Puberty onset is at 5-8 months of age and is dependent on breed, growth rate and boar exposure. Cycle length is 21 days with 1-3 days of sexual receptivity. Ovulation occurs late on the second day of sexual receptivity. Pigs can be bred by natural service or AI; pigs have a corkscrew penis and corresponding corkscrew cervix. Gestation length = 115 days (3 months, 3 weeks and 3 days). Pregnancy diagnosis is by return to estrus, rectal palpation, ultrasound (A-mode identifies intrauterine fluid days 30-90 of gestation, Doppler can be used days 30-115 of gestation. Parturition may be induced after day 111 with prostaglandin - planned farrowing ensures presence of personnel during farrowing, and allows equalization of pig size within litters and litter size between sows. The goal is for sows to farrow 2 to 2.5 times per year. Factors influencing litter size include genetics, parity (litter size decreases after the fourth pregnancy), mating management (most sows are bred to more than one male during a given heat cycle = heterospermic mating), season, and farrowing management. Normal sperm number is boars is 45 billion per ejaculate.
Pig diseases you should know - All of these diseases can cause SMEDI
(stillbirths, mummification, embryonic death and infertility).
Brucellosis - Brucella suis - Minnesota is free of porcine brucellosis
Pseudorabies - Minnesota is not free of pseudorabies
Erysipelas
PRRS (porcine respiratory and reproductive syndrome)