Swine Reproduction - Development Program, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
Animal. 2013 Oct;7(10):1681-9. doi: 10.1017/S1751731113001249. Epub 2013 Jul 3.
The consequences of a low litter average birth weight phenotype for postnatal growth performance and carcass quality of all progeny, and testicular development in male offspring, were investigated. Using data from 25 sows with one, and 223 sows with two consecutive farrowing events, individual birth weight (BW) was measured and each litter between 9 and 16 total pigs born was classified as low (LBW), medium (MBW) or high (HBW) birth weight: low and high BW being defined as >1 standard deviation below or above, respectively, the population mean for each litter size. Litter average BW was repeatable within sows. At castration, testicular tissue was collected from 40 male pigs in LBW and HBW litters with individual BW close to their litter average BW and used for histomorphometric analysis. LBW piglets had a lower absolute number of germ cells, Sertoli cells and Leydig cells in their testes and a higher brain : testis weight ratio than HBW piglets. Overall, LBW litters had lower placental weight and higher brain : liver, brain : intestine and brain : Semitendinosus muscle weight ratios than MBW and HBW litters. In the nursery and grow-finish (GF) phase, pigs were kept in pens by BW classification (9 HBW, 17 MBW and 10 LBW pens) with 13 males and 13 females per pen. Average daily gain tended to be lower in LBW than HBW litters in lactation (P = 0.06) and throughout the nursery and GF phases (P < 0.01), resulting in an increasing difference in body weight between LBW, MBW and HBW litters (P < 0.05). Average daily feed intake was lower (P < 0.001) in LBW than HBW litters in the nursery and GF phases. Feed utilization efficiency (feed/gain) was similar for LBW and HBW litters in the nursery, but was lower (P < 0.001) in HBW than LBW litters in the GF phase. By design, slaughter weight was similar between BW classifications; however, LBW litters needed 9 more days to reach the same slaughter weight than HBW litters (P < 0.001). BW classification did not affect carcass composition traits. In conclusion, LBW litters showed benchmarks of intrauterine growth retardation, LBW had a negative impact on testicular development and germ and somatic cell populations, and was associated with decreased postnatal growth during all phases of production; however, no measurable effect on carcass composition traits was established.
本研究旨在探讨低窝均初生重表型对所有后代的产后生长性能和胴体品质以及雄性后代睾丸发育的影响。使用 25 头母猪单胎和 223 头母猪双胎的产仔数据，测量个体初生重（BW），并将每窝 9-16 头总产仔分为低（LBW）、中（MBW）和高（HBW）初生重窝：低和高 BW 分别定义为低于或高于每个窝大小的群体平均值 1 个标准差。窝均 BW 在母猪内具有可重复性。在去势时，从 LBW 和 HBW 窝中接近窝均 BW 的 40 头雄性仔猪采集睾丸组织，用于组织形态计量分析。LBW 仔猪睾丸中的生殖细胞、支持细胞和间质细胞数量绝对较少，且脑：睾丸重量比高于 HBW 仔猪。总体而言，LBW 窝的胎盘重量较低，脑：肝、脑：肠和脑：半腱肌重量比高于 MBW 和 HBW 窝。在保育和育肥（GF）阶段，根据 BW 分类（9 头 HBW、17 头 MBW 和 10 头 LBW 栏）将仔猪饲养在栏中，每栏 13 头公猪和 13 头母猪。哺乳期（P = 0.06）和保育和 GF 阶段（P < 0.01），LBW 窝的平均日增重均低于 HBW 窝，导致 LBW、MBW 和 HBW 窝之间的体重差异逐渐增大（P < 0.05）。保育和 GF 阶段，LBW 窝的平均日采食量均低于 HBW 窝（P < 0.001）。保育阶段，LBW 和 HBW 窝的饲料利用效率（饲料/增重）相似，但 GF 阶段，HBW 窝低于 LBW 窝（P < 0.001）。设计时，BW 分类之间的屠宰体重相似；然而，LBW 窝比 HBW 窝需要多 9 天才能达到相同的屠宰体重（P < 0.001）。BW 分类不影响胴体组成性状。综上所述，LBW 窝表现出宫内生长迟缓的特征，LBW 对睾丸发育和生殖及体细胞群产生负面影响，并与所有生产阶段的产后生长减少相关；然而，尚未确定对胴体组成性状有可测量的影响。
