OESTRUS BEHAVIOUR AND HORMONAL CHANGES IN NIGERIAN INDIGENOUS JENNIES DURING THE OESTROUS CYCLE AND POSTPARTUM PERIOD
OESTRUS BEHAVIOUR AND HORMONAL CHANGES IN NIGERIAN INDIGENOUS JENNIES DURING THE OESTROUS CYCLE AND POSTPARTUM PERIOD
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Date
2016-09
Authors
HASSAN, Rahilah
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Abstract
This study was carried out to evaluate oestrus behaviour patterns and hormonal changes during the oestrous cycle and postpartum period in indigenous Jennies. Fourteen (14) cycling Jennies aged 3.0 ± 1.0 years were used to study the oestrus behaviour and hormonal characteristics (Experiment I). Fifteen (15) jennies aged 4.5 ± 1.5 years and in the third trimester were used to study resumption of postpartum ovarian activities (Experiment II). The 14 jennies for oestrus behaviour patterns were randomly assigned to 4 groups as follows; Group 1 (n=2) were control for the study (not treated); Group 2 (n=4) were jennies treated with a single injection of 10mg of Lutalyse®; Group 3 (n=4) were jennies treated with double injection of 10mg of Lutalyse®, 11 days apart while Group 4 (n=4) were jennies treated with double injection of 375μg of Synchromate®, 11 days apart, while jennies for the postpartum studies were brought into the experiment as they foaled. The treated groups and postpartum jennies after foaling were observed for behavioural oestrus three times daily (8-10 am, 12-2 pm and 4-8 pm) for two oestrous cycles and parameters of oestrus assessed were; Time to onset of oestrus, duration of oestrus, oestrus response rate and intensity of synchronization. Blood was collected from the jennies for extraction of serum, for progesterone and oestradiol estimation using Enzyme-linked Immunosorbent Assays (ELISA). One-way analysis of variance was used to analyze the results. For oestrus behaviour patterns, the Time to Onset of Oestrus of 2.34 ± 0.32, 10.07 ± 4.91, 3.98 ± 0.95 and 1.78 ± 0.29 hours in groups 1, 2, 3 and 4, respectively were significantly different (P<0.05). The duration of oestrus was 48 ± 24.0, 24.0 ± 0.0, 78.0 ± 22.7 and 120 ± 16.97 hours in groups 1, 2, 3 and 4, respectively (P<0.05). Oestrus response rate
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were 50, 25, 75 and 100% in groups 1, 2, 3 and 4, respectively. Group 4, had 100% intensity of synchronization within 48 hours while groups 1, 2 and 3 had 50, 50 and 75% intensity of synchronization (P<0.01). The characteristic oestrus behaviour of jennies were; tail raising from the perineum, opening and closing of mouth (mouth clapping), flehmen and winking of the vulva. The duration of oestrus was longer, onset of oestrus was shorter and intensity of synchronization was 100% in jennies treated with double injections of 375μg PGF2α (Cloprostinol-Synchromate®). From this study it was established that the average oestrus period of Nigerian indigenous jennies was 9.75 ± 1.75 days and their average oestrous cycle length was 23.80 ± 3.07 days. Two different progesterone profiles were observed in the postpartum studies, these varied in time when foal heat was observed in the jennies. In the first profile (n=10), foal heat was observed at 28 days postpartum while in the second profile (n=5), foal heat was observed at 35 days postpartum. Thereafter normal cyclical ovarian activity resumed at 56 to 63 days postpartum. The oestrous cycle length postpartum was 28 days. It was concluded from this study that synchronization of jennies is possible using exogenous PGF2α. Double treatments with cloprostenol and dinoprost tromethamine produced similar effects on the oestrus characteristics in jennies. However, cloprostinol produced better response and was more efficient in oestrus synchronization. This study has shown that, plasma progesterone and oestradiol analyses is a valuable tool for the study of fundamental reproductive endocrinology and provide information regarding the postpartum reproductive events in Nigerian indigenous jennies. Foal heat occurred between 28 to 35 days postpartum followed by a normal cyclical ovarian activity between 56 to 63 days in Nigerian indigenous jennies. Consequently, Nigerian
jennies can be bred from day 56 to 63 days (8-9 weeks) postpartum so as to ensure optimum fertility.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE IN THERFOR TIOGENOLOGY AND PRODUCTION DEPARTMENT OF THERIOGENOLOGY AND PRODUCTION, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
OESTRUS BEHAVIOUR,, HORMONAL CHANGES,, IN NIGERIAN INDIGENOUS JENNIES,, OESTROUS CYCLE,, POSTPARTUM PERIOD.