Mills Kayla M, Schinckel Allan P, Stevens Jebadiah G, Casey Theresa M, Stewart Kara R
Department of Animal Sciences, Purdue University, West Lafayette, IN.
Ag Production Enterprises, Greensburg, IN.
Transl Anim Sci. 2020 Nov 20;4(4):txaa210. doi: 10.1093/tas/txaa210. eCollection 2020 Oct.
Selection of replacements for the sow herd is one of the most important facets in swine production. Although our current methods of selection are effective, there is still a large amount of variation in sow reproductive performance traits such as pigs per sow per year (PSY). Therefore, the objective of this study was to determine if on-farm phenotypic traits at 21 d postnatal (PN) or perinatal environmental factors could predict sow reproductive performance. Data were prospectively collected from 2,146 gilts born on a commercial sow production facility and included birth and weaning weights, vulva length and width at 21 d PN, birth and nursing litter size, days nursed, average daily gain from birth to weaning, and age at first estrus. Of the initial animals, 400 (17%) were selected for the sow herd, 353 remained after removal of animals culled for non-reproductive reasons. Animals were assigned to 1 of 5 reproductive performance categories based on observation of estrus or pigs per sow per year (PSY) across two farrowings: High Fertility (HF; 23%; = 82; ≥26 PSY), Middle Fertility (MF2; 12%; = 43; 20-25 PSY), Low Fertility (MF3; 15%; = 54; <20 PSY), Infertile-Estrus (IFe; 10%; = 36; estrus, no pregnancy), and Infertile-No Estrus (IFno; 39%; = 138; no estrus, no pregnancy). Generalized linear model analysis indicated vulva width ( = 0.03) was related to PSY, however, it only explained 1.5% of the total variation in PSY. To determine if preweaning variables were predictive of gilt fertility outcome, animals were grouped as those that became pregnant ( = 179) or not ( = 174). Vulva width tended to be greater in fertile animals versus infertile ( = 0.07). Binomial regression analysis revealed a positive relationship between vulva width and gilt fertility, however, this relationship is not strong enough to make sow herd selection decisions.
母猪群的替代选择是养猪生产中最重要的方面之一。尽管我们目前的选择方法是有效的，但母猪繁殖性能性状，如每年每头母猪产仔数（PSY），仍存在大量差异。因此，本研究的目的是确定出生后21天（PN）的农场表型性状或围产期环境因素是否可以预测母猪的繁殖性能。前瞻性收集了来自一个商业母猪生产设施出生的2146头后备母猪的数据，包括出生体重和断奶体重、出生后21天的阴门长度和宽度、产仔数和哺乳仔猪数、哺乳天数、出生至断奶的平均日增重以及初情期年龄。在最初的动物中，400头（17%）被选入母猪群，去除因非繁殖原因淘汰的动物后，剩下353头。根据两次产仔的发情观察或每年每头母猪产仔数（PSY），将动物分为5个繁殖性能类别之一：高繁殖力（HF；23%；n = 82；PSY≥26）、中等繁殖力（MF2；12%；n = 43；PSY 20 - 25）、低繁殖力（MF3；15%；n = 54；PSY<20）、不育 - 发情（IFe；10%；n = 36；发情但未怀孕）和不育 - 未发情（IFno；39%；n = 138；未发情且未怀孕）。广义线性模型分析表明阴门宽度（P = 0.03）与PSY相关，然而，它仅解释了PSY总变异的1.5%。为了确定断奶前变量是否可预测后备母猪的繁殖力结果，将动物分为怀孕（n = 179）或未怀孕（n = 174）两组。与不育动物相比，可育动物的阴门宽度往往更大（P = 0.07）。二项式回归分析揭示了阴门宽度与后备母猪繁殖力之间的正相关关系，然而，这种关系不够强，无法用于做出母猪群选择决策。
