Van Ryssen J B, Bradfield G D, Van Malsen S, De Villiers J F
Department of Animal Science, University of Natal, Pietermaritzburg, Republic of South Africa.
J S Afr Vet Assoc. 1992 Dec;63(4):148-55.
The response to selenium supplementation of sheep grazing cultivated pastures was investigated on different farms in the Natal Midlands, Republic of South Africa. Over a period of one year, a significant (P < 0.01) improvement of 18.2% in live mass gain and of 13.7 and 15.8% (P < 0.05) in greasy and clean wool production, respectively, was measured in response to selenium supplementation in young ewes at the Cedara Research Station. In ewes injected with a long-acting barium selenate product, the glutathione peroxidase (GSH-Px) activity in the erythrocytes was maintained at elevated levels, above that of the control group, for almost 2 years. On 6 private farms, mature ewes were dosed approximately 6 weeks before mating, with a long-acting intraruminal selenium pellet. On 2 of the farms, a significant improvement (P < 0.05) in fertility of ewes was observed with no response to supplementation in the birth mass, lamb growth rate, or in lamb mortality. The long-acting pellets maintained elevated erythrocyte GSH-Px activity in the ewes for approximately one year. Although sheep on some farms in the Natal Midlands responded to selenium supplementation, it seems advisable to establish the selenium status of a flock before embarking on a supplementation programme. The risk of an excessive selenium intake, through the inadvertent supplying of selenium in different feed sources, has been demonstrated and should be guarded against.
在南非共和国纳塔尔中部地区的不同农场，对放牧于人工草场的绵羊补充硒的效果进行了研究。在 Cedara 研究站，对年轻母羊补充硒后，经过一年时间，测定发现活体重增加显著（P < 0.01），提高了 18.2%，含脂羊毛产量提高了 13.7%，净毛产量提高了 15.8%（P < 0.05）。给母羊注射长效硒酸钡产品后，红细胞中的谷胱甘肽过氧化物酶（GSH-Px）活性在近 2 年时间里维持在高于对照组的升高水平。在 6 个私人农场，在配种前约 6 周给成年母羊投放长效瘤胃内硒丸。在其中 2 个农场，观察到母羊的繁殖力有显著提高（P < 0.05），但在出生体重、羔羊生长率或羔羊死亡率方面对补充硒没有反应。长效硒丸使母羊红细胞 GSH-Px 活性维持升高水平约一年。尽管纳塔尔中部地区一些农场的绵羊对补充硒有反应，但在开始补充计划之前，确定羊群的硒状况似乎是明智的。已经证明存在因不同饲料来源无意中供应硒而导致硒摄入过量的风险，应加以防范。
