Reproductive Characteristics in Sinclair Miniature Swine

摘要: Three hundred seventy one litter records collected between 1985 and 1993 from 156 Sinclair(S-1) miniature sows, a Hormel derived strain of swine, were analyzed retrospectively compared with previously published representing 1950 to 1952 1963 1965. Effects several variables, such as season month parturition, age sow, parity size, on reproductive parameters Sinclair swine evaluated. Preovulatory follicular ovulation rates evaluated in 230 virgin gilts. Means ± SEM for number liveborn, stillborn size at weaning 7.20 ±0.12, 6.57 0.63 0.06 5.75 ±0.12 piglets, respectively. From total 2436 liveborn 2133 (87.6%) weaned. Litter birth was similar that reported this swine; whereas, mean increased 4.7 piglets during 1965 5.8 our study. Average weight decreased 0.90 kg 0.72 0.59 Reproductive variables affected miniswine reproduction included size. Primiparous sows had the smallest lowest weaned piglets. Sows their second third or 2 4 yr old best performances. sow resulting fewer older sows. curvilinear effect preweaning mortality highest occurring small large litters. The overall preovulatory 9.0 0.4 7.5 0.1, At 10.7, 20.5 27.0 mo, 6.6, 7.9 8.1, Ovulation rate paralled Overall, production efficiency has been stable improved since 1950, all evaluated, except season, found have an reproduction; Sinclair(S-l) increases until about 20 mo levels off thereafter; is related low rate.