INTEREST IN BUTTERF AT PERCENTAGES

Bay of Plenty Beacon, Volume 15, Issue 93, 8 September 1950, Page 5

INTEREST IN BUTTERF AT PERCENTAGES

The new final sheets of group herd testing members provide average test for each cow. The value of this practice is so obvious that the Dairy Division has been requested to include it on the cci ti~ ficate of record of “C.O.R. tested” cows. What is it that urges tins interest in the butterfat percentage in the milk of each cow?

For many years, night and day, cows have been milked in New Zealand largely for supply to butter and cheese factories, but also an increasing number for “town supply.” The lower testing breeds have become well established in the liquid milk industry largely because of their greater gallonage. In .fact in England a good cow is referred to as a 1000 gallon cow in the same way as we speak of a 500 lb fat yield. Only legal standards force some recognition of the fact that the Jersey generally is a higher tester than the Friesian and other breeds. It was therefore considered that to maintain the requisite fat .percentage an odd Jersey should be present in a town supply herd. It was seldom considered that some Friesians might test higher than some Jerseys. There was of course a great swing from Shorthorns to Jerseys in the industry after the First World War when herd testing farmers found that the higher testing breed was more economic for supply to butter factories. However, farmers are now demanding bulls from strains proven for high test within’ their fancied breed. This interest in high test has mainly been due to analytical work of the Dairy Board Recording Department. This work presented in annual reports of the department and in the forewords of sire survey and merit registers then warrants careful study. In fact some rather uninformed criticism of the herd improvement movement would not be made if these practical writings had been more widely read.

It is now well known that breeding influences production by 30-40 per cent while feeding and management are responsible for 60-70 per cent. For several years now the - sire survey work has emphasised the generally higher butterfat production of those herds, strains, and cows that have high test for the breed. This is not surprising when it is realised that the 30-40 per cent attributed to breeding is largely controlled by the factors affecting butterfat test. It is of course obvious that the low tester to produce a reasonable amount of fat must have a more imposing udder than the high tester. This will generally improve her type testing, but it is likely also to end in early breakdown through overloading the central suspensory ligament, which —regardless of theories about front and rear udder attachments —takes the weight. Typical Example

A typical example of two cows may be cited. Over the same period they both produced about . 66,000 pounds of milk, but the Jersey with the low test of 5.0 per cent gave 3,2001 b fat while the other with 6.3 per cent yielded 4,200. it is as well to remember that most New Zea-* land farmers—especially with Jersey herds are paid on a fat basis There, is little wonder then that the demand for average test for pedigree records is increasing. This is due to the acceptance by commer-. cial dairymen of advice by the industry’s own officers. Five years ago the importance of test was stressed in the second edition of the sire survey and merit register in which the following caution was also expressed. “Although high butterfat production is strongly associated with high percentage of butterfat in milk, it does not follow that breeding lor high butterfat percentage will in all cases result in high butterfat production. In other words, it does not mean that all herds or all bulls with high testing daughters are by any means all high in butterfat production. It does mean, however, that a far greater number of herds or bulls will be found in the higher butterfat producing groups if the average fat percentage for cows m those herds, or ' daughters of those bulls, is above average.” “Whilst not in any way overlooking or under-estimating the importance of high milk production, the of this work does indicate that within a breed high percentage of fat in milk is of /ery considerable importance in building up high levels of buttferfat production by breeding.”