128 AGRICULTURAL, APPROPRIATION BILL, 1924. 



one and find that it contains the same amount by analysis, but you 

 will not obtain the same results, because this diiTerent protein has 

 various amounts of amino acids in it, and results seriously on the 

 milk. We have found that some of these proteins are necessary in 

 some parts of the milk, and in one circulation of the blood as much 

 as 30 per cent of some these are taken out; in other words, in passing 

 through the udder. We are satisfied that some of these factors are 

 limiting the production of our animals. I also said that it is necessary 

 to get a balance of the feeds. It is not simply a problem of deter- 

 mining the amount of milk you get out of a cow to-day, but over a 

 period of time throughout the year. On simply the record of the 

 milk production for a lactation period it is impossible, we find, to 

 take that and learn what she is going to do the next period. We have, 

 therefore, started what we call digestion trials in which we analyze 

 the feed, the milk, and the urine and feces, and in that way we can 

 get a definite idea as to what is happening to the feed and milk 

 during this digestion period. \Miile we are making these careful 

 tests, it is necessary^ that the cows be kept away from the herd. 

 Our barns now are used for breeding barns and we have no places 

 for this nutrition work. 



Mr. AxDERSox. Will you have to buy animals for this work? 



Doctor Larson. No, sir; we have our animals increasing in our 

 breeding herds, and we will not reciuire additional animals for nutri- 

 tion work. 



INCREASE IN HERD. 



Mr. Anderson. How much has 3'our herd increased in the last 

 four or five years ? 



Doctor Larson. In the herd at Beltsville we have increased, per- 

 haps, in the last four or five years, from <S0 to l.')0. 



^Ir. Anderson. Do you sell any of those animals at all ? 



Doctor Larson. L^p to this time only those that have become 

 sterile or unfit — unproductive. L^p to this year the foundation stock 

 of the breeding herd — many of them will have completed their rec- 

 ords. We have gotten the measure of the foundation animals — that 

 is, we know what they will produce, and we have their sons and 

 daughters, so that we can dispose of those animals. We feel the work 

 in animal nutrition is going to be handicapped very mnterinlly unless 

 we can get a building for it. 



Mr. Anderson. S20,()00 ought to build 



NEED FOR LABORATORY BUII.DINO. 



Doctor Larson (interposing). It is not an ordinary barn; it is a 

 laboratory. It is the nutrition building, with places for the cattle, 

 special stalls and devices for making these tests, and the laboratory v 

 rooms for mi.xing the samples and storing them. This is very iutri- 

 cate work. We have to be sure we are using the same feed, for 

 instance, tiirou<^liout a wjiole period. That nu'ans that that feed is 

 all mixed carelully in thousands of pounds and put away carefully, T 

 and the same way with the hay and othi'r nii.xod feeds. 



Then the urine and feces are collected carefully ami mixed and sam- 

 pled, all r(>(|uiring safe and special treatment. We have lunnlreds of 



