Peri-partum posture and behaviour of gilts and the location of their piglets in lines selected for components of efficient lean growth

Peri-partum posture and behaviour of gilts from lines selected for differen t components of efficient lean growth were studied to determine if behaviou ral changes may have been associated with the observed responses in reprodu ctive performance. The proportions of time that gilts expressed defined pos ture and behaviour traits and the locations of their piglets were determine d from video recordings of observations made at 5 min intervals in the peri od extending from 2 h pre-farrowing to 2 h post-farrowing. The 137 gilts st udied were from four pairs of Large White lines which had been divergently (high and low) selected for either daily food intake (DFI), lean food conve rsion efficiency (LFC), lean growth rate on ad libitum feeding (LGA) or lea n growth rate on a restricted feeding scale (LGS). Almost all the significant (P < 05) changes occurred in the LGS pair of lin es. In the pre-farrowing period, relative to the low LGS gilts, high LGS gi lts spent a higher proportion of their time lying on their sides (0.92 vers us 0.69), and less time in the upright postures of standing, sitting or lyi ng on their bellies (0.08 versus 0.33) and engaging in nesting behaviour (0 .02 versus 0.10). During farrowing, high LGS gilts again lay on their sides more often than low LGS gilts (0.96 versus 0.80) and were upright less oft en (0.04 versus 0.20). High LGS gilts changed posture less often than low L GS gilts (0.05 versus 0.31) but were more often alert (0.79 versus 0.61). D uring farrowing, high LGS piglets were seen less often at their mother's he ad, back and vulva or at the creep than low LGS piglets (0.06 versus 0.15). Post-farrowing, there were no significant differences between the lines, a lmost all gilts lying on their sides with their piglets at the udder. Diver gent selection for components of efficient lean growth rate on ad libitum f eeding was not associated with consistent responses in gilt posture and beh aviour or in piglet location. Selection for high lean growth on restricted feeding had effects on gilt posture and behaviour which may have been benef icial to her welfare and that of her piglets. (C) 2001 Elsevier Science B.V . All rights reserved.