PHYSIOLOGICAL APPROACHES TO INCREASE THE EFFICIENCY OF PORK PRODUCTION THROUGH IMPROVED NUTRITIONAL AND REPRODUCTIVE COMPETENCE
Location: Reproduction Research
Title: Finishing Growth and Carcass Characteristics Following Reciprocal Embryo Transfer between Meishan and White Crossbred Pigs
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 4, 2010
Publication Date: July 1, 2010
Citation: Miles, J.R., Vallet, J.L., Freking, B.A., Ford, J.J., Shackelford, S.D., Wheeler, T.L. 2010. Finishing Growth and Carcass Characteristics Following Reciprocal Embryo Transfer between Meishan and White Crossbred Pigs [abstract]. Journal of Animal Science. 88 (E-Supplement 2):355. (Abstract #T152).
Crossbreeding studies between Meishan (MS) and contemporary White crossbred (WC) pigs have shown that increased lean, finishing growth of WC pigs is affected by the direct genotype of the piglet. The objective of the current study was to determine the contributions of the piglet and maternal genotypes and their interactions on finishing growth and carcass characteristics following reciprocal embryo transfers between MS and WC gilts. Twenty-five pregnancies were produced in two farrowing seasons that represented all piglet and maternal genotype combinations; MS x MS (n=4 litters), WC x WC (n=7 litters), MS x WC (n=7 litters), and WC x MS (n=7 litters). Starting at d 105 of age, gilts (n=50) and barrows (n=40) were weighed and backfat was recorded every 3 weeks. At d 165 of age, pigs were slaughtered and hot carcass weights were recorded. Within 3 days of slaughter, leaf fat was weighed and loin eye color, marbling, and area were determined. All data were analyzed using MIXED model procedures. There were piglet breed effects (P<0.01) for body weight. As a result, average daily gain during grow-finish was greater (P<0.001) in WC pigs. In contrast, average back fat measurements were greater (P<0.001) in MS pigs. At slaughter, a piglet breed effect (P<0.001) was observed in hot carcass weight in favor of WC pigs. Conversely, there was a direct breed effect (P<0.05) of leaf fat weight in favor of MS pigs. No significant genotypic effects were observed for loin eye marbling between the breeds. However, loin eye color was darker (P<0.01) in the MS pig. Furthermore, there was a piglet breed effect (P<0.001) for loin eye area in favor of WC pigs. This study detected no significant interactions between the piglet and maternal genotypes of MS and WC pigs on finishing growth and carcass characteristics, and supports crossbreeding studies illustrating that differences in finishing growth are attributed to the genotype of the piglet.