A study on some aspects of lifetime production in Targhee and Columbia sheep

Abstract

The relative lifetime lamb and wool production data for Targhee and Columbia sheep maintained by the Agricultural Experiment Station at Montana State University was analyzed for ewes born from 1950 to 1962. The productive traits concerned were analyzed by least square analysis of variance with interaction, phenotypic correlation and heritability was estimated. The total number of animals studied was 732 Targhees and 411 Columbias. In Targhees, it was observed that type of birth of the ewes sire affects the number of lambs born, whereas in Columbias the type of birth of ewe affects the trait. The interaction of type of birth was observed to be significant for number of lambs weaned in Targhees. The fleece production showed a significant effect of type of birth of ewe and her sire in Targhees but not in Columbias. Multiple births showed a positive significant correlation in Targhees with type of birth of the ewes sire whereas in Columbias type of birth of ewe was significant. Lamb and wool production showed variable significant correlations with yearling and weaning weights in both the breeds but were of low magnitude. The heritability for weaning and yearling weight were observed to be quite high in both the breeds in comparison tp other traits studied. The heritability of multiple births in Targhees was observed to be quite high compared to other breeds of sheep.