FARM AND DAIRY

Rotorua Morning Post, Volume 1, Issue 64, 6 November 1931, Page 5

FARM AND DAIRY

FEEblNG DAIRY COWS TEMPORARY STERILITY SIGNIFICANCE OF MINERAL STARVATION. (All Rights Reserved.) The average farmer believes when he turns his cows on to luscious pastures that he is supplying them with all they can reasonahly want in the wa'y of nourishment to maintain themselves in health, develop a ealf, and produce an abnormal amount of milk I and butterfat. But is he? To answer this question one must consider for a moment what a cow demands for these processes. For her own maintenance she needs proteins and carbohydrates to form blood and tissue; lime phosphates and vari- = ous other minerals to form the skeleton and to supply the blood and various glands. For her calf, while she j, is carrying it, she needs these ingredients, but with the differenee that mineral matter is still more in demand than for the mature animal. For the abnormal supply of milk which she is bred to produce she must ' have these minerals in abundance — they are the chief ingredients of the milk. Handicaps* One of the greatest handicaps dairy farmers have to face is termed "temporary sterility." By careful selection and the use of the best sires procurable, a dairy farmer builds a choice herd of heavy-producing cows. Then, just when he should enjoy the benefit of his care and skill, he iinds a- number of his cows do not get in calf. The most unfortunate, and yet significant feature is that those cows which are temporarily sterile are almost invariably the heaviest producers in his herd. The significance of the matter lies in the circumstance, that so far research directed to the cause of this trouble has not disclosed any germ likely to cause the steriie condition of the animal; and because there appears to be a definite relationship between milk yield and temporary sterility. Research into problems of animal reproduction would seem to show that all life is subject to three main laws of nature, which in their order of importance are survival, reproduction and production. In fine, the first urge of natnre is that the animal shall if possible survive; secondly, that as soon as possible it shall reproduce its own kind; finally, that ali surplus vitality left after the two preceding urges have been satisfied shall be devoted to sustaining some life other than its own. Nature Intervenes. Now, it is obvious that, if survival and reproduction exhaust the forces of an animal, production must go by the board. Similarly, if survival is threatened because production has exhausted all the surplus force, and more, Nature steps in, and by making the animal temporarily sterile ensures its survival. Year by year, we continue to carry our dairy cows on the same pastures, content so long as there is grass in abundance, forgetting that essential minerals are being exhausted from the soil and therefore from the grass; that our cows consequently suffer through mineral starvation. Nature intervenes when the cow's survival is threatened by this draining of minerals from her system. It may well be that when a cow is called upon to take from her own system minerals which should be in her feed, Nature protects the animal by rendering her sterile, pending recovery of the cow's mineral balance. In the light of the foregoing the eonclusion must be: Prevention of sterility may be found in the feeding of minerals for which animals are being starved.