School of Animal Sciences
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The School of Animal Sciences merged Dairy Science and Animal and Poultry Science in 2022.
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Browsing School of Animal Sciences by Subject "0707 Veterinary Sciences"
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- Free-Living Aquatic Turtles as Sentinels of Salmonella spp. for Water BodiesHernandez, Sonia M.; Maurer, John J.; Yabsley, Michael J.; Peters, Valerie E.; Presotto, Andrea; Murray, Maureen H.; Curry, Shannon; Sanchez, Susan; Gerner-Smidt, Peter; Hise, Kelley; Huang, Joyce; Johnson, Kasey; Kwan, Tiffany; Lipp, Erin K. (Frontiers, 2021-07-22)Reptile-associated human salmonellosis cases have increased recently in the United States. It is not uncommon to find healthy chelonians shedding Salmonella enterica. The rate and frequency of bacterial shedding are not fully understood, and most studies have focused on captive vs. free-living chelonians and often in relation to an outbreak. Their ecology and significance as sentinels are important to understanding Salmonella transmission. In 2012–2013, Salmonella prevalence was determined for free-living aquatic turtles in man-made ponds in Clarke and Oconee Counties, in northern Georgia (USA) and the correlation between species, basking ecology, demographics (age/sex), season, or landcover with prevalence was assessed. The genetic relatedness between turtle and archived, human isolates, as well as, other archived animal and water isolates reported from this study area was examined. Salmonella was isolated from 45 of 194 turtles (23.2%, range 14–100%) across six species. Prevalence was higher in juveniles (36%) than adults (20%), higher in females (33%) than males (18%), and higher in bottom-dwelling species (31%; common and loggerhead musk turtles, common snapping turtles) than basking species (15%; sliders, painted turtles). Salmonella prevalence decreased as forest cover, canopy cover, and distance from roads increased. Prevalence was also higher in low-density, residential areas that have 20–49% impervious surface. A total of 9 different serovars of two subspecies were isolated including 3 S. enterica subsp. arizonae and 44 S. enterica subsp. enterica (two turtles had two serotypes isolated from each). Among the S. enterica serovars, Montevideo (n = 13) and Rubislaw (n = 11) were predominant. Salmonella serovars Muenchen, Newport, Mississippi, Inverness, Brazil, and Paratyphi B. var L(+) tartrate positive (Java) were also isolated. Importantly, 85% of the turtle isolates matched pulsed-field gel electrophoresis patterns of human isolates, including those reported from Georgia. Collectively, these results suggest that turtles accumulate Salmonella present in water bodies, and they may be effective sentinels of environmental contamination. Ultimately, the Salmonella prevalence rates in wild aquatic turtles, especially those strains shared with humans, highlight a significant public health concern.
- Northern fowl mite infestation affects the nocturnal behavior of laying hensJacobs, Leonie; Vezzoli, Giuseppe; Beerda, Bonne; Mench, Joy A. (Elsevier, 2019-07-01)The northern fowl mite (Ornithonyssus sylviarum) is a key pest for caged laying hens. High infestation levels can lead to anemia, reduced production, and mortality. Although the mites cause skin irritation and thus likely affect resting behavior, the nocturnal behavior of infested chickens has not yet been studied. We investigated the impact of mite infestation on nighttime behavior of 16 beak-trimmed White Leghorn hens. The hens were housed individually in wire cages. They were experimentally inoculated with approximately 35 mites at 25 weeks of age and observed for the behaviors dozing, sleeping, preening and being active. Continuous observations were made from video recordings taken from 22:00 h until 06:00 h for two consecutive nights at pre-infestation week 0 and post-infestation weeks 3, 5 and 7. Mite infestation levels were measured weekly on an 8-point scale (0 (no mites) to 7 (≥10,000 mites per hen)). For statistical analyses with linear mixed models, mite infestation levels were categorized as score 0 (no mites), 3–4 (51–500), 5 (501–1000) and 6–7 (>1000). Higher levels of mite infestation were associated with hens spending less time dozing (P < 0.001) and more time preening (P < 0.001) and being active (P = 0.012). Dozing decreased from 90% of the observed time for mite score 0 to 76% for score 6–7. Preening increased from 2% (score 0) to 9% (6–7) and time spent being active increased from 1% (0) to 7% (6–7). Mite infestation increased the number of uninterrupted bouts of all behaviors (P ≤ 0.020), especially dozing and preening (P < 0.001), suggesting restlessness in the mite-infested hens due to irritation and itching. The mite-infested hens’ increased nocturnal activity, including preening, as well as the fragmentation of behavioral activities together with decreased dozing, indicate disturbed resting behavior and suggest a reduction in the welfare of mite-infested hens.