Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS 66506-0201, USA.
Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-0201, USA.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad169.
A total of 21 litters (11 early and 10 late maturing Duroc × DNA 241) resulting in 241 pigs were used in 170 d trial to determine the effect of sire lines selected for either early or late maturing growth rates and creep feeding on the cortisol concentration, intestinal permeability, and growth performance of nursery and finishing pigs. Treatments were arranged in a 2 × 2 factorial with main effect of Duroc sire line (early or late maturing) and creep feeding (with or without). Creep feed was provided for 14 d prior to weaning. After weaning (approximately 21 d of age; initially 6.4 kg), no interactions were observed for blood cortisol. However, blood cortisol levels were increased (P = 0.011) in late maturing pigs compared to early maturing pigs. A lower percentage (P < 0.001) of early maturing pigs lost weight 3 d post-weaning compared to late maturing pigs. Likewise, early maturing pigs had improved (P < 0.001) average daily gain (ADG) and average daily feed intake (ADFI) during the first 3 d in the nursery and also had increased ADFI (P < 0.001) from days 2 to 14 in the nursery. Creep feeding had no effect on initial nursery performance. On day 7, after a 2-h fast, a subsample of pigs was administered an oral gavage of lactulose and mannitol dissolved in distilled water. No differences by sire line, creep feeding, or their interactions were observed in lactulose:mannitol ratio. For overall nursery growth performance, an interaction was observed for ADG (P = 0.007) and ADFI (P < 0.001), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. Early maturing pigs had poorer gain-to-feed ratio (G:F) (P < 0.001) than late maturing pigs. For overall finishing performance, an interaction was observed for ADG (P = 0.037) and ADFI (P = 0.007), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. This resulted in an interaction for final body weight (P = 0.005), with late maturing pigs that did not receive creep feed having decreased market weights (P ≤ 0.003) compared to the other treatments. In summary, early maturing pigs had decreased cortisol concentration at weaning and improved ADG and ADFI until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Late maturing pigs had improved G:F from 46 d of age until market. Interestingly, creep feeding late maturing pigs resulted in increased day 170 weight compared with providing no creep feed, whereas creep feed did not impact early maturing pigs (sire line × creep feed interaction, P < 0.005).
共有 21 窝（11 窝早期成熟和 10 窝晚期成熟杜洛克×DNA241），共计 241 头猪，用于 170 天的试验，以确定选择早期或晚期成熟生长速度和早期补料的公猪系对仔猪和育肥猪的皮质醇浓度、肠道通透性和生长性能的影响。处理采用 2×2 因子设计，主效为杜洛克公猪系（早期或晚期成熟）和早期补料（有或无）。在断奶前 14 天提供早期补料。断奶后（约 21 日龄；最初体重 6.4 公斤），血液皮质醇无相互作用。然而，与早期成熟猪相比，晚期成熟猪的皮质醇水平升高（P=0.011）。与晚期成熟猪相比，断奶后 3 天体重减轻的早期成熟猪比例较低（P<0.001）。同样，早期成熟猪在保育期的前 3 天表现出更好的（P<0.001）平均日增重（ADG）和平均日采食量（ADFI），并且在保育期的第 2 天至第 14 天也增加了 ADFI（P<0.001）。早期补料对初始保育期性能没有影响。在第 7 天，禁食 2 小时后，对一小部分猪进行了口服灌胃，将乳糖醇和甘露醇溶解在蒸馏水中。未观察到公猪系、早期补料或它们的相互作用对乳果糖：甘露醇比值有影响。对于整体保育期生长性能，ADG（P=0.007）和 ADFI（P<0.001）存在交互作用，早期补料对晚期成熟猪有益，但对早期成熟猪无益。早期成熟猪的增重/饲料比（G:F）较差（P<0.001），而晚期成熟猪则较差。对于整体育肥性能，ADG（P=0.037）和 ADFI（P=0.007）存在交互作用，早期补料对晚期成熟猪有益，但对早期成熟猪无益。这导致最终体重出现交互作用（P=0.005），未接受早期补料的晚期成熟猪的市场体重下降（P≤0.003）与其他处理相比。总之，早期成熟猪在断奶时皮质醇浓度降低，ADG 和 ADFI 增加，直到大约 100 公斤，此时晚期成熟猪开始表现出更大的 ADG。晚期成熟猪从 46 日龄起的 G:F 提高。有趣的是，与不提供早期补料相比，晚期成熟猪的早期补料导致 170 天体重增加，而早期补料对早期成熟猪没有影响（公猪系×早期补料交互作用，P<0.005）。
