| Autor: |
Bullock, K. D., Kuhlers, D. L., Jungst, S. B. |
| Zdroj: |
Journal of Animal Science; April 1991, Vol. 69 Issue: 4 p1409-1419, 11p |
| Abstrakt: |
Duroc boars from a line previously selected over five generations for 200-d weight and those from a randomly selected control line were mated to Landrace sows either from a line previously selected for increased 70-d weight or from a randomly selected pedigree control line. From these matings, 900 pigs were farrowed to examine the effects of crossing lines of pigs mass selected for weight at two ages on growth rate, survival, and carcass composition. A greater (P <.01) percentage of pigs farrowed survived birth from control-line sows (.974) than from select-line sows (.914). Of those pigs born alive, a greater (P< .05) percentage of pigs out of control-line sows survived to 21 d (.893) than out of select-line sows (.829). Pigs sired by select-line boars weighed 2.1 kg heavier (P <.05) at 70 d than pigs sired by control-line boars. Pigs out of select-line sows weighed .11 kg less (P <.10) at birth and .3 kg less (P< .10) at 21 d of age but grew .026 kg/d faster (P< .10) from 70 d to slaughter, weighed 3.9 kg more at 165 d of age (P< .05), and reached 100 kg 7.0 d sooner (P< .05) than pigs out of control-line sows. Carcasses from barrows sired by select-line boars had .29 cm more (P< .10) fat at the 10th-rib than carcasses from barrows sired by control-line boars. Marbling scores were .31 unit greater (P < .05) and muscle color scores were .25 unit greater (P < .10) for carcasses from pigs out of select-line sows than for carcasses from pigs out of control-line sows. Selection for increased 70-d weight decreased age at 100 kg without increasing fat deposition. However, survival rates up to 100 kg were reduced. Mass selection for 200-d weight effectively increased 70-d weight, but fat thickness at 100 kg also increased. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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