Hogs Benefit From Crops Grown on Fertile Soils
ECONOMY IN CORN USE, or more pork per barrel, is the constant watchword of the corn belt hog feeder. The continued search for less costly, but yet effective, supplements to the corn grain involves the desire to make the combination a completely “home grown” ration as far as possible.
Forage farming is coming in as a desirable shift in land use and we are going away from excessive corn acreage to put erodible soils under more continuous and compact crop covers which will reduce erosive effects of heavy rainfall. These changes naturally raise this question in the minds of hog men, “How effectively can the different forage crops be used as corn supplements?” Such a question is perfectly natural when we remember that the wild hog as progenitor of our domestic one was an herbaceous feeder and certainly not accustomed to living on much corn.
The hog carcass with its high percentage of fat makes us appreciate this animal’s consumption of carbohydrates as fattening foods. It makes us classify it as a “starch burner” more than a “straw burner.” For consumption of roughages we scarcely think of the hog, but rather of the cow and sheep.
Satisfied on Grass
It is well to remember, however, that the cow and the sheep must be solving their protein and mineral problems when they are stoking their paunches with grass and converting it into protein-rich meat and milk. That pork production can move the hog to no small degree into the animal group of forage consumers was shown by the work of Prof. L.A. Weaver of the Missouri College of Agriculture, when an acre of alfalfa with corn as its supplement gave almost 600 pounds of pork. This forage use turned out 100 pounds of pork for each five and one-half bushels of corn. This small amount of grain catches our attention immediately in contrast to much larger figures commonly quoted in speaking of corn-hog ratios. It is deserving of more attention when we note that no concentrates or purchased protein supplements were used.
The experimental trials of growing hogs on forages under Professor Weaver’s direction, as reported in bulletin 247 of the experiment station, show wide differences in pork output to the acre of the different forage crops. These differences are better shown in the tabular form where there are given also (a) the pounds of corn required per pound of pork, and (b) the bushels of corn per hundred pounds of pork. As another help in our appreciation of the differences, the tables gives the pounds of pork per acre on a constant amount of corn, which is a figure obtained by dividing the pounds of pork per acre by the pounds of corn per pound of pork on a particular forage.
Most Pork From Alfalfa
The outstanding amount of pork delivered by the alfalfa crop catches the eye immediately. This crop produced the most pork an acre in total and as related to the corn constant. Another legume crop, red clover, is also very efficient when used alone. But one cannot say that it is the legume aspect alone of the forage crop that speaks for efficiency in pork making, when the red clover mixed with rape (rapeseed) and oats as their nurse crop is second only to alfalfa on the acre basis in either way of using the figures.
The difference in total pork to the acre are in no small way connected with the differences in the length of the season the crops supply grazing feed for hogs. But even then the different pork values to the acre cannot be arranged in true order on this basis either. Bluegrass, which is commonly a pasture throughout a relatively long season, gave much less pork to the acre than oats and rape as a forage of similar length of season, and 30 percent less than rape, the nonlegume crop, used alone for a shorter season. Quite disappointing would be the figures for soybean or cowpeas alone, if it is not recognized that these crops are limited to the warmer season of the year, to a short growth period of service as feed, and to a rapid shift from a palatable leafy herbage to one of woodiness or mainly of proteinaceousness in the seeds of which a large portion is apt to be wasted.
Certainly, then, the different forage crops differ widely in their total amounts of pork to the acre when a perennial legume like alfalfa will make 591 pounds and cowpeas, an annual legume, just about one-fourth as much or 149 pounds an acre. Such differences in efficiency of forages blot out the differences in length of grazing season as their possible causes. Their tonnage yields per acre are also pushed out of the way as significant causes of differences in efficiency.
Wide Differences in Corn Needed
Their contrasts are even more significant when for bluegrass, a non-legume of long grazing season, the corn requirements as supplement per 100 pounds of pig growth was 7.8 bushels, but for rape, another nonlegume, it was 5.3 bushels. For the soybeans, which is a legume, the corn requirement dropped to the startling low figure of 4.6 bushels. With such figures for the amount of pork that can be made on an acre of land, and such figures for pork per bushel of corn, there is every reason for any pork producer to begin figuring and planning how he can use either legume or nonlegume forage crops, more extensively, and to struggle for an understanding of what underlying causes make some of these crops so much more efficient in the pork per acre or per bushel of corn.
Perhaps you have been thinking that these forage crops differ in efficiencies because they are different in their contents of protein, carbohydrates, fats, nutritive ratios and other similar chemical properties usually listed in the common feed analysis. Unfortunately, these chemical differences are not as wide as the pork production differences per acre. Alfalfa isn’t twice as high in carbohydrates, fats, or even proteins as is bluegrass: nor is it four times as concentrated in these respects as is cowpea forage, which are their differences in the pork they give per acre.
Soil Fertility Counts
It will be more helpful in understanding these differences in feeding efficiencies of forages for hogs if we will begin to think, and to believe that the delivery of fertility by the soil through the crop enters into the picture. Making the growth of an animal is a natural manufacturing business that is much more complicated than simply burning starch to convert some of it into fat, or than merely packing plant protein into animal muscular tissues. The better feed plants are grown on the more fertile soils. Back of these different values of forages combined with corn as hog feed are the different levels of soil fertility required to grow the forage crops.
Making the growth of a plant is another natural manufacturing business that is much more complicated than merely having plenty of acres and getting plenty of rainfall and good weather. It is one of providing a list of a dozen or more chemical elements in the soil. It is one of delivering these to the plant roots at rates sufficiently high to match the needs of the synthetic performances in the plant top that is giving off water and taking in sunshine energy and carbonic acid gas from the air. It is the internal manufacturing business of the plant that covers some of the secrets of these differences in feeding values of forages whether considered as pork per acre or per bushel of corn. These differences of forages as a combination with corn for a hog feed come “from the ground up” as internal performances first by the plant and second by the animal, that are not so easily detected as differences in feed analysis, in growing season, or in tonnage yields per acre.
Soil Minerals Best
Feeding our animals mineral mixtures as supplements or substitutes is a new phase in the thinking about feeding by many men. Ground limestone as a means of providing calcium, and bonemeal as a help to make up the shortage of phosphorus in the feeds were not given to the hogs by the generation of husbandmen just ahead. Have you ever thought that this increasing practice of dosing animals with mineral mixtures is a finger pointing to the declining supplies of soil fertility and decreasing amounts of calcium and phosphorus coming in the deficient crops from the deficient soil?
We need to remind ourselves that the crops at the head of the list of better forages for pork production are the crops which like the animals, are also suffering shortages of lime and phosphate in their diet delivered by the soil. Any crop grown on the less fertile soil is delivering less of the essentials for the animals. The animal denied calcium and phosphorus cannot build bone or carry on the blood-making business within the bone. The plant, too, cannot carry on its internal creative performance without these fertility elements, calcium, phosphorus, and about ten others coming from the soil. Here are common shortages in the soil that are disturbing the secret internal workings of the plants, which, as a consequence, are disturbing the profitable internal workings of the animal. Forages are more efficient in making pork according as the higher level of soil fertility makes them more efficient manufacturers of the many compounds and complexes that combine with corn to help the pig make a hog of itself in the shortest time.
It is true that the better forages give to the animal more of calcium and phosphorus, the two elements in the components of the common mineral mixtures. But even in the simple service of hauling limestone and phosphate from the field to the feed lot the forage crops are widely different. Rape, a nonlegume, and red clover, a legume, both give large pork yields per acre. These crops are also rich in lime and must have plenty of it in the soil to grow well. Because rape has not been so universally tried as red clover, we do not appreciate so highly the demand for lime in the soil by it and by its close relatives in the cabbage family for good crop growth.
Lime Aids Other Elements
These more efficient pork making forages, with which lime and phosphate associate themselves as responsible for both the plant and the pork, do more with these fertility elements or nutrients than pack them into their tissues as a means of hitchhiking to the animal’s stomach. Lime in the soil pays for its transportation costs to this animal destination. It may be instrumental in mobilizing from the soil into the roots of the crop larger quantities of phosphorus and many other nutrient essentials less abundantly delivered from lime-deficient soils. Lime serves within the plant in the manufacture of protein, the one particular feed essentially credited to lime-loving legumes and a big help toward solving the problem of the “home-grown” supplement.
Such differences in the plant as a feed that are brought on by greater intake of calcium alone leave suggestions of many other improvements in the plant’s delivery and manufacturing businesses that may be encouraged by more phosphorus, magnesium, potassium, and other fertility items provided by the soil. It is through these minute betterments in the soil’s contribution that all the plant activities may record their more efficient services in the better animal growth. Pork production and crop production are performances that are both premised on the fertility of the soil.
Already you have been asking yourself these questions. Can’t we expect better pork or better animal production in general from such soil treatments as phosphate and limestone? This question can be answered in the affirmative as experiments and increasing farmer experience testify. Trials with sheep have shown better gains from the same grain combined with soybean hays and lespedeza hays grown on adjoining plots but given different soil treatments. Even the qualities of the fleeces of wool were different.
Forage crops can go into pork production more extensively but not merely as a shift in land use by juggling the crops as to different kinds or as to different successions in their coming on the field. Soil conservation is more than keeping the same fertility-deficient soil at home by putting it under forage crop cover, and expecting greater farm economy by sending the animal out to harvest it rather than doing so ourselves. Soil erosion has come upon us, in no small measure, because the soil fertility was too low for nature to grow its crop cover quickly enough. With soil erosion came the less efficient feeds and the higher costs of animal production. Hope lies ahead only in remedying the troubles at their basis, which is the fertility of the soil. Farmer experience with the extensive use of limestone, phosphate, and fertilizers going above any amounts ever used in the state is ample evidence that soil conservation is going forward on a basis that is making more efficient use of the soil, and of the crops in the services for which land is intended, namely the production of food. Soil fertility is at the basis of Missouri’s farming, and pork production as one phase is no exception.