MINERALS FOR COWS.

Southland Times, Issue 20445, 24 March 1928, Page 14 (Supplement)

MINERALS FOR COWS.

INVESTIGATIONS BEING MADE. NEW PHASE OF FEEDING. The knowledge of mineral requirements of dairy cows has not advanced far enough to enable one to say how much of the different minerals should be supplied in the feed of a cow to meet her requirements of body maintenance and for specified amounts of milk. The principal reason for this is the fact that all of the factors governing the assimilation storage, and use of minerals by the cow are not clearly understood. For a time, experimentalists in animal nutrition were of the opinion that where an adequate supply of protein, carbohydrates, and fats was fed in the correct proportions, the requirements of cows were met. New knowledge in nutrition, however, shows that under certain conditions this is not necessarily true. In other words, it has been definitely shown that some attention must be given to the mineral requirements of cows, especially those of comparatively high production and persistent tendency. Thus far there 'is nothing to indicate that our commonly used feeds are deficient in any of the mineral elements needed excepting calcium phosphorus, and iodine. In certain sections where the soil is quite low in iodine the crops grown thereupon are likewise low in this element. The addition of iodine has been found to be helpful in prevention of goitre. A section has been found in Minnesota where crops grown on soils low in calcium and phosphorus when fed continuously to cattle generation after generation produced stunted, scrub-like appearance in the cattle and resulted in decreased production and in considerable breeding difficulties, principally premature birth and failure to conceive. It has been observed that the calcium and phosphorus requirements of high producing cows during their periods of maximum production are not fully met in the feeds given even though these feeds supply liberal quantities of both elements. In connection with this it has been shown that cows during these periods of maximum production deplete the normal level of calcium and phosphorus in their bodies, principally of the bony skeleton. In fact, it has been shown that a persistent milker fed on a calcium deficient ration will deplete as much as twenty-five per cent, of the calcium in her bones. This led to a study of the factors that have the greatest influence on calcium and phosphorus assimilation, storage, and use. If these cows deplete their skeletons of these elements during periods of maximum production, when and how do they replenish the amounts taken for milk? Thus far it has been shown that fresh, green feed, such as pasture grass and soiling crops, sunlight, and the rest period are the factors having the greatest influence in restoring the normal calcium and phosphorus balances of the body. The situation with

respect to the mineral requirements of cows is much like a statement once made by a Dutch scientist of plant breeding. He said, “What we know is limited; what we don’t know is infinite.” Enough has been learned thus far to indicate the advisability of providing adequate supplies of calcium and phosphorus and of iodine in certain sections. There is nothing to indicate that the average cow, fed on winter ration that includes liberal quantities of good legume hay, such as alfalfa, clover, or soy bean hay, and given rest period of six weeks or two months during the summer while she is on pasture, will suffer from mineral deficiency. Of the roughages, alfalfa, clover, and soy bean hay have the most calcium. Dried beet pulp is fairly high in calcium. Linseed and cottonseed meal have more calcium than do other commonly used concentrates. Corn is very low in this element. The legume hays are likewise richer in phosphorus than are the other roughages commonly used. Of the concentrates, cottonseed meal, wheat bran, wheat middlings, linseed meal, soy beans, and gluten feed are richest in phosphorus in the order named. Wheat bran has about twice as much phosphorus as soy beans or gluten feed. Corn is quite low in phosphorus. Bone flour contains about twenty-three times as much calcium and fourteen times as much phosphorus as the best legume hay and the best concentrate. Steamed bone meal, finely ground limestone, finely ground rock phosphate, and wood ashes are good sources from which to make mineral supplements. The bone meal and rock phosphate supply both calcium and phosphorus. The limestone supplies calcium; lOOOlbs of wood ashes supply five lbs phosphorus, fifty lbs postassium, and 5001bs calcium carbonate. A mixture of equal parte steamed bone meal, finely ground limestone, wood ashes, and salt would be satisfactory. Where cows are stanchioned, three to five ounces of this mixture per head per day fed with the grain mixture is a good way of feeding. Where cows run loose a part of the day or are on pasture, the mixture may be fed at will like salt in the salt box. It is advisable to keep this mixture before the dairy cattle during the entire year. A separate feeding of salt will not be needed as a rule when this mixture is being fed at a rate sufficient to supply one ounce of salt daily. SHRINKAGE OF CHEESE. EFFORTS TO REDUCE LOSS. The Minister of Agriculture, Hon. 0. J.

Hawken, was present with 100 representa- j tives of dairy factories at Hawera last | week, at the opening of a plant for the manufacture of vacuum cheese containers and the opening of a number of containers in which cheese was packed several months ago under the supervision of Mr P. 0. Veale, scientist at the Hawera dairy laboratory. Twelve containers were opened containing cheeses, some at two days after manufacture and the others at 14 days. In contrast were a number of cheeses crated in the ordinary way. The object was to ascertain the amount of shrinkage in the different methods af handling. Mr Veale found after careful weighing that the shrinkage under vacuum was very small, 141 b for four white unpasteurised cheeses and 41b for four coloured pasteurized cheeses. In contrast the shrinkage in crated cheeses was 22|lb and 211 b respectively. These were all cheeses taken into a container at two days from manufacture. With the cheeses taken at 14 days the shrinkage was a little more. At the same time a container was opened which had been sealed for 14 months and the shrinkage was found to be only 11b. Mr T. A. Winks, president of the Taranaki Dairy Federation, said the saving could be estimated when it wss realised that an average for the first 14 days was 1 per cent, and from that time to arrival on the London market 22 per cent. PIG IMPORTATION. Mr S. Austin Carr, a well-known Auckland business man, has recently imported 17 pedigree Tamworth and Berkshire pigs from Canada. Mr Carr has established a herd of 30 purebred pedigree Friesian dairy cattle on his farm at Hoe-o-tinui, Morrinsville. Mr Carr intends to have shortly none but Friesians on his farm as he is satisfied that these cows are not only the highest producers of butter-fat, but that the great quantities of skim milk make them the ideal cows to combine with pig raising.