Slow-Feathering Turkeys: Good Growers but Inferior Breeding Performance
CANADA - R.A. Renema and colleagues at the University of Alberta have published a paper in Poultry Science that indicates slow-feathering strains have reproductive efficiency traits inferior to standard commercial genotypes despite similar growing performance.
22 September 2008
3 minute read
"This study was conducted to compare bodyweight gain, carcass composition and reproductive fitness in fast- and slow-feathering turkey females between 29 and 56 weeks 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," researchers in Canada report.
"Birds were photostimulated at 29 or 31 weeks of age. Data on bodyweight and carcass characteristics (keel and shank, keel, breast muscle, fat pad, 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%.
FF 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 weeks (8.3) compared with birds photostimulated 2 weeks earlier (7.8). Absolute ovary weight and oviduct weight were increased by 21 and 18%, respectively, in birds photostimulated at 31 weeks compared with 29 weeks. 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 days).
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 bodyweight, fleshing and conformation traits to FF birds, the SF strain had inferior reproductive efficiency traits," wrote the researchers.
They concluded, "This problem will need to be remedied before an SF turkey strain can become commercially viable."
Reference:
Renema R.A. et al., 2008. Effects of nutrient density and age at photostimulation on carcass traits and reproductive efficiency in fast- and slow-feathering turkey hens. Poultry Science, 2008, 87(9):1897-1908.
