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United States Department of Agriculture

Agricultural Research Service

Title: Incidence and Microbiology of Unabsorbed Yolk Sacs (Attached Or Free Floating) in Commerical Broilers

Authors
item Cox, Nelson
item Hiett, Kelli
item Buhr, Richard
item Richardson, Larry
item Northcutt, Julie
item Cray, Paula
item Bailey, Joseph
item Fairchild, B - UGA
item Mauldin, J - UGA

Submitted to: Campylobacter Helicobacter and Related Organisms International Workshop
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2005
Publication Date: September 4, 2005
Citation: Cox Jr, N.A., Hiett, K.L., Buhr, R.J., Richardson, L.J., Northcutt, J.K., Cray, P.J., Bailey, J.S., Fairchild, B.D., Mauldin, J.M. 2005. Incidence and microbiology of unabsorbed yolk sacs (attached or free floating) in commerical broilers [abstract]. Campylobacter Helicobacter and Related Organisms International Workshop. H4. 102.

Technical Abstract: In the developing avian embryo, the main energy source is yolk. Towards the end of the incubation period, the remaining yolk sac is internalized into the abdominal cavity. At hatch, yolk comprises 20% of the chick’s body weight and provides the nutrients for growth. The yolk should be depleted and the yolk sac completely absorbed leaving the yolk stalk, known as Meckel’s diverticulum. Post hatch, chicks initiate the transition from yolk dependence to utilization of exogenous feed. However at present, it is unknown at what frequency unabsorbed yolk sacs remain in commercial broilers at the time of processing and what bacteria can be found associated with them. For experiment 1, 100 six week old defeathered broiler carcasses were obtained from a commercial processing facility during each of three visits. In the second experiment, 100 eight week old defeathered broiler carcasses were obtained from a different commercial processing plant on four separate instances. For all repetitions, each carcass was aseptically opened and inspected for the presence of an unabsorbed yolk sac. Five carcasses containing a free floating yolk sac (within the abdominal cavity) and stalk and five carcasses containing an attached yolk/yolk stalk (Meckel’s diverticulum) from each repetition were analyzed for levels and types of total bacteria (TPC), Enterobacteriaceae (ENT) and for the presence of Campylobacter (Cj) and Salmonella (Sal) spp. Overall, 32% of the carcasses had an unabsorbed yolk sac attached to the yolk stalk and 17% were free floating. Campylobacter spp. were found in 29% of the yolk stalks, 32% of the attached and 13% of the free floating yolk sacs, while Salmonella spp. were in 26%, 48%, and 23% of these tissues respectively. All Campylobacter isolates were determined to be C. jejuni and the majority of Salmonella isolates were S. Typhimurium. The TPC ranged from log 3.3 to greater than log 6.0 and the ENT from log 2.8 to greater than log 6.0. Staphylococcus and Streptococcus were the predominant organisms in TPC while Escherichia coli and Hafnia alvei were found to comprise the ENT. The significance of these bacterial reservoirs and carcass contamination during processing has not been determined.

Last Modified: 12/17/2014