Abstract
1. On the basis of 5000 records from twelve leading herds of Ayrshire cattle in south-west Scotland for the period 1930–9, a statistical study has been made of some of the causes of variations which occur in butterfat percentage.2. Butterfat percentage was found to be affected only very slightly by month of calving, age and length of calving intervals.3. Selection for milk yield would not affect butterfat percentage adversely to any appreciable extent.4. The average repeatability of butterfat percentage was 0·691 in the present material, and heritability was of the order of 0·50–0·60.5. Mass selection would be an effective tool in bringing about improvement in butterfat percentage.
Publisher
Cambridge University Press (CUP)
Subject
Genetics,Agronomy and Crop Science,Animal Science and Zoology
Cited by
4 articles.
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