Back fat measurements in sows from three commercial pig herds: relationship with reproductive efficiency and correlation with visual body condition scores

Abstract

Evaluating the body condition of sows in modern pig herds has become an issue of considerable importance because of the economic pressure to achieve optimal production targets. The aims of this study were to investigate back fat levels in sows ( n=743) of three commercial pig herds and to assess whether they were associated with reproductive efficiency. The correlation between back fat measurements and visual scoring of the body condition was also assessed. Back fat levels varied significantly between the three herds, mainly because of differences in breed and level of feeding. The highest overall coefficient of variation in back fat levels was observed in parity 2 sows (30.8%), compared to other parities, and in sows at weaning (30.0%), compared to the variation at D80 of pregnancy and at farrowing. In two herds, a significant negative association was found between back fat levels at the end of gestation and percentage of stillborn piglets ( P<0.05), implying that sows with limited back fat levels at parturition should be avoided. Higher back fat losses during lactation tended to precede decreased reproductive efficiency, but the effects were not significant ( P>0.05). Back fat measurements and visual scoring of the body condition of the sows were only moderately correlated ( r=0.30–0.60). Correlations were lowest in parity 1 sows (0.32) and at farrowing (0.38) and differed slightly between the two breeds (0.45 versus 0.53). The study showed that back fat measurements constitute a valuable tool to monitor and improve the productivity and efficiency of high producing pig herds.