Effect of injecting 2- and 3-year-old ewes with selenium and selenium–vitamin E on reproduction and rearing of lambs

Abstract The experiment was conducted on 150 Polish Merino ewes divided into six groups. Three groups consisted of 2-year-old ewes, before their first lambing and three groups of the 3-year-old ewes after the first lambing. Within each age category, one group of ewes was treated with 5 ml 0.1% sodium selenate and 250 mg vitamin E while the third one was a control group. The effect of i.m. injection of Se and Se plus vitamin E on oestrus, fertility, prolificacy, number of lambs reared, the weight of lambs at birth and the live weight gain for 28 days was investigated. The blood plasma was sampled twice before injection, the mean Se concentration in 2-year-old ewes were 1.7 and 1.47 μmol l −1 and in 3-year-old were 1.11 and 1.37 μmol l −1 , respectively. The corresponding values for vitamin E concentration were 3.47 and 5.73 μmol l −1 in younger and 3.38 and 5.0 μmol l −1 in older ewes. Two consecutive injections of Se (before mating and lambing) significantly ( p p p p p p