Diogo Magnabosco

Lysine supplementation in late gestation of gilts: effects on piglet birth weight, and gestational and lactational performance

Lysine requirements for gain in maternal body reserves and piglet birth weight, during pregnancy, in contemporary prolific genotypes, are not well established. This study aimed to evaluate the effect of dietary lysine in late pregnancy on piglet birth weight, and on the gestational and lactational performance of gilts. Pregnant gilts were uniformly distributed into two groups and received, from 85 to 110 days of gestation, either of two lysine levels in their diet: Control group - 28g lysine/day (n=136), and Lysine group - 35g lysine/day (n=141). There were no effects (P>0.10) of supplemental lysine on body weight and backfat (BF) gain of females or on piglet birth weight. Gilts supplemented with lysine tended to have a lower percentage of stillbirths (P=0.077), reduced within-litter birth weight variation (P=0.094) and a lower percentage of piglets weighing less than 1100g (P=0.082) than in the Control group. During lactation, the performance of sows and litters was also evaluated in a subgroup of sows (n=26/group). There were no differences between the Control and Lysine groups (P>0.10) in voluntary feed intake, body reserve losses (weight and BF), weaning-to-estrus interval of the sows, and litter weaning weight. In conclusion, an increase in lysine (from 28 to 35g/day) in late gestation of gilts (85 to 110 days) tends to reduce the rate of stillbirths and to improve the uniformity of litter weight at birth, but does not affect the performance of females until farrowing or during subsequent lactation.

Indução de puberdade em leitoas com diferentes idades em dois sistemas de manejo

The objective of this work was to determine the effect of boar-exposure method and of gilt age at exposure on the percentage of first estrus manifestation, puberty age, and interval between stimulus and puberty. Danbred F1 Landrace x Large White gilts were induced to puberty with two different systems of boar exposure - Baia, stimuli done by putting a male inside the pens of gilts; Bear, stimuli done by putting the females in an area with males - , and three ages at the beginning of stimulation - 150, 170 and 200 days. There was no difference between the stimulation systems for the percentage of gilts in estrus, puberty age, and the interval between stimulation and estrus onset. This interval was lower when stimulus started at 200 days, and the proportion of gilts which reached puberty at 10, 20, 30 and 42 days after the beginning of boar-exposure was higher. Puberty induction has higher success when the female exposure to the male is done at 200 days, regardless of the boar-exposure system.