MAINE AGRICULTURAL EXPERIMENT STATION. 1 5 



For an anal3'sis of Jersey inbreeding records two results, 

 among others, stand out with particular clearness and signifi- 

 cance. These are : 



1. That American Jersey cattle at the present time, may be 

 said in general and on the average to be about one-half as 

 intensely inbred, when account is taken of the eighth ancestral 

 generation, as would be the case if continued brother X sister 

 breeding had been followed. The form of the inbreeding curve 

 is. however, very different in the two cases, the brother X sis- 

 ter curve being concave to the base line throughout, while the 

 actual Jersey curves tend to have their principal curvature con- 

 vex to the base. 



2. That, in general and on the average. Register of Merit 

 animals are less intensely inbred than the general population of 

 Jersey cattle. 



A detailed report of the work on inbreeding in Jerseys will 

 be published shortly. The above notes are intended to be 

 merely of a preliminary character. 



III. Cooperative Cattle Breeding Records. 



During the past year this project has gone forward smoothly 

 and satisfactorily. We are accumulating a unique and ex- 

 tremely valuable collection of data regarding many problems ' 

 in the physiology of cattle breeding. Some of the original co- 

 operators have, of course, dropped the work during the year, 

 for various good reasons. A substantial group of progressive 

 breeders have remained faithful to the project and sent in 

 carefully made records with unfailing regularity. 



At this time we wish to take occasion again to thank most 

 heartily the breeders who have so kindly cooperated in this 

 work. We realize that it is some trouble to the breeder to 

 fill out these blanks and that when he does it, it is without any 

 thought of immediate personal gain, but from the altruistic 

 motive of helping along the general knowledge of the laws of 

 breeding in dairy cattle. We are extremely grateful to those 

 who are helping us. 



We are always glad to add new cooperators to this list. Any- 

 one interested in taking up the work, whether a resident of 

 A'laine or some other part of the country, should communicate 



