Efficiency of wool production of grazing sheep. 2. Differences between breeds and strains varying in age.

Abstract

The intake and wool production of grazing Border Leicester, fine-wool Merino, and South Australian Merino ewes were estimated for a period of 58 days in experiment 1. The South Australian Merino was the most productive and most efficient (wool grown per unit intake) of the three groups. The Border Leicester had the greatest intake but was the least efficient. In experiment 2 the intakes and wool productions of grazing Border Leicester, Dorset Horn, Southdown, and fine-wool Merino ewes aged 8, 20, and 32 months were estimated over a 102-day period. Intake increased with age whereas intake per unit weight declined. The fine-wool Merino was the most efficient followed in order by the Border Leicester, the Dorset Horn, and the Southdown. From these experiments and others reported in the literature, it was shown that the intakes of adult Dorset Horns, Border Leicesters, and South Australian Merinos were about 30, 50, and 10 per cent greater, and that of Southdowns about 10 per cent less than the corresponding intakes of the fine-wool Merinos. The efficiency of the South Australian Merino was approximately 50 per cent greater, and those of the Border Leicester, Dorset Horn, and Southdown were approximately 25, 45, and 63 per cent less than the efficiency of the fine-wool Merino.