Hogs Discriminate Feed Differences as Delicate as Kinds of Green Manures Used
WHEN PROFESSOR EVVARD of Iowa once said “If you will give the pig a chance, it will make a hog of itself in less time than you will,” he was the first to point to the hog as a capable assayer of the nutritional values of the components of its ration. As a feed chemist the hog is demonstrating a much more refined technique than we might believe when just watching it as it balances its carbohydrates against proteins and minerals from the supplies of these we have put into the self-feeder. In fact the hog, like many other animals both wild and domestic, is capable of selecting its feeds according as these reflect the higher fertility of the soil growing them. Have you ever thought that better soils make better hogs because of the higher nutritive value per unit in the feeds through higher fertility in the soils growing them?
“Yes,” you may say “the hog is closer to the soil than most other animals, since it wallows in the mud puddle in the warmer summer and usually roots up the sod during the spring. It eats so much of its feed right off the ground too, so of necessity it is ingesting much soil and gets much that is purely mineral.” However, the question may well be raised as to just why the hog roots; when it does so mainly in the spring after a winter on low-protein and mineral-deficient feeds; then, too, when it doesn’t root later in the season after it has gotten green feeds; and when it seldom roots if it has access to good green alfalfa. We are slow to believe that the hog — once a roamer but now confined by fences — is trying to report the poorer quality of feed because of the declining fertility of the land also enclosed inside of them. What we might be prone to consider just plain “cussedness” in the hogs’ breaking through the fence to the highway and their insistence on rooting, may be our failure to appreciate (a) what all is demanded to give most efficient feeding of them, and (b) their behavior as indicators, or helps to tell us what in the way of extra nutrients they need.
The Hampshire, which in its domestication has not yet been turned so completely to “slothfulness and gluttony” as possibly some other breeds, is credited with being “a good rustler.” Might this not be merely a good ability to search out the essentials for making up its own well balanced ration. Along with this ability as a rustler goes the reward for it, namely, the larger number of pigs per litter for which this breed has the claimed and granted reputation. All this suggests that if we will give the pig a chance to meet up with better soil fertility over which it feeds, it will not only make a hog of itself quickly, but will make more hogs as offspring as well.
The part of the forty-acre field where Mr. Cliff Long of Johnson County, Missouri, once used lime and other fertilizers was taken first by the hogs. They “cut corn” to the very exact border. (Photo by Virgil Burk, Columbia, Missouri.)
Corn on More Fertile Soil “Hogged Down” First in Search for More Than Only Minerals
That the hog will select its feed according to the fertility of the soil growing it was forcibly demonstrated in Missouri some years ago on the farm of Mr. Cliff Long in Johnson county. In attempting to “hog down” some corn, the tankage and water were kept at the gate of the forty acre field. The hogs came out for water daily and went back and disappeared. The absence of indication of their activity caught Mr. Long’s attention. He was becoming concerned at about the same time that his neighbor, across the road along the opposite side of the field, reported to him about the clean job of corn harvesting the hogs were doing.
On examination of the area hogged down, Mr. Long found that the hogs were carefully working to the very border lines of the small part of the field where several years before he had limed and fertilized the soil to grow some alfalfa. The hogs had roamed the forty acre field; they had selected this more fertile area; and they had taken first the grain grown on it. They had mapped the soils of this field according to the differences in their fertility, and with an accuracy no soil surveyor could even imitate.
“Just what is the characteristic of the corn that is being searched out and recognized by the hogs?” you are already asking. Much has been said about it being the minerals, because hogs eat soil, coal and other minerals, and too it was mineral fertilizers that were added as the original soil treatments for the alfalfa. There could be nothing else but minerals, though not necessarily directly, responsible for making this particular soil area in the forty acre field different from the rest of it. Of course if the chemist should analyze the grain he would burn it down to ash for his determinations in search of differences. Consequently, any difference would be reported as one of the minerals.
There is doubt, however, whether the hog is assaying its feed wholly according to deficiencies or differences in the ash or mineral constituents. The hog is taking part of its foods as carbohydrates for energy more than these for their ash. It takes food for its protein content more than for the ash associated with this dietary constituent. Doesn’t the plant do more for the hog than just haul minerals to the trough and the self-feeder? Certainly it is within the plants — and only by the processes there — that synthesis occurs of the amino acids out of which proteins are constructed by the animal body. It is of proteins that muscle is built. It is the plants that construct carbohydrates through photosynthesis. It is the carbohydrates that help the hog to lay on its fat and that give energy to its body. These services performed for the animal by carbohydrates and proteins result from them as complex compounds synthesized by the plant’s life processes and can not be performed by the mere presence of the plant’s ash-comprising minerals. The hog is not assaying for the mineral contents of its feeds. It is assaying for the degree of balance which its feed contains of the many complex nutritional substances — carbohydrates, proteins, fats, minerals, vitamins, etc. — that only the plant can put together and then most effectively only by the help of a good store in the soil of all the elements of mineral fertility.
Crops Requiring More Fertile Soil Grow More Protein and More Pork per Acre
It was Professor L.A. Weaver of the Missouri College of Agriculture, who demonstrated the significance, and good performance of high soil fertility in terms of pasture for hogs. He used a series of different crops as grazing for them and used corn as the supplement. If this series of crops is arranged as they require less fertility from the soil for their growth — or as “they can be grown more easily” as it is more often said — his results show that they also make less pork per acre. Alfalfa, which is considered the hardest to grow is at the top of the list of the crops with its recognized high pork production per acre of 591 pounds. Then the other crops follow in this order, namely, red clover 449; rape 394; sorghum 275; blue-grass 274; soybeans 174; and cowpeas 149 pounds of pork per acre. These are their capacities to support the hog in its inclination to become pork when corn was a supplement. In respect to the amount of corn, as bushels, required to make a hundred weight of pork, these hog pasture crops listed themselves with the following figures: Alfalfa 5.5; red clover 5.2; rape 5.3; sorghum 7.1; bluegrass 7.8; soybeans 4.6; and cowpeas 5.2 bushels.
When we say a crop is “hard to grow” because it requires fertilizers like lime, phosphate, magnesium, potash, boron and other nutrient elements, we forget that it is just those “hard-to-grow” crops that are more nearly manufacturing all that it takes to convert a pig into a hog quickly. Alfalfa, for example, grows naturally today on the soils that made buffaloes as big and numerous as the Forty-niners found them. No one ever reported the buffalo as having a separate source of protein supplements. He found his protein synthesized by the short grass that bears his name. But that grass was undergirded in its protein manufacture and its mineral delivery by an ample fertility supply in the soil that had not been leached out by heavy annual rainfalls. It had not been weathered out to the degree where forests or wood was about all that the plants could synthesize.
The hog as producer of a higher percentage of its body as fat, than is the case with the buffalo, or cattle and sheep, is able to do better than these on soils that grow carbohydrates, like corn, more commonly and more easily than they grow protein, like hard wheat. Nevertheless, the hog must also have its proteins. Unfortunately, for the better upkeep of our soils, proteins are too commonly considered as something that must be purchased in a bag rather than grown right on the farm in our non-legume crops by giving the soil some lime, phosphates, and legumes or other nitrogenous fertilizers, which increasingly greater areas of the soils now require to produce it.
Hogs Discriminate Feed Differences as Delicate As Kinds Of Green Manures Used, and as Kinds of Minerals Applied on Soils Growing the Feed
That the hog discriminates between the corn or the wheat, for example, according as it was grown on soils with the different fertility levels or different fertilizer treatments has been demonstrated very positively. The hog has been recognized, under experimental tests, as a very good assayer of differences in the soil fertility growing its feeds. The same hybrid corn or the same variety of wheat was grown, for example, on three plots of soil given (a) lime, phosphate and potash, (b) lime and phosphate, and (c) lime only. One hundred pounds of the grain harvested from each of these plots is put into separate compartments of the self-feeder and the hogs allowed to consume these according to their choice. Regularly the remnant amounts are weighed, and the compartments refilled with weighed quantities but not in the same order or position of the different grains in the self-feeder. This is the procedure used to test other kinds of soil treatments. This method of asking the hog to assay the values of different soil fertility treatments does not report them as increases in bulk, such as bushels or tons per acre. Rather, it is the pig’s report on the nutritional quality of this part of its feed and the pig’s suggestion on what we can do in helping it to make a hog of itself most efficiently.
When turning under a green manure like sweet clover to make more bushels of corn, we must also ask the hog whether the corn resulting would be taken first among other kinds.
What then are some of the reports by these pigs as endorsers of our efforts to improve the feed at the source of its production? When the three soil treatments listed above were used under a rotation with red clover turned under ahead of the corn which was followed the next year by wheat and this latter grain was fed, it was consumed (a) 100 percent; (b) 95 percent; and (c) 85 percent, respectively, for the order of fertilizer combinations given. The complete treatment of lime, phosphate and potash was the hog’s first choice in terms of the wheat grain so grown. But when sweet clover was the green manure ahead of the corn to be followed by the wheat, this second grain was chosen first when only lime and phosphate were used. The second choice was the more complete fertilizers, namely lime, phosphate and potash; and their third choice was lime only.
When a variety of different green manures was tested, each used separately, and with the same complete mineral addition given above; and when the corn grown immediately after the green manure had been turned under, was offered to the hogs; their choice of the corn grown immediately after these green manures ranked the soil treatments as follows: lespedeza 100 percent; red clover 90 percent; sweet clover 81 percent; and timothy 66 percent.
In both of these citations given, the hogs were seemingly “turning thumbs down” on the wheat and on the corn grains when sweet clover was used as a leguminous green manure either immediately ahead or one year ahead of the grain crop offered them. This was a case of the hogs seemingly voting against the sweet clover when it was used distinctly as a green manure.
Such was not the vote of the hogs, however, when the corn followed a crop of sweet clover grown to maturity for the harvest of sweet clover seed. Corn was grown on a set of plots with corn, oats and sweet clover as the crop rotation. On one plot the sweet clover was turned under ahead of the corn as a green manure to make this a 2-year rotation. On the other the sweet clover was allowed to mature and its seed was harvested. This left the sweet clover trash on the land during the third year in the rotation ahead of the corn.
With sweet clover as green manure and with (a) lime, (b) lime and phosphate, and (c) lime, phosphate and potash, to give increasing amounts of sweet clover to be turned under with the resulting more bushels of corn per acre as more fertilizers were put on the land, the hogs recorded their choices as follows: (a) 100 percent; (b) 80 percent; and (c) 67 percent, respectively for the above order of the fertilizers. They were not voting in favor of putting more sweet clover under by the help of more kinds of fertilizers, nor were they voting for more bushels of corn yield per acre. In fact they were “again” all of it. But with the sweet clover as a seed crop using the entire crop year ahead of the corn, and with these same soil treatments the hog’s vote was for the exactly reversed order of these soil treatments with the figures (a) 62 percent; (b) 85 percent; and (c) 100 percent, respectively.
In the case of this hog choice it was not the minerals added to the soil that corresponded with the particular selection of the grain by the hogs. Surely, then, it was not an increased ash content of the corn or of the wheat as a result of putting mineral fertilizers on the soil ahead of that particular crop that guided their selections. Rather it was some effects prompted by the nature of the organic material turned under as a green manure. When the hog, by its choice of the corn, votes against more kinds of fertilizer elements applied to the soil for sweet clover used as a green manure under that corn, and then votes in the very reverse order when the sweet clover matures as a crop ahead of the same kind of corn under test, surely it is not the simple aspect of the mineral fertilizers as deliverers of such elements that exercises the effects recognized by the hog. Surely mineral fertilizers are not of influence only as minerals. Rather they are in control of what products the plants manufacture in consequence of the minerals’ presence in the soil. Here by their most discriminating selections from amongst these different soil treatments, the hogs were demonstrating the same uncanny capacity as able compounders of their rations that they demonstrate before the self-feeder.
Hogs May Well Help Us Find the Better Feeds for Them
Now that we have been farming long enough in this country to have seen soft or starchy wheat follow the hard or protein-rich wheat going westward; and when the pork market centers have been following the beef market centers also moving in that direction, are we not about ready to believe that the exhaustion of the soil fertility is compelling the production of less protein in both the plant and animal crops and is limiting animal output more to mainly fat? When the wild animals roamed so widely and searched out the feed so carefully according to the soils growing it, can’t we see that the fence that encloses the hog throws on us as husbandmen the responsibility of selecting the nutrients for the hog’s ration with somewhat near the accuracy and delicacy with which the hog could do it herself? Have you ever thought that you might use the hog to test the corn lots from different parts of your farm for their differences in feed value? Are we not now approaching the time when perhaps an animal assay may be a good basis for discriminating against the use of one lot of corn from soil of neglected fertility and for acceptance of another lot of feed according to the hog’s approval of the better fertility of the soil growing it? If your skepticism about this flares up why not let the hog demonstrate for you before the self-feeder in your own hog lot where you can try a few hundred pounds of each different grain and have the hog’s judgment support you in the decision? When more hogs can speak to us by this method we shall not delay long our increased attention to the fertility of our soils for higher feed values. The conviction will soon become universal that more efficient hog production can well be founded on the fact that better soils make more and better hogs.
