Observations on the breeding season of Romney ewes in Northland

Authors: Black H
Publication: New Zealand Veterinary Journal, Volume 22, Issue 11, pp 225-226, Nov 1974
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Breed/breeding, Environment, Reproduction, Reproduction - female, Seasonality/photoperiod
Article class: Correspondence

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Abstract: Although several workers (Groot, 1949; Wallace, 1958; Coop, 1962; Averill, 1964; Quinlivan and Martin, 1971) have studied the breeding season of Romney sheep in New Zealand, little published information pertaining to the Northland situation is available. This communication reports an investigation aimed at defining the time of onset of ovarian activity and the period of peak breeding potential for Romney ewes in Northland. The investigation was prompted by the observation that lambing percentages in this part of the country are low when compared with the national average (80 to 90% as against 92 to 96%) (Sheen Surveys, Ministry of Agriculture and Fisheries). It is common practice for commercial flocks in Northland to be joined as early as the first week in March, and Quinlivan (1971) has reported that 80% of this region`s stud Romney flocks commenced joining before March 20. The effect of such early mating on Northland`s low lambing figures appeared to warrant study…

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