A comparative trial of crossbred ewes by Finnish Landrace and other sires

Abstract

1. A comparison lasting 3 years has been made of 5 types of crossbred ewes produced by mating Border Leicester, Clun Forest, Dorset Horn, Finnish Landrace and Tasmanian Merino rams to Scottish Blackface ewes. Data from a total of 576 ewe years became available.2. In body weight at mating time when they were 7, 19 or 31 months old, the Border Leicester and Dorset Horn crossbred ewes were heaviest, followed by Cluns. Finnish and Merino crossbreds were about 15–20% lighter than the Border Leicester crossbreds.3. In fleece weight, Finnish crossbreds were lower by about 1·0—1·5 lb relative to Border Leicester crossbreds.4. In fertility, Finnish crossbreds were highest with 1·5, 2·0 and 2·3 lambs born per ewe lambing at ages 1, 2 and 3 years respectively. The corresponding averages for the combined Border Leicester, Clun and Dorset Horn crossbreds were 1·1, 1·6 and 1·6 and for Merino crossbreds 1·0, 1·1 and 1·2. Numbers weaned were similarly ranked.5. Lambs out of crossbred ewes showed a sequence of group differences in weight at birth and at weaning corresponding to those shown by their mothers at mating time. The heaviest lambs were produced by Dorset Horn and Border Leicester crossbreds, and the lightest by Merino crossbreds. As a percentage of ewe weight at mating, lamb weight at weaning was highest for the Finnish group.6. In terms of litter weight at weaning, fitted values for the Merino group were the lowest while those for the Finnish group were the highest. The other three groups gave similar and intermediate values.

A Relationship Between the Duration of Oestrus, Ovulation Rate and Litter Size of Sheep

“…(Donald, Read & Russell, 1968) compared to 1-9 for the Blackface (Wiener, 1967). The indication that the correlation between the duration of oestrus and subse¬ quent litter size is mediated through ovulation rate rather than differential embryonic mortality, however, suggests that the longer oestrous period of the ewe which subsequently produces a large litter is due to an increase in the output of ovarian steroids and not to the greater sensitivity of those ewes to steroids.…”

Lifetime (Seven Years) Production of 1/4 and 1/2 Finnish Landrace Ewes from Rambouillet, Targhee and Columbia Dams Under Range Conditions

“…Results from the initial studies of crossing the Finnish Landrace (Finn) with local breeds of sheep in Great Britain (Donald et al, 1968) stimulated considerable interest in the Finn as a potential means of rapidly increasing the reproductive performance of domestic breeds of sheep in the United States. However, there were serious reservations about the acceptability of fleece and carcass characteristics of the purebred Finn; and there was little information about the adaptability of the Finn to environmental and management conditions in the United States.…”

Productivity of Purebred and Crossbred Finnsheep. II. Lamb Weights and Production Indices of Ewes

“…Total annual output of the ewe flock is based on a combination of lamb and wool production. Total weaned litter weight is a function of litter size and individual lamb weight at weaning (Maijala, 1966;Donald et al, 1968). The effect of individual lamb birth weights on total weight of lamb weaned has been regarded as less important than the effect of lamb number.…”