1Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE),University of Padova,Viale dell'Università 16,35020 Legnaro,Italy.
2Department of Animal Medicine, Production and Health,University of Padova,Viale dell'Università 16,35020 Legnaro,Padova,Italy.
Animal. 2017 Dec;11(12):2309-2319. doi: 10.1017/S1751731117001227. Epub 2017 May 31.
Blood serum proteins are significant indicators of animal health. Nevertheless, several factors should be considered to appropriately interpret their concentrations in blood. Therefore, the objectives of this study were (1) to assess the effect of herd productivity, breed, age and stage of lactation on serum proteins and (2) to investigate association between serum proteins and somatic cell count (SCC) in dairy cattle. Milk and blood samples were collected from 1508 cows of six different breeds (Holstein Friesian, Brown Swiss, Jersey, Simmental, Rendena and Alpine Grey) that were housed in 41 multi-breed herds. Milk samples were analyzed for composition and SCC, while blood samples were analyzed for serum proteins (i.e. total protein, albumin, globulin and albumin-to-globulin ratio (A : G)). Herds were classified as low or high production, according to the cow's average daily milk energy yield adjusted for breed, days in milk (DIM) and parity. Data were analyzed using a linear mixed model that included the fixed effects of DIM, parity, SCS, breed, herd productivity and the random effect of the Herd-test date within productivity level. Cows in high producing herds (characterized also by greater use of concentrates in the diet) had greater serum albumin concentrations. Breed differences were reported for all traits, highlighting a possible genetic mechanism. The specialized breed Jersey and the two dual-purpose local breeds (Alpine Grey and Rendena) had the lowest globulin concentration and greatest A : G. Changes in serum proteins were observed through lactation. Total protein reached the highest concentration during the 4th month of lactation. Blood albumin increased with DIM following a quadratic pattern, while globulin decreased linearly. As a consequence, A : G increased linearly during lactation. Older cows had greater total protein and globulin concentrations, while albumin concentration seemed to be not particularly affected by age. A linear relationship between serum proteins and SCS was observed. High milk SCS was associated with greater total protein and globulin concentrations in blood. The rise in globulin concentration, together with a decrease in albumin concentrations, resulted in a decline in A : G as SCS of milk increased. In conclusion, such non-genetic factors must be considered to appropriately interpret serum proteins as potential animal welfare indicator and their evaluation represents an important first-step for future analysis based on the integration of metabolomics, genetic and genomic information for improving the robustness of dairy cows.
血清蛋白是动物健康的重要指标。然而，为了正确解释血液中这些物质的浓度，有几个因素需要考虑。因此，本研究的目的是：（1）评估牛群生产力、品种、年龄和泌乳阶段对血清蛋白的影响；（2）研究奶牛血清蛋白与体细胞计数（SCC）之间的相关性。从 6 个不同品种（荷斯坦弗里生、瑞士褐牛、泽西牛、西门塔尔牛、伦巴第牛和阿尔卑斯灰色牛）的 41 个多品种牛群中采集了 1508 头奶牛的牛奶和血液样本。对牛奶样本进行了成分和 SCC 分析，对血液样本进行了血清蛋白（即总蛋白、白蛋白、球蛋白和白蛋白/球蛋白比值（A:G））分析。根据牛的平均日奶能产量，结合品种、泌乳天数（DIM）和胎次，将牛群分为低产和高产。使用包含 DIM、胎次、SCS、品种、牛群生产力和生产力水平内的牛群测试日期的随机效应的线性混合模型分析数据。高产牛群（其饮食中还更多地使用浓缩饲料）的血清白蛋白浓度更高。所有性状都报告了品种差异，突出了可能的遗传机制。专用品种泽西牛和两个兼用本地品种（阿尔卑斯灰色牛和伦巴第牛）的球蛋白浓度最低，A:G 最高。在泌乳过程中观察到血清蛋白的变化。总蛋白在泌乳的第 4 个月达到最高浓度。白蛋白随 DIM 呈二次模式增加，而球蛋白呈线性下降。因此，A:G 在泌乳期间呈线性增加。年龄较大的奶牛总蛋白和球蛋白浓度更高，而白蛋白浓度似乎不受年龄影响。观察到血清蛋白与 SCS 之间存在线性关系。牛奶 SCS 高与血液中总蛋白和球蛋白浓度增加有关。球蛋白浓度升高，白蛋白浓度降低，导致随着牛奶 SCS 的增加，A:G 下降。总之，为了正确解释血清蛋白作为潜在的动物福利指标，必须考虑这些非遗传因素，它们的评估代表了基于代谢组学、遗传和基因组信息整合来提高奶牛健壮性的未来分析的重要第一步。
