Effect of Low Temperature and Long Duration Scalding on Feather Removing and Breast Meat Over Heated of Spent Laying Hens

The purpose of this study was to reduce the loss of spent laying hens during slaughtering by adjusting the parameters of scalding. The research object of this study was the spent laying hens with a rearing age of more than 400 days. The research meant to explore the effect of scalding methods on feather removing and muscle overheating. Three scalding parameters were set as follow: 65 ℃-3 min (high temperature scalding, HS), 60 ℃-4 min 20 s (medium temperature and slow scalding, MSS), and 58 ℃-4 min 20 s (low temperature and slow scalding, LSS). Broilers without scalding were set as the control group. The defeathering effect was characterized by measuring the feather retention force (FRF) and counting the number of feathers remaining after defeathering. The overheating degree of breast muscle was characterized by measuring meat color, depth of overheating area, DSC scanning and Raman spectrum scanning. The results showed that no significant difference in feather removal effects between HS treatments and LSS treatments, while the feather retention force and residual feather number of MSS treatment were significantly lower than those of the other two groups (P