M. J. Barhorst,
K. M. Irvin 1,
S. J. Moeller
S. M. Neal
The Ohio State University Department of Animal Sciences
The primary objective of this experiment was to estimate both maternal and individual heterosis expressed by comparing the Yorkshire and Large White breeds and their crosses. A second objective of the experiment was, based on the estimates of heterosis, to conclude if the two breeds are the same or different. The study was conducted at the Western Branch of the Ohio Agricultural Research and Development Center, in South Charleston, Ohio. Maternal heterosis was estimated by the performance of females of Yorkshire, Large White, and their crosses mated to Hampshire sires. Preweaning traits used in this analysis included birth weight, number of pigs born, number of pigs born alive, number of stillborn and mummified pigs, 21-day weight, weaning weight, and number of pigs weaned. Maternal heterosis was found (P<0.05) for weaning weight (3.07%), average adjusted 21-day weight (3.08%), and average birth weight (3.26%). Individual heterosis was estimated by the performance of individual pigs and average pig performance in pens. Postweaning traits used in this analysis included gain and feed efficiency. Individual heterosis estimates demonstrated crossbred pigs to have gained faster during the testing period than purebred pigs. Crossbred pigs had significant (P<0.05) levels of heterosis for gain during the second half of the testing period (4.47%) and for gain during the entire testing period (3.87%).
1For more information, contact at: The Ohio State University, 110F Animal Science Building, 2029 Fyffe Road, Columbus, OH 43210; 614-292-6407; fax: 614-292-2929 ; e-mail: irvin.3@osu.edu