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 Gowen, J. W. Search for Related Content PubMed Articles by Gowen, J. W.

Studies in Milk Secretion

X. Relation Between the Milk Yield of One Lactation and the Milk Yield of a Subsequent Lactation in Guernsey Advanced Registry Cattle¹

Maine Experiment Station, Orono, Maine

ABSTRACT

This study presents the data on the Guernsey breed to determine the worth of an advanced registry record for milk yield as an indicator of the milk yield of a subsequent lactation. The major conclusions may be stated briefly.

Environment may materially effect the milk yield of a cow. Thus Guersey cows on retest produced over 1000 pounds milk more than their sisters on first test at the same age.

The variation of Guernsey milk yield agrees with that of the other breeds.

The relation of the milk yield of one lactation to that of another is high, ranging from 0.462 to 0.811 in the correlation scale. Compared with a pure-bred herd of Jerseys, the average coefficient of correlation is nearly 0.15 higher for the Guernsey advanced registry cattle than it is for the Jerseys. Compared with the records for egg production, the Guernsey milk records indicate with much greater accuracy what the subsequent retest milk record will be than do the egg records for one month indicate what the subsequent eleven months' egg record will be for White Leghorn hens.

Equations are presented to determine from one lactation's advanced registry record what will be the probable record at a subsequent lactation.

¹ Paper from the Biological Laboratory of the Maine Agricultural Experiment Station, No. 144. This paper is one of a series of investigations in animal husbandry the continued prosecution of which has been made possible by a grant to the author from the Rockfeller Institute for Medical Research.