Age and weight at first mating affects plasma leptin concentration but no effects on reproductive performance of gilts

Abstract

The objective of this study was to verify the best mating age of gilts at the first parity. Gilts (n = 86) were divided into nine groups in a factorial arrangement with three Ages (AG1, ≤ 220 d; AG2, 220 to 240 d; AG3, 240 ≤ d), and three weights (WT1 ≤ 140 kg; WT2, 140 to 149 kg; WT3, 150 ≤ kg). A higher body weight gain in AG2 sows during gestation. Sows in AG2 group showed a higher body weight gain at first parity and backfat gain in the parity 2 and 3 during gestation. A greater insulin–like growth factor-1 (IGF-1) was observed in AG1 sows compared with AG3 sows at weaning in the second parity. Sows in WT1 group showed a significant positive effect on the plasma IGF-1 at breeding and weaning time in parity 2. Sows in AG3 group showed a higher plasma leptin at breeding, farrowing, and weaning in the parity 1, and at farrowing in parity 2. Sows in WT3 group showed a higher plasma leptin at breeding, farrowing, and weaning in the parities 1 and 2. Considering the insignificant longevity results, the most efficient time for gilts insemination can be at 220 d when their body weight is 140 kg or lower.

Effect of Sow Body Weight at First Service on Body Status and Performance during First Parity and Lifetime

“…In this regard, genetically increasing the NBA decreases piglet quality, due to lower birth weight, and increases preweaning mortality [ 30 ]. Weaned piglets (NWP) were also not significantly affected by the sow BW at first service, in agreement with the results found by Lee et al [ 31 ], who used sows of similar weight to ours.…”

Importance of dietary supplementation of soluble and insoluble fibers to sows subjected to high ambient temperatures during late gestation and effects on lactation performance

“…Prolonged labor is a painful period and induces stress on sows and piglets, thereby increasing the number of stillbirths ( Thorsen et al., 2017 ). As the duration of farrowing exceeds 4 h, the rate of piglet mortality increases ( Jiang et al., 2019 ; Lee et al., 2019 ). In this study, the high average farrowing duration (4.65 h) may be due to the adverse influences of heat stress.…”

Dietary Fiber for Gestating Sows During Heat Stress: Effects on Reproductive Performance and Stress Level

“…This involves greater survivability of piglets, more live-born piglets during lactation to ensure the capability of piglets in accessing the udder as soon as after birth [41]. However, several factors including genetics, body weight, litter size, constipation index, and parity affect farrowing duration [33,42], it recommended that the farrowing duration should not normally be prolonged over than 4 h [14]. In the current study, the average farrowing duration (4.84 h) was higher than recommended values, possibly because of adverse effects of heat stress.…”