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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #311484
Title: Defeathering of broiler carcasses subjected to delayed scalding 1, 2, 4, and 8 hours after slaughter

Author
item HARRIS, CAITLIN - University Of Georgia
item Bourassa, Dianna
item WILSON, KIMBERLY - University Of Georgia
item Buhr, Richard - Jeff

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/20/2014
Publication Date: 1/26/2015
Citation: Harris, C.E., Bourassa, D.V., Wilson, K., Buhr, R.J. 2015. Defeathering of broiler carcasses subjected to delayed scalding 1, 2, 4, and 8 hours after slaughter [abstract]. Meeting Abstract. 94:(E-Suppl.1)P246. p.72, 2015.

Interpretive Summary:

Technical Abstract: With implementation of farm slaughter, scalding and defeathering could be delayed for a minimum of 2 to 4 h. This research evaluated the potential for delaying scalding and defeathering up to 8 h after slaughter. Following 12 h feed withdrawal broilers were cooped and transported to the pilot plant, batches of 10 broilers were stunned at 15 V for 10 s, and bled for 2 min. Carcasses that were held prior to scalding were transferred to stationary shackles and remained suspended by their feet. The 1st batch stunned was held for 8 h, the 2nd batch for 4 h, the 3rd batch for 2 h, the 4th batch for 1 h, and the 5th batch remained on line and was scalded and defeathered after bleeding. All batches were hard scalded at 60ºC/140ºF a total immersion time of 90 s (30 s in each of three tanks). The picker had been adjusted to achieve acceptable defeathering with minimal overpicking of the hips and elbows. All carcasses were defeathered for 30 s in a single 4 bank picker. Carcasses scalded and defeathered immediately following bleeding were scored as excellent with >95% of the carcass feathers removed. Carcasses held for 1 h did not defeather well in the first pass through the picker with more than 50% of the feathers retained and most of the cuticle. The picker was adjusted in, narrowing the distance between the picking disks by 2 cm which resulted in adequate defeathering with 90% of the feathers removed. Carcasses scalded and defeathered at 2 h also had 75% of the feathers removed. Carcasses held for 4 or 8 h before scalding and defeathering were not acceptably defeathered. Carcasses held for 2 h or longer were rigid, in rigor, and unable to flex or turn when in the picker. The pH recorded for breast muscle indicated a continued drop from 6.37 at 0 h, to 6.22 at 1 h, 5.98 at 2 h, 5.81 at 4 h, and 5.75 at 8 h indicating that the onset of muscle rigor had occurred between 1 and 2 h (pH 6.0) and ultimate pH values of 5.4 were not attained. These experiments reveal that carcasses subjected to delayed defeathering will require modification of present scalding and picking protocols to achieve acceptable defeathering of the less pliable in-rigor carcasses.