Abstract：
Abrupt weaning of four-week-old pigs is associated with multiple stressors. Housing pigs in intact litters is a way to reduce the stress associated with moving and mixing of unfamiliar pigs. Furthermore, higher weaning weight may improve pigs\' robustness against postweaning stressors. In the present study, it was investigated whether: (1) A heavier pig hybrid, and (2) weaning intact litters in the farrowing pen for loose-housed sows could increase postweaning feeding behaviour and growth. Two sow hybrids (DanBred LY (DB) and Topigs Norsvin TN70 (TN)) and two weaning strategies (the litter stayed intact in the farrowing pen after removing the sow (STAY), or two litters were moved and mixed in conventional weaner pens (MOVE)) were compared in a 2 × 2 factorial design. In total, 57 litters from four batches were included in the study. The TN hybrid sows gave birth to heavier piglets but smaller litter sizes and had more functional teats than DB sows. At weaning, TN pigs were heavier than DB. The number of feed trough (FT) visits on the day before weaning was low in both hybrids. On the day after weaning, the number of FT visits was higher in MOVE compared to STAY, and in TN-STAY compared to DB-STAY. The average daily gain the first two days postweaning was negative in both hybrids and weaning strategies but more pronounced in DB than TN, and STAY tended to lose more weight than MOVE. Over the entire 28-day postweaning period, there was an interaction between hybrid and weaning strategy in that TN-STAY (392 g/d) had higher growth than both TN-MOVE (251 g/d) and DB-MOVE (283 g/d), whereas growth of DB-STAY (316 g/d) was intermediate. In addition, higher weaning weight was associated with a lower number of FT visits and greater weight loss the first two days postweaning but higher growth over the 28-day postweaning period. The results show that abrupt weaning at four weeks of age causes weight loss the first days postweaning despite being housedas intact litters, most likely due to low feed consumption. However, the combination of a heavier pig hybrid and housing intact litters in the farrowing pen postweaning resulted in a higher growth performance over the 28-day postweaning period. In conclusion, pigs that are heavier at weaning reach better growth performance in the longer term, despite having the largest acute postweaning growth depression and fewest FT visits on the day before and after weaning.
摘要：
四周龄猪突然断奶与多种应激源有关。将猪放在完整的窝中是一种减少与不熟悉的猪的移动和混合相关的压力的方法。此外，较高的断奶体重可能会提高猪对断奶后压力源的稳健性。在本研究中,调查了是否：(1)较重的猪杂种，（2）在松散饲养的母猪的产仔圈中断奶完整的窝可以增加断奶后的喂养行为和生长。两种母猪杂种（DanBredLY（DB）和TopigsNorsvinTN70（TN））和两种断奶策略（去除母猪（STAY）后，产仔在分娩围栏中保持完整，或在2×2阶乘设计中比较了移动和混合在常规断奶笔（MOVE）中的两个窝。总的来说,来自四个批次的57窝被包括在研究中。TN杂交母猪产下的仔猪较重，但产仔数较小，并且比DB母猪具有更多的功能性乳头。断奶时,TN猪比DB重。两个杂种在断奶前一天的饲料槽（FT）访问次数都很低。在断奶后的第二天,与保持相比，移动中的FT访问次数更高，并且在TN-STAY中与DB-STAY相比。在杂交和断奶策略中，断奶后前两天的平均日增重为负，但在DB中比TN更明显，和STAY倾向于失去比移动更多的重量。在整个28天的断奶后期间，杂种和断奶策略之间存在相互作用，TN-STAY（392g/d）的生长高于TN-MOVE（251g/d）和DB-MOVE（283g/d），而DB-STAY(316克/天)的生长是中等的。此外,较高的断奶体重与较低的FT访视次数和断奶后前两天的体重减轻有关,但与断奶后28天的增长有关.结果表明，尽管是完整的窝窝，但在4周龄时突然断奶会导致断奶后第一天体重减轻，很可能是由于饲料消耗低。然而,较重的猪杂种和断奶后产仔圈中完整窝的结合导致断奶后28天的生长表现更高。总之,断奶时较重的猪在较长期内达到较好的生长性能，尽管断奶前后有最大的急性断奶后生长抑郁症和最少的FT访问。
