| TAI is a new technology of artificial insemination, which based on the synchronization oestrus and ovsynch, and can inseminate accurately without detecting estrus. It can improve the reproductive performance of sows and promote the management of batch production. In order to establish an effective TAI and discusses the application in sows, two large-scale pig farms(A and B) were choised. The same floor adjacent batches weaned sows were divided into treatment group and control group randomly. Treatment group use TAI and control group use normal AI. Comparing estrus rate, pregnancy rate and parturition rate within one week, and litter size, number of qualified piglets, reproductive efficiency and interval of weaning to parturition between two group to evaluate the efficacy of TAI. At the same time, collecting blood from precava and prepare serum from each group(6 each group). The levels serum of reproductive hormones(E2, LH, FSH and P4) were measured by radioimmunoassay between two groups and analysis the changes of hormone to improve the TAI technology. Hoping provide a reference for the physical mechanism and complete TAI technology. The main research results are shown below:(1) The total estrus rate of treatment group is over 97.78%, which is higher than control group(P < 0.05). However, the pregnancy rate and parturition rate are no significant difference(P > 0.05). But the parity can affect effect of TAI. In farm A, the pregnancy rate of 3-4 parity sows(96.79%) is higher than control group(78.04%)(P < 0.05), and the pregnancy rate(100%) was higher than control group(78.04%)(P < 0.01). In farm B, the parturition rate of 2 parity sows(84.52%) was higher than control group(63.06%)(P < 0.01), and the pregnancy rate of 3-4 parity sows(85.83%) was higher than control group(P < 0.01). However, the estrus rate of 7-8 parity sows(83.75%) and the pregnancy rate(53.75%) were less than control group(100% and 97.22%)(P < 0.01).(2) The litter size, number of qualified piglets and reproductive efficiency are higher than control group, but the difference was not significant(P > 0.05). Among them, the litter size of 2 and 3-4 parity are above 11.94 heads, especially 2 parity sows in farm B, the litter size(13.00 heads) is higher than control group(10.55 heads)(P < 0.05).(3) The weaned to parturition interval is less than control group(P < 0.01), of which A field trial group was 118.92 d, 2.69 d less than those in control group, and B field is 120.04 d, 0.87 d less than those in control group. It indicated that the program can effectively shorten the sow non-production days(NPD).(4) Within one week after weaning, E2 levels of treatment group are higher than control group, after the injection of PMSG, the content of E2 rising rapidly, however the content of E2 in control group rise slowly, and at 90 h, it reaches maximum(24.15pg/m L) and is higher than control group(10.44pg/m L)(P < 0.01). The level of P4 changes between 0.26 ~ 0.92 ng/m L, and relatively stable at 24-144 h after weaning, and the P4 concentration is lower than the control group. After mating the level of P4 started rising rapidly and the treatment group is higher than control group. LH and FSH levels between the two groups have no significant differences, both present wave changes. |
PDF Full Text Request