Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 1998
Publication Date: N/A
Interpretive Summary: Removing feathers from each bird during the initial steps of processing takes time and requires a large amount of hot water. If the feathers could be removed with less effort, poultry processors would save money, water, and time. In this study we determined if the force necessary to pull feathers from broiler chickens could be reduced by cutting the nerve leading to the small muscles surrounding the base of each feather. The nerve leading to the feathers was surgically severed under anesthesia in some birds and left intact in others. Cutting the nerve did not affect the force required to remove the feathers during processing. The results indicate that the nerve leading to the feathers does not directly control the force needed to remove the feathers during processing. The absence of nervous control explains how anesthetics and tranquilizers can lower feather removal force indirectly by altering blood flow to the skin and therefore metabolism of the skin; and why there has been consistently a lack of any carryover affect on feather pull force after death.
To determine if feather retention force (FRF) was influenced by the presence or absence of cutaneous innervation, nerve trunks for the pectoral and sternal feather tracts were severed unilaterally (left side) in Trial 1. In Trial 2 the sternal cutaneous nerve trunk was severed either unilaterally (left or right side) or bilaterally. The pectoral feather tract ante- and post-mortem FRF values did not differ significantly for innervated or denervated tracts. In Trial 1, the sternal feather tract ante- and post-mortem FRF values were 13% higher (44 g) for the denervated (left side) than for the innervated (right side) treatments. In Trial 2, both the left and right sternal feather tracts were represented in equal numbers for the innervated and denervated treatments, and there were no significant differences in FRF related to innervation, left and right side, or ante- and post-mortem sample times. In conclusion, the presence or absence of cutaneous nerve innervation does not appear to influence FRF ante- or post-mortem in 6- wk-old commercial broilers. These results suggest that changes in FRF are indirectly mediated by pathways other than cutaneous nerves. This finding indicates that treatments disabling the central nervous system ante-mortem may lower FRF indirectly by altering cutaneous metabolism and therefore have been unsuccessful in substantially altering post- mortem FRF.