Erb R E, Sitarz E, Malven P V
J Dairy Sci. 1977 Feb;60(2):197-203. doi: 10.3168/jds.s0022-0302(77)83854-x.
Relations of techniques of sampling milk to its composition and concentrations of prolactin in blood plasma and milk from 59 suckled ewes were compared; Prolactin in milk and blood samples 0 to 2 h (hour 0) after removal of lambs did not differ significantly within autumn or summer, but both were doubled in summer. After the hour 0 sampling (summer only), one side of the udder of each of 12 ewes (group 1) was milked hourly for 4 h, and the opposite side was milked only at 0 and 4 h. Group 2 ewes were milked only at 0 and 4 h and blood was collected from both groups at 0 h and 4 h. Concentrations of prolactin were correlated in pairs of milk or blood samples from the same ewe and in plasma and milk of ewes in group 2 but not in group 1. Prolactin in milk increased between 0 h and 4 h in groups 1 and 2. Although milk lactose and prolactin concentrations differed among hourly samples, their average was similar to that of milk accumulated in the contralateral side for 4 h (group 1). Variations among ewes in progesterone of plasma indicated luteal activity during autumn and none during summer. Prolactin was unchanged in milk stored at -23 C for 30 days. The hour-0 milk-sampling technique was satisfactory to compare among individuals the concentrations of prolactin, total protein, or somatic cells in milk but not percentage fat and lactose, or milk yield due to variable time from last suckling to milking at hour 0.
比较了59只哺乳母羊的采奶技术与其乳汁成分以及血浆和乳汁中催乳素浓度的关系；在秋季或夏季，羔羊被移走后0至2小时（0小时）采集的乳汁和血液样本中的催乳素含量没有显著差异，但夏季两者均增加了一倍。在0小时采样后（仅夏季），12只母羊（第1组）中的每只母羊的一侧乳房每小时挤奶一次，持续4小时，另一侧仅在0小时和4小时挤奶。第2组母羊仅在0小时和4小时挤奶，并在0小时和4小时从两组母羊中采集血液。同一母羊的乳汁或血液样本对以及第2组母羊的血浆和乳汁中的催乳素浓度呈正相关，但第1组中不相关。第1组和第2组母羊乳汁中的催乳素在0小时至4小时之间增加。尽管每小时样本中的乳汁乳糖和催乳素浓度有所不同，但其平均值与对侧乳房4小时积累的乳汁平均值相似（第1组）。母羊血浆中孕酮的变化表明秋季有黄体活动，夏季则没有。乳汁在-23℃下储存30天，催乳素含量不变。0小时采奶技术对于比较个体间乳汁中催乳素、总蛋白或体细胞的浓度是令人满意的，但对于脂肪和乳糖百分比或产奶量则不然，因为从上次哺乳到0小时挤奶的时间不同。
