One-day supplementation with tyrosine did not affect reproductive traits of sows

Abstract

Primiparous and multiparous sows received a single dietary supplement of L-tyrosine in their feed on the day after weaning, and the effects on various reproductive traits were evaluated. Sows received either none (control; n = 21) or 45.5 mg L-tyrosine/lb BW (tyrosine; n = 22) on the day after weaning. In Exp. 1, days from weaning to estrus (5.1 ± 1 vs 5.3 ± .9 d) and ovulation rate (number of corpora lutea on ovaries on d 5 after estrus) (16.3 ± 4.4 vs 16.2 ± 4) were similar in control and tyrosine-supplemented sows. In Exp. 2, (control; n = 63; tyrosine; n = 53) days to estrus were extended by tyrosine supplementation (6.4 ± .5 d) compared to control sows (4.6 ± .5 d), but total numbers of piglets born (10.6 ± .4 vs 10.1 ± .4) were similar in control- and tyrosine-treated groups. Therefore, a single dietary supplementation with tyrosine on the day after weaning failed to influence interval to estrus, ovulation rate, or litter traits.