The genetic correlations between birth, weaning, and two-teeth weight of Dorper ewes at Neudamm AGricultural College for the 1988 and 1999 seasons

Abstract

Abstract by author:

Many opinions have been raised on which traits selection can be based on. This study shows clearly that body weight above all the others is the more economical because it is mostly positively correlated to other traits, e. g. milk production and it determines the income of the enterprise as price is set per kilogram, meaning the animals with high weight will yield the most income. The age at which selection should be done is a weaning and the following are the reasons of selecting at weaning rather than at birthand two-teeth age: (a) The correlation between birth and two-teeth weight is low, this means that it is not the lamb with the highest birth weight that will have the highest two-teeth weight. At two-teeth age the animals will have proved their adaptation as well as performance. The weight of the ewe is positively correlated to milk production, which means it will produce lambs with high birth weight, although care must be taken not to breed too heavy animals, as they tend to be not adapted. (b) Selecting at two -teeth age is difficult in slaughter lamb production as the animals are marketed immediately after weaning, although it can be aided by raising more than the replacement ewes so that a further selection can be done at two-teeth age

Since the animals disperse at weaning, it is reasonable to select the best animals at that age. The better the animal performs on its own, the better it will transfer its genetic performances to the offspring