In this experiment it also was possible to compare the relative nutritive 

 values of each concentrate mixture with each animal. The sixteen complete 

 digestion and utilization experiments were carried out according to the 

 schedule below: 



Feed Consumption Experiment 1952-53 



Twelve milking cows representing the Ayrshire, Guernsey, Holstein, 

 and Jersey breeds were used in an experiment to study the relative consump- 

 tion of coarse and fine feeds. They were paired within breeds according to 

 weight and stage of lactation. The experiment was divided into three five- 

 week periods in order that a double reversal in grain feeding could be 

 achieved. Random selection was used to determine which cow of each pair 

 would receive the coarse feed and which the fine during the first period. At 

 the end of five weeks the cows were changed abruptly to the opposite tex- 

 tured grain and at the end of another five weeks thev were changed back 

 to their original textured grain. The coarse and fine feeds were made from 

 the same lots of ingredients and differed only in texture. They were mixed 

 fresh for each period according to the coarse and fine formulae given in 

 Table 1. 



All cows received their grain at the same time, just prior to milking. 

 The refuse was weighed back at the end of one hour. The amount fed each 

 cow was such that no less than one pound would be refused. The cows were 

 fed all the roughage they would consume. This consisted of a morning feed 

 of first-cutting red clover hay and an afternoon feed of third-cutting red 

 clover silage. Having the cows filled up with good quality roughage was 

 an important factor in emphasizing differences in their desire or ability to 

 consume the two types of concentrates. Records were kept of feed con- 

 sumption, body weight, and milk and fat production. 



Digestion and Utilization Experiment 1954 



Despite the evidence reported both from this Station and elsewhere 

 that there is no important advantage in feeding coarse-textured feeds over 

 comparable high qualitv ones of the ground type and that coarse-textured 

 feeds are nutritionally inferior to comparable ground feeds, the coarse- 

 textured feeds still continue to be popular with many dairymen. Mindful 

 of this popularity, it was decided to find out if there are any ingredients 

 which can be used in the mixture in the coarse form without affecting the 

 nutritive value adversely. Because of their importance both as a source of 

 nutrients and also as a source of coarseness, corn and oats were chosen to 

 be fed to the animals in both the fine and coarse forms. 



Twenty-six complete digestion and utilization experiments were carried 

 out using procedures similar to those outlined above. Five heifers 20-24 

 months of age were used as experimental subjects. The corn studied all 

 came from one lot. Part was steamed and flaked by a large corn processor; 

 the remainder was ground by means of a hammer mill. Two lots of oats 

 were studied, part of each being steamed and crimped by a local feed man- 



