Abstract: To investigate the effects of different insemination methods on the reproductive performance of sows and to explore the optimal number of effective spermatozoa in the application of automatic bionic insemination (CAPSULE) technology, 340 healthy sows with similar body condition, batch, breed, parity, and age were randomly divided into experimental and control groups. The experimental groups, A1, B1, C1, D1, and E1, consisted of 180 sows in total, with 40 sows each in A1, B1, C1, and D1, and 20 sows in E1, all inseminated using the automatic bionic method. The control groups A2, B2, C2, D2, and E2, consisted of 160 sows in total, with 40 sows each in A2, B2, and C2, and 20 sows each in D2 and E2, all inseminated using the conventional method. The number of effective spermatozoa per insemination for A1 and A2 groups, B1 and B2 groups, C1 and C2 groups, D1 and D2 groups, and E1 and E2 groups were 2 billion, 1.5 billion, 1.2 billion, 1 billion, and 0.8 billion, respectively. By comparing the reproductive performance indicators of the sows after insemination, it was found that the automatic bionic insemination technology significantly improved the breeding efficiency of sows without affecting their reproductive performance. Specifically, the group using 1 billion sperm with automatic bionic insemination (CAPSULE) achieved farrowing rate nearly 20% higher than the conventional method with the same sperm count, along with an average increase of 3 piglets per litter. Thus, the automatic bionic insemination (CAPSULE) method with 1 billion effective spermatozoa performed the best, not only using fewer spermatozoa but also achieving good reproductive results, making it worthy of promotion and use.

Key words: sows; method of insemination; artificial insemination; automatic bionic insemination; spermatozoa number; reproductive performance; delivery rate