LIFE OF THE COW.

Auckland Star, Volume LXI, Issue 162, 11 July 1930, Page 17

LIFE OF THE COW.

MAXIMUM OF PRODUCTION. EXPERTS' INVESTIGATIONS. DEMONSTRATIONS AT EXHIBITION. Many a New Zealander lias asked what is the average life of 'a cow in the dairy herd? No doubt this question will arise when the various breeds are beiEg demonstrated at this year's Auckland Winter Exhibition. Recently a statement was made by a professor at one of the agricultural colleges in England that it averages about two and a half years—a statement that nearly took the 'breath away from some of tile farmers he was addressing. It has since occasioned much discussion in agricultural journals in Great Britain. The question has been made the subject of investigation by Messrs. R. R. Kay and Andrew MeCandlish, of the West of Scotland Agricultural College, Glasgow, and their opinion is that the average'life of the cow in the dairy herd is four years.

Result of Inquiry. " Messrs. Kay and MeCandlish have been inquiring into the factors that affect the yield and quality of milk, and have come to 'the conclusion that maximum production in a cow is iisually reached between seven and eight years of age; and on Ayrshire cow is generally expected to bc'at her best at that age, though in some cases greater production may be reached a little earlier or a little later. Then they state definitely that "the average life of a cow in a dairy herd is around four years," and they infer that a very large percentage of cows are removed from the herd before they reach the age of greatest usefulness. A considerable number, of course, are removed as poor producers, -but the investigators say that every possible effort should be made to increase the percentage of animals that remain in the herd until maturity is attained. In this •way the average production could be raised appreciably and considerable economies effected. Increasing the Retained Cows. In the course of their inquiries Messrs. Kay and MeCandlish' found a fairly regular increase in milk and fat production up to the age of seven years', while above it the production tended to decline. Even when a cow had reached maturity she did not necessarily deteriorate rapidly in production. This was another argument in favour of keeping a mature cow actively producing in the herd. They concluded' from the evidence they had obtained that not only had the dairy cow a considerable period of usefulness after she reached maturity but also that there was a tendency to retain good producing cows even longer than other individuals. The practice was justified owing to the breeding value of good producers. It would pay to retain them even after they declined in production if they were still capable of breeding. In the ordinary range of age up to eight or nine years, there appeared to be little risk of a fall in butterfat content large enough to bring it below the legal limit in "the ordinary run of cases. But there was a risk of old cows being below the presumptive standard—a risk that should not b.e neglected.