Suckling hierarchy and performance of piglets in the farrowing phase with artificial ventilation and roof sprinkles

Abstract The hierarchy between pigs occurs in the first days after birth and can be influenced by the sequence in which piglets breastfeed on teats. This study aimed to evaluate whether the artificial ventilation and roof sprinklers causes hierarchical changes in feeding and weight gain of piglets. The study was conducted at a farrowing unit with 26 individual stalls, half of them with fans and roof sprinklers. Twenty-six females and 281 piglets, of second birth order, with weaning at 21 days were evaluated. The piglets were numbered and distributed in weight categories. The teats were delimited on the left and right sides, forming classes. The recording of the teats where the piglets breastfed and the disputes were carried out from the second day of birth to weaning, three times a week, in two daily evaluations. The imposition of the hierarchy was attributed to the registration of agonistic behaviors among the piglets, identifying the sender, receiver, the type of behavior performed by the aggressor and the counter-reaction of the victim. Higher means of seeking teats were found in the intermediate, upper and lower classifications, with no statistical difference between environments and periods of the day. In the establishment of the hierarchy, no strictly dominant, intermediate or subordinate animal was found. Piglets classified as heavier at birth were heavier at weaning in both environments evaluated. It was concluded that the sequence of piglets in the mammary gland influences the weight gain of pigs at the end of the farrowing phase.