Comparison between different methods of artificial insemination in swine

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">This study was performed to compare the Hands-free insemination method, i.e., the high degree automation procedure, with an intermediate method, which allows less participation of the inseminator during the application of the inseminating dose (ID), and the conventional method, which is widely used in Brazil. The comparison was based on infusion time and losses due to semen backflow during AI and 120 minutes after AI, degree of difficulty experienced during AI procedure, and reproductive performance data. A number of 604 sows on the parity up to 7 and a weaning to estrus interval 7 days were used. Females were distributed into 3 treatments: T1= hands-free AI method, with long coilable shaft pipettes (Supertip®), semen stored in flexitubes® and AI device consisting of an abdominal belt and a saddlebag; T2= intermediate method, Supertip® pipettes, flexitubes®, without AI device; T3= traditional method, Melrose-type pipettes, semen stored in tubs, without AI device. AI time was associated with the inseminator’s performance. The average AI time was different (P0.02) among treatments (1.7±1.6; 2.2±1.8 e 3.6±1.1 minutes for T1, T2 and T3 respectively). One hundred eight sows distributed into the three treatments, had the semen backflow collected up to 120 minutes after AI in a colostomy bag fixed by the vulva. Semen backflow volume during AI was higher (P0.02) in T1 (7.7±13.5 mL) as compared to T3 (5.8±10.8 mL). There were no differences among treatments in the number of spermatozoa eliminated by semen backflow up to 120 minutes after AI. Regardless of the treatment, nearly 70% of the volume and 30% of the total spermatozoa contained in the ID were eliminated by semen backflow up to 2 hours after AI. Concerning the degree of difficulty of the AI procedure, 85.6%, 92.9 and 97.7% of T1, T2 and T3 females were inseminated with up to 1 intervention (P0,05 between all treatments). There were no differences among treatments (P0.05) in return to estrus rate, adjusted farrowing rate and number of born piglets. The return to estrus rates were 10.3, 7.4 and 8.5%, adjusted farrowing rates were 90.8, 94.0 and 91.7%, with 10.9, 11.1 e 11.1 total born piglets in T1, T2 and T3, respectively. The Hands free method and the intermediate method allowed faster AI and can replace the traditional method without influence on the reproductive performance.