Supplemental biotin for swine. III. Influence of supplementation to corn- and wheat-based diets on the incidence and severity of toe lesions, hair and skin characteristics and structural soundness of sows housed in confinement during four parities.

The influence of supplementing 0 (NB) or 440 (SB) micrograms biotin/kg to corn- or wheat-based diets on toe lesions, hair characteristics and structural soundness in 116 crossbred female swine was studied from selection (100 kg) until completion of four parities. Gilts that had been previously fed corn-soybean meal diets with 0 or 220 micrograms supplemental biotin/kg diet during growth and development, remained on either the biotin unsupplemented or supplemented diet. Females were housed in buildings containing partially slatted and solid concrete floors. Toe, hair and soundness evaluations were made at a mean age of 240, 521, 732, 916 and 1,090 d. Type of grain fed did not influence (P greater than .10) any response criteria evaluated. Six types of toe lesions were observed across all dietary treatments and varied in severity from minor to very severe. The percentage of females with heel cracks, heel-horn junction cracks and side-wall horn cracks was reduced (P less than .01) when females were fed SB diets. Females fed SB diets had fewer (P less than .001) total lesions, heel cracks, heel-horn junction cracks, side-wall horn cracks and white-line horn cracks (P less than .03) compared with females consuming NB diets. In general, biotin supplementation was more effective in reducing the number and percentage of toe lesions in multiparous sows compared with gilts and primiparous sows. Biotin supplementation increased (P less than .001) the number of hairs/cm2 skin and improved (P less than .001) hair scores. Histological evaluation and soundness scores were not affected (P greater than .10) by level of biotin fed.(ABSTRACT TRUNCATED AT 250 WORDS)