The American farmer did a first-rate job of feeding hogs during the war. Feed takes 70 to 85 percent of the cost of production and it was necessary to get as much efficiency as possible out of the feed on hand in order to meet the need for the large increase in numbers of hogs. Farmers realized that protein feeds saved corn or cereal grains in the swine ration, and could speed up gains so that hogs would be ready for market earlier.
A combination of feeds of both animal and plant origin are more efficient supplements to grain than either one used alone as a supplement. On the other hand, a protein feed of animal origin should be part of the ration of sows during the gestation and suckling periods and for the young pig until it reaches at least 75 pounds. Consequently, when the supply of animal protein feeds, like tankage and fishmeal, is limited, they should be fed to the animals that need it most for proper development.
For growing and fattening pigs, over 75 pounds in weight, feeds of plant origin, like meals of soybean, linseed, cottonseed, peanuts, and alfalfa, used in various combinations to supplement the grain ration, will produce satisfactory results if the supply of protein feeds from animal sources is low or lacking. During this period, however, hogs receiving some animal protein in the supplement will gain faster than those on an all-vegetable supplement.
Wartime shortages of protein feeds of animal origin led to a series of tests at Beltsville on the value of plant proteins. We found that a good all-vegetable protein supplement can be used during the gestation period, but that a ration containing some animal protein is necessary to increase growth rate in growing and fattening pigs. In the tests, the sows and litters were handled under conditions similar to those found on many hog farms. Pasture crops were fed during the gestation and suckling periods. Considerable corn and other grains were saved when high-protein supplements were used to provide a well-balanced diet.
We think a farmer will do well to grow his own protein supplements so that he need buy little extra feed. Skim milk is a valuable supplement of animal origin. Soybeans are good in small quantities, when combined with other supplements and minerals. The practice of exchanging whole soybeans for soybean meal, which can be used safely in large quantities, Is often profitable. For fattening hogs over 100 pounds in dry lot, a mixture of three parts soybean meal and one part ground alfalfa hay may be self-fed in one compartment of a feeder with corn and a mineral mixture in separate compartments.
Legume hays and hay meals, like alfalfa, soybean, red clover, Ladino clover, and lespedeza, provide proteins, minerals, and vitamins of excellent quality. They may be fed separately, as hay, or ground and mixed with concentrates.
The hog's stomach is small and requires feed in concentrated form. The bulkiness and relatively high fiber content of hay and hay meals limit the amount that can be fed profitably. In general, 5 to 10 percent of good legume hay, either ground or unground, has been considered the most desirable level, although more may be fed with good results. A growing and fattening hog can tolerate as much as 8 percent fiber; that permits the use of as much as 20 percent of a hay of 30 percent fiber content in a mixture of corn, tankage, and linseed meal.
Tests at the Wisconsin Agricultural Experiment Station show that brood sows fed only 5 percent alfalfa in a ration made up largely of corn and soybean meal did not produce enough milk to suckle their litters satisfactorily. On the other hand, sows that received 15 percent alfalfa had strong litters. The addition of 15 percent of alfalfa hay was also favored in a ration containing tankage as well as those with only vegetable-source protein feeds. Rations containing 15 percent ground alfalfa hay also gave excellent results for growing and fattening pigs.
It is not necessary to use ground legume hays in rations where pigs have access to good pasture. If pigs are fed in dry lot or in fields where the pasture is poor, ground hays are valuable in the ration. The winter ration for fall-farrowed pigs should contain liberal amounts of good hay to promote general health and rapid and economical gains.