Study On Estrous Synchronization And Fixed-time Insemination In Goat

With the development of the economy and people's living standards in Southwest of China, the goat production tends to factorization and intensive management. It is the challenging and pivotal reproductive issue how simply and efficiently to reproduce the goat meat. New reproductive technology is essential to be used to solve the problem aiming to control doe ovulation with the ovulation synchronization methods and predict the accurate ovulation time. Furthermore, promoting the technicians to conduct artificial insemination at the optimum span for the high conception rate. Goat timed artificial insemination (TAI), which including estrus synchronization, artificial insemination and other technical methods, is simple, economical and practical and be one of the assisted-reproduction technologies (ART). At present, the technology in dairy cattle, beef cattle and sheep production are widely used, but there are few reports on goat. In order to explore in different natural conditions, to compare the effect of goat estrus synchronization methods, and to find a simple and effective procedure, we focus this study on estrous synchronization and fixed-time insemination in goat.Aiming to the difficult goat production problem, fixed artificial insemination was designed on ewes to study three sections. Firstly, choosed the healthyLezhi Black does from the same feedlot environment and conduct synchronization of estrus on them, then tested the synchronization rate, pubescence starting time and pubescence lasting time to survey the treated does' ovarian wave and judge the degree of ovulation synchronization. Secondly, a total of 13 Lezhi Black goat bucks were selected and analysed for the semen qualities. Determinate the effect of synchronization of estrus on does reproduction performance through testing kidding rate, conception rate and other parameters.The group of the 8μg LHRH-A3 resulted in 100% of estrus synchronization, and had relatively small side effects. Therefore the optimum concentration of LHRH-A3 using the Ovsynch method is the 8μg per doe. During the breeding season (10～11), the rates of estrus synchronization were 86.76%.85.29% and 84.38%, respectively, but the difference during the three methods was not significant (P>0.05), the pubescence starting time of Long Vagina Plug method was significantly longer than the two other methods (P<0.01); in the non-breeding season(5～6), the estrus synchronization rates of the Ovsynch, Short-plug and Long-plug were 23.53% 35.29% and 50.00%. short-plug were significantly higher than the Ovsynch group(P<0.05). The duration of the estrus, Short-plug group was 8.25h longer than the Ovsynch(P<0.01), Short-plug group was 7.87h longer than the Long-plug(P<0.01). Using Ovsynch comparing with the virgin ewe and multiparous ewe, the estrus synchronization rate of the vigin ewe had 21.10% lower than multiparous ewe(P<0.05) and occurred estrus of the vigin ewe was 14.45h earlier than multiparous ewe(P<0.01).Detection of semen qualities of every samples of 13 bucks showed milky white or gray, cloudy, slightly fishy smell in non-breeding season and breeding season. The volume of ejaculation was 0.87±0.56mL, and 0.93±0.27mL; The sperm motility were 0.71±0.08 and 0.69±0.11; The sperm densities were (3.18±0.75)×109 and (3.32±0.52)×109; The sperm deformations were (8.88.±3.10)% and (8.32±2.67)%, below average,but the basic character united artificial insemination requirements. Choose 10 ewes for ultrasonic testing, Ovulation testing indicate that:breeding season (10～11) treatment of ewes with Ovsynch after estrus synchronization, Ultrasonic testing Detection 4 ewes ovulation occurs in 12～24h; in the non-breeding season (5～6) and the virgin goat found in the 6～12h each 1 and 2 ovulation occurs. During the breeding season, the best time in the Ovsynch method insemination last for18～24h after treatment; in non-breeding season, the best ewes of different parity insemination time needs further study. The ovulation synchronization and fixed-time insemination did not statistically affect the reproduction performance.The experiment was conducted to study the effect of synchronization ovulation on the does'reproduction performance. Results indicate:during the reproductive season, the estrus rate of Ovsynch, Long-Plug, Short-Plug treatment were 67.80%,65.52% and 70.37%, respectively, whereas, the difference during the three methods were not obvious (P>0.05). Ovsynch treatment incrassated (P<0.01) the kid weight by 165.18g and 180.63g compared with the Long-Plug and Short-Plug treatment, Long-Plug treatment decreased (P>0.05) the kidding rate by 0.15% and 0.06%; in the non-reproductive season, the estrus rate of Ovsynch, Long-Plug, Short-Plug treatment were 62.05%,66.67% and 65.63%; Ovsynch treatment decreased the kid weight by 129.26g and 218.00g. compared with the Long-Plug and Short-Plug treatment and Ovsynch treatment (P<0.01). Long-Plug treatment increased (P>0.05) the kidding rate by 0.14% and 0.21%. The kidding rate of multiparous does was increased 19.79% than primiparous ones treated by Ovsynch method. In conclusion, the method of synchronization ovulation could promote the does estrus synchronization, which is convenient to intensively mating and managing production. According to the study of goat fixed-time insemination it showed the method of synchronization ovulation is preferable to the traditional methods by getting the same conception rate and kidding rate, which could afford theory evidences for the next application of intensive kidding technique.