North Dakota State University * Dickinson Research Extension Center
1133 State Avenue, Dickinson, ND 58601 Voice: (701) 483-2348 FAX: (701) 483-2005
BREEDING AND FARROWING
Nowhere is sanitation and disease prevention more important than in the farrowing house. Pork producers have many drugs that can effectively control disease conditions. However, if you follow excellent sanitary precautions routinely, disease prevention is a simpler matter. To begin the most effective sanitation and disease prevention program during the farrowing and nursing stage, you should begin a few weeks before farrowing.
Only healthy, prolific sows should be saved from one farrowing to another. Take into consideration the number of pigs farrowed and number weaned, rate of gain and evenness of the litter.
In selecting replacement gilts consider their rate of gain, feed efficiency, backfat, weight of age, and any carcass data from the litter or other pigs sired by the same boar. Select gilts from quiet sows with good dispositions and mothering ability. Do not select a boar or gilts from litter where some pigs have ruptures or any of the boars are ridglings. Gilts at least 200 pounds should not probe more than 1.5 inches of backfat. Also consider carcass cutout information from other pigs in the same litter, if it is available. Gilts can be removed from the finishing pen at 125 pounds. If they are in a trial, they can be removed when the trial is completed, at between 200 and 220 pounds. After gilts weigh about 200 pounds they can be hand fed a gestation ration until about 2 weeks before breeding. They can also be self-fed a gestation ration. If on pasture, the feeder can be closed every other day, or if in dry lot the feeder can be closed the afternoon and evening of each day.
The breeding season is of utmost importance in a brood sow operation. Boars, sows and gilts should be gaining at the beginning of the breeding season, to make sure they are in top physical condition. Sows and gilts should be flushed for at least two weeks before the breeding season and until one week after being bred. Take care that boars, especially mature animals, do not carry more than a moderate amount of condition or they may get too heavy and become inactive. It is desirable to keep their weight down enough so they can be fed to gain in weight beginning at least 2 weeks before breeding. Excess handling and over exertion, including overeating, should be guarded against before the breeding season. Try to keep away from medication during this pre-breeding season. Always provide plenty of clean water and shade. The breeding herd can be handled best on a clean pasture where adequate grazing is available. Plenty of exercise is important.
Boars should be checked on several sows or gilts before the regular breeding season starts, to determine if they will breed and settle the sows. Boars over one year of age can breed three sows per day, while young boars should breed about one less each day. Young boars, because of their lighter weight, can best be used on gilts, with the older boars on sows. By checking the females carefully, an accurate determination can be made as to when they were bred. If hand mating is followed with only one mating, it should be about 24 hors after the heat period starts. If two matings can be made, matings will be most productive late on both the first and second days of the heat period.
When pasture mating, the sows and gilts should be separated into herds of about 18 to 20, and two boars used on each herd, if possible, one during the day and removed at night and the second one turned in until morning. If possible, this should be kept up until one half to two thirds of the sows are bred, then one boar can be used to finish the job. If information on the performance of the boar is desired, sows or gilts should be separated into smaller lots, with the same boar used on the entire lot. In this way performance data can be obtained on each litter a boar sires.
During the gestation period sows and gilts can be self-fed or hand fed 4 to 5 pounds of feed per day up to farrowing. If a self-feeder is used, the ration should be bulked up with alfalfa, and if they begin to gain more than is desired, close the feeders down and open the feeder moderately every half day or less often if they are on summer range. Watch the condition of the sows and gilts, and let that be a guide for the feed they should receive.
The pregnant sows should be wormed about one month before farrowing. If erysipelas is a problem, vaccinate about 4 weeks before each farrowing. Handle pregnant sows in a quiet, gentle manner. The easiest way to immunize sows is to have a holding crate and inject the bacterin under the skin either back of the elbow or behind the ear as each sow goes through the crate.
Move the sow into the farrowing house about 3 days before farrowing. Wash her with warm water and a detergent. Rinse following the washing. A mild, odorless disinfectant may be sprayed over the sow following rinsing. Use limited amounts of straw for bedding, so it can't be banked into a nest that serves as trap for the little pigs when the sow lies down. Dry shavings make better bedding than straw and will absorb moisture. Dry sawdust like shavings also is excellent since the sow cannot build up a ridge high enough to trap little pigs. Bedding is not used if the house has a slatted floor. Clean floors regularly, or at least once a day.
Stalls are satisfactory and can best be used with guard rails and a brooder in one corner. In a conventional brooder like this a 150 watt lamp is satisfactory, using a cheap metal reflector to keep the bulb in place and direct the maximum heat on the pigs. A hardware cloth screen should be used below the reflector and on top of the brooder to prevent glass from falling into the litter in case the bulb should break. A heat lamp can be used in place of the brooder.
If a farrowing pen is used, guard rails should be on brackets and held about 8 inches off the floor and 6 inches out from the wall. These should be on all wall surfaces where a sow could crush the pigs when lying down, except next to the brooder and along front gates. The gates shown in figure 12 make excellent protective devices. They protect the brooder and can serve as a farrowing crate. If the sow is restless, the gates can be closed to serve as a farrowing crate of the width desired. When open wide, the gates limit the space the sow can move around in, and are of real value in protecting the pigs from being injured or laid on.
A farrowing pen is 8 x 7 feet is very satisfactory for sows of almost any size. Plans for farrowing crates, brooders, and a most other hog equipment is outlined in the "Swine Housing and Equipment Handbook" mentioned below.
If farrowing crates are used they can be placed far enough apart so one heat lamp can be placed between, and serve two crates. For information on the construction of stalls, see Extension Circular "Swine Housing and Equipment Handbook", available through your county extension agent.
If a farrowing crate is set on a cement floor, a wood plank or plywood under the crate makes the sow more comfortable. The crate should be placed on the floor so that it is pitched to the rear. The slatted floor in farrowing crates separates the pigs from the sow's dung and urine. A 1-inch spacing between slats can be used and covered with a soft mat the first day or two to protect the baby pig's legs. Narrow spacing will not keep the crate clean.
Optimum temperatures for sows at time of farrowing is about 50o to 60oF. Be sure the houses have god ventilation, and that drafts are kept to a minimum. Floors should be kept as dry as possible (heated if concrete) and cleaned each day.
Be on hand for farrowing. It will save pigs in many cases. If the sow is in labor over an extended period with no pigs being farrowed, she needs help. If the herdsman does not know exactly what to do, call a veterinarian.
After farrowing, the first feeding should be in about 10 or 12 hours, and, if possible, should be about half a pound of wheat bran. The next day, switch to a light feeding of about 2 pounds of the lactation ration. Increase this by about 2 pounds each day until the sow is on full feed. If the pigs begin to scour because of too much milk, decrease the feed to the sow. If the sow doesn't appear to feel well after farrowing and refuses to eat, 10 cc of streptomycin penicillin given each day until she begins to eat often is beneficial. If she refuses to let her milk down, give an injection of oxytocin, following directions. Separate the pigs from the sow for 30 minutes, give the oxytocin and put the pigs back with the sow at once. When a sow is restless and doesn't want to claim her pigs, a proper dose of a tranquilizer and Tylan 50 mg per cc or Tylan 200 often will quiet her and relieve the distress. If she doesn't appear to be giving her milk down, give her oxytocin according to directions when she quiets down.
It is desirable to switch the sow to a self-feeder once she is on full feed. Always be sure she has plenty of clean, fresh water.
Pigs usually are not weaned until they are 4 or 5 weeks of age. Some wait until they are 6 weeks old, and a few still wean at 8 weeks. Early weaning helps in disease control and treatment and gets the pigs away from the sow where parasites are a severe problem. It also makes less work than handling the sow and her litter together. The Dickinson station does not recommend weaning the pigs before they are at least 4 weeks old.
If the sow is to be re-bred in her first heat cycle following weaning, leave her on the self-feeder with the lactation ration until about one week after she is bred. Then switch her to the gestation ration hand fed, or, if self fed, you may open the feeder only every other day, depending on her condition following the policy outline above.
If a time will elapse before breeding, reduce her feed, or keep the self-feeder open only for certain periods, so she does not gain excessive weight. Increase the feed about 2 weeks before breeding and one week after she is bred.
If it is undesirable to have a uniform crop of pigs, keep 10 to 15 more sows than gilts than needed, and pick out those that will farrow at the time desired. The others can be marketed as bred sows. if any come in heat after the second cycle they are not reliable breeders and should be marketed.