title: Influence of the dwarfing gene dw on egg production and viability under summer heat stress.
abstract: 1. Dwarf egg layer (Narmada XL) dwarf broiler (DB) and normal bodied sib (NB) hens were studied under cyclic summer hot and dry heat stress of 21.1 to 45.5 degrees C for a period of 50 d. The genotype effect for egg production was significant (P less than 0.01). 2. N-XL and DB genotypes laid 12.1% more eggs than NB. Egg production declined by 3.17, 1.27 and 3.25% for a rise in temperature (maximum) of 1 degree C for N-XL, DB and NB genotypes respectively. 3. Egg production in Narmada XL declined by 42% compared to 25% in the dwarf broilers. The regression coefficients differed significantly. 4. For polygenically identical DB and NB broiler breeder hens the heat stressor significantly reduced egg production 1.98% more in the NB genotype compared with DB with a 1 degree C rise in temperature. 5. Mortality was less in the N-XL as compared to DB, but NB hens showed 11.7% more mortality than dwarfs.
authors: Department of Poultry Science, College of Veterinary Science and Animal Husbandry, Jawaharlal Nehru Agricultural University, Madya Pradesh, India.
authors: A G
authors: AG
authors: Khan
authors: R N
authors: RN
authors: Tiwari
authors: K K
authors: KK
authors: Baghel
authors: R D
authors: RD
authors: Gupta
mesh_terms: D000818:Animals; D002645:Chickens / Q000235:genetics*; D005260:Female; D005796:Genes; D005838:Genotype; D006358:Hot Temperature / Q000009:adverse effects*; D010058:Oviposition; D011201:Poultry Diseases / Q000401:mortality / Q000503:physiopathology*; D013045:Species Specificity; D013312:Stress, Physiological / Q000401:mortality / Q000503:physiopathology / Q000662:veterinary*