52 



Journal of Agricultural Research 



Vol. XV. No. I 



Table XXX. — Transmission of fat concentration from parental to first filial generation 



Tables XXIX and XXX show that high milk production tends to 

 behave as dominant — that is, in a cross of high-producing lines to low- 

 producing lines the ofifspring tends to have the high production of the 

 high line. This agrees well with some unpublished studies on a large 

 series where the productions of both parental lines are known. 



Unfortunately a like result can not be said for percentage of fat. 

 Here the parental high fat percentage is suppressed in the offspring 

 when this parent is crossed to a low line. 



SUMMARY 



This constitutes a preliminary paper on the crossbred herd now being 

 brought together by the Maine Agricultural Experiment Station for the 

 purpose of studying some of the outstanding problems of dairy hus- 

 bandry. 



The first section of the paper is devoted to a study of the inbreeding 

 in the foundation herd. It is shown that the inbreeding as measured by 

 the best mathematical methods is no greater than would be expected to 

 occur in any of the modern breeds when the animals were selected at 

 random. Consequently it is safe to assume that the results of the study 

 are not due to the width of the crosses, for, as has been pointed out, a 

 number of the animals famous in their breed have been far more inbred 

 than any of the parental stock used in these experiments. 



The individual records of the animals composing both the parental 

 generation and the first and second filial generations are given. 



(i) Black body color is dominant to the other color in the first genera- 

 tion. In the second generation an orange-coated bull and a dark Jersey 

 dun-coated heifer were segregated out. This is to be explained on the 

 basis of a recessive dilutor in the Guernsey, segregated out along with 

 the black color. The dark heifer shows that the Jersey does not nor- 

 mally possess this factor. 



(2) It has been shown that white marking of the body taken as a whole 

 appears as a dominant. Study of the individual white areas, however, 

 indicate that this is due to white in the inguinal region only, for this 



