MILK PRODUCTION

Opunake Times, 24 February 1933, Page 3

MILK PRODUCTION

QUESTION OF QUALITY. BUTTEE-FAT CON TENT. In “The Farmers' Guide to Agricultural Eeseaich, compiled by the Eoyal Agricultural Society ot England, there is an interesting review bv Mr. James Mackintosh of the progress made in dairying research during 19J2. He refers to practical possibilities, so far as butter-fat content is concern ed.

The circumsances which influence the composition of milk, such as the breed of cow, Lie stage of lactation, and the efficiency of the milker, are known to most; dairy farmers. It is also recognised that when a longer interval than 12 hours occurs between milkings, as through the night, the percentage of fat is lowered, and when the time interval is less than 12 hours, as through (he day, „the fat is increased. It has been suggested that the decrease in fat is not due simply to the long interval and that it is necessary to consider other factors which may operate. Interval Between Milkings.

An experiment with six cows has been carried out which gave a 15-hour milking interval during the day for two to three months and a 15-hour period during the night for the same period subsequently. The results from all the cows showed that a bigger proportion of the 24 hours’ yield was obtained after the night interval than after the dav interval, and that in four out of the six cows a higher fat percentage was found after the day interval than after the night interval. The inference is that during the winter period of milk production night itself, or factors operating at night, tend to high milk production of low fat content. Such factors include darkness, restfulness, quiet ness, temperature, and, in some cases, scarcity of water. The results of milking cows three times daily and of irregubuity in milking and feeding are often discussed by dairy farmers, and some useful additional information on these points is available as n result of experiments made in the United States, Four cows, similar in every respect, receiving the same quantities of food, were milked twice and thrice daily in alternate periods of 40 days throughout a lactation period. The results showed an increased production for the thrice-milking period of about 11 per cent milk and 10 per cent fat, and at every change from twice-daily to thrice-daily milking there was an immediate increase in production and vice versa.

Three-Daily Milking. Another experiment on the same subject was carried on throughout successive lactation periods in order to obtain a measure of the effect of thrice-daily milking over a long period. In this case eight Friesian cows were used and the increase, as a result of milking' thrice daily, varied greatly for different cows, ranging from 7.8 per cent to 42.8 per cent, with an average increase of 2U per cent for milk and 21 per cent for weight of fat over periods of seven to 12 mouths. This experiment showed increases approximately twice those obtained in the shorter test, which may be attributed mainlv to a greater persistence in milk vield.

These experiments also shed some light on an aspect of thricedaily milking which is of interest to many fanners in this country, It is shown that milking three times daily increases the yield of milk and of fat to practically the same extent, hence the fat percentage in the milk is not affected. It. has been noted by fanners that cows milked thrice dailv at equal intervals give very uniform yields at each milking, but there is a marked variation in the fat percentages, the morning yield containing least fat,_ and the afternoon vield containing most. The same results have been noted at the London Dairy Show, but the American experiments do not deal with this aspect: of the question. A Kentucky Test.

It is often said that, cows with yellow shin will yield milk with a higher luitter-fat content. But a test made in Kentucky disputes this popular opiniofi. Careful examination was made of 165 Jersey cows and the conclusion readied was that there is no correlation in this breed between the milk and butter production and (he amount of colour secretion in the skin, it was found that on numerous occasions cows witli the highest secretions gave milk with little colour. Another investigator states that the chief American dairy breeds rank in milk colour from highest to lowest as follows: —

Jersey, Guernsey, Ayrshire, and Friesian, but that every breed shows a marked variation in intensity with different animals, and that in every breed there aic some cows which yield milk as deep in colour as many Guernseys.