Smith N E, Collar L S, Bath D L, Dunkley W L, Franke A A
J Dairy Sci. 1981 Nov;64(11):2209-15. doi: 10.3168/jds.S0022-0302(81)82831-7.
Four lactating Holstein cows producing about 21 kg milk/day were fed complete rations containing 0, 5, 15, and 25% whole cottonseed in a 4 X 4 Latin square design. Diets were fed ad libitum. Periods were 21 days in length with total collections of feces and urine during the last 7 days of each period. Digestibilities o nitrogen, lipid, and energy increased with increasing cottonseed in the diet. There were no significant effects of cottonseed on digestibility or availability of fiber components, calcium, phosphorous, and magnesium. Cottonseed feeding did not affect dry matter intake or milk yield but did increase yields of milk fat and fat-corrected milk and decrease milk protein and solids-not-fat percentages. Synthesis of fatty acid in the mammary gland was depressed by about 50% on the 25% cottonseed diet, but transfer of dietary fat resulted in twofold increases in yields of stearic and oleic acids. Hydrogenation of cottonseed fatty acid in the rumen resulted in a fourfold increase in yield of trans oleic acid in milk fat. Samples from bulk milk tank and data collected from 55 commercial dairies showed similar changes in fatty acid composition of milk from cows fed whole cottonseed. There was no apparent effect of feeding up to 2.9 kg cottonseed dry matter per cow per day on calving interval or on incidence of displaced abomasum, ketosis, milk, fever, or retained placenta.
选用4头日产奶量约21千克的泌乳荷斯坦奶牛，采用4×4拉丁方设计，分别饲喂含0%、5%、15%和25%全棉籽的全价日粮。日粮自由采食。试验期为21天，在每个试验期的最后7天收集粪便和尿液。随着日粮中棉籽含量的增加，氮、脂肪和能量的消化率提高。棉籽对纤维成分、钙、磷和镁的消化率或利用率没有显著影响。饲喂棉籽不影响干物质采食量或产奶量，但确实提高了乳脂和乳脂校正乳的产量，降低了乳蛋白和非脂固形物的百分比。在25%棉籽日粮中，乳腺中脂肪酸的合成下降了约50%，但日粮脂肪的转运使硬脂酸和油酸的产量增加了两倍。棉籽脂肪酸在瘤胃中的氢化作用使乳脂中反式油酸的产量增加了四倍。从储奶罐采集的样品以及从55个商业奶牛场收集的数据表明，饲喂全棉籽的奶牛所产牛奶的脂肪酸组成有类似变化。每头奶牛每天饲喂高达2.9千克棉籽干物质，对产犊间隔或真胃移位、酮病、乳热或胎衣不下的发生率没有明显影响。
