Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-18T06:49:26.678Z Has data issue: false hasContentIssue false
  • English
  • Français

The influence of contemporaneity, genetic variation and herd differences on variation in milk yield and butterfat percentage

Published online by Cambridge University Press:  01 February 1961

J. H. Watson
J. H. Watson
Affiliation:
A.R.C. Animal Breeding Research Organisation, Edinburgh, 9
Get access

Extract

1. Paired lactation records of milk yield and fat percentage from experimental twins and commercial twins, full-sisters and half-sisters are used in a study of the influence of contemporaneity, genetic variation and herd differences.

2. The design of the investigation was such that members of a pair were alike in:

(i) both time of calving and lactation number,

(ii) time of calving only,

(iii) lactation number only, or

(iv) neither time of calving nor lactation number.

3. Intra-class correlations between pair members in respect both of yield and fat percentage were highest for contemporary records. Differences in time of calving and in lactation number produced, in aggregate, a decline in correlation of about 20%. However, the separate estimates varied considerably between the different types of pair.

4. The within-pair and between-pair variance components independently confirm these effects of contemporaneity. As the degree of contemporaneity of pair members declines the within-pair variance increases in size and the between-pair component decreases.

Type
Research Article
Information
Animal Production , Volume 3 , Issue 1 , February 1961 , pp. 65 - 72
Copyright
Copyright © British Society of Animal Science 1961

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

Donald, H. P., 1953. A study of variation in twin cattle. I. General description. J. Dairy Res., 20: 355.CrossRefGoogle Scholar
Donald, H. P., 1958. Evidence from twins on variation in growth and production of cattle. Proc. Xth. int. Congr. Genet. (Montreal), 1958, 1: 225.Google Scholar
Johansson, I., 1958. The genetics of milk yield. Proc. Xth int. Cong. Genet. (Montreal), 1958, 1: 236.Google Scholar
Johansson, I., & Hansson, A., 1940. Causes of variation in milk and butterfat yield of dairy cows. K. Lantbr. Akad. Tidskr., 6½, 127 pp.Google Scholar
Kempthorne, O., 1955. The theoretical values of correlations between relatives in random mating populations. Genetics, 40: 153.CrossRefGoogle ScholarPubMed
KingJ., W. B. J., W. B., & Donald, H. P., 1955. A study of variation in twin cattle. III. Growth. J. Dairy Res., 22: 1.CrossRefGoogle Scholar
Le Roy, H. L., 1957. Methodisches zur Bestimmung der Erblichkeit von Merkmalen bei Zwillingsuntersuchungen. Z.menschl. Vererb.- u. KonstLehre, 34: 145.Google Scholar
Patchell, M. R., 1956. A uniformity trial with monozygous twin cows. N.Z. J. Sci. Tech., Agric, 38: 1.Google Scholar
Robertson, A., & Khishin, S. S., 1957. The effect of selection for heifer milk yield on the production level of mature cows. J. agric. Sci., 50: 12.CrossRefGoogle Scholar
Robertson, A., & Rendel, J. M., 1954. The performance of heifers got by artificial insemination. J. agric. Sci., 44: 184.CrossRefGoogle Scholar
Watson, J. H., 1960. Milk yield and butterfat percentage of twin and single-born cattle under experimental and field conditions. Anim. Prod., 2: 67.CrossRefGoogle Scholar