Behavioral and physiological responses of Meishan, Yorkshire and crossbred gilts to conventional and turn-around gestation stalls

Abstract

A 5-wk study involving 48 bred gilts was conducted to evaluate behavioral and physiological responses of four geneotypes (Meishan = MM, Yorkshire = YY and crossbred (sire/dam = MY and YM) to two types of gestation stalls (conventional and turn-around). The behavior of gilts was video-recorded on days 0, 7, 21, and 35. Blood samples were taken by venipuncture on days 0, 3, and 36 to determine plasma cortisol haptoglobin, and the neutrophil:lymphocyte (N:L) ratio. A skin-fold thickness response to the mitogen phytohemagglutinin (PHA) was determined on days 1 and 37. Gilts with a Yorkshire sire lay down less often (P < 0.05), spent more time performing chain manipulation (P < 0.05) and drinker manipulation (P < 0.01) and tended to be more active (P < 0.13) than gilts with a Meishan sire. Furthermore, their plasma cortisol levels and N:L ratios were found to be lower (P < 0.01), suggesting genetic differences in adaptive abilities or strategies. Gilts in turn-around stalls stood more frequently, performed more nosing/licking of the stall bars, and more chain manipulation than gilts in conventional stalls (P < 0.05). They also had a lower plasma cortisol level (P < 0.05). The percentage of time spent manipulating the chain increased from day 0 to day 7 (P < 0.05) and then remained constant throughout the experiment. According to our data, providing stalled gilts with the opportunity to turn increases certain activity levels and reduces plasma cortisol level, but does not affect immune system functioning. Key words: Gilts, genotype, gestation stall, behavior, stress