HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Alexander, M. H. Articles by Yapp, W. W. Search for Related Content PubMed Articles by Alexander, M. H. Articles by Yapp, W. W.

Comparison of Methods of Estimating Milk and Fat Production in Dairy Cows

Department of Dairy Science, University of Illinois, Urbana

ABSTRACT

Production records of milk and fat constitute an important and necessary part of the program of herd improvement in dairy cows. In Illinois there are at present about 1,123,000 dairy cows of milking age, of which less than 4 per cent are being tested for production. This is too small a number to afford a satisfactory basis for any widespread improvement.

Cost may be a limiting factor in restricting the scope of testing. This is suggested by the fact that in Illinois in 1936 there were 29 herds, including 326 cows, on Advanced Registry test. The numbers on this type of test had increased by 1945 to 48 herds and 652 cows. In 1936 there were in Illinois 27 herds, including 619 cows, in Herd Improvement Registry testing. By 1945, this number had increased to 165 herds including 3,586 cows. In 1936 there were 23,812 cows tested in Illinois in Dairy Herd Improvement Associations. This figure rose to 44,282 in 1941. The number declined seriously during the war and is not yet back to the 1941 peak. Table 1 gives the comparative costs of the three different types of testing.

This investigation was carried out to devise a method of testing that will lessen the amount of time and labor required on the part of the tester and the cow owner, and so to spread testing efforts over a wider area.

The semi-official test, the test used in this study for the standard or measure of reliability of other tests, either now in use or proposed, was adopted by the various breed associations as a sufficiently accurate method of measuring production. It departed from the method of the official test by the device of using only a 2-day test period each month together with daily milk weighs. Later the test period was reduced to 1 day per month. Later still the bi-monthly 1-day test period was adopted as optional with the producer. The results obtained by this departure from the strictly official method of supervision of tests encourages the belief that some further departure from the present methods of testing may yield sufficiently satisfactory results to merit consideration.