A two-diet system and ad libitum lactation feeding of the sow. 2. Litter size and piglet performance

Sixty gilts were allotted to one of the following feeding regimes:CR, a conventional diet offered at a restricted level according to Swedish feeding standards; SA, a simplified gestation diet (mainly oats and barley) offered at a restricted level and a conventional diet offered ad libitum during lactation: CA, a conventional gestation diet offered at a restricted level and the same diet offered ad libitum during lactation. The sows were followed for four parities. Piglet birth weight was unaffected by sow feeding, but differences in piglet live weight were found form 3 weeks of age to the end of experiment when the piglets were 9 weeks old. CA piglets were heavier than SA piglets at 3 and 9 weeks of age and heavier than both CR and SA piglets at weaning (35+/-3 days). Litter size was unaffected by treatment as was piglet mortality, whereas the cause of death varied with treatment. Mortality due to trauma was higher among CA piglets than among others, while mortality due to weakness was higher among SA piglets than others and ther was also a tendency for higher mortality due to diarrhoea among Cr piglets. It was concluded that the Ca feeding regime was superior with regards to piglet performance.