Production Animal Hospital, Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Adaptation Physiology Group, Department of Animal Sciences, Wageningen University & Research, Wageningen, The Netherlands.
Animal. 2020 Jul;14(7):1493-1501. doi: 10.1017/S1751731120000063. Epub 2020 Jan 29.
Piglet birth weight and within-litter birth weight variation are important for piglet survival and growth. Pre-mating diets may improve IGF-1 and follicle development during the weaning-to-oestrus interval (WEI) and subsequent piglet birth weight. The objective of this study was to modulate IGF-1 concentration during late lactation and the WEI of young sows by using specific pre-mating diets supplemented with microfibrillated cellulose (MF), l-carnitine (LC) or l-arginine (AR). A further objective was to investigate the relationship between IGF-1 and subsequent follicle development and oestrus and ovulation characteristics. In total, 56 first-parity and 20 second-parity sows in three consecutive batches were used for this experiment. Sows received daily either wheat (CON) or wheat plus MF, LC or AR at one of two supplementation levels (low and high) during last week of lactation and WEI. From weaning onwards, follicle and corpus luteum (CL) diameters were repeatedly measured with ultrasound. Blood samples were collected during the WEI for IGF-1 and on day 21 of pregnancy for progesterone analyses, respectively. Insulin-like growth factor-1 concentration, follicle diameter, oestrus and ovulation characteristics and CL diameter were not affected by pre-mating diets. Low IGF-1 class (≤156 ng/ml, N = 22) sows had smaller follicles at weaning (3.5 v. 3.8 mm, P < 0.05) and a longer weaning-to-ovulation interval (147.2 v. 129.8 h, P < 0.05) than high IGF-1 class sows. In first-parity sows, high loin muscle depth (LM) loss sows (≥8%, N = 28) had lower IGF-1 concentrations at weaning (167 v. 214 ng/ml, P < 0.05) compared to low LM loss sows (<8%, N = 28). However, after weaning, IGF-1 concentrations increased and did not differ between high LM loss and low LM loss sows. In conclusion, the different supplemented compounds in pre-mating diets did not improve IGF-1 concentrations around weaning in young sows. Furthermore, high body condition loss caused lower IGF-1 concentrations at weaning, but these levels rapidly recovered after weaning and were related to follicle development and the interval from weaning to ovulation.
仔猪初生重和窝内初生重变异对仔猪的存活和生长很重要。配种前的饮食可以改善 IGF-1 和卵泡在断奶发情间隔（WEI）期间的发育，并随后提高仔猪的出生体重。本研究的目的是通过使用补充了微纤维纤维素（MF）、左旋肉碱（LC）或精氨酸（AR）的特定配种前饮食来调节泌乳后期和青年母猪 WEI 期间的 IGF-1 浓度，并进一步研究 IGF-1 与随后的卵泡发育以及发情和排卵特征之间的关系。总共使用了三批共 56 头初产和 20 头经产母猪进行了这项实验。母猪在泌乳期的最后一周和 WEI 期间，每天分别接受小麦（CON）或小麦加 MF、LC 或 AR，以两种补充水平（低和高）中的一种进行补充。从断奶开始，通过超声反复测量卵泡和黄体（CL）直径。在 WEI 期间采集血液样本用于 IGF-1 分析，在妊娠第 21 天采集血液样本用于孕激素分析。配种前饮食对 IGF-1 浓度、卵泡直径、发情和排卵特征以及 CL 直径没有影响。低 IGF-1 类（≤156ng/ml，N=22）母猪在断奶时的卵泡较小（3.5 v. 3.8mm，P<0.05），断奶至排卵的间隔时间较长（147.2 v. 129.8h，P<0.05）。在初产母猪中，高腰肌肉深度（LM）损失母猪（≥8%，N=28）断奶时的 IGF-1 浓度较低（167 v. 214ng/ml，P<0.05），与低 LM 损失母猪（<8%，N=28）相比。然而，断奶后，IGF-1 浓度增加，高 LM 损失母猪和低 LM 损失母猪之间的 IGF-1 浓度没有差异。总之，配种前饮食中的不同补充化合物并没有提高青年母猪断奶时的 IGF-1 浓度。此外，高体况损失导致断奶时 IGF-1 浓度降低，但这些水平在断奶后迅速恢复，并与卵泡发育和断奶至排卵的间隔有关。
