Effects of teasing and nutrition on the duration of the breeding season in Romney ewes

T.W. Knight, D.R.H. Hall, L.D. Wilson

Whatawhata Hill Country Research Centre, Ministry of Agriculture and Fisheries, Hamilton

Proceedings of the New Zealand Society of Animal Production. 1983, 43: 17 20

Seventy-nine Romney ewes were allocated to high (H) or low (L) pasture allowances from 27 January. Half of each group (R) was joined with teaser rams on 9 February while the other half (I) remained isolated from rams until 10 March.

R ewes exhibited oestrus 13 days earlier than the I ewes but there was no effect of nutrition. L ewes had fewer oestruses than H ewes (7 v9) and more abnormal oestrous intervals (16% v 7%). There was a negative relationship between number of oestruses and GGT levels and a positive relationship with live weight. There was no effect of teasing on the number of oestruses, thus R ewes returned to anoestrus 16 days earlier than I ewes. Similarly L ewes returned to anoestrus 20 days earlier than H ewes.

Keywords: NZSAPAB; Sheep; breeding season; ram teasing; nutrition; facial eczema; Romney ewes

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Last Updated 03-05-1997