Different rearing intensities of gilts:: II. Effects on subsequent leg weakness and longevity

Abstract

The objective of this study was to evaluate the effects of rearing intensity (feeding level during the growing phase between 6 weeks of age and mating) on subsequent leg weakness symptoms and longevity in sows, i.e., the age at culling due to leg weakness. Seventy-two gilts were fed at three feeding levels from 6 weeks of age to mating: Semi ad lib., Control, or 75% Control. During subsequent pregnancy and lactation periods, all sows were fed according to Danish standards. They were scored for leg weakness problems at six months of age and late in each pregnancy until they were culled. Reason for culling was recorded. Feeding level affected some of the leg weakness traits, and for the `total leg weakness score' the effect of rearing intensity was significant ( P=0.004). Leg weakness scores were the poorest in the Semi ad lib. treatment, causing 48% culling, compared to 26 and 21% in Control and 75% Control treatments, respectively. Longevity defined as age at culling due to leg disorders was lower in the Semi ad lib. treatment, whereas low feeding level (75% Control) did not affect longevity. In summary, high rearing intensity resulted in an increase in leg weakness problems and a reduced longevity in sows.