INTERVAL BETWEEN INSEMINATIONS AND END OF ESTRUS AS PARAMETERS IN AI PROGRAMS

摘要

Artificial Insemination (AI) has brought great benefits to swine production, even though there is a necessity of cost reduction. Some studies suggest that the interval between AIs can vary from 12 to 28 h (3, 4, 7). However, some experiments have shown that there is no significant difference in the average farrowing rate (FR) and litter size (LS) when the interval between AIs is 12 or 24 hours (2, 5). An additive effect of the number of AI doses/sow on LS has been described (1). To ensure an enough quantity of viable sperm in the fertilization moment, AIs should be performed up to the end of estrus, due to the high variation of the estrus length in sows (6). The aims of this experiment were to compare a traditional schedule of AI (C) against othersschedules (Tl and T2), using the beginning of estrus and AI interval, the end of estrus and the AI interval as parameters.