The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya

A study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the...

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Main Authors: Carles, A.B., Kipngeno, W.A.K.
Format: Journal Article
Language:Inglés
Published: Cambridge University Press 1986
Subjects:
Online Access:https://hdl.handle.net/10568/66919
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author Carles, A.B.
Kipngeno, W.A.K.
author_browse Carles, A.B.
Kipngeno, W.A.K.
author_facet Carles, A.B.
Kipngeno, W.A.K.
author_sort Carles, A.B.
collection Repository of Agricultural Research Outputs (CGSpace)
description A study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the length of the oestrous cycle (P < 0.01). The mean lengths of the oestrous cycle were 17.2 (s.d. 3.21), 17.5 (s.d. 2.24), 17.9 (s.d. 2.99), 17.5 (s.d. 2.57) and 16.5 (s.d. 3.41) days for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. The mean percentage of ewes of the different breeds showing oestrus in 20-day periods were 69.8 (s.d. 22.57), 49.9 (s.d. 18.67), 63.4 (s.d. 25.70), 79.2 (s.d. 20.30) and 33.2 (s.d. 23.50) % for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. Time-series analysis did not detect any evidence of seasonal variation in oestrous activity, although there was an indication that the Merino and Romney Marsh breeds showed a marked increase in oestrous activity following the introduction of rams. It was concluded that the variation in level of oestrous activity was short term and random.
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spelling CGSpace669192024-11-15T08:52:22Z The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya Carles, A.B. Kipngeno, W.A.K. sheep oestrous cycle seasons sexual behaviour A study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the length of the oestrous cycle (P < 0.01). The mean lengths of the oestrous cycle were 17.2 (s.d. 3.21), 17.5 (s.d. 2.24), 17.9 (s.d. 2.99), 17.5 (s.d. 2.57) and 16.5 (s.d. 3.41) days for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. The mean percentage of ewes of the different breeds showing oestrus in 20-day periods were 69.8 (s.d. 22.57), 49.9 (s.d. 18.67), 63.4 (s.d. 25.70), 79.2 (s.d. 20.30) and 33.2 (s.d. 23.50) % for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. Time-series analysis did not detect any evidence of seasonal variation in oestrous activity, although there was an indication that the Merino and Romney Marsh breeds showed a marked increase in oestrous activity following the introduction of rams. It was concluded that the variation in level of oestrous activity was short term and random. 1986-12 2015-06-05T12:18:24Z 2015-06-05T12:18:24Z Journal Article https://hdl.handle.net/10568/66919 en Limited Access Cambridge University Press Carles, A.B. and Kipngeno, W.A.K. 1986. The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya. Animal Production Science 43(3): 447-457.
spellingShingle sheep
oestrous cycle
seasons
sexual behaviour
Carles, A.B.
Kipngeno, W.A.K.
The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title_full The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title_fullStr The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title_full_unstemmed The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title_short The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya
title_sort effect of season and the introduction of rams on oestrous activity in somali nandi merino karakul and new zealand romney marsh ewes in kenya
topic sheep
oestrous cycle
seasons
sexual behaviour
url https://hdl.handle.net/10568/66919
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