Litter-of-origin trait effects on gilt development

Authors: Vallet, Jeff; CALDERON-DIAZ, JULIA - Iowa State University; STALDER, KENNETH - Iowa State University; PHILLIPS, CHRISTINA - Murphy Brown Llc; Cushman, Robert - Bob; Miles, Jeremy; Rempel, Lea; Rohrer, Gary; Lents, Clay; Freking, Bradley - Brad; Nonneman, Danny - Dan

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2015
Publication Date: 1/1/2016
Publication URL: http://handle.nal.usda.gov/10113/61803
Citation: Vallet, J.L., Calderón-Díaz, J.A., Stalder, K.J., Phillips, C., Cushman, R.A., Miles, J.R., Rempel, L.A., Rohrer, G.A., Lents, C.A., Freking, B.A., Nonneman, D.J. 2016. Litter-of-origin trait effects on gilt development. Journal of Animal Science. 94(1):96-105.

Interpretive Summary: During a recent National Pork Board funded study of the effect of diet on the growth and pubertal development of female pigs, immunocrits (a measure of colostrum acquisition), birth weights, preweaning growth rates, parity of the birth sow, and the number weaned in the birth litter were also measured, providing an opportunity to examine relationships between these litter of origin traits and subsequent growth, puberty, and reproductive tract development traits of the same females. Growth traits (weight, back fat, and loin eye area) were affected by all litter of origin traits measured, with weight and loin eye area being most influenced by birth weights, and back fat being most influenced by preweaning growth rates. Later age at puberty was associated with increased birth weights and reduced preweaning growth rates. Uterine length was related to birth weight, but most other reproductive traits measured were not associated with litter of origin traits. Collectively, these results indicate that characteristics of young females measured at birth and during the preweaning period provide some value in predicting subsequent growth and reproductive characteristics, which could be exploited to improve swine production.

Technical Abstract: The preweaning litter environment of gilts can affect subsequent development. In a recent experiment designed to test the effects of diet on gilt development, individual birth weights, immunocrits, sow parity, number weaned, and individual weaning weights were collected for gilts during the preweaning period. Subsequently, body weight, loin eye area and back fat were measured at 100 days of age and at 28 day intervals until slaughter (260 days). From 160 days to slaughter, gilts were observed daily for estrus. At slaughter, the reproductive tract and one mammary gland were recovered. The reproductive tract was classified as cyclic or prepubertal and the number of corpora lutea was counted. Uterine horn lengths and ovarian dimensions were measured. Samples of uterus and ovary from every tenth gilt were prepared for histological evaluation of uterine gland development and follicle counts, respectively. Mammary gland tissue was assayed for protein and fat. Day of the estrous cycle at slaughter was calculated using the most recent first day of standing estrus (day 0) recorded previous to slaughter. Each gilt development trait was analyzed for association with each litter of origin trait, after adjusting for effects of dietary treatments. Uterine length, ovarian dimensions, mammary gland protein and fat and uterine gland development were also adjusted for day of the cycle at slaughter. All litter of origin traits were associated (P < 0.05) with growth traits. Top down multiple regression analysis indicated that body weight growth and loin eye growth of gilts was positively associated with immunocrit (P < 0.01), birth weight (P < 0.01), preweaning growth rate (P < 0.01) and parity. Back fat growth was positively associated with preweaning growth (P < 0.01), number weaned (P < 0.05) and parity (P < 0.05). Age at puberty was associated with birth weight (positive, P < 0.01) and preweaning growth rate (negative, P < 0.01). Total uterine length was positively associated only with birth weights (P < 0.05). Mammary gland protein was negatively associated with preweaning growth (P < 0.01). Mammary gland fat was positively associated with birth weight and number of piglets weaned (P > 0.05). These results indicate that colostrum, birth weights, preweaning growth, number weaned and parity are associated with gilt development traits during later life.