|
|
||||||||
Journal of Animal Science, Vol 69, Issue 2 551-558, Copyright © 1991 by American Society of Animal Science
JOURNAL ARTICLE |
M. J. Kaplon, M. F. Rothschild, P. J. Berger and M. Healey
Dept. of Anim. Sci., Iowa State University, Ames 50011.
Performance test records collected from 1978 to 1987 from on-farm tests of young Polish Large White boars from 94 herds and reproductive records of Polish Large White sows from 81 nucleus farms were used to estimate the phenotypic, environmental, and genetic trends. There were, after editing, 114,347 boar performance records and 41,080 litter records on sows. Both data sets were analyzed by use of an animal model. Estimated annual phenotypic and environmental trends were relatively large and desirable and were, respectively, .17 +/- .05, .11 +/- .05 (number born alive); .16 +/- .04, .10 +/- .04 (21-d litter size); 1.86 +/- .63, 1.43 +/- .62 (21-d litter weight, kg); 6.80 +/- .60, 6.76 +/- .72 (average daily gain, g/d); -.065 +/- .007, -.058 +/- .023 (backfat thickness, mm); -2.76 +/- .28, -2.75 +/- .29 (days to 110 kg). In contrast, all estimated genetic trends were relatively small and not always favorable. The genetic trends estimated from animal, sire and dam genetic values were, respectively, .01 +/- .01, .02 +/- .01, .01 +/- .01 (number born alive and 21-d litter size); .04 +/- .06, .10 +/- .05, .05 +/- .04 (21-d litter weight, kg); .04 +/- .04, .50 +/- .10, -.43 +/- .05 (average daily gain, g/d), -.009 +/- .001, -.015 +/- .002, -.004 +/- .0004 (backfat thickness, mm); and -.01 +/- .01, -.17 +/- .04, .19 +/- .02 (days to 110 kg). Neither examination of selection practices nor boar utilization provided an explanation for the lack of genetic progress.
This article has been cited by other articles:
![]() |
C. R. Schwab, T. J. Baas, K. J. Stalder, and J. W. Mabry Deposition rates and accretion patterns of intramuscular fat, loin muscle area, and backfat of Duroc pigs sired by boars from two time periods J Anim Sci, June 1, 2007; 85(6): 1540 - 1546. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. R. Schwab, T. J. Baas, K. J. Stalder, and J. W. Mabry Effect of long-term selection for increased leanness on meat and eating quality traits in Duroc swine J Anim Sci, June 1, 2006; 84(6): 1577 - 1583. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Chen, T. J. Baas, J. W. Mabry, K. J. Koehler, and J. C. M. Dekkers Genetic parameters and trends for litter traits in U.S. Yorkshire, Duroc, Hampshire, and Landrace pigs J Anim Sci, January 1, 2003; 81(1): 46 - 53. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |