Improve Litter Size and Weaning Weight with Management

Age

Good litter size requires that gilts not be mated until they are 230 days old. Every 30 days under 230 days, results in one less pig born per litter, for each litter of the female’s entire reproductive life.

Time of Mating

Mating 10-12 hours before ovulation results in maximum size litters. Mating 20 hours past ovulation results in 32% embryo survival rate. Since there is no method to tell exactly when ovulation occurs the solution is to mate as soon as heat is shown and keep lots of boars or semen available . Early weaned sows, like many MEW sows, usually are mated on second heat and produce larger litters compared to mating them on first heat.

Human Interaction

Sows and gilts, afraid of barn workers, average one pig less per litter, according to Australian work . Test your animals to see if they are afraid of you. Walk up to a sow in a crate and see if she comes to you or goes to the back of the crate. If she is at the back, change your handling procedures and pick up one pig per litter.

Nutrition

Nutrition has the largest impact on litter size prior to mating and just after. It is necessary to monitor the sow herd during the year, especially when seasonal changes occur. Lactation rations are higher in energy than gestation rations and should be fed where indicated. The proper type of fat must be added to lactation rations. Some vegetable oils may cause palatability problems and will reduce consumption, which will decrease litter size and weaning weights.

It is NOT possible to visually score Babcock gilts and sows as to their physical condition. The only accurate evaluation method is measurement with a backfat detector at point P2 (P2 is forward approximately 4" from the last rib, 2 ¾" off the midline). The ideal is to maintain ¾" (19mm) of fat cover throughout gestation and lactation. Do not exceed 1" (25mm). There are seasonal effects that will increase and decrease backfat. Producers may be surprised to find that their Babcock sows are well under this ideal level, which means they can be losing up to one pig per litter. Measurements should be taken at weaning, during gestation at days 35, 84, and again at move to farrowing. Measure all sows and gilts to effectively implement the correct feeding program for your herd.

NOTE: If the female’s backfat measurement is below the ideal, feed the higher amounts when a range is suggested. Weigh feed in gestation frequently, do not trust the weight shown on the overhead boxes or size of feed scoops.

Feeding Guide for Gilts and Sows