Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh Original cung cấp cho các bạn kiến thức về sinh học đề tài:Phenotypic plasticity of body pigmentation in Drosophila: Réponse à la chaleur de poules pondeuses issues de lignées sélectionnées pour une faible (R ou forte (R consommation ) ) + alimentaire résiduelle. | Genet Sei Evol 1997 29 279-290 @ Elsevier Inra 279 Article original Réponse à la chaleur de poules pondeuses issues de lignées sélectionnées pour une faible R OU forte R consommation alimentaire résiduelle A Bor das F Minvielle Laboratoire de génétique factorielle Institut national de la recherche agronomique 78352 Jouy-en-Josas cedex France Regu le 6 janvier 1997 accepté le 21 avril 1997 Summary - Effects of temperature on egg laying hens from divergent lines selected on residual feed consumption. A sample of females from the 19th generation of the R and R lines divergently selected for the residual feed intake in the laying period was separated at 18 weeks of age in climatic rooms into two groups one kept at a constant temperature of 21 1 C control the other kept at 31 1 C heated group . Egg production was recorded until the age of 45 weeks individual feed consumption was measured between the ages of 31 and 35 weeks and water consumption was measured at 51 weeks. The usual effects of high ambient temperature compared to moderate temperature were observed in both lines reduction of food intake - 16 egg number and egg mass - 13 mean clutch length more days of pauses depression of body weight - 8 and mean egg weight - 4 . Similarly over both treatments the differences found previously between lines in total feed consumption 25 and in its residual part 19 in comb and wattle size shank length and in water intake 51 were observed. However for several variables the line X treatment interaction was significant especially for residual food intake water intake 48-week body weight and adult body weight variation indicating that the overconsuming line R was better adapted to the high temperature with a reduction in egg number of only 10 versus 22 for the underconsuming line R_ . The better adaptation of the R line may be due partly to a reduction of thermogenesis during feeding and perhaps more probably to a higher capacity for heat dissipation. Finally breeding for a laying
