Field experience with d-biotin supplementation to gilt and sow feeds.

At a pig breeding farm with 130 sows, the culling rate in respect of the young replacement stock was more than 50% and was in particular caused by lameness. The effect was investigated of d-biotin supplementation of the feed on culling percentage, reproduction, claw lesions and lameness of gilts (young replacement stock) and sows, and piglet mortality. The young pigs were divided into a group of 23 young replacement pigs aged 2.5 months (12 controls and 11 treated) and a group of 47 gilts aged 7 months (23 controls and 24 treated). Both treatment groups received feed supplemented with 1250 mcg/kg d-biotin. Furthermore, all sows received feed supplemented with 500 mcg/kg d-biotin. The basic feed contained 175 mcg/kg biotin, of which about 100 mcg/kg was biologically available biotin. Biotin supplementation resulted in an increase in the plasma biotin levels from the critical deficiency level of about 50 ng/100 ml to about 300 ng/100 ml in young replacement stock, to about 179 ng/100 ml in the gilts, and to about 123 ng/100 ml in the sows. After 2.5 months of biotin supplementation the claw lesion score of the gilts had decreased by 28% (p less than 0.001). In the young replacement stock a reduction of the claw lesion score by 52% (p less than 0.001) was found after 4 months supplementation. The effect of biotin supplementation was greatest in the soft heel region (improved by 35%) and somewhat less on the claw wall (improved by 23%). After 11 months' supplementation with 500 mcg/kg biotin the effects on production performance of the sows compared to the previous year can be summarized as follows: --the overall culling rate dropped from 54.0% tot 30.8%, --the culling rate due to lameness decreased by 11% from 25% to 14%, --the culling as a result of 'insufficient production' was reduced from 11% to 4%, --a positive trend in piglet mortality was observed (17.7% compared to 19.2%). An increase of the biotin content of Dutch pig feeds and regular monitoring of its biotin content would appear to be advisable.