Cummins K A, Russell R W
J Dairy Sci. 1985 Aug;68(8):2009-15. doi: 10.3168/jds.S0022-0302(85)81062-6.
Eight lactating Holstein dairy cows were fed corn silage-based diets with or without whole cottonseed at 18.5% of the dietary dry matter. At 42 days postpartum, a pulse injection of 100 mg glucose/kg body weight was given intravenously and plasma glucose concentration was monitored for 45 min. At 50 d postpartum, biopsies of adipose tissue and mammary tissue were taken and tissue slices were incubated in vitro with either uniform carbon-14 glucose or 1-carbon-14 palmitate. Basal concentration of plasma glucose was not affected by diet, although apparent distribution volume of glucose did seem to decrease due to feeding whole cottonseed. Feeding whole cottonseed decreased uptake of glucose and palmitate in both adipose tissue and mammary tissue and also decreased oxidation of glucose to carbon dioxide in both tissues. Palmitate oxidation was not affected by diet. Incorporation of carbon-14 from glucose into adipose tissue lipids was decreased in cows fed whole cottonseed. Results indicate that fat supplementation in the form of whole cottonseed may decrease palmitate incorporation and glucose utilization for glycerol and reducing equivalent synthesis in both adipose tissue and mammary tissue of lactating dairy cows.
八头泌乳期的荷斯坦奶牛被饲喂以玉米青贮为基础的日粮，日粮干物质中分别含有或不含有18.5%的全棉籽。产后42天，静脉注射100毫克葡萄糖/千克体重，并监测45分钟的血浆葡萄糖浓度。产后50天，采集脂肪组织和乳腺组织活检样本，组织切片在体外与均匀的碳-14葡萄糖或单碳-14棕榈酸酯一起孵育。尽管由于饲喂全棉籽，葡萄糖的表观分布容积似乎确实降低，但日粮对血浆葡萄糖的基础浓度没有影响。饲喂全棉籽降低了脂肪组织和乳腺组织中葡萄糖和棕榈酸酯的摄取，也降低了两个组织中葡萄糖氧化为二氧化碳的量。棕榈酸酯氧化不受日粮的影响。在饲喂全棉籽的奶牛中，葡萄糖中碳-14掺入脂肪组织脂质的量减少。结果表明，以全棉籽形式补充脂肪可能会减少泌乳奶牛脂肪组织和乳腺组织中棕榈酸酯的掺入以及用于甘油和还原当量合成的葡萄糖利用。
