Darrin Karcher

Dr. Darrin Karcher

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2019 in Poultry Science
Verified
Journal Article
Open access
PDF file
SWS L Weimer
S L Weimer
CRC I Robison
C I Robison
RTR J Tempelman
R J Tempelman
DJD R Jones
D R Jones
DKDarrin Karcher
Darrin Karcher
Many laying hen companies in the United States are pledging to move away from intensive conventional cages to extensive housing systems. Enriched col

9 March 2022 in Poultry Science
Verified
Journal Article
Open access
SWShawna Weimer
Shawna Weimer
SZS. Zuelly
S. Zuelly
MDMelissa Kaye Davis
Melissa Kaye Davis
DKDarrin Karcher
Darrin Karcher
MEM.A. Erasmus
M.A. Erasmus
The fast growth rate of broiler chickens is a welfare concern that has increased consumer interest in chicken from slower growing (SG) broilers. Replacing conventional (CONV) broilers with SG broilers will reduce chicken supply and SG broilers require different management practices than CONV. This study evaluated the effects of 2 stocking densities on the carcass composition and meat quality of CONV broilers that reach market weight at 42 d and SG broilers that reach market weight at 63 d. Male broilers from each strain were exclusively stocked into 16 pens at a density of either 29 kg/m2 or 37 kg/m2. Live body, carcass without giblets (WOG), and part weights were recorded and used to calculate yield. Initial and 24-hour pH, color (L*, a*, and b*), cooking loss, and Warner Bratzler shear force of the breast and thigh muscles were measured. Birds from both strains reached similar live body and carcass WOG weights. CONV had 3.4%, 13.0%, and 2.8% greater (P ≤ 0.002), carcass WOG, breast, and tenderloin yields, while SG had 2.7%, 5.0%, 7.5%, and 1.2% greater (P < 0.0001) wings, leg quarters, frame, and skin yields, respectively. CONV breast 24-h pH and cooking loss were greater (P ≤ 0.04) than SG. While SG thigh shear force was greater than CONV (P = 0.008), breast shear force was the lowest for CONV stocked at 29 kg/m2 and the greatest for SG stocked at 37 kg/m2 (P = 0.04). SG had a paler breast than CONV, while CONV had a yellower breast than SG (P < 0.0001). While SG had a redder thigh than CONV (P = 0.002), SG stocked at 29 kg/m2 had a redder breast than SG stocked at 37 kg/m2, with both CONV groups intermediate (P = 0.04). These results indicate that differences in male broiler meat quality were affected more by strain than by stocking density. Compared with CONV, SG broiler meat quality was more affected by stocking density in this study.

1 October 2017 in Poultry Science
Verified
Journal Article
Open access
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PRP. Regmi
P. Regmi
NNN. Nelson
N. Nelson
RHR. C. Haut
R. C. Haut
MOM. W. Orth
M. W. Orth
DKDarrin Karcher
Darrin Karcher
This study was aimed at analyzing bone properties of Lohmann White hens in different commercial housing systems at various points throughout producti

18 August 2021 in Poultry Science
Verified
Journal Article
Open access
RGRichard K. Gast
Richard K. Gast
DJDeana R. Jones
Deana R. Jones
RGRupa Guraya
Rupa Guraya
KAKenneth E Anderson
Kenneth E Anderson
DKDarrin Karcher
Darrin Karcher
Contaminated eggs are a leading source of human Salmonella infections and this problem continues to challenge public health authorities and egg industries around the world. Salmonella invasion of the ovaries and oviducts of infected laying hens can result in bacterial deposition inside the edible portions of developing eggs. The introduction, persistence, and transmission of salmonellae in commercial egg-laying flocks are influenced by flock management practices, but the food safety ramifications of different types of laying hen housing remain unresolved. The present study assessed the frequency of internal contamination of eggs after experimental Salmonella Enteritidis and S. Typhimurium infection of laying hens in indoor cage-free housing. Groups of 72 hens were housed on wood shavings in isolation rooms simulating commercial cage-free barns with community kick-out nest boxes and perches and 1/3 of the hens in each room were orally inoculated with 8.0 × 107 cfu of 2-strain mixtures of either S. Enteritidis (2 rooms) or S. Typhimurium (2 rooms), and the entire internal contents of all eggs laid 5 to 30 d postinoculation in nest boxes or on the flooring substrate were cultured to detect Salmonella. Contaminated eggs were laid between 8 and 28 d postinoculation. The overall incidence of S. Enteritidis isolation from eggs (3.41%) was significantly (P = 0.0005) greater than S. Typhimurium (1.19%). The contamination frequencies associated with the 2 egg collection locations were not significantly different (P > 0.05). These results demonstrate that oral infection of a relatively small proportion of laying hens in indoor cage-free housing with invasive Salmonella serovars can result in the production of internally contaminated eggs at low frequencies over a period of nearly a month postinoculation.

1 December 2005 in Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology
Verified
Journal Article
Closed access
DKDarrin Karcher
Darrin Karcher
JMJ.P. McMurtry
J.P. McMurtry
TATodd Applegate
Todd Applegate

1 February 2019 in Poultry Science
Verified
Journal Article
Open access
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NCNicholas J. Chargo
Nicholas J. Chargo
CRCara I. Robison
Cara I. Robison
SBSydney L. Baker
Sydney L. Baker
MTMichael J. Toscano
Michael J. Toscano
MMMaja M. Makagon
Maja M. Makagon
DKDarrin Karcher
Darrin Karcher
Damage to the keel bone is a major issue in the laying hen industry. The goal of this study was to compare palpation results of live laying hens to d