Lactation Response to Artificially-Dehydrated and Pelleted Alfalfa Added to a Ration of Timothy-Grass Mixed Hay and Grain

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Abstract
The lactation response to the addition of graded levels of artificially-dehydrated and pelleted alfalfa to a basal ration of timothy-grass mixed hay fed ad libitum and grain fed on the basis of 1 lb./5 lb. of FCM was studied in a 100-day trial. Twelve Guernsey and 12 Holstein cows whose avg. daily production of FCM and avg. live wt. during a 30-day base period were 33.7 [plus or minus] 1.9 lb. and 1083 [plus or minus] 42 lb., respectively, were used. For each addition to the basal ration of 0.5 lb. of pelleted alfalfa from 0.0 through 1.5 lb./l00 lb. of live wt., the following changes were found: the ad libitum consumption of timothy-grass mixed hay decreased 1.6 [plus or minus] 0.1 lb./cow/ day; the grain fed increased 0.9 [plus or minus] 0.1 lb./cow/day; the dry matter, total digestible nutrient (TDN) and NE intakes increased 4.0 [plus or minus] 0.3 lb., 3.0 [plus or minus] 0.2 lb., and 2.7 [plus or minus] 0.1 therms/cow/day, respectively; the FCM increased 2.7 [plus or minus] 0.4 lb./cow/day; the carotenoid and vit. A concn. in the milk increased by 5 [plus or minus] 1 and 1.3 [plus or minus] 0.1 /[mu]g., respectively; the live wt. increased 0.20 [plus or minus] 0.05 lb./cow/day; and the lbs. of TDN and NE required to produce a ib. of FCM after accounting for maintenance requirements increased 0.066 [plus or minus] 0.015 lb. and 0.065 [plus or minus] 0.013 therms, respectively. With the exception of vit. A concn. of the milk for which Guernseys increased at a greater rate than did Holsteins, no significant breed difference in response was observed.