The Relative Feeding Value of Alfalfa Hay and Alfalfa Light Timothy Mixed Hay at Approximately The U. S. No. 1 Grade Level

The relationships between hay grades and classifications, as defined by accepted standards, and true feeding value have not been definitely established.This study reports results of an investigation of the relative feeding value of hays classified as Alfalfa Light Timothy Mixed (10-15% timothy) by using 24 Holstein heifers as the experimental animals.The resulting weight gains do not justify the present 5% limit on timothy in alfalfa h~y by U. S. standards.Editor.The present system of grading hay according to standards published by the U. S. Department of Agriculture (5) has contributed much in the way of uniform definitive terminology.As a result the system and its terminology are rather widely used in the hay trade, for reporting of experiments, and in educational publications.However, the relationships between hay grades and classifications, as defined by the standards, and true feeding value have not been adequately investigated.Alfalfa, being the major legume hay for dairy farms, has received more attention in this respect than most other classes of hay.A comparison of U. S. No. 1 Extra Leafy Green Alfalfa Hay and U. S. No. 3 Leafy Brown Alfalfa Hay 1 by Kelkas and Gullickson (4) showed the former to be of higher feeding value as measured by weight gains in dairy heifers and the need for grain supplements.In work previously reported by the authors (2) it was shown that in alfalfa hay of U. S. grades No. 1, No. 2, and No. 3, the higher grades were associated with significantly higher feeding value, although some overlapping of grades occurred.More recent work reported by the authors (3) demonstrated that hay classified as Alfalfa Heavy Timothy Mixed having an average timothy content of 44% was of significantly lower feeding value than hay classified as alfalfa, in which class the timothy content is limited to 5%.Alfalfa normally matures at an earlier date than timothy, the harvesting date of alfalfa-timothy mixtures usually being governed by the maturity stage Received for publication November 19, 1955. 1 These grade designations are not in accord with the USDA standards (5).1142