Physiological characteristics of a molt and second cycle of egg laying in turkey breeder hens

Large White turkey hens were housed in light-controlled pens in molting experiments. In each experiment, a group of hens was molted (MO) and nonmolted control hens (CON) were maintained in an adjacent room. Body weight and absolute and relative weights (g organ weight/100 g body weight) of the ovary with ova, oviduct, and liver were observed in MO and CON throughout the molting period and after photostimulation. Further determinations were made of the percentage of liver dry matter (PLDM) and ash (PLA). The MO hens lost body weight during feed deprivation but regained it and continued to gain body weight until they were heavier at the beginning of the second cycle than at the end of the first cycle. Hematocrit and body temperature of MO hens exhibited significant (p less than or equal to .05) changes during molt. Hen-day egg production averaged 44.7% +/- 1.3 during the second cycle. Mean value for eggs per hen-housed was 62.6 +/- 1.8. Egg weight remained constant (96.8g +/- .2 g) and egg specific gravity averaged 1.076 +/- .0001 in MO hens. The molt was characterized by significantly (P less than or equal to .05) reduced relative liver weight during feed deprivation, decreased relative ovary and oviduct weights that did not begin to increase until after photostimulation. No consistent differences were observed in PLDM or PLA.