Hatchability, hematological indices, and growth of turkey embryos incubated at high altitude with supplemented oxygen during the first and fourth weeks of incubation. Poult

ABSTRACT Turkey eggs were incubated at high altitude (1,700 m). Hatchability, hematology, and growth data were analyzed for the following treatments: 1) eggs receiving supplemented oxygen (SO) during the 1st wk of incubation (control eggs received no SO during the 1st wk); 2) eggs receiving SO during the 4th wk (control eggs received no SO during the 4th wk); and 3) the interaction effect of oxygen the 1st or 4th wk with SO the 1st and 4th wk or with no SO. Data analysis was carried out using orthogonal contrasts. Exposing incubating turkey embryos to oxygen the 1st wk or the 4th wk of incubation improved hatchability significantly (P£.05) compared with the remaining treatments. When SO was given during the 4th wk of incubation, hemoglobin concentration in embryos decreased (K.05) during pipping compared with that of embryos without SO the 4th wk. Hemoglobin was increased (PS.05) by increasing red blood cell numbers if SO was not given during Week 4, otherwise, the embryos increased (PS.05) in mean cellular hemoglobin to increase hemoglobin. When oxygen was supplemented the 1 st wk of incubation, reticulocyte maturation was slowed (K.05) compared with no SO the 1st wk. Oxygen exposure during the 1st wk or 4th wk of incubation reduced (P5.05) body weights of embryos during pipping and at hatching compared with those of embryos in the remaining treatments. Oxygen supplementation during Week 4 affected (PS.05) heart growth at the prenatal, internal pipping, and postnatal stages of respiration. At time of external pipping, embryos with no SO during Week 1 had heavier (K.05) livers than embryos with SO during Week 1, and SO during Week 4 increased (PS.05) liver weight compared with no SO during the 4th wk. It was concluded that turkey embryos may hatch, increase hemoglobin concentration, and grow differently in response to SO depending upon the time of SO exposure