432 ANNUAL REPORT OF THE Off. Doc. 



the block. It may be profitable for instance to cross aged Merino 

 ewes with males of some better mutton breed and to prepare both for 

 the mai-kci by fattening them on rich pastures, but ordinarily such 

 crossing should stop with the first cross. To cany it further would, 

 probably, for a time at least, introduce elements of reversion. 



But, it may be asked, are there no instances in which alien blood 

 may be introduced with animals that have been up-graded? There 

 are such instances as when the animals thus graded have partially 

 lost some useful property or properties. It is possible to restore 

 those properties or at least to improve them greatly in some in- 

 stances by the introduction of an outcross, that is by making one 

 cross from sires of another breed. 



This may be illustrated in the condition of many of the high grade 

 herds of Poland Chinas in the corn belt at the present time. Many of 

 these have too little bone, too little stamina and weakened breeding 

 properties. One cross from sire of either the large Yorkshire or Tam- 

 worth breeds would lead to wonderful improvement along these lines. 

 The breeders could then fall back again upon Poland China blood if 

 they desired to do so. Such teaching may sound like rank heresy to 

 some, but that it rests on a sound basis will be found by all who put 

 it to the test. 



The way to improve the average stocks of the country is, therefore, 

 so plain that any can understand. It is so entirely feasible that all 

 may practice it, and it is so inexpensive, comparatively, that every 

 one may adopt it. But the thought should ever be present, that in 

 all up-grading the food must be adapted to the needs of the animals, 

 otherwise the improvement sought will be hindered in proportion as 

 such adaptation is lacking. 



The CHAIRMAN: Now gentlemen, if there are any questions that 

 you want to ask the Professor, this is the opportunity. He is here as 

 he has said, to help us all he can. 



DEPUTY SECRETARY MARTIN: Mr. Chairman, I would like to 

 inquire, since dairying is one of the most important industries of 

 Pennsylvania, if it is wise for a dairyman in building up his herd, to 

 use a sire in what we call line breeding? 



PROF. SHAW: Yes, I think it would be wise as long as he does 

 not reach the danger line, the line of individual deterioration, or 

 lack of stamina, or loss of vigor; I think it is perfectly safe until that 

 point is reached. 



MR, WELD: I would like to inquire of Prof. Shaw what his views 

 are, if we take an ordinary cow — if we wish to build up in a certain 

 line, and get a good thoroughbred sire of some desired breed, how 

 many crosses is it safe to make with that sire; how long is it safe to 

 keep him before you get another one from a different family? 



PROF. SHAW: I will answer that question in this way. Under- 

 stand, gentlemen, that I was not advocating inbreeding for the 

 ordinary farmer. Now this question bears upon inbreeding rather 

 than upon line breeding; the two things are different. Now I would 

 answer the question in this way, that if a man has a herd of rugged 

 cows, and if he chooses a sire that is rugged and right, that he can 



