Growth performance of lambs from purebred and crossbred Finnsheep ewes

Abstract

Evaluation of Finnsheep (Finn) and their crosses is necessary to determine their potential in commercial sheep production. Birth weight, 70-day adjusted weaning weight, age at a constant market weight, pre- and postweaning daily gain were recorded on 467 lambs. Breeds included purebred Finn, Suffolk, Targhee and Dorset, F 1 Finn crossbreds, and multiple crosses from crossbred Finn ewes mated to Suffolk, Targhee, Dorset and Lincoln sires. Purebred Suffolk lambs consistently ranked first for all traits ( P<0.05), followed by Targhee, Dorset and Finn lambs. Performance of F 1 crossbreds was similar among sire breeds. No significant differences in performance of multiple-cross lambs were found among sire breeds, or dam breeds except for birth weight. Age of dam effects were important for preweaning traits if yearling ewes were used. The weight advantage of single-born over multipleborn lambs was significant at birth, reduced by weaning and nonsignificant thereafter. Lambs reared by the ewe generally grew faster than nursery-reared lambs, with singles slightly superior to twins. In a terminal sire production system, using 1 2 or 1 4 Finn crossbred ewes would take advantage of increased reproductive capacity in the ewe with little or no reduction in lamb performance to market weight. No specific sire breed could be recommended based on these results.