It is already known that both the age of the breeder hen and the type of incubator can in-fluence the efficiency of the hatching process. However, the literature lacks information on the interaction of these factors. We evaluated the effects of incubator machine type (mul-ti-stage and single-stage) and breeder hen age (35 and 61 weeks) on hatching parameters, oxidative stress of the embryo, performance, carcass yield and meat quality of the male broiler chickens. The embryo livers from the multi-stage incubator presented a higher NOX value (p=0.022). We observed a significant interaction between the breeder age and type of incubator factors for the thiols variable, where embryos from older multi-stage hens presented higher values compared to single-stage ones. The chickens from these birds had higher breast yield, feed intake, and weight gain without changing the feed conversion. The single-stage incubator provided lower oxidative stress to the embryos, lower egg weight losses during hatching and better performance of the birds in the first week of life. The chickens from the older breeders presented higher breast yield, feed intake and weight gain. In addition to the known advantages of single-stage incubators, this work showed that they cause less oxidative stress to embryos.
Linzmeier et al. (Tue,) studied this question.