EFFECT OF GESTATION HOUSING ON REPRODUCTIVE-PERFORMANCE OF YORKSHIRE AND YORKSHIRE X LACOMBE SOWS

Yorkshire (Y) (48) and 48 Yorkshire .times. Lacombe (YL) primiparous sows were used to evaluate the effect of outside lot and confinement housing from weaning to parturition on reproductive performance over the 2nd-4th parity. Feed intake of the sows housed in the outside lots was adjusted monthly to provide a similar average gain (54 kg) to that of sows housed in confinement (56 kg). All sows were bred by AI [artificial insemination]. Sows that did not conceive to mating at the 1st or 2nd estrus were culled from the experiment. More (P < 0.05) sows housed in the outside lots than in confinement completed the experiment (77.1 vs. 52.1%, respectively). The number of sows that failed to conceive was similar for both treatments but 12 sows housed in confinement and 1 housed in outside lots were culled due to injury or death. The sows housed in outside lots weaned more (P < 0.01) piglets (8.42 .+-. 0.23 vs. 7.49 .+-. 0.25) than those housed in confinement while the number of piglets born (10.20 .+-. 0.15) and born alive (9.79 .+-. 0.14) and the weight at birth (1.31 .+-. 0.02 kg) and weaning (9.45 .+-. 0.09 kg) were similar. As anticipated, the YL sows farrowed and weaned more and heavier piglets (P < 0.01) than the Y sows. The housing environment did not have a significant effect on the farrowing interval which averaged 159.3 .+-. 0.6 days. Effects of housing conditions from weaning to parturition were limited to the number of sows culled and the number of piglets weaned.