The effect of virginiamycin on sow and litter performance

Abstract The present paper discusses the results of a trial study, which was carried out to demonstrate the potential beneficial effects of virginiamycin (VM) on sow and litter performance. VM was added to the sow food at the levels of 0, 20 and 40 mg/kg, for a period of two breeding cycles, covering pregnancy and lactation. VM supplementation of the sow food improved sow performance by: (i) decreasing sow weight loss from farrowing to weaning (first period: 8·78 v. 3·54 v. 2·88 kg, P < 0·05; second period: 8·98 v. 3·93 v. 2·32 kg, P < 0·05), (ii) decreasing the duration of the reproductive cycle (first period: 154·5 v. 152·2 v. 151·2 days, P < 0·05; second period: 153·8 v. 151·5 v. 250·6 days, P < 0·05) and (in) increasing milk fat content (second period: 63·7 v. 81·3 v. 83·3 g/kg, P<0·05). Litter performance was also improved in terms of: (i) litter size at weaning (first period: 8·16 v. 8·88 v. 9·18, P < 0·05; second period: 8·98 v. 9·30 v. 9·76, P < 0·05), (ii) body weight at weaning (first period: 5·78 v. 6·29 v. 6·56 kg, P < 0·05; second period: 5·88 v. 6·38 v. 6·60 kg, P < 0·05), (Hi) average daily gain (first period: 172 v. 189 v. 197 g, P < 0·05; second period: 178 v. 292 v. 198 g, P < 0·05) and (iv) food conversion ratio (first period: 0·356 v. 0·331 v. 0·324, P < 0·05; second period: 0·363 v. 0·334 v. 0·325, P < 0·05). These beneficial effects of VM were more pronounced at the higher of the two inclusion levels.