Reproductive performance and estimates of labor requirements associated with combinations of artificial insemination and natural service in swine.

A study was conducted to examine effects of mating systems composed of natural service (NS) and AI in swine on farrowing rate, litter size, and labor requirements. Sows and gilts were bred once per day via one of the following treatments (d 1/d 2): NS/NS, NS/AI, AI/AI, and NS/none. Gilts bred with NS/AI, AI/AI, and NS/NS had higher (P less than .

Effect of feeding fat and altering weaning schedule on rebreeding in primiparous sows.

Primiparous sows that farrowed on a commercial farm during late summer in 1980 (n = 65) or late winter in 1981 (n = 62) and lactated 3 to 4 wk were used. Sows were assigned in a factorial experiment to one of two lactation diets (control or 10% fat-supplemented) and one of three periods (0, 2 or 5 d) of early weaning of the heaviest one-half of the litter. Days from weaning to estrus averaged 16.