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ROOTS, TUBERS, AND OTHER SUCCULENT FEEDS
Root crops are grown for stock feeding to only a relatively limited extent in this country. There can be no question as to their value for this purpose; all agree that they are highly nutritious feeds and greatly relished by farm animals. The main objection to their use is the cost and the difficulty of growing them. It may be that this objection is, in general, well founded, and that there are crops equally valuable as stock feeds that can be grown with less labor and expense,e.g.,Indian corn in the central and eastern States, and alfalfa in the West, to mention only those two important forage crops. But roots have a special place to fill in the feeding of livestock. They have a very beneficial effect on the health and the production of milch cows, ewes, and other farm animals and can often be produced in immense quantities, making it well worth while for stock farmers to look into their culture.
The main reason why roots are not grown more extensively in the dairy sections of our country and elsewhere is that corn silage is now a common feed on dairy and stock farms. Silage compares favorably with roots as regards nutritive effect and can, as a rule, be produced at less expense and in larger yields of dry matter per acre.
Relative Yields of Roots and Silage.-A number of experiment stations have furnished data for a comparison of the yields and the cost of production of roots and corn silage; in these experiments roots of different kinds were raised for one or more years under similar conditions as those for Indian corn. The following table shows the average yields per acre of four kinds of root crops and of Indian corn obtained in experiments at the Maine, Pennsyl. vania, Ohio, and Ontario (Guelph) experiment stations:
Comparative Yields of Root Crops and Fodder Corn.
Yield of root crops per acre
Yields of fodder corn
Total weight, pounds
Dry matter, pounds
Green substance, pounds
Dry matter, pounds
The figures in the table show that larger gross yields were obtained in the case of all roots, except sugar beets, than of corn; on the average for all four root crops, nearly 17 tons were harvested per acre, against 16 tons of fodder corn. The amounts of dry matter harvested in these crops were, however, 3792 pounds in roots and 5757 pounds in the corn, a difference of 52 per cent in favor of the latter crop. The roots have a somewhat higher digestibility than fodder corn. If we assume that the dry matter in the former crops is 87 per cent digestible, on the average, and that of the fodder corn 70 per cent digestible, we find that there is a difference of 22 per cent in the yield of digestible matter obtained per acre in favor of the fodder corn. It is fair to assume that both kinds of crops were grown under as favorable conditions as possible in these experiments, and may, therefore, conclude that fodder corn will produce, on the average, about onehalf more dry matter and over one-fifth more digestible matter per acre than root crops under conditions similar to those which prevailed in these experiments.
While accurate information as regards the cost of raising roots and fodder corn is limited, it seems evident, from the accounts published by different stations, that it will cost at least twice as much to grow, harvest, and store a ton of roots as to grow and put a ton of Indian corn in the silo. When calculated on a basis of the cost of total dry substance or digestible matter in the two crops, the comparison, therefore, comes out still more unfavorably for root crops. Both in point of the actual yields secured and the expense of growing, roots are, in general, less desirable crops to raise than Indian corn wherever the conditions are favorable for the culture of the latter crop.'
In view of the facts stated, it is not surprising that root crops are grown to only a relatively small extent for feeding purposes in this country, and no system of farm management can be safely advocated that would give prominence to the growing of root crops by American farmers as a general proposition. There are, however, conditions where it may be advisable to grow roots to a much larger extent than is now done, outside of the culture of sugar beets for the sake of sugar production; this is a different proposition from the growing of roots for stock feeding, and is not considered in the present discussion. The more important ones of these conditions are discussed in the following paragraphs.
Value of Roots.—Root crops are especially valuable as appetizers, for exhibition animals, and for dairy cows that are being
See Ohio Monthly Bul. i, 2.
fed heavy rations with a view to securing a maximum production of milk. For these purposes no crops are equally valuable to farmers and breeders. Roots are also grown to advantage where Indian corn will not do well on account of climatic and other conditions. They grow best in a cool and moist climate. This may be inferred from the fact that they are important crops in European countries, especially Great Britain, where the growing of turnips is a distinctive feature of farming and figures largely in the making of the fine quality of mutton and beef produced there. Also in Denmark, a highly specialized dairy country, the growing of roots, especially mangels and rutabagas, is largely practised, and their culture has increased in a marked manner during the present century, because the dairy farmers have found it advantageous on agricultural and economic grounds.
Roots are, in general, characterized by a high digestibility and palatability. They contain large proportions of water, as has been shown, viz., 70 to 90 per cent, and only small amounts of both fat and fiber. The protein is also low, and about 40 per cent thereof is in non-protein form. The nitrogen-free extract, on the other hand, is relatively high and consists largely of soluble carbohydrates. The root crops are, therefore, especially valuable sources of carbohydrates. They are greatly relished by stock and have a favorable influence on their digestion and general health. The only exception is that care is necessary in case of feeding root crops (mangels and sugar beets) to breeding rams and perhaps also to ewes and cattle, on account of the possibility of formation of kidney and bladder stones. There is no danger in this respect in the case of fattening animals, according to the Iowa station.la
The main root crops used for feeding farm animals in this country are mangels, rutabagas, turnips, sugar beets, and carrots. Cabbage, rape, and kale belong to the same botanical genus as turnips and rutabagas (brassica), of the mustard family (Latin name, cruciferæ), and parsnips belong to the carrot family (umbellifera). These crops will now briefly be considered.
Mangels are also called mangel-wurzels or field beets (Beta vulgaris, Fig. 22). Like root crops in general, mangels have a high feeding value for the amount of dry matter they contain, which is less than that of any other root crop, viz., 9 per cent on the average. There is considerable difference in different varieties in this respect, the average dry matter contents of these ranging between 6 and 16 per cent. The average digestion coefficients for the dry matter of mangels is 87 per cent, and that of the carbohydrates 95 per cent. The carbohydrates are largely sugar and pectins, and make up nearly 70 per cent of the total dry matter. The protein substances (nitrogen x 6.25) consist of only 40 per cent of true protein, the balance being amides and nitric acid combined with alkalies. Very large yields of mangels are grown on rich land and with an ample water supply. Ontario Agricultural College reports a yield of nearly 28 tons to the acre, and Cornell station 23.6 tons, the fine average for five different stations being about 20 tons.
la Bulletin 112; Farmers' Bulletin 465.
Mangels grow considerably out of the ground and are easily pulled by hand. In the mild winter climate of the southern States
and California they are generally left in the field until wanted for feeding, while in the eastern and central States they are stored in root cellars in the fall and kept cool and ventilated. They should not be fed for a few weeks after harvesting, as the freshly-harvested mangels tend to scour stock. Mangels furnish a good feed for all kinds of livestock, except perhaps horses. They are usually run through a root cutter or pulped before feeding. Danish feeding experiments have shown that the dry matter of mangels has a feeding value similar to grain feed, pound for pound, and that they may largely replace grain in feeding milch cows when substituted in this ratio—say 1 part of grain for 10 to 15 parts of roots, according to the water content, or, on the average, 1 to 121/2 by weight. Danish dairy farmers feed as much as 100 pounds of mangels per head daily to their cows, and similar heavy root feed
ing is also practised by eastern dairy farmers who are feeding their cows for official tests with a view to securing a maximum milk yield. Half-sugar mangels are recommended by the Cornell station as the most desirable root crop to grow for stock feeding.?
Rutabaga or Swedish turnip (Brassica campestris, Fig. 23) gives yields similar to mangels and, as a rule, contains somewhat more dry matter. It is considered a good sheep feed and also makes an excellent winter feed for swine, especially for brood sows. Rutabagas are extensively grown by British and Canadian farmers, but less than mangels or sugar beets in this country.
Kohlrabi (Brassica caulorapa) has been developed for its thickened stem instead of for its leaves and root. Although not a root in the botanical sense, it may be discussed under this heading, as it serves the same purpose as roots in stock feeding. According to the Cornell station, kohlrabi can be grown wherever rutabagas are grown, and will thrive under similar conditions. In the middle West, where rutabagas have a tendency to run to necks and form little root, this crop is a good substitute. The yields of the two crops appear to be about the same; as kohlrabi grows well out of the ground, it may be readily pastured by sheep, and these animals also relish greatly the leaves of the plant.
2 Bulletin 317.