The effects of season of birth (PE) and age of sow at birth (IMP) on litter size (TL); season of birth, age of sow and litter size on average weight at birth (PMN); season of birth age of sow, number of alive piglets at birth (NV), and percentage of alive males on average weight at 21 days of age (PM21) of 3259 Large White piglets born from June/85 to June/96 were evaluated by multiple regression analyses. The IMP effect on TL was significant. The average TL was 9.73±2.78. Larger litters were observed for sows from 2.84 to 3.83 years of age. The average PMN and PM21 were 1.35kg±0.18 e 5.06kg±1.00, respectively. The IMP and TL effects on PMN traits were linear and significant. A decrease of 20g on piglet weight was estimated for each additional piglet in the litter. The effect of NV was significant only for PM21 trait.
reproductive efficiency; age of the head office; pig; percentile of male; litter size
