468 



TwHNT^-KicjiTii Annual Report 



ALFALFA HAV vs. ALFALFA H W AND SILAtJF FOR DAIRY COWS 



During the spring of 1917 an experiment was conducted to de- 

 termine the vahie of corn silage as a supplement for alfalfa hay 

 when fed to dairy cows. Corn silage can be produced to good 

 advantage on Arizona farms, and dairymen are beginning to use it 

 quite extensively for balancing the highly nitrogenous ration sup- 

 plied by alfalfa. Many dairymen want information regarding the 

 use of silos, and it is highly important that some preliminary v/ork 

 be done to ascertain the desirability of adding silage to alfalfa hay. 



Seven cows were used for this test and these were divided into 

 two groups, three in one and four in the other. Since the groups 

 could not be evenly balanced in number, quantity of milk produced, 

 and similarity in lactation period the feeds were alternated so that 

 each lot was given each ration the same length of time. The cows 

 were maintained in separate corrals and an accurate (|uantity of 

 hay given each lot. The corn silage was fed individually at the 

 time of milking. An interval of ten days was allowed between each 

 period in order to accustom the cows to a change in ration. During 

 the first period of 21 days Lot 1 was fed a ration of 20 ])ounds of 

 alfalfa hay and 35 pounds of corn silage, and Lot 2 was given 30 

 pounds of alfalfa hay. During the second period the rations were 

 reversed. Table XVII gives the result oi the experiment. 



TABLE XVIL — AVERAGE DAILY YIELD AND COST OF RATION OF COWS FED 

 ALFALFA HAY COMPARED WITH ALFALFA HAY AND CORN SILAGE 



The amount of milk and butter fat produced was practically the 

 same for both rations. Where alfalfa is priced at $20 and corn 

 silage at $6 per ton, the cost of the rations per day was the same 

 for each lot. The experiment shows that 35 pounds of corn silage 

 may replace 10 pounds of alfalfa hay in the ration. Most of the 

 cows lost weight during the test period, but it was found that 30 

 pounds of alfalfa hay tnaintained the live weight more uniformly 

 than the ration consisting of 20 pounds of alfalfa hay and 35 pounds 

 of silage. The silage was dry and inferior in quality and it is be- 

 lieved that more favorable results would have been secured from 



