Effect of estrus and ovulation synchronization protocols in local goats during the breeding season

Gidena, A. 2017. Effect of estrus and ovulation synchronization protocols in local goats during the breeding season. MSc thesis in Livestock Production and Pastoral Development. Mekelle Ethiopia: Mekelle University.

Sixty four (n=64) non-descripte local does weighing approximately 25 -40kgs was selected for this study. one rural kebeles of Kilte-Awlaelo district was purposively selected in the semiarid part of the district. Study animals were ear taged and kept as per their group of treatment in the Farmers Training Center of the Kebele. Data collected were analyzed using SPSS version 20. Experiment was designed to determine the effect of different synchronization protocols. The double PGF2α group of goats (n=16) received an intramuscular(IM)injection of PGF2α analogue (125μg cloprostenol as total dose 0.5ml) on day 0 and the second dose was given 14 days apart with the same amount. The Ovsynch group of goats (n = 16) received an IM injection of a GnRH analogue (10μg Receptal as a total dose 1ml) on day 0 and a treatment of PGF2α analogue 125μg cloprostenol), on day 7 followed by a second injection of the GnRH analogue on day 9. The 3rd treatment group (n=16) with GnRH – PGF2α was given the same dose as above 7 days apart. Estrus response and conception was higher in double PGF2alpha, GnRH-PGF2alpha-GnRH , GnRH-PGF2alpha and control group treatment groups (81.25%, 81.25, 75.00% and 50.00% respectively). However, there is a greater variation among the control group and other treatment groups in comparison. The maximum onset of estrus time in this study were recorded as 26.30h, 30.55h, 54.00h and 24.30h for control, doublePGF2α, GnRH – PGF2α – GnRH and GnRH – PGF2α respectively. Conception rate were determined by observing the non-return to heat and also by conducting pregnancy diagnose using an instrument called PREGTONE- Pregnancy examination test. Among the treatment groups does treated with Ovcynch (GnRH- PGF2α) show the highest conception rate (91.70%) as compared to double PGF2α treatment group (61.54%). However, conception rate and estrus response not differ significantly (p >0.05). The interval to the onset of estrus in different parity were not differ significantly (p>0.05). In addition, there was no significant difference between body score and estrus sign. The overall conception rates after synchronized estrus by different protocols were 73.91%. Parity and BCS of does not influence estrus response, onset of estrus and estrus duration but influenced certain estrus sign and conception rate. It could be concluded that the Ovsynch treatment appeared to be similar to the double PGF protocol in terms of the reproductive response. However, this needs to be tested on a larger herd size. Furthermore, it would seem that the use of combination of GnRH and PGF2α improves some reproductive traits in local goats. Research trends on ovulation synchronization in nonbreeding seasons are expected in future using different goats breeds with duplicate experiments in distinct areas of the region.