A total of 7,472 progeny from 4 lines of chickens, a Black Australorp, a New Hampshire and 2 Leghorn lines, their crosses and reciprocal
crosses were assessed for their pre- and post-hatching body weights, pre-
and post-hatching growth rates and their associated egg weights. The
interrelationships of these traits as they influenced growth and 7-week
body weight were evaluated. The effects of these relationships were
jointly considered as they influenced the genetic variation and subsequent
estimates of the heritability (h²) of these traits.
The results of the investigation showed that an adverse environmental
effect due to hatching was definitely established. It took 2 weeks of growth after hatching for the chicken body weights to attain the same level of association with 7-week body weight that was previously shown in the body weights of 18-day old embryos. Multiple regression
analyses showed that 1-week body weight and any subsequent growth periods
successfully accounted for variation in 7-week body weight. The h² estimates obtained for all weekly growth rates as well as the 1-3, 3-7, and 1-7 week growth rates strongly indicated a major source of additive genetic variance was available in poultry populations that heretofore has not been directly utilized in body weight selection programs. / Land and Food Systems, Faculty of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/33246 |
| Date | January 1972 |
| Creators | Phalaraksh, Kanok |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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