Mena H, Santos J E P, Huber J T, Tarazon M, Calhoun M C
Department of Animal Science, University of Arizona, Tucson 85721-0038, USA.
J Dairy Sci. 2004 Aug;87(8):2506-18. doi: 10.3168/jds.S0022-0302(04)73375-5.
Effects of varying amounts of gossypol from whole Upland cottonseed (WCS) and cottonseed meal (CSM) were evaluated in 40 midlactation Holstein cows. After 14 d of pretreatment, cows were assigned to 1 of the 5 treatments for 84 d: control (no gossypol), 931 mg/kg total gossypol (TG) and 850 mg/kg free gossypol (FG) from WCS (moderate TG and high FG); 924 mg/kg TG and 91 mg/kg FG from CSM (moderate TG and low FG), 945 mg/kg TG and 479 mg/kg FG with equal amounts of TG from WCS and CSM (moderate TG and FG), or 1894 mg/kg TG and 960 mg/kg FG with equal amounts of TG from WCS and CSM (high TG and FG). Concentrations of plasma gossypol (PG) and its isomers were directly proportional to FG intake. Concentrations of PG reached a plateau after 28 d on treatment, and they were highest in cows receiving a diet with high TG and FG. Erythrocyte fragility differed among treatments and increased with increasing FG intake. Plasma gossypol returned to negligible concentrations 28 d after withdrawal of cottonseed products from the high TG and FG diet. Serum vitamin A was similar among treatments, but vitamin E increased with increasing FG intake. Serum enzymes were generally unaffected by treatments, but urea N increased in diets higher in TG and FG. Intake of dry matter was higher for the diet high in TG and FG than for the control diet, but was similar for other treatments. Cows receiving the high TG and FG diet produced more milk and 3.5% fat-corrected milk, with no changes in milk composition. Feeding a diet containing 1894 mg/kg TG and 960 mg/kg FG for 84 d increased PG concentrations and erythrocyte fragility and resulted in minor changes in blood metabolites and enzymes, but no detrimental effect on lactation performance was observed. Indicators of liver, kidney, and muscle cell viability suggest that the higher amounts of gossypol consumed in this study had only minor effects on those tissues in lactating dairy cows.
在40头处于泌乳中期的荷斯坦奶牛中评估了来自全陆地棉籽（WCS）和棉籽粕（CSM）的不同棉酚含量的影响。经过14天的预处理后，奶牛被分配到5种处理中的一种，为期84天：对照组（无棉酚）、来自WCS的931毫克/千克总棉酚（TG）和850毫克/千克游离棉酚（FG）（中等TG和高FG）；来自CSM的924毫克/千克TG和91毫克/千克FG（中等TG和低FG）、来自WCS和CSM的等量TG的945毫克/千克TG和479毫克/千克FG（中等TG和FG），或来自WCS和CSM的等量TG的1894毫克/千克TG和960毫克/千克FG（高TG和FG）。血浆棉酚（PG）及其异构体的浓度与FG摄入量成正比。处理28天后PG浓度达到平稳状态，在接受高TG和FG日粮的奶牛中最高。红细胞脆性在各处理间存在差异，并随FG摄入量增加而增加。从高TG和FG日粮中撤出棉籽产品28天后，血浆棉酚浓度恢复到可忽略不计的水平。各处理间血清维生素A相似，但维生素E随FG摄入量增加而增加。血清酶一般不受处理影响，但在TG和FG含量较高的日粮中尿素氮增加。高TG和FG日粮的干物质摄入量高于对照日粮，但其他处理相似。接受高TG和FG日粮的奶牛产奶量和3.5%乳脂校正乳更多，乳成分无变化。饲喂含1894毫克/千克TG和960毫克/千克FG的日粮84天会增加PG浓度和红细胞脆性，并导致血液代谢物和酶有微小变化，但未观察到对泌乳性能有不利影响。肝脏、肾脏和肌肉细胞活力指标表明，本研究中摄入的较高量棉酚对泌乳奶牛的这些组织只有轻微影响。
