Cox-Ganser J M, Jung G A, Pushkin R T, Reid R L
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26506.
J Anim Sci. 1994 Jul;72(7):1832-41. doi: 10.2527/1994.7271832x.
Blood composition of lambs grazing Brassicas and stockpiled grass or grass-clover pastures in the fall of 4 yr was monitored to assess possible effects of plant metabolites (e.g., glucosinolates, S-methyl cysteine sulfoxide) on health and performance. Serum thyroxine (T4) concentrations in lambs grazing Brassicas decreased upon initiation of grazing, with a subsequent recovery, and concentrations were increased by oral dosing with I or I+CuO. Serum triiodothyronine (T3) increased gradually with time and did not differ between lambs on Brassicas and on pasture at most time periods. In Exp. 3 and 4, T4 levels were lower in lambs grazing Tyfon chinese cabbage hybrid (Brassica rapa L. x B. pekinensis [Lour.] Rupr.) than in lambs on Forage Star hybrid turnip (B. rapa L.). Heinz body formation increased rapidly in lambs on Brassicas, with small decreases in packed cell volume (PCV); dosing with I+CuO reduced Heinz bodies in lambs on Tyfon and turnip pastures. In Exp. 2, I+CuO treatment increased liver Cu concentrations but had no effect on serum Cu. Serum cholesterol and urea N concentrations declined rapidly in lambs on Brassicas, with little change in lambs on stockpiled pastures. Decreases in serum triglycerides, and an increase in glucose concentration, were noted in Exp. 3 and 4 in lambs grazing Tyfon and Forage Star turnip. Although a number of differences related to plant composition were noted in blood of lambs grazing Brassica forages relative to stockpiled pastures, the changes did not seem sufficiently severe to affect animal performance.
对4年秋季放牧芸苔属植物以及采食堆贮牧草或禾本科-三叶草混播牧场牧草的羔羊的血液成分进行了监测，以评估植物代谢产物（如硫代葡萄糖苷、S-甲基半胱氨酸亚砜）对健康和生产性能可能产生的影响。放牧芸苔属植物的羔羊血清甲状腺素（T4）浓度在开始放牧时下降，随后恢复，通过口服碘或碘+氧化铜后浓度升高。血清三碘甲状腺原氨酸（T3）随时间逐渐升高，在大多数时间段，放牧芸苔属植物的羔羊与放牧牧场的羔羊之间没有差异。在试验3和4中，放牧泰丰大白菜杂交种（芜菁甘蓝×大白菜）的羔羊的T4水平低于放牧饲草之星杂交芜菁的羔羊。放牧芸苔属植物的羔羊中，海因茨小体形成迅速增加，红细胞压积（PCV）略有下降；用碘+氧化铜处理可减少泰丰和芜菁牧场羔羊的海因茨小体。在试验2中，碘+氧化铜处理增加了肝脏铜浓度，但对血清铜没有影响。放牧芸苔属植物的羔羊血清胆固醇和尿素氮浓度迅速下降，采食堆贮牧草的羔羊变化不大。在试验3和4中，放牧泰丰和饲草之星芜菁的羔羊血清甘油三酯下降，葡萄糖浓度升高。尽管与采食堆贮牧草的羔羊相比，放牧芸苔属植物饲草的羔羊血液中存在一些与植物组成相关的差异，但这些变化似乎并不严重到足以影响动物的生产性能。
