FOR BUTTERFAT

Nelson Evening Mail, Volume LXXII, 16 January 1939, Page 7

FOR BUTTERFAT

FEEDING OR BREEDING ? VALUE OF RECORDS ANCESTRY THE CHIEF FACTOR Farmers are always trying to discover some method of feeding their cows which will improve the fat content of the milk. But the opinion among scientists, as well as the experienced practical men, on the whole, is that feeding has very little if any, influence. The weight of milk yielded oy a covv can usually be modified fairly easi’y by changes in feeding. On the other hand the butterfat content of any.cow's milk seems to depend almost entirely on her ancestry. When a female calf is born she is endowed with a capacity to produce milk, when mature, containing a certain percentage of fat, which varies slightly with the animal’s age. but which cannot be altered by changing her diet. Jersey and Guernsey cows are, ot course, famous for the high butterfai percentage of their milk, while among Shorthorns and other breeds some individuals and strains yield much richer milk than that given by others of the same breed. If it is desired to level up the average butterfat yield of a herd, the only means of doing so is to breed from parents who come of strains noted for the richness of their milk. SOME EXCEPTIONS To the general rule that feeding has no influence on the quality of the milk, there are, it is true, a few apparent exceptions. One is seen in the effect of the early summer pasture in lowering the percentage of fat—a well-known and annual occurrence. Again, ir cow:* have been underfed, either through accident or ignorance, and are afterwards put on a properly-balanced ration, there is almost certain to be an increase, not only in the quantity of milk yielded, but also in the butterfat percentage of the milk. Liberal feeding when a cow is dry. too, will cause her to store up fat on her body which she may use to increase the fat percentage of her milk for a few weeks after calving. Thus a cow which calves down in good flesh is likely to give a higher yearly fat content in her milje than if she were in poor condition when she calved. The experience of most farmers will corroborate this.

138 cows were 84721 b milk, 6.05 average | test. 5121 b butterfat. I The production economics show that, whereas the other breeds required 17} food ts to produce 2.21 b butter, the average Jersey requirement was only 15 iood units. The Jersey produced from each 100 fond units 2.21 b butter more than the other dairy breeds, and her average butterfat test was 1.7 per cent, higher.