Resumo

SNYMAN, M.A.  e  HERSELMAN, M.J.. Comparison of productive and reproductive efficiency of Afrino, Dorper and Merino sheep in the False Upper Karoo. S. Afr. j. anim. sci. [online]. 2005, vol.35, n.2, pp.98-108. ISSN 2221-4062.

The productive and reproductive performance of, as well as income generated by Afrino, Dorper and Merino sheep at two localities in the False Upper Karoo region were evaluated. A total of1242 ewe reproductive records was available, while data of respectively 772 and 405 lambs were analysed for the growth traits and slaughter traits. Percentage of lambs weaned per ewe in the flock was 132.0%, 100.0% and 93.7% for Afrino, Dorper and Merino ewes at Grootvlei, respectively. Corresponding values for Twistkraal were 153.3%, 114.7% and 96.4%, respectively. Body weights of 52.3 ± 1.4 kg, 56.6 ± 1.4 kg and 43.4 ± 1.4 kg were recorded for Afrino, Dorper and Merino ewes, respectively. Merino ewes produced on average 1.3 kg more clean wool, of a 0.6 (im stronger diameter than Afrino ewes. At each locality Dorper lambs were the heaviest at weaning, followed by Afrino and then by the Merino lambs. Dorper lambs were slaughtered earlier than Afrino lambs, with Merino lambs taking the longest interval to reach slaughter weight. A definite seasonal effect was also evident, where the autumn-born lambs reached slaughter weight earlier than spring-born lambs in all breeds. With the current wool and mutton prices, Afrino sheep had the highest gross income per ewe, followed by Merino and Dorper ewes respectively. However, Merino sheep had the highest gross income per hectare at both localities, followed by Afrino and then Dorper sheep. The combination of low ewe body weights, high wool production and a relatively high reproductive rate, resulted in Merino sheep generating the highest income per hectare, compared to Afrino and Dorper sheep. Reproductive rate, mature body weight and fibre production are the primary factors determining profitability of a specific sheep enterprise. These parameters should thus be considered when changing from one breed or commodity to another.

Palavras-chave : Body weight; wool production; slaughter traits; income.

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