. Principles and practice of poultry culture . Poultry. repeatedly been found by breeders who had made marked increase in egg production by simple selec- tion and good care, and by close breeding for a term of years, that when they went outside of their stock for new blood, the introduction of males of different breeding was im- mediately followed by a sharp decline in egg pro- duction. This fact has been one of the strong arguments in favor of the theory that the number of elementary eggs was rela- tively small and was pro- gressively increased by individual variation and selection. Such resu
. Principles and practice of poultry culture . Poultry. repeatedly been found by breeders who had made marked increase in egg production by simple selec- tion and good care, and by close breeding for a term of years, that when they went outside of their stock for new blood, the introduction of males of different breeding was im- mediately followed by a sharp decline in egg pro- duction. This fact has been one of the strong arguments in favor of the theory that the number of elementary eggs was rela- tively small and was pro- gressively increased by individual variation and selection. Such results are often attributed to the use of males not of heavy- laying strains. Within heavy-laying stocks the lack of uniformity in results of breeding shows that the sons of heavy-laying hens reproduce that quality in the same manner as the daughters. Some males do unques- tionably have a strong influence on the laying capacity of their daughters, but it seems to be due to transmission of the characters that give capacity to develop eggs. Mating for table poultry. In the development of poultry for food pur- poses, more than in any other line of poultry breeding, the conditions of production tend constantly toward an undesirable modification of form and 1 These birds won prizes for best- shaped Light Brahmas at the Boston Show when this variety was one of the big classes there. They are birds of a good utility type. Fig. 484. Light Brahma cock 1. Fig. 485. Light Brahma heni. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Robinson, John H. (John Henry), 1863-1935. Boston ; New York : Ginn and Company
Size: 1395px × 1792px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorrobinson, bookcentury1900, bookdecade1910, bookyear1912
