Pastures for Pigs

Green pastures furnish proteins, vitamins, and minerals, and when they are properly rotated are the basis of a good sanitation program and save as much as one-fourth of the grain ration and one-half of the protein supplement ordinarily fed to pigs.

Scientists at the University of Illinois, after experiments in which pigs were grazed on excellent alfalfa pasture, credited the pasturage with about 1,000 pounds of pork an acre, besides the gain credited to the corn that was fed.

At the same experiment station, rye pasture furnished excellent grazing for sows and March-farrowed pigs. An acre of good rye pasture carried 100 early pigs and their dams until alfalfa was ready to graze about May 1. In those tests, an acre of rye pasture saved almost 100 bushels of corn and 560 pounds of protein supplement. In another instance, sows and pigs fed only corn on rye pasture made more gain with less feed per 100 pounds gain than sows and litters fed corn and supplement in dry lot.

Winter oats is an excellent grazing crop for sows and early spring litters. An acre of winter oats pasture ordinarily furnishes pasture for four sows and their litters during the suckling period. In sections of the country where it can be planted early to get a good fall growth it is one of the best early spring pasture crops.

Year-Round Grazing

In the South, soil and climate make it possible to produce a variety of crops that can be hogged off almost the year round. Under such systems, litters can be farrowed so as to provide a more uniform supply of market hogs throughout the year.

The Georgia Coastal Plain Experiment Station began a series of tests in 1936 to determine the value of different crops in a year-round grazing program. Only grain crops were used that could be harvested by the hogs. A sufficient acreage was planted so that each crop would carry a given number of hogs until the succeeding crop was ready. Over an 8-year period, data were obtained on the value of 14 feed and grain crops to determine their place in such a program.

The sequence of crops found best for the Coastal Plains area of Georgia was: Mature oats, to be hogged off in May and June; early dent corn to furnish feed in July, August, September, and October; either runner peanuts or sweet potatoes for feed in November, December, and January; and field corn for February and March. Early dent corn, which returned $2.59 for each dollar of cost, was the most profitable of the crops tested. Only two crops, sweet potatoes and sunflowers, failed to return enough pork per acre to cover expenses. The average amount of pork produced to the acre ranged from 542 pounds for corn and Spanish peanuts to 305 for corn and soybeans. On the average, it required approximately 0.4 of an acre of fattening crops to grow out and fatten a pig from weaning to market weight.

The year-round hogging-off program saves labor in harvesting the crop, increases soil fertility, distributes labor and income more evenly through the year, establishes good sanitation practices to control parasites, and uses soil-building crops that could not be harvested economically and fed to hogs.

Going to Market

What is the best weight at which to market hogs in relation to feed costs per unit of gain? At Beltsville we tried to determine the amount of feed required for each 50 pounds of gain between 75 and 375 pounds of live weight. Hogs of the intermediate type were self-fed, with these results :

We found that 275 pounds is about the limit to which the in-between hogs can be fed profitably under normal conditions. Beyond that, the rate of gain dropped significantly, and the feed needed for each succeeding 50 pounds of gain increased appreciably. Therefore, unless lard is needed, it is desirable from the standpoint of feed utilization to market hogs at live weights of 200 to 225 pounds, because it requires less feed to produce lean meat than it does to produce fat.

The use of distillers' dried grains with solubles as a feed for swine grew out of war conditions. The shortage of protein feeds and the large quantities of distillers' dried grains resulting as a byproduct of alcohol production led to tests at Beltsville to determine the value of the product. Besides their high protein content, the products contain the B vitamins.

Dried distillers' grains with solubles were fed to pigs at different levels as protein supplements. The distillery product made up 9.4 to 12 percent and from 18 to 26 percent of a ration composed of corn, tankage, soybean meal, alfalfa meals, and minerals. The tests, in which the hogs were fed to market weights of approximately 225 pounds, showed that at the level of 9 to 12 percent of the ration, rate and economy of gains were comparable to those of pigs in the check lot without distillers' grains. However, when the dried grains with solubles were fed at the second level, the rate of gain was slowed up by about 30 percent while 40 percent more feed was required per 100 pounds of gain. It was apparent that the added high fiber content of the ration at higher levels hindered normal gains.

Tests conducted at the Kentucky Agricultural Experiment Station confirmed our results and indicated that the distillers' feed products do not contain all the essential amino acids at a level required to promote satisfactory growth. Further tests at Kentucky, and some at the Illinois Agricultural Experiment Station, show that when distillers' dried solubles were used as a supplement to certain basic rations, an improvement in quality was obtained, with an increase in rate and economy of gains. It seems likely that this improvement is due to vitamin factors contained in the distillers' solubles. Results to date indicate that growing pigs receiving distillers' products in the ration, nevertheless may be expected to produce more economical gains when given access to good pasture than when fed these products in dry lot.