Department of Animal and Rangeland Sciences, College of Agriculture, Oregon State University, Corvallis 97331, USA.
J Anim Sci. 2012 Dec;90(12):4536-43. doi: 10.2527/jas.2011-5019. Epub 2012 Jul 5.
Selenium is an essential micronutrient in sheep, and deficiency can limit lamb growth and survival. To evaluate how different chemical forms of Se administered to mature ewes at comparative dosages affect ewe and progeny performance, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly with no Se; at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk); with inorganic Na-selenate (8.95 mg Se/wk); or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk, respectively). The treatment period started approximately 2 wk before breeding and lasted for 62.5 wk. Ewes of the no-Se and Se-yeast groups continued treatments for another 21 to 24 wk through a second lambing season. Chemical form or dosage of Se did not affect ewe reproductive performance based on proportion of ewes lambing in each treatment group, or number of lambs born, nursed, or weaned per ewe (all P > 0.10). Ewes receiving the highest supplementation rate of Se-yeast at 24.5 mg Se/wk had higher BCS (scale 1 to 5) at the end of yr 1 (2.95 vs. 2.66; P = 0.05) than ewes receiving Se-yeast at 4.9 mg Se/wk. Performance was better in lambs from ewes receiving Se-yeast at 24.5 mg Se/wk than in lambs from ewes receiving Se-yeast at 4.9 mg Se/wk or no Se. In yr 1, lambs from ewes receiving Se-yeast at 24.5 vs. 4.9 mg Se/wk were heavier at 120 d of age (37.0 vs. 34.2 kg; P = 0.05). In yr 2, lambs from ewes receiving Se-yeast at 24.5 mg Se/wk were or tended to be heavier at 60 d of age than lambs from ewes receiving no Se (21.2 vs. 19.0 kg; P = 0.04) or lambs from ewes receiving Se-yeast at 4.9 mg Se/wk (19.2 kg; P = 0.09). This effect was more pronounced in ewes raising multiple lambs. We conclude that supranutritional supplementation of ewes with Se-yeast at 24.5 mg Se/wk improves lamb growth and ewe health without negatively affecting reproductive performance.
硒是绵羊必需的微量元素，缺乏会限制羔羊的生长和存活。为了评估以不同化学形式给予成熟母羊的硒在比较剂量下如何影响母羊和后代的性能，将 240 只母羊分为 8 个治疗组（每组 30 只），每周用无硒、最大 FDA 允许浓度的无机亚硒酸钠或有机硒酵母（每周 4.9mg Se）、无机硒酸钠（每周 8.95mg Se）或超营养浓度的无机亚硒酸钠和有机硒酵母（每周分别为 14.7 和 24.5mg Se）进行灌服。治疗期从配种前约 2 周开始，持续 62.5 周。无硒和硒酵母组的母羊在第二个产羔季通过第二次产羔继续治疗 21-24 周。根据每个治疗组的母羊产羔率或每只母羊产羔、哺乳或断奶的羔羊数，化学形式或硒剂量并未影响母羊的繁殖性能（均 P＞0.10）。接受硒酵母最高补充率 24.5mg Se/wk 的母羊在第 1 年末（2.95 对 2.66；P=0.05）的体况评分（1-5 分制）高于接受硒酵母 4.9mg Se/wk 的母羊。接受硒酵母 24.5mg Se/wk 的母羊所产羔羊的性能优于接受硒酵母 4.9mg Se/wk 或无硒的母羊所产羔羊。在第 1 年，120 日龄时，接受硒酵母 24.5mg Se/wk 的母羊所产羔羊比接受硒酵母 4.9mg Se/wk 或无硒的母羊所产羔羊重（37.0 对 34.2kg；P=0.05）。在第 2 年，接受硒酵母 24.5mg Se/wk 的母羊所产羔羊在 60 日龄时比接受无硒的母羊（21.2 对 19.0kg；P=0.04）或接受硒酵母 4.9mg Se/wk 的母羊（19.2kg；P=0.09）的羔羊更重。在多胎母羊中，这种影响更为明显。我们得出结论，以 24.5mg Se/wk 的硒酵母对母羊进行超营养补充可改善羔羊生长和母羊健康，而不会对繁殖性能产生负面影响。
