Vande Pol Katherine D, Bautista Raphael O, Olivo Alicia, Harper Heath, Shull Caleb M, Brown Catherine B, Ellis Michael
Department of Animal Science, University of Illinois, Urbana-Champaign, IL 61801, USA.
The Maschhoffs LLC, Carlyle, IL 62231, USA.
Transl Anim Sci. 2021 Oct 2;5(4):txab193. doi: 10.1093/tas/txab193. eCollection 2021 Oct.
Litter sizes of commercial sows have increased considerably over recent decades, and often exceed the number of functional teats on the sow. The objective of this study was to evaluate the effect of litter size after cross-fostering relative to sow functional teat number on piglet preweaning growth and mortality. A total of 39 litters (561 piglets) were used in a randomized complete block design; blocking factors were farrowing day and sow parity, body condition score, and functional teat number. Three Litter Size treatments were compared (relative to sow functional teat number): Decreased (two piglets less); Control (same number of piglets); Increased (two piglets more). Piglets were randomly allotted to treatment at 24 h after birth to form litters of the appropriate size, with similar mean and CV of birth weight within block. Weaning weights (WW) were collected at 19.5 ± 0.50 d of age; preweaning mortality (PWM) was recorded. Litter sizes were between 11 and 17 piglets, depending on block and treatment. The Decreased treatment had lower ( ≤ 0.05) PWM than the Increased (7.7% and 17.9%, respectively); the Control was intermediate (11.5%) and not different ( > 0.05) from the other treatments. The rate of decline in litter size from birth to weaning was greater ( ≤ 0.05) for the Increased than the Decreased treatment (-0.16 vs. -0.05 piglets per day), with the Control (-0.09 piglets per day) being intermediate and different ( ≤ 0.05) to the other two treatments. Litter sizes at weaning were greater ( ≤ 0.05) for the Increased than the Decreased treatment (13.3 and 11.3, respectively); the Control treatment was intermediate (12.6) and not different ( > 0.05) to the other treatments. The log odds of PWM increased with the decreasing birth weight, at a similar rate ( > 0.05) for all Litter Size treatments. However, the intercept was greater ( ≤ 0.05) for the Increased compared with the Decreased treatment; the Control was intermediate and different ( > 0.05) to the other two treatments. Mean WW tended ( = 0.07) to be greater for the Decreased (6.17 kg) compared to the Control and Increased treatments (5.86 and 5.84 kg, respectively). In conclusion, increasing litter size after cross-fostering relative to the number of functional teats of the sow increased piglet PWM, and tended to decrease WW.
近几十年来，商业母猪的窝产仔数大幅增加，且常常超过母猪功能性乳头的数量。本研究的目的是评估交叉寄养后的窝产仔数相对于母猪功能性乳头数量对仔猪断奶前生长和死亡率的影响。在随机完全区组设计中总共使用了39窝（561头仔猪）；区组因素为产仔日、母猪胎次、体况评分和功能性乳头数量。比较了三种窝产仔数处理（相对于母猪功能性乳头数量）：减少组（少两头仔猪）；对照组（仔猪数量相同）；增加组（多两头仔猪）。仔猪在出生后24小时被随机分配到各处理组，以形成合适大小的窝仔，同区组内出生体重的均值和变异系数相似。在19.5±0.50日龄时收集断奶体重（WW）；记录断奶前死亡率（PWM）。窝产仔数在11至17头仔猪之间，具体取决于区组和处理。减少组的PWM低于增加组（分别为7.7%和17.9%，P≤0.05）；对照组居中（11.5%），与其他处理组无差异（P＞0.05）。从出生到断奶，增加组窝产仔数的下降速率高于减少组（分别为每天-0.16头和-0.05头仔猪，P≤0.05），对照组（每天-0.09头仔猪）居中，且与其他两组有差异（P≤0.05）。断奶时增加组的窝产仔数大于减少组（分别为13.3头和11.3头，P≤0.05）；对照组居中（12.6头），与其他处理组无差异（P＞0.05）。PWM的对数几率随出生体重的降低而增加，所有窝产仔数处理组的增加速率相似（P＞0.05）。然而，增加组的截距大于减少组（P≤0.05）；对照组居中，且与其他两组有差异（P＞0.05）。减少组的平均WW（6.17千克）高于对照组和增加组（分别为5.86千克和5.84千克，P=0.07）。总之，交叉寄养后相对于母猪功能性乳头数量增加窝产仔数会增加仔猪PWM，并可能降低WW。
