Poultry Breeds, Selection and Breeding
Breed categories
A breed is a group with common ancestry and characteristics; a variety is a subdivision, and a strain is a selected line within a breed. Breeds are grouped as layer, broiler or dual-purpose, and as indigenous or exotic. White Leghorn is a small-bodied layer; Rhode Island Red is dual-purpose; Cornish is the basis of many broiler strains; Aseel and Kadaknath are indigenous breeds with slow growth and adaptation. Vanaraja and Gramapriya are improved dual-purpose varieties.
Selection and breeding rules
Selection uses records, not appearance alone. Traits include egg number, egg weight, shell strength, age at first egg, growth rate, feed conversion, livability and conformation. Methods include individual selection, family selection, pedigree selection and progeny testing. Breeding systems include inbreeding (increases uniformity but risks inbreeding depression), outcrossing, crossbreeding (exploits hybrid vigour) and upgrading (using superior males on local females).
Worked example. A farmer wants more eggs in a 200-hen Rhode Island Red flock. Cockerel A's dam laid 280 eggs in 72 weeks; cockerel B's dam laid 220. Both are healthy, but A is slightly smaller. Choose A for initial use because the dam's egg record predicts daughter performance, then progeny-test A's daughters and cull if their egg numbers are poor.
Traps. Kadaknath is not a fast-growing commercial broiler; crossbreeding does not create a new breed instantly; choosing the biggest bird does not always improve egg production; and inbreeding is not a quick fix for small flocks.