（PCA），得出了总结不同管理实践的四个聚类描述。进行了多次成对比较，以确定MF突出参数与产奶量（MY）之间的关系。通过这些不同分析，MF与MY之间的关系得到了证实，即第1和第2聚类中的系统，其MF最低，每天每头奶牛的MY也最低。在这些聚类中，放牧的草是奶牛日粮的重要组成部分，低饲养成本弥补了MY的降低。第3和第4聚类中描述的管理方案通过在AMS喂料槽补充精饲料或部分混合日粮，或在牛舍提供这些饲料，从而维持了MF和MY。所选的管理方案与论文的地理来源密切相关，这表明其他因素（如气候条件或可用草原）可能是AMS管理策略的决定性关键点。
