BULLETIlSr -No. 191. 



DEPARTMENT OF POULTRY HUSBANDRY. 



PRACTICAL RESULTS FROM STUDIES ON 

 EGG PRODUCTION. 



H. D. GOODALE. 



Introduction. 



A series of short papers, dealing with phases of egg production from the 

 purely practical standpoint, has been planned. They will be published 

 from time to time as circumstances admit. Their aim is to present as 

 definite information on the subject of each as the evidence warrants. The 

 detailed data on which these practical papers are based are in process of 

 being published elsewhere. Those already published are — 



Internal Factors Influencing Egg Production in the Rhode Island Red Breed of 



Domestic Fowl. American Naturalist, Vol. LII, No. 614, 1918, 3 parts, pp. 65- 



94, 209-232, 301-321. 

 Winter Cycle of Egg Production in the Rhode Island Red Breed of Domestic Fowl. 



Journal of Agricultural Research, Vol. XII, No. 9, 1918, pp. 547-574. 

 The Bearing of Ratios on Theories of the Inheritance of Winter Egg Production. 



Journal of Experimental Zoology, Vol. 28, No. 1, 1919, pp. 83-124. 



I. Inbreeding. 



The poultryman often is in a quandary regarding inbreeding. On the 

 one hand it is advocated, and on the other just as strongly condemned. 

 What, then, are the facts? 



Inbreeding may be defined as the mating of relatives, and just as there 

 are degrees of relationship so there are degrees of inbreeding. Line breed- 

 ing involves inbreeding, so designed, however, as to keep its amount at a 

 minimum. 



In the work at this station close matings of various sorts have been made 

 as well as unrelated matings. The results afford a practical answer to the 

 question, shall I inbreed? The answer is found in a paraphrase of an old 

 saying, which is applicable to all breeding, "Handsome is that hand- 

 some breeds," that is, inbreeding is to be judged by its results. This is a 

 special application of the well-known progeny test. Now experience shows 



