B. Kafantaris, G. Papadopoulos

The combined effect of beta-carotene (300mg/sow/day one week before weaning to 4 weeks after weaning), vitamin E (50mg/kg feed), biotine (0,2mg/kg feed), folic acid (4mg/kg feed) and vitamin C ( ;only in the summer period at 300mg/kg) on the reproductive performance of sows was investigated in a large-scale trial carried out in a comercial pig unit. 630 sows were randomly assigned to two experimantal groups (supplemented and control). Supplementation with the five nitamins was above a normal vitamin supplementation of sow feeds. The five vitamins reduced the culing rate of sowe significantly, improved the cinception rate and reduced the returns to oestrus. Number of piglets born alive tended to be higher in the supplemented groups and litter size at wearing was improved significantly due to lower prewearing mortality. The treatment with the five vitamins resulted in higher birth weight and reduced the weaning to conception interval. Based on the results it is concluded that productivity and profitability of swine units may be considerably improved by simply using higher levels of these five vitamins compared to those units not using a higher level of the reffered vitamins