DEPRECIATION OF DAIRY HERDS

Southland Times, Issue 23438, 19 February 1938, Page 19

DEPRECIATION OF DAIRY HERDS

Present Rate Too High NORMAL COW’S MILKING CAREER The present rate of herd depreciation in the Dominion is extravagantly high. Estimated to average 22 per cent, it is costing the dairy industry onetwelfth of its butterfat returns. How can it be reduced? (asks H. A. S. in The New Zealand Herald). The question of what is a fair depreciation rate, may be discussed. All dairy men know of cases of remarkable old cows, that go on and on, producing returns that could be envied by many younger matrons. I know of several cows, aged from 10 to 14 years, that are still going strong. When the Wairarapa Herd Testing Association s results were- published last winter, I analvsed the statistics and found a remarkable percentage of aged cows, from nine to 13 years in the top flight. Such cows indicate what possibilities there are of prolonging the useful life of our herds. A CONTRAST

What a contrast their careers afford with that of the average dairy cow, which comes to profit at two and aquarter years, milks for four and a-half seasons and is culled at six and threequarter years. A normal life is thus:—To cojne to profit at two years, to milk in ascending production to six years, then to decline gradually, so as to give in her ninth year, her first season’s production only. The vetc'jn cows referred to are unusual. Hie normal cow’s active milking career is thus one of seven seasons, contrasting with our present average of but four and a-half seasons. It is evident, therefore, that the present rate of herd depreciation is over 50 per cent, excessive. Could all our cows work out their full normal careers, New Zealand’s dairy farmers would be saved £700,000 a year on herd replacement. THREE APPROACHES

The problem of lengthening the useful life of our dairy cows may be approached from . three angles—husbandry, veterinary and breeding. The best of cows can be ruined by bad handling, by which term is meant their feeding and milking and the general attention they receive. On the other hand, cows constitutionally weak,.in the widest sense of the term, will give trouble even though they are “kept in glass houses.” In fairness to our cows, it must be admitted that they are not as bad as the culling rate would paint them. It is not wholly their fault that they

knock off work after but fou» and ahalf years’ productive effort. Winter starvation, food deficiencies, faulty milking, unhygienic conditions and other husbandry faults, unquestionably take heavy toll of our herds. MAJOR SOURCES OF TROUBLE These factors are all within the farmer’s control; they are not matters for veterinarians, or for breeders. They are a major source of those diseases and afflictions which the veterinary people are asked to cure. Recently a significant report was issued by Mr Alan 1 Leslie, officer in charge of the veterinary service of the Federation of Taranaki Dairy Factories. The essence of that report was that a close relationship had been found to exist between maladjustment of milking machines and the incidence of mammitis. It has been decided, therefore, to cartry out a thorough investigation of all factors controlling the efficiency of milking machines, a valuable practical research project. There is considerable opportunity for improvement in the attention arid, feeding given our dairy herds. This is one of the first steps to be taken in lessening the toll of herd depreciation. Veterinary service may rightly be grouped with husbandry, being a specialized form thereof. This service applied both to field and laboratory work, fulfills a dual purpose—to cure and prevent. BREEDING SUPERIOR COWS The third and final approach to the problem of lessening herd depreciation lies in the field of breeding. The great endeavours of our dairy breeders have been concentrated upon the raising of butterfat yields. No like effort has been directed toward constitutional improvement. Reference has been made to veteran cows earning their keep at 12, 13 and 14 years old. A cow law of nature is, that “like begets like.” In New Zealand no real attempt has been made to capitalize such strains. A recent overseas pacer tells of the Ayrshire breeders

“100,000 Club” in the United States. Cows of that breed exceeding a 100,0001 b milk yield become members. There are 118 of them. Those now admitted comprise cows aged, 10, 11, 12 13 and 15 years with butterfat figures around the 40001 b mark.

We have in this country many scores of cows with equal records. It is time we becarpe conscious of longlife production that we honoured a cow, not for a season’s record, but for consistent, long-service production. Appreciation of this factor in breeding and practical application of the principle, would greatly extend the productive life of our dairy herds. There is a tremendous opportunity here,