A Field Study of the Relationships between Behavior, Lifetime Reproductive Performance and Salivary Cortisol in Stalled Gestating Female Pigs

Abstract

This study aimed to investigate the relationships between behavior, lifetime reproductive performance and salivary cortisol in stalled gestating female pigs. A commercial farm with approximately 300 female pigs was visited eight times for three years. Three postural behaviors and the vacuum chewing behavior were recorded at 15-min intervals for 6 hours by using point sampling. Of 1,570 observations, 1,285 were farrowed, and 427 females were culled during the study period. Relative frequency (%) of vacuum chewing was used to divide 30 gestating females into two groups : no-vacuum chewing and high-vacuum chewing. Salivary samples were collected from the gestating female pigs in the two groups. The correlations between consecutive parities in each behavior were analyzed. Associations between behaviors and lifetime performance were separately analyzed at each parity. As parity increased from 0 to 3, vacuum chewing increased from 8.14 to 13.1%. Relative frequencies (%) of vacuum chewing between consecutive parities 0 and 5 were positively correlated (P<0.05). No differences in salivary cortisol concentrations were found between the high- and the no-vacuum chewing groups. In parities 4 and 5, lower vacuum chewing frequency was associated with greater lifetime average total pigs born and pigs born alive (P<0.05).