Performance of Romney and crossbred sheep on east coast hill country

Abstract

A total of 1250 Romney ewes was divided into 5 flocks each of 250 sheep. Two flocks were used to breed Perendales by crossing the Romney ewes with either Cheviot or Perendale rams. Two more flocks were used to produce Border-Leicester × Romney sheep (Border-Romneys), by crossing the Romney ewes with either Border-Leicester or Coopworth rams. The fifth flock was kept as straightbred Romneys. The five flocks were run together from 1969 to 1972 under hill country conditions typical of that of the east coast of the North Island. Lamb birth, weaning, and fleece weights were recorded, as well as reproductive performance of the ewes expressed as barrenness, multiple birth rate, lamb survival, lamb weaning percentage, and weight of lamb weaned. Breed differences were small in all traits recorded and failed to reach significance. The most important breed differences were in weaning weight of F₁ lambs where all breeds exceeded the Romney. Also, this trait was the only one in which the Cheviot and Border-Leicester exceeded the Perendale and Coopworth. These results showed that changing from the Romney to the Perendale or Border-Romney does not guarantee improved performance.