Rehemujiang Halidai, Yimamu Aibibula, Wang Yong Li
College of Grassland and Environmental Science, Xinjiang Agricultural University, Urumqi 830052, China.
Xinjiang TianShan Animal Husbandry Bio-engineering CO., LTD, Changji 831100, China.
Asian-Australas J Anim Sci. 2019 Feb;32(2):233-240. doi: 10.5713/ajas.18.0057. Epub 2018 Aug 27.
This study was to investigate the effects of dietary cotton stalk on nitrogen and free gossypol in sheep.
Treatments included 25% cotton stalk (Treat 1), 50% cotton stalk (Treat 2), and a control (no cotton stalk). Six Xinjiang daolang wethers were cannulated at the rumen and duodenum and fed one of these diets. The effects of these diets on nitrogen and free gossypol absorption and metabolism were determined. Fifteen healthy Xinjiang daolang wethers were assessed for daily gain, tissue lesions, and free gossypol accumulation.
Dry matter intake decreased with increasing dietary cotton stalk. Total tract dry matter digestibility did not significantly differ among treatments. Dietary cotton stalk significantly decreased volatile fatty acids and increased ammonium nitrogen in the rumen. Nitrogen intake was significantly higher in Treat 2 than in the control or Treat 1. Nitrogen retention and free gossypol intake increased with dietary cotton stalk. Duodenal free gossypol flow did not increase, and free gossypol almost disappeared from the rumen. The free gossypol content of plasma and tissue was increased with dietary cotton stalk with liver free gossypol> muscle free gossypol>kidney free gossypol. Elevated dietary free gossypol decreased platelets, hemoglobin, and serum iron. Aspartate aminotransferase and γ-glutamyltransferase increased in Treat 2. With high long-term dietary cotton stalk intake, liver cells were swollen, and their nuclei dissolved. Renal cells were necrotic and the interstitia were enlarged.
With short-term cotton stalk administration, only a small amount of free gossypol is retained in the body. In response to long-term or high free gossypol cotton stalk feeding, however, free gossypol accumulates in, and damages the liver and kidneys.
本研究旨在探讨日粮中棉花秸秆对绵羊氮和游离棉酚的影响。
处理组包括25%棉花秸秆（处理1）、50%棉花秸秆（处理2）和对照组（无棉花秸秆）。六只新疆刀郎阉羊在瘤胃和十二指肠处安装瘘管，并饲喂其中一种日粮。测定这些日粮对氮和游离棉酚吸收及代谢的影响。对15只健康的新疆刀郎阉羊进行日增重、组织损伤和游离棉酚蓄积情况的评估。
随着日粮中棉花秸秆比例的增加，干物质采食量下降。各处理组间全消化道干物质消化率无显著差异。日粮中的棉花秸秆显著降低了瘤胃挥发性脂肪酸含量，增加了铵态氮含量。处理2组的氮摄入量显著高于对照组或处理1组。氮潴留和游离棉酚摄入量随日粮中棉花秸秆比例的增加而增加。十二指肠游离棉酚流量未增加，游离棉酚在瘤胃中几乎消失。血浆和组织中的游离棉酚含量随日粮中棉花秸秆比例的增加而升高，肝脏游离棉酚>肌肉游离棉酚>肾脏游离棉酚。日粮中游离棉酚含量升高会降低血小板、血红蛋白和血清铁含量。处理2组的天冬氨酸转氨酶和γ-谷氨酰转移酶升高。长期高比例摄入棉花秸秆日粮后，肝细胞肿胀，细胞核溶解。肾细胞坏死且间质增大。
短期饲喂棉花秸秆时，体内仅留存少量游离棉酚。然而，长期或高比例饲喂游离棉酚含量高的棉花秸秆时，游离棉酚会在体内蓄积并损害肝脏和肾脏。
