Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-22T15:41:00.790Z Has data issue: false hasContentIssue false

The incidence of swayback among lambs with particular reference to genetic factors

Published online by Cambridge University Press:  27 March 2009

Gerald Wiener
Affiliation:
Animal Breeding Research Organization, West Mains Road, Edinburgh, 9
M. R. Sampford
Affiliation:
A.R.C. Unit of Statistics, Buccleuch Place, Edinburgh, 8

Summary

The incidence of swayback among lambs in two flocks, previously reported, was reanalysed by a specially developed modification of the probit analysis technique in order to allow for the joint complications of an all-or-none trait and a large number of possible classifications for the animals in each flock. The form of analysis described yields predictions of the probability of swayback among lambs for the given circumstances.

Breed and sire within breed each affected the probability appreciably even when allowance for live weight of ewe and lamb was made. The effects of live weight, though significant in each flock, were not consistent in direction between the flocks. Other significant factors affecting swayback incidence were the manner of rearing the lambs, week of birth, and, in one flock, the sex of the lamb.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1969

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

Barlow, R. M., Purves, D., Butler, E. J. & MacIntyre, I. Jean (1960). Swayback in South-East Scotland. II. Clinical, pathological and biochemical aspects. J. comp. Path. Ther. 70, 411–28.CrossRefGoogle ScholarPubMed
Finney, D. J. (1952). Probit Analysis, 2nd ed.Cambridge University Press.Google Scholar
Sampford, M. R. (1951). Studies in the principles of phytotoxicity. II. Experimental designs and techniques of statistical analysis for the assessment of toxicity. J. exp. Bot., 3, 2846.CrossRefGoogle Scholar
Wiener, G. (1960). Genetic and other factors in the occurrence of swayback in sheep. J. Comp. Path. Ther. 76, 435–47.CrossRefGoogle Scholar
Wiener, G. (1967). A comparison of the body size, fleece weight and maternal performance of five breeds of sheep kept in one environment. Anim. Prod. 9, 177–95.Google Scholar
Wiener, G. & Field, A. C. (1966). Blood copper levels in sheep in relation to genetic factors, parity and previous swayback history. Nature, Lond. 209, 835–6.CrossRefGoogle ScholarPubMed
Wiener, G. & Field, A. C. (1969). Copper concentrations in the liver and blood of sheep in relation to genetic factors and swayback history. J. Comp. Path. Ther. 79, 714.CrossRefGoogle Scholar
Wiener, G., Field, A. C. & Wood, Jean (1969). The concentration of minerals in the blood of genetically diverse groups of sheep. 1. Copper concentration at different seasons in Blackface, Cheviot, Welsh Mountain and crossbred sheep at pasture. J. agric. Sci., Camb. 72, 93101.CrossRefGoogle Scholar