With the intensive and large-scale management of farms,the traditional high consumption and low efficiency oestrus identification methods can not meet the requirements of oestrus identification standards,which restricts the economic benefits of farms.With the development of technology,the oestrus identification of cows has gradually developed from manual identification to automatic identification.The change rule of physiological parameters of cows is the basis of developing automatic estrus identification technology,so it is of great significance to explore the change rule of physiological parameters in estrus cycle of cows.For this reason,the first experiment of this study used the activity recording device(pedometer)and vaginal temperature monitoring device developed by our team to collect the activity and body temperature parameters of cows in estrus cycle through synchronous processing method,and analyzed the data of estrus and estrus period to explore the change rule,so as to promote the development of automatic estrus identification technology and farm automation Intelligence provides scientific reference.In order to explore the change rule of tail activity of beef cattle during estrus,the experimental design is as follows: 10 healthy young(16-18 months old)and 10 simmental multiparous beef cattle at 30-50 days after delivery were randomly selected,the tail pedometer was worn on the root of the tail,and the vaginal temperature activity detection device was implanted into the vagina.After that,the cows were randomly treated with GPG estrus synchronization on one day in winter(December).During this period,the cow estrus automatic detection system was used to collect the real-time tail activity and body temperature data of the cows.The system will automatically give oestrus warning,and the technicians will directly check and confirm it.The results showed that the average amount of tail activity increased by 11.66 ± 12 times,lasting for 11.07 ± 2.09 h;After the onset of the oestrus,the tail activity and body temperature of the experimental cows were significantly higher than that of the cows during the estrus period(P <0.05).The results of automatic estrus monitoring showed that the amount of tail activity can be used as an important index to identify whether cattle are estrous or not.Although the emergence of automatic estrus identification technology has improved the estrus identification rate of cows,it can not achieve 100% detection.Synchronization estrus technology and pre synchronization estrus technology across the estrus identification of cows,reduce labor costs,but also get effective pregnancy rate,which is of great significance to the breeding management of cows.Therefore,the second experiment of this study explored the effect of pre estrous synchronization on the reproductive performance of beef cattle.In order to explore the effect of timing insemination with pre synchronization treatment on the reproductive performance of beef cattle,the experimental design was as follows: 141 simmental beef cattle were randomly selected and G6 G pre synchronization treatment was carried out in batches.15 days after insemination,the situation of re-estrus was observed manually.The cows with re-estrus were inseminated again.35 days after insemination,B-ultrasound was used to diagnose the pregnancy and check the pregnancy.65 days after insemination,further diagnosis was conducted to determine the survival of the embryo and record the data.The results showed that the 35 day pregnancy rate of 141 beef cattle was 60.28%,and the application effect in spring and summer was significantly lower than that in autumn and winter(P <0.05).The pregnancy rate of multiparous cattle was 69.90 ± 20.31%,which was significantly higher than that of young cattle(39.30 ± 1.80%)(P <0.05).The results showed that the pre synchronization scheme had a great positive effect on improving the reproductive efficiency of beef cattle. |