1. Monogastric Production Swine Section Swine Reproduction

2. Reproduction in the Female Gilts reach puberty = 5-8 months of age Estrous cycle = 21 d Length of estrus = 2-3 d Weaning to estrus interval = 5 d Length of gestation = 114 d Pregnancies per year = 2.0-2.3 Pigs per sow/yr = 14-20

3. Litters/Sow/Yr 5 d + 114 d + 21 d = 140 d/litter 365 d/140 d = 2.5 litters/sow/yr 5 d = weaning to estrus 114 d = gestation length 21 d = age of pigs at weaning

4. Reproduction continued Females should be mated at least 2X during the estrus period. Ovulation occurs about 12 hours before the end of estrus or 36 hours from the onset of estrus.

5. Male Reproduction Semen volume/ejaculate = 150 to 200 ml Total sperm/ejaculate = 30-60 billion Total sperm/week = 120-150 billion Boars reach puberty at approximately 9 months of age

6. Boar Power Boar power needs refer to the number of females that can be mated (serviced) by one boar.

7. What factors affect boar power? Boar’s age System of mating Frequency of farrowing

8. Boar Power Guidelines Age of BoarHand MatingPasture Mating Young boar20-30 females10-15 females Aged boar35-40 females15-20 females

9. Boar Power Continued Actually the number of services per week is a better guide to boar usage (2X/d or 10X/wk) Ratios as high as 20:1 and as low as 4-5:1 are encountered in the swine industry. Certainly the use of AI will greatly increase the number of females bred/boar.