|FORD, JOHNY - Retired ARS Employee|
|Freking, Bradley - Brad|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2015
Publication Date: 5/1/2015
Publication URL: https://handle.nal.usda.gov/10113/60862
Citation: Miles, J.R., Vallet, J.L., Ford, J.J., Freking, B.A., Oliver, W.T., Rempel, L.A. 2015. Contributions of the maternal uterine environment and piglet genotype on weaning survivability potential: II. Piglet growth, lactation performance, milk composition, and piglet blood profiles during lactation following reciprocal embryo transfers between Meishan and White crossbred gilts. Journal of Animal Science. 93(4):1555-1564.
Interpretive Summary: Crossbreeding studies between Meishan and Large White pigs have illustrated improved preweaning survival is attributed to the direct genotype in favor of the Meishan piglet. In contrast, increased piglet growth prior to weaning is attributed to the maternal genotype of Large White sows. The objective of this study was to investigate the contributions of the piglet and maternal genotypes and their interactions on the piglet growth and piglet blood profiles during lactation following reciprocal embryo transfer between Meishan and White crossbred gilts. This study demonstrated that piglet growth during lactation was influenced by maternal breed in favor of White crossbred dams, which supports previous crossbreeding studies. However, blood components pertaining to survivability and growth displayed complex interactions between the piglet and maternal breed, which may signify possible mechanisms for improved preweaning survivability but slower lactational growth of Meishan piglets.
Technical Abstract: Crossbreeding studies between Meishan (MS) and Large White (LW) pigs have illustrated that increased piglet growth prior to weaning is attributed to the maternal genotype of LW dams. The objective of this study was to determine the contributions of the maternal uterine environment (MUE), piglet genotype (PigG), piglet age (PA), and their interactions on piglet growth, lactation efficiency, milk composition, and piglet blood profiles during lactation following reciprocal embryo transfers between MS and White crossbred (WC) gilts. Twenty-five successful pregnancies were generated by embryo transfer in two farrowing years representing all MUE by PigG combinations; MS x MS (n = 4 litters), MS x WC (n = 7 litters), WC x MS (n = 7 litters), WC x WC (n = 7 litters). At d 1, 10, and weaning, piglets (n = 147, 96, and 94, respectively) were weighed and blood samples were collected and measured for hematocrit, hemoglobin, glucose, nitrogen, NEFA, albumin, lactate, and cortisol. In addition, sows were manually milked from a medial mammary gland to determine milk proximate analysis. All data were analyzed by ANOVA using MIXED model procedures with the fixed effects of MUE, PigG, PA, and their interactions. Piglet weight was greater (P < 0.001) in piglets from WC dams compared to MS dams at d 10 and weaning but not at d 1. In addition, ADG were greater (P < 0.05) from piglets from WC dams compared to MS dams. However, milk composition was increased (P < 0.05) for GE and fat content from MS dams compared to WC dams, illustrating differences in milk quality between the breeds. There were significant MUE by PigG by PA interactions for hematocrit and hemoglobin levels in which greater (P < 0.001) levels were observed in MS piglets, irrespective of MUE, at d 1 of lactation and in MS piglets from MS dams at d 10 of lactation. Blood glucose was greater (P = 0.01) at d 1 in piglets for WC dams regardless of PigG but at weaning glucose was greater (P = 0.01) in WC piglets regardless of MUE. Serum NEFA levels were greater (P = 0.02) in piglets from MS dams throughout the lactation period. This study demonstrated that WC dams were superior to MS dams for piglet growth during lactation in agreement with previous crossbreeding studies. However, blood components measured displayed complex interactions between the piglet and maternal breed, which signify possible mechanisms for improved pre-weaning survivability but slower lactational growth of MS piglets.