Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-19T18:33:24.620Z Has data issue: false hasContentIssue false
  • English
  • Français

The effect of different levels of management on the assessment of differences between varieties of chickens. 1. Eight-week body weight

Published online by Cambridge University Press:  01 October 1962

J. C. Bowman  and
J. C. Powell
J. C. Bowman
Affiliation:
Research Division, Thornber Bros. Ltd., Mytholmroyd, Halifax
J. C. Powell
Affiliation:
Research Division, Thornber Bros. Ltd., Mytholmroyd, Halifax
Get access

Extract

1. Analyses of records of eight-week body weight in broiler chickens have been carried out to estimate the effect of management level (measured by mean body weight of all varieties on each farm) on the components of variance due to differences between and within varieties, and to find out if there is any evidence of genotype-environment interaction.

2. It was found that as management improved, the between-variety genetic variance remained constant or possibly increased whilst the withinvariety (genetic and environmental) variance decreased markedly. The cause of these regressions is not known.

3. In four cases out of six there were significant genotype-environment interactions. In two cases, the genetic correlation between the performance of varieties on different locations was significantly different from 1·0.

4. It is suggested that on the basis of these findings it would be necessary to select between varieties on records taken from chickens maintained under conditions similar to those in which they will eventually be used. However, fewer chickens would be required to measure, with a predetermined level of accuracy, mean differences on well managed farms than on poorly managed ones.

Type
Research Article
Information
Animal Production , Volume 4 , Issue 3 , October 1962 , pp. 319 - 327
Copyright
Copyright © British Society of Animal Science 1962

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Abplanalp, H., & Menzi, M., 1961. Genotype and environment interactions in poultry. Brit. Poult. Sci., 2: 71.Google Scholar
Becker, W. A., & Berg, L. R., 1959a. Homeostasis and the sensitivity of experiments using chickens. Poult. Sci., 38: 362.CrossRefGoogle Scholar
Becker, W. A., & Berg, L. R., 1959b. Effect of growth rate, homozygosity and heterozygosity of chickens on the sensitivity of experiments. Poult. Sci., 38: 1409.CrossRefGoogle Scholar
Dickerson, G. E., 1962. Implications of genetic-environmental interaction in animal breeding. Anim. Prod., 4: 47.Google Scholar
Falconer, D. S., 1952. The problem of environment and selection. Amer. Nat., 86: 293.CrossRefGoogle Scholar
Falconer, D. S., 1960. Selection of mice for growth on high and low planes of nutrition. Genet. Res., 1: 91.CrossRefGoogle Scholar
Falconer, D. S., & Latyszewski, M., 1952. The environment in relation to selection for size in mice. J. Genet., 51: 67.CrossRefGoogle Scholar
Hammond, J., 1947. Animal breeding in relation to nutrition and environmental conditions. Biol. Rev., 22: 195.CrossRefGoogle ScholarPubMed
Johansson, I., 1953. The manifestation and heritability of quantitative characters in dairy cattle under different environmental conditions. Ada genet., 4: 221.Google ScholarPubMed
Legates, J. E., 1957. Heritability of fat yields in herds with different production levels. J. Dairy Sci., 40: 631.Google Scholar
Mcbride, G., 1958. The environment and animal breeding problems. Anim. Breed. Abstr., 26: 349.Google Scholar
Mason, I. L., & Robertson, A., 1956. The progeny testing of dairy bulls at different levels of production. J. agric. Sci., 47: 367.CrossRefGoogle Scholar
Merritt, E. S., & Gowe, R. S., 1956. Environment and poultry breeding problems. III. The performance of 8 crossbred and 2 purebred broiler strains at three locations. Canad. J. agric. Sci., 36: 72.Google Scholar
Nordskog, A. W., & Kempthorne, O., 1960. Importance of genotype-environment interactions in random sample poultry tests. In Biometrical Genetics, p. 159. Pergamon Press, New York.Google Scholar
Robertson, A., 1959. The sampling variance of the genetic correlation coefficient. Biometrics, 15: 469.CrossRefGoogle Scholar
Robertson, A., O'Connor, L. K., & Edwards, J., 1960. Progeny testing dairy bulls at different management levels. Anim. Prod., 2: 141.Google Scholar