These studies make it apparent that physiological efficiency in feeds is far from uniform, and so far as cattle are concerned,

FIGURE 1. COW FED EXCLUSIVE CORN RATION

Compare vigorous condition of this animal with that of the wheat-fed cow (Figure 3). leave no doubt as to the disastrous effect of exclusive wheat raticns. Our present feeding standards, however, make no effort

ments which have heretofore been the basis on which many accepted conclusions have been founded.

STUDIES IN PROTEIN NUTRITION

Heretofore the determination of the so-called "nitrogen balance," which is a study of the relation between the nitrogen taken into the body in the food, and that excreted from the body,

has been a laborious and expensive process of ascertaining important facts in animal nutrition. Prof. McCollum, using nitrogen

FIGURE 3. COW FED EXCLUSIVE WHEAT RATION

Note less thrifty condition of this animal compared with corn-fed cow (Figure 1).

free rations (starch, water, and inorganic salts) with swine has confirmed the observations of Folin, in finding the nitrogenous body known as creatinin, a constant factor in the urine of mammals. As creatinin re

presents an end product of the activity of the body cells, it was thought that the determination of this substance might be used as an index of the maintenance needs of an animal for protein. Prof. McCollum has shown that the amount of creatinin eliminated daily by a growing animal rises in proportion to the amount of nitrogen retained in the body. Sufficient experimental work has been done to warrant proposing a provisional factor for expressing this relationship. If later investigations definitely establish a relation between the amount of nitrogen retained in the body during growth, and the simultaneous rise in the amount of creatinin eliminated, this would make possible an accurate estimation of the nitrogen retention.

during a long feeding experiment, by observing the creatinin excretion for a few days at the beginning and again at the end of the experimental period. The use of such a "creatinin index" would replace the much more laborious and expensive continuous "nitrogen balance" method, and be of great service in simplifying these laboratory processes in animal nutrition work.

Young pigs were fed on pure proteins with results which indicate that certain proteins may maintain a normal condition as to nitrogen in the animal, and yet be unable to produce growth. From this it appears highly probable that the processes of maintenance and growth are not wholly the same, and that certain proteins may serve one function, but not the other.

The apparatus for these metabolism studies in animal nutrition has been decidedly improved during the past three years, and a description of this technical apparatus published.

MINERAL REQUIREMENTS OF FARM ANIMALS

The Agricultural Chemistry and Animal Husbandry departments have continued this past year their cooperative work on the lime (or calcium) requirements of swine during various stages of development. The normal grain feeds are found to contain insufficient lime for the best development of growing animals, and the addition of floats (calcium phosphate), ground limestone (calcium carbonate), or finely ground leguminous hays, such as alfalfa or clover (which are rich in lime), are especially helpful in developing a strong skeleton. The experimental results indicate that mature swine not forming new muscular tissue, or undergoing such physiological processes as milk secretion and reproduction, can be maintained in a normal condition on a low lime supply. It has been claimed that if pregnant animals are supplied with an abundance of lime, the skeleton of the offspring will be larger and heavier than normally, and contain increased quantities of lime. A study of this particular problem with swine indicates no apparent influence where the mother received a high lime intake.

The theory has been advanced that rations containing a large amount of magnesium compared with the amount of calcium present will not produce a normal development of skeleton, and may even lead to disease. It is asserted that when an excess of magnesium is taken into the body, the calcium salts are with

drawn from certain tissues, to counteract the poisonous effect of magnesium, and that later both calcium and magnesium are excreted from the body. The so-called "bran disease," "shorts disease," or "miller's-horse rickets" in horses (which is an affection of the bone) has been attributed to an excess of magnesium in relation to calcium in the food. This problem has been studied with swine, and it has been found that where magnesium salts are directly injected into the blood or added with the food as sulphates or chlorides, an increased excretion of calcium occurs in the urine. However, where such feeds as wheat middlings or wheat bran are given, which contain a large amount of magnesium compared to the content of calcium, this increased! calcium excretion does not occur. The poor results with such feeds do not appear to be due to the excess of magnesium, but possibly to an insufficient supply of calcium.

GRAIN MIXTURES FOR FITTING SHOW SHEEP

The value of various grain mixtures for fattening wethers for show yard competition has been studied for three years by the Animal Husbandry department. Each year Mr. Kleinheinz has fitted four lots of wethers which have been fed the following grain mixtures: lot I, five parts oats, four parts corn, one part wheat bran; lot II, same with peas substituted for corn; lot III, same with barley in place of peas or corn: lot IV, five parts oats, five parts barley. Each lot received in addition, the same kind and quantity of roughage and succulents, consisting of clover or mixed hay, cabbage, and roots.

The sheep thus fitted have been shown each year at the International Live Stock Exposition and judged in the ring and on the block.

On the basis of the awards, lot II has ranked first for the past three years; lot III, second; lot IV, third; and lot I, fourth. The ration containing corn, fed to lot I, had a tendency to produce a soft, flabby carcass, the fat being deposited largely on the exterior of the body. With scarcely an exception, all the wethers of lot II showed carcasses in which the fat and lean were wel! mixed and the flesh was of firm texture and of the desired cherry red color that meat experts demand.

These wethers were fitted early in the season from August to the last of November, during a period which is not considered

suitable for the economical production of mutton, and the ra tions were on the whole more expensive than those ordinarily used for mutton production. Consequently these trials will be of special interest and value only to show men who feed for the show ring with the idea of bringing out all the possibilities of the individual selected, and to farmers desiring to produce the most superior type of mutton carcass.

SOILAGE VS SILAGE FOR DAIRY COWS

During the past two summers the Animal Husbandry department has compared the value of soiling crops and corn silage as means of supplying summer feed to the dairy herd. Soiling crops sown from April to June furnished a continuous supply of green forage during the dry season from July to September. In 1910 green clover, a mixture of peas and oats, sweet corn, sorghum, and field corn, were used, but in 1911 green clover and sorghum were discontinued.

Half of the dairy herd was fed corn silage and half, soiling crops, each lot being kept on scant pasture and receiving equal amounts of concentrates. Silage was greatly preferred to the early soiling crops, such as green clover, sorghum, and peas and oats, and the silage-fed animals produced a greater amount of milk. Larger yields of corn than of soiling crops were secured. Another important factor is that the soilage system required much more time daily, and that too, during the busiest season of the year.

A consideration of all the factors involved indicates that the farmer can well afford to have corn silage available for summer feed up to the time the corn crop reaches the milk stage, when he can perhaps better afford to feed green corn than to continue feeding silage.

DIAGNOSIS OF CONTAGIOUS ABORTION

From many points of view, the disease of contagious abortion. is more to be dreaded by dairymen than tuberculosis, because heretofore it has not been possible at the outset to diagnose it readily, and no known method of treatment has proved successful.

Some years ago Dr. Bang of Denmark isolated the specific organism of this disease, and recently a scientific test, known as