مطالعه اثر دوزهای متفاوت هورمون eCG طی فصل تولید مثل بر عملکرد صفات تولید مثلی بز مهابادی

The objective of this study was to evaluate the effectiveness of ecg injections on reproductive performance in mahabadi goats during the breeding season. in this study ninety-six adult goats with ages of 2 to 5 years old and average live weight of 53.5±5.8 kg were randomly divided into three equal treatments. in all three treatments the goats were treated with cidr for 18 days and after cidrs withdrawal 300 & 450 iu pmsg were injected intramuscularly to goats of treatment 2 and 3, respectively and the first group was used as control. in animal estrus signs were displayed during the first four days after cidr removal .estrous response in all groups were 100 percent. during the experiment, goats were freely fed in pasture. the results of least square mean indicated that the average litter size in treatment iii was significantly higher than control (1.65 vs 1.29), but compared with treatment ii was not found significant difference. birth rates in all three treatments, was respectively, 87.5, 84.37 and 84.37 percent, and not differ significantly. fecundity for treatments i, ii and iii was 21.78%, 43.75% and 75%, respectively. there was no significant effect between treatment i and ii but treatment iii was significantly affected by both treatments i and ii (p < 0.05). kidding rate in all three treatments was 109.37%, 134.37% & 165.6%, respectively. there was significantly differences between i and ii treatments with iii treatment (p < 0.05). the results of the study indicated that use of cidr and higher doses of ecg in comparison with lower doses will increase fecundity and kidding rate.