Chickens have been sexed based on feather development at hatching for many years, but the slow-feathering gene has only recently been incorporated into a commercial line of turkeys. Female turkeys of a fast- and a slow-feathering strain were compared with regard to BW, gain, and carcass composition to 29 wk of age. A total of 432 fast-feathering (FF) and 432 slow-feathering (SF) poults were reared to 198 d on a control (CON) or a high-energy, high-protein (HIGH) diet. Data concerning BW and carcass characteristics (thoracic circumference and width, shank, keel, breast muscle, fat pad, and liver), feather scores, and breast muscle morphology were assessed over the course of the trial. Strain did not affect BW of the CON-fed birds until after 112 d, when FF birds were 3.1% heavier than SF birds. From 11 to 112 d, feeding the HIGH diet increased BW of SF birds significantly compared with birds fed the CON diet. From 170 to 198 d, FF birds were approximately 0.8 kg heavier than SF birds. At 42 and 84 d in FF birds, and at 84 d in SF birds, increased diet density increased measures of frame size and decreased liver weight. Breast muscle weight, area, and thickness were greater in SF than in FF birds at 42 and 84 d. Increased nutrient density increased feather score in SF birds at 32 (9.8%) and 56 d (7.1%).

This study was conducted to compare BW gain, carcass composition, and reproductive fitness in fast- and slow-feathering turkey females between 29 and 56 wk of age. A total of 452 Hybrid standard fast-feathering (FF) and experimental slow-feathering (SF) hens (226/group) were fed either a control or a high-energy, high-protein diet. Birds were photostimulated at 29 or 31 wk. Data on BW and carcass characteristics (keel and shank, keel, breast muscle, fatpad, liver, ovary, and oviduct weight) and egg production were assessed. At photostimulation, FF birds had an increased shank length (2.6%) compared with SF birds. After photostimulation, FF birds were heavier than SF birds by 7.8%. Fast-feathering hens had greater ovary weight (49%), oviduct weight (52%), keel length (2.8%), and had one more large yellow follicle at the end of lay. The number of large yellow follicles was greater in birds photostimulated at 31 wk (8.3) compared with birds photostimulated 2 wk earlier (7.8). Absolute ovary weight and oviduct weight were increased by 21 and 18%, respectively, in birds photostimulated at 31 wk compared with 29 wk. These effects of delayed photo-stimulation were greater in SF birds. Ultimately, FF hens had a greater total hen-housed egg production (55 vs. 33%), peak egg production (76 vs. 68%), and laying sequence length (5.7 vs. 3.3 d). Although delaying photostimulation did not affect total egg production, it did reduce the number of double-yolked eggs. Nutrient density had minimal effects on production in this trial. These data indicate that despite having similar BW, fleshing, and conformation traits to FF birds, the SF strain had inferior reproductive efficiency traits. This problem will need to be remedied before an SF turkey strain can become commercially viable.