Campus Units

Animal Science

Document Type

Article

Publication Version

Published Version

Publication Date

1980

Journal or Book Title

Journal of Dairy Science

Volume

63

Issue

7

First Page

1138

Last Page

1144

DOI

10.3168/jds.S0022-0302(80)83059-1

Abstract

An individual quarter milker was used to measure milk yields at staggered 20-s intervals from 198 Holstein cows in the Beltsville Agricultural Research Center herd. Several flow rate variables were calculated. The 2792 quarter samples of milk yield were taken during afternoon milkings. Yields and rates of individual quarters were examined as were effects of lactation, stage of lactation, machine, and cow. Differences between rear and front quarters were .78 kg for yield and .12 kg/min for maximum rate. Differences between left and right quarters were .02 kg/min for maximum rate and .10 kg for yield during the period of maximum rate. Yields departed from front-rear and left-right side patterns. This lack of symmetry, interactions of front-rear by side, for the yield traits may have been from permanent environmental causes such as developmental error, mastitis, or injury. Cow effects were important for all traits as were the effects of lactation, stage of lactation, and machine for many of the traits. Repeatabilities were .63 for maximum rate and .60 for average rate. Designers of milking machines may wish to account for differences between quarters in newer milking machines.

Comments

This is an article from Journal of Dairy Science 63 (1980): 1138, doi:10.3168/jds.S0022-0302(80)83059-1. Posted with permission.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

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