Abstract: After artificial breeding of cows,if it is not possible to timely and accurately determine whether they are pregnant and deal with non-pregnant individuals in a timely manner,it will reduce reproductive efficiency,and also cause prolongation of calving intervals,affecting the lifetime milk production and milk production efficiency.And the prolongation of calving intervals increase the non-breeding feeding period,leading to increased feeding costs.Therefore,pregnancy diagnosis is an important part of dairy cow breeding management.Only by detecting non-pregnant cows as early as possible after mating and minimizing non-breeding feeding costs can improve breeding efficiency.Traditional pregnancy diagnosis methods such as rectal palpation,ultrasound examination and progesterone testing have achieved good diagnostic results,but they require a large amount of manpower and resources,and require professional technicians to conduct tedious examinations,resulting in low efficiency and increased management costs.In recent years,ELISA detection kits and colloidal gold test strips based on pregnancy related glycoproteins have become popular for diagnosing pregnancy in breeding cows.Although they have greatly improved the accuracy and convenience of detection,blood collection,testing,and ear number verification are still cumbersome and not suitable for large-scale promotion and use.The revelation of the patterns of activity and body temperature changes in pregnant cows also promotes the emergence of new technologies for diagnosing cow pregnancy.By developing automated technology for pregnancy diagnosis,collecting and analyzing physiological indicators of cow activity and body temperature,and determining whether cows are pregnant,cost savings and efficiency can be achieved,hoping to provide new ideas for improving the efficiency of cow pregnancy diagnosis.

Key words: early pregnancy diagnosis; automation; body temperature; activity amount