Differences in udder health and immune response traits of Holstein-Friesians, Norwegian Reds, and their crosses in second lactation
Differences in udder health and immune response traits of Holstein-Friesians, Norwegian Reds, and their crosses in second lactation
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DOI：
10.3168/jds.2008-1356
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发表时间：
2009-02-01
影响因子：
3.5
通讯作者：
Mallard, B. A.
中科院分区：
文献类型：
--
作者：
Begley, N.;Buckley, F.;Mallard, B. A.
本研究的目的是研究30个爱尔兰商业奶牛场荷斯坦-弗里西亚奶牛（HF）、挪威红奶牛（NR）和NR × HF奶牛（NRX）乳房健康和免疫反应性状的潜在差异。用蛋清溶菌酶（HEWL）免疫648头泌乳奶牛（HF n=274, NR n=207, NRX n=167），诱导抗体介导的免疫应答（AMIR）。白色念珠菌被用来诱导细胞介导的免疫反应，体内延迟型超敏反应被用作指标。采用ELISA法检测抗体对HEWL的反应。乳牛的乳房健康（定义为哺乳期间的平均体细胞评分（SCS）、免疫开始后30天内的平均SCS、哺乳期每头奶牛的SCS峰值以及乳腺炎的发生率）在统计学上都优于天然奶牛。与HF和NRX相比，天然奶牛具有更高的原发性AMIR，在第14天产生更高浓度的抗hewl免疫球蛋白G。在继发性AMIR（免疫后21 d）或细胞介导的免疫反应的程度上，不同品种组之间没有差异。高反应和低反应的比例在不同品种组之间相似。高AMIR和高细胞介导免疫应答的奶牛在免疫开始后30天内的平均SCS显著降低，但临床乳腺炎的发生率更高，这是泌乳期的双重特征。此外，高应答和低应答奶牛的乳房健康状况无显著差异。虽然品种组平均SCS值的差异与组平均AMIR值一致，但在奶牛个体基础上相关的性状之间没有发现关联。研究结果强调了NR在奶牛乳腺健康方面的优势，并表明与NR杂交可能会改善奶牛的乳腺健康。然而，所研究的免疫反应性状被证明是奶牛乳腺健康的不一致指标。
The objective of this study was to investigate potential differences in udder health and immune response traits among Holstein-Friesian (HF), Norwegian Red (NR), and NR x HF (NRX) cows on 30 commercial Irish dairy farms. A total of 648 second-lactation cows (HF n=274, NR n=207, and NRX n=167) were immunized with hen egg white lysozyme (HEWL) to induce antibody-mediated immune response (AMIR). Candida albicans was used to induce a cell-mediated immune response, with in vivo delayed-type hypersensitivity used as the indicator. Antibody response to HEWL was measured by ELISA. Udder health defined as mean somatic cell score (SCS) over the lactation, mean SCS within 30 d of the beginning of the immunization, peak SCS for each individual cow during lactation, and incidence of mastitis were statistically superior for the NR. The NR had a greater primary AMIR, producing greater concentrations of anti-HEWL immunoglobulin G on d 14 compared with HF and NRX. No difference was observed among the breed groups in the magnitude of secondary AMIR (d 21 post-immunization) or cell-mediated immune response. The proportion of high and low responders was similar across breed groups. Cows with high AMIR and high cell-mediated immune response had significantly lower mean SCS within 30 d of the start of the immunization, but greater occurrence of clinical mastitis, recorded as a binary trait over the course of the lactation. Otherwise, no significant difference in udder health was evident between cows designated as high and low responders. Although differences in mean breed group SCS values were in line with group mean AMIR values, no association was found among the traits when correlated on an individual cow basis. Results highlight the superiority of the NR with regard to udder health and suggest that improvements to udder health may result from crossbreeding with the NR. However, the immune response traits investigated proved to be inconsistent indicators of udder health.