Effect of Ovarian Structures upon the Clinical Signs of Estrus and Conception Rates in Bulgarian Murrah Buffaloes after Synchronization of Estrus and Ovulation

摘要

The purpose of the present study was to investigate the clinical signs of estrus and conception rates after synchronization of ovulation in Bulgarian Murrah buffaloes depending on ovarian structures. Sixty buffaloes age between 4-8 years, weighing 550-650 kg with body condition score 3.5 were included in the study. Depending on ovarian structures, two experimental groups were formed. All animals had their estrus synchronized according to the GnRH-PGF_{2 alpha} -GnRH protocol. The ease of cervical passage, uterine tone and presence of cervical mucus were determined. The conception rates and the signs of spontaneous oestrus in non-fertilized animals were also registered. An increased uterine tone, good ease of cervical passage and cervical mucus were observed in 100, 77.4 and 35.5% of buffaloes from group I, respectively and in 100, 62.1 and 41.4% of animals from group II. Spontaneous estrus in non-fertilized animals until the 20th day after the artificial insemination was detected in 52.2 and 25% of animals from group I and II, respectively (p<0.05). The ultrasound identification of ovarian structures in buffaloes could be recommended in decision making when selecting candidates for synchronization schedules. The presence of cervical mucus at the time of artificial insemination indicated a better conception rate. The application of schedules for estrus and ovulation synchronization with fixed-time insemination could be successfully used in Bulgarian Murrah buffaloes.