Department of Animal Science and Food Sciences, Texas Tech University, Lubbock, Texas 79409, USA.
J Dairy Sci. 2012 Dec;95(12):7319-30. doi: 10.3168/jds.2012-5970. Epub 2012 Oct 11.
The objective was to determine the influence of breed and planes of preweaned milk replacer (MR) nutrition on the immune responses of pre- and postweaned dairy calves. Forty-two bull calves (n=20 Holstein and n=22 Jersey, 2±1 d old) were studied. Holstein and Jersey calves came from separate dairies. Calves were fed either a higher plane of MR nutrition or a lower plane of MR nutrition. Holstein and Jersey calves on the lower planes of MR nutrition were fed 454 g (as fed)/d of a 20% crude protein (CP)/20% fat MR. Holstein calves on the higher plane of MR nutrition were fed 810 and 1,180 g (as fed)/d of a 28% CP/20% fat MR for wk 1 and wk 2 to 6, respectively. Jersey calves on the higher plane of nutrition were fed 568 and 680 g (as fed)/d of a 28% CP/25% fat MR for wk 1 and wk 2 to 6, respectively. On d 4, 42, and 77, peripheral blood was collected for ex vivo immunological analyses, and on d 7 all calves were challenged subcutaneously with commercially available lipopolysaccharide (LPS) from Escherichia coli (4 µg/kg of body weight); clinical and biochemical responses were evaluated at 0, 1, 2, 3, 4, 5, 6, 9, 12, 24, and 72 h. We observed a breed difference in total serum protein, wherein Jersey calves had higher concentrations than Holsteins. Holsteins and calves fed the higher plane of MR nutrition had greater glucose concentrations following the LPS challenge. With the exception of plasma haptoglobin concentrations at 24 h postchallenge, we observed no treatment × time interactions following the LPS challenge. Calves fed higher planes of MR nutrition had greater plasma haptoglobin concentrations 24h following the LPS challenge. Isolated mononuclear cells from Holstein calves secreted more tumor necrosis factor-α than did cells from Jersey calves when stimulated ex vivo with LPS on d 77. In addition, when whole blood was incubated with a live enteropathogenic E. coli culture, blood from Holsteins had a greater killing capacity than did whole blood from Jerseys. Calves fed higher planes of MR nutrition had greater neutrophil oxidative burst intensities at d 77 when cocultured with E. coli for 10 min. In addition, Jersey calves fed the lower plane of MR nutrition had reduced neutrophil oxidative burst capacity and whole blood E. coli killing at d 77 compared with the other groups. These data indicate that Jersey calves had lower measures of many innate immune variables despite likely having greater passive transfer, as evidenced by greater total serum protein concentrations. Furthermore, feeding a higher plane of MR nutrition to Jersey calves improved some postweaning innate immune responses.
本研究旨在确定在预断奶和断奶后阶段，不同品种和代乳品营养水平对奶牛犊牛免疫反应的影响。共选择 42 头公牛犊（20 头荷斯坦牛，22 头泽西牛，2±1 日龄）参与本试验。荷斯坦牛和泽西牛来自不同的牛场。犊牛接受高或低水平的代乳品营养。接受低水平代乳品营养的荷斯坦牛和泽西牛每天分别饲喂 454 克（实际采食量）20%粗蛋白（CP）/20%脂肪代乳品；接受高水平代乳品营养的荷斯坦牛在第 1 周和第 2 至 6 周每天分别饲喂 810 克和 1180 克 28%CP/20%脂肪代乳品；接受高水平代乳品营养的泽西牛在第 1 周和第 2 至 6 周每天分别饲喂 568 克和 680 克 28%CP/25%脂肪代乳品。在第 4、42 和 77 天，采集外周血进行体外免疫分析；在第 7 天，所有犊牛均接受皮下注射商业来源的大肠杆菌脂多糖（LPS，4μg/kg 体重）；在 0、1、2、3、4、5、6、9、12、24 和 72 小时评估临床和生化反应。我们观察到总血清蛋白存在品种差异，其中泽西牛的浓度高于荷斯坦牛。接受高水平代乳品营养的荷斯坦牛和犊牛在 LPS 挑战后血糖浓度更高。除了 LPS 挑战后 24 小时的血浆触珠蛋白浓度外，我们没有观察到 LPS 挑战后处理与时间的相互作用。接受高水平代乳品营养的犊牛在 LPS 挑战后 24 小时的血浆触珠蛋白浓度更高。第 77 天，当分离的单核细胞在 LPS 刺激下进行体外培养时，荷斯坦牛的细胞分泌的肿瘤坏死因子-α多于泽西牛的细胞。此外，当全血与活的致病性大肠杆菌培养物孵育时，荷斯坦牛的全血具有比泽西牛更强的杀菌能力。第 77 天，当与大肠杆菌共培养 10 分钟时，接受高水平代乳品营养的荷斯坦牛的中性粒细胞氧化爆发强度更高。此外，与其他组相比，接受低水平代乳品营养的泽西牛在第 77 天的中性粒细胞氧化爆发能力和全血大肠杆菌杀菌能力降低。这些数据表明，尽管泽西牛可能具有更高的被动转移（表现为更高的总血清蛋白浓度），但它们的许多先天免疫变量的测量值较低。此外，给泽西牛饲喂高水平代乳品营养可以改善断奶后的一些先天免疫反应。
