Suntinger M, Fuerst-Waltl B, Obritzhauser W, Firth C L, Köck A, Egger-Danner C
ZuchtData EDV-Dienstleistungen GmbH, 1200 Vienna, Austria; Department of Sustainable Agricultural Systems, Division of Livestock Sciences, University of Natural Resources and Life Sciences, Vienna, 1180 Vienna, Austria.
Department of Sustainable Agricultural Systems, Division of Livestock Sciences, University of Natural Resources and Life Sciences, Vienna, 1180 Vienna, Austria.
J Dairy Sci. 2022 Jun;105(6):5167-5177. doi: 10.3168/jds.2021-20832. Epub 2022 Mar 26.
In addition to somatic cell count records and clinical mastitis diagnoses, results of bacteriological milk analyses provide valuable information regarding udder health. The pathogen causing an udder infection is currently not considered in Austria as part of the information used for estimation of routine breeding values for mastitis resistance. Therefore the objective of this study was to estimate heritabilities for, and genetic correlations between, udder traits of bacterial infection (bacterial infection, gram-positive and gram-negative bacterial infection) and routinely recorded udder health traits [acute mastitis, chronic mastitis, culling due to udder health problems, and somatic cell score (SCS)] in Austrian Fleckvieh cows. The basis for the genetic analyses was a data set with results from bacteriological milk analyses collected from 237 dairy farms and 6,822 cows over a period of 1 yr. Traits were defined as binary, apart from SCS, for which measures were available continuously. Multivariate analyses using a linear animal model were applied for estimating genetic parameters. The heritabilities for the occurrence of bacterial udder infection traits were 0.01. Heritabilities were 0.04 for acute mastitis, 0.02 for chronic mastitis, 0.02 for culling due to udder health problems, and 0.20 for SCS. Genetic correlations between bacteriological infection and the routinely recorded udder health traits were positive and ranged from 0.62 to 0.96. The genetic correlation between gram-positive and gram-negative bacterial infection was -0.20. The genetic correlation between acute and chronic mastitis was also close to zero. These results show that mastitis caused by different pathogens may be seen as different traits. As analyses were based on a relatively small data set and results were associated with rather high standard errors, further research with a larger data set should be carried out to confirm these results.
除了体细胞计数记录和临床乳腺炎诊断外，细菌学乳汁分析结果还能提供有关乳房健康的宝贵信息。在奥地利，目前导致乳房感染的病原体不作为用于估计乳腺炎抗性常规育种值的信息的一部分。因此，本研究的目的是估计奥地利弗莱维赫奶牛乳房细菌感染性状（细菌感染、革兰氏阳性和革兰氏阴性细菌感染）与常规记录的乳房健康性状[急性乳腺炎、慢性乳腺炎、因乳房健康问题淘汰以及体细胞评分（SCS）]之间的遗传力和遗传相关性。遗传分析的基础是一个数据集，该数据集包含了从237个奶牛场的6822头奶牛在1年时间内收集的细菌学乳汁分析结果。除了SCS可以连续获得测量值外，其他性状均定义为二元性状。使用线性动物模型进行多变量分析以估计遗传参数。乳房细菌感染性状发生的遗传力为0.01。急性乳腺炎的遗传力为0.04，慢性乳腺炎为0.02，因乳房健康问题淘汰为0.02，SCS为0.20。细菌感染与常规记录的乳房健康性状之间的遗传相关性为正，范围在0.62至0.96之间。革兰氏阳性和革兰氏阴性细菌感染之间的遗传相关性为-0.20。急性和慢性乳腺炎之间的遗传相关性也接近零。这些结果表明，由不同病原体引起的乳腺炎可能被视为不同的性状。由于分析基于相对较小的数据集且结果的标准误差较高，因此应使用更大的数据集进行进一步研究以证实这些结果。
