Institute of Animal Breeding, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Anim Sci J. 2012 Feb;83(2):162-8. doi: 10.1111/j.1740-0929.2011.00930.x. Epub 2011 Jul 26.
The aim of the study was to determine the changes in composition and physicochemical features (pH, density, thermostability and acidity) of mare colostrum and milk, and of protein fraction contribution (serum albumin, β-casein, γ-casein, α-lactalbumin, G class immunoglobulins) depending on lactation stage. The research material was colostrum and milk samples from 12 Arabian mares. Colostrum samples were collected within 2 h after parturition and milk samples were collected twice, in the 3rd and 6th weeks of lactation. The level of basic milk components decreased significantly (only lactose content increased) as compared to colostrum. Total bacteria count and somatic cell count decreased significantly with an increase in resistance and urea level. The changes observed were connected to differentiated contribution of particular protein fractions and their relative proportions. Lower levels of γ-casein (P ≤ 0.05), β-casein, serum albumin as well as α-lactalbumin were observed in colostrum as compared to those in milk. Any relationship between lactation stage and β-casein content was observed. Serum albumin and α-lactalbumin content increased in subsequent milkings. The level of G class immunoglobulins decreased significantly and its highest level was noted in colostrum. Any significant differences between the 3rd and 6th lactation weeks were obtained.
本研究旨在确定母马初乳和牛奶的组成和理化特性（pH 值、密度、热稳定性和酸度）以及蛋白质组分（血清白蛋白、β-酪蛋白、γ-酪蛋白、α-乳白蛋白、G 类免疫球蛋白）随泌乳阶段的变化。研究材料为 12 匹阿拉伯母马的初乳和牛奶样本。初乳样本于分娩后 2 小时内采集，牛奶样本分别在泌乳第 3 周和第 6 周采集。与初乳相比，基本牛奶成分的水平显著降低（仅乳糖含量增加）。总细菌计数和体细胞计数随着抵抗力和尿素水平的增加而显著降低。观察到的变化与特定蛋白质组分的差异贡献及其相对比例有关。与牛奶相比，初乳中γ-酪蛋白（P ≤ 0.05）、β-酪蛋白、血清白蛋白和α-乳白蛋白的水平较低。观察到泌乳阶段与β-酪蛋白含量之间存在任何关系。随后的挤奶中血清白蛋白和α-乳白蛋白含量增加。G 类免疫球蛋白的水平显著下降，在初乳中达到最高水平。在第 3 周和第 6 周泌乳期间获得了任何显著差异。
