@article{nelson_robison_1976, title={COMPARISONS OF SPECIFIC 2-WAY AND 3-WAY CROSSES OF SWINE}, volume={42}, ISSN={["0021-8812"]}, DOI={10.2527/jas1976.4251150x}, abstractNote={Comparisons of specific two- and three-way crosses were made. Crossbred pigs were produced from all possible reciprocal crosses of the Duroc (D), Yorkshire (Y) and Hampshire (H) breeds of swine. Two-way cross females were retained from these litters and mated to the third breed of boar or to Poland (P) boars. These data included records on 2,905 pigs from 352 litters. Among the two-breed crosses, breed of dam effects were nonsignificant for litter size and pig survival. However, Y dams farrowed slightly larger litters (10.08) than D (9.33) or H (9.08) dams. Also their pigs had a higher survival rate (Y-86%; D-83.3%; H-83.7%). Pigs from Y dams were smaller (P<01) at birth and weaning. Breed of sire effects were nonsignificant for preweaning traits. However, the H sired pigs had a lower survival rate (80.8%) than D (88.2%) or Y (84.0%) sired pigs. Breed of sire and breed of dam were significant for 140-day weight and backfat. Hampshire sired pigs were the lightest and had the least backfat, while D sired pigs were the heaviest and intermediate in fatness. Differences in total litter weight at 140 days were nonsignificant. Average litter weight ranged from 530 (H-D) to 734 (D-Y) kg among the two-way crosses. Among the three-way crosses, breed of sire was significant for all traits except litter size born and 140-day weight. Poland sired pigs had the lowest survival rate (80 vs 88%) and hence the lowest average litter weight at 140 days. Yorkshire and P sired pigs were fattest at 140 days of age while the H and D sired pigs were the leanest.}, number={5}, journal={JOURNAL OF ANIMAL SCIENCE}, author={NELSON, RE and ROBISON, OW}, year={1976}, pages={1150–1157} }
 @article{nelson_robison_1976, title={EFFECTS OF POSTNATAL LITTER SIZE ON REPRODUCTION OF FEMALE MICE}, volume={42}, ISSN={["1525-3163"]}, DOI={10.2527/jas1976.424824x}, abstractNote={A group of 98 dams weaned 588 female mice to be mated and allowed to reproduce. These females were assigned at birth to be reared in a litter of eight or 14 mice. Such litters were intended to represent postnatal environments equivalent to small and large litters. However, average litter size was approximately 15 mice in this line and comparisons were more correctly those between small and average litter sizes. A slight bias, genetically in favor of females raised in large litters, was noted due to allotment. A sample of 123 females was slaughtered at 10 days of pregnancy and 325 were allowed to litter. Body weights at 12, 21 and 42 days were positively correlated with each other and with reproductive traits. Weights at 12, 21 and 42 days were consistently larger (P<.01) for females raised in small litters. Sexual maturity (days to vaginal opening) was negatively associated with weights to 42 days. Mice raised in litters of eight were earlier maturing (2.11 days) and reached maturity at heavier weights (1.61 g). These differences (P<.01) indicate that age at maturity could not be completely explained by weight differences. An advantage (P<.05)in corpora lutea numbers (.93) was found for females from small litters. The advantage for number of embryos at 10 days of pregnancy was only .48 and was not significant. Females from small litters had .31 and .23 more mice born and mice born alive, respectively, but these differences were not significant. Heritability estimates for litter size born, numbers born alive and litter weight were .34, .48 and .64, respectively, when calculated for females from small litters. The corresponding}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={NELSON, RE and ROBISON, OW}, year={1976}, pages={824–830} }
 @article{nelson_robison_1976, title={Effects of postnatal maternal environment on reproduction of gilts}, volume={43}, DOI={10.2527/jas1976.43171x}, number={1}, journal={Journal of Animal Science}, author={Nelson, R. E. and Robison, O. W.}, year={1976}, pages={71} }