Rearing, fattening performance and slaughter indicators of lambs after selenium, zinc and vitamin E supplementation
Abstract. The experiment was conducted on 80 Polish Merino ewes, their 82 lambs and 40 fattening rams. Merino ewes were divided into two groups: experimental (E) and control (C), each composed of 40 animals. Four weeks before lambing, 1 day, 3 weeks and 6 weeks after lambing 40 ewes of the experimental (E) group received intramuscular injection of 5 ml 0.1 % Na2SeO4 (selenium [Se]: 2.09 mg), 10 ml 10 % ZnSO4 (Zinc [Zn]: 227 mg) and 250 mg vitamin E (α-tocopherol), and control group (C) – no received. From birth all the lambs were maintained with their dams and then weaned at the age of 8 weeks, placed in individual straw-bedded pens and fattened individually with a granulated concentrate mixture until reaching a body weight about 32 kg. During fattening 20 lambs from experimental group (E) was given per os 1 ml 0.1 % Na2SeO4, 3 ml 10 % ZnSO4 and 60 mg vitamin E (α-tocopherol) daily, and control group (C) – no administered. The levels of Se, Zn and vitamin E in the blood plasma of ewes and ram- lambs were within the reference values. The lambs born by the treated ewes (E) experienced much lower body live weight at birth (P≤0.05), body weight on day 28 and 56 (P≤0.01), compared to lambs born from group (C). Also the daily live weight gain from birth to 4 week and from birth to 8 week were significantly lower (P≤0.05) in lambs born by the treated ewes. Se, Zn and vitamin E treated rams contained less fat in leg (P≤0.05), less fat thickness over ribs (P≤0.01) and less fat thickness over loin-eye than non treated rams.