Scotti Hester's Main Page
Dual-energy X-ray absorptiometry is being used to measure bone mineral density and content of the humerus and tibia of live chickens.
Animal well-being, stress, and environmental physiology.
Dr. Hester's research expertise is in the
area of animal welfare with emphasis on skeletal integrity in meat and egg-type
domesticated fowl. Working with male turkeys, Dr. Hester and her graduate
students designed lighting programs that reduced the incidence of lameness by one-half
as compared to more conventional lighting by stimulating bird activity. Feeding
low compensatory plane diets also lowered the incidence of leg abnormalities in
turkeys by slowing growth during critical stages of bone development.
Work by Dr. Hester’s team
has identified a unique non-invasive technology for measuring skeletal
integrity in live birds using dual energy X-ray absorptiometry (DEXA). This
capability, which has been validated through comparisons with more conventional
invasive tests of skeletal integrity such as bone breaking force and bone ash,
has led to important discoveries that have improved the welfare of laying hens
in commercial flocks. The biggest impact on improving bird welfare were the
results dealing with a non-fasted molt which showed that bone mineralization
was not as adversely affected as in a fasted molt. These data, along with
research from other universities, convinced the United Egg Producers to phase
out fasted molts to be replaced with non-fasted molts in their commercial
operations. In addition, collaborative work with Dr. Moody Spurlock identified
suggestive quantitative trait loci affecting bird skeletal integrity. Several purebred lines of meat-type chickens
expressed large differences in bone mineralization, suggesting the potential to
genetically select birds for improved bone strength. A recent finding shows
that mechanical loading achieved through perching has beneficial effects on
pullet and laying hen health by stimulating leg muscle deposition and
increasing bone mineralization.
- Dual-energy x-ray absorptiometry (DEXA)
- Mineral analysis
- Inductively coupled plasma atomic emission spectrometry
- Atomic absorption spectrophotometry
Selected Refereed Journal Articles
Schreiweis, M. A., J. I. Orban, M. C. Ledur, D. E. Moody and P. Y. Hester, 2005 Validation of dual-energy X-ray absorptiometry in live White Leghorns. Poult. Sci. 84:91-99.
Mazzuco, H. and P. Y. Hester, 2005. The effect of an induced molt and a second cycle of lay on skeletal integrity of White Leghorns. Poult. Sci. 84:771-781.
Hester, P. Y. 2005. Impact of science and management on the welfare of egg laying strains of hens. Poult. Sci. 84:687-696 (invited symposium paper).
Mazzuco, H. and P. Y. Hester, 2005. The effect of an induced molt using a non-fasting program on bone mineralization of White Leghorns. Poult. Sci. 84:1483-1490.
Mazzuco, H., J. P. McMurtry, A. Y. Kuo, and P. Y. Hester, 2005. The effect of pre- and postmolt diets high in omega-3 fatty acids and molt programs on skeletal integrity and insulin-like growth factor-I of White Leghorns. Poult. Sci. 84:1735-1749.
Schreiweis, M. A., P. Y. Hester, and D. E. Moody, 2005. Identification of quantitative trait loci associated with bone traits in an F2 resource population of chickens. Genetics, Selection, Evolution 37:677-698.
Schreiweis, M. A., P. Y. Hester, P. Settar, and D. E. Moody, 2005. Identification of quantitative trait loci associated with egg quality, egg production, and body weight in an F2 resource population of chickens. Animal Genetics 37:106-112.
Bennett, A. K., P. Y. Hester, and D. E. Moody Spurlock, 2006. Polymorphisms in vitamin D receptor, osteopontin, insulin-like growth factor 1 and insulin, and their associations with bone, egg, and growth traits in a layer - broiler cross. Animal Genetics 37:283-286.
Bennett, A. K., P. Y. Hester, and D. M. Spurlock, 2007. Relationships of a transforming growth factor b single nucleotide polymorphism and mRNA abundance with bone and production traits in chickens. Poultry Sci. 86:829-834.
Zhai, W., S. L. Neuman, M. A. Latour, and P. Y. Hester, 2007. The effect of dietary L-carnitine on semen traits of White Leghorns. Poultry Sci. 86:2228-2235.
Zhai, W., S. L. Neuman, M. A. Latour, and P. Y. Hester, 2008. The effect of in ovo injection of L-carnitine on hatchability of White Leghorns. Poultry Sci. 87: 569-572.
Zhai, W., S. L. Neuman, M. A. Latour, and P. Y. Hester, 2008. The effect of male and female supplementation of L-carnitine on reproductive traits of White Leghorns. Poultry Sci. 87: 1171-1181.
Kim, W. K., T. M. Herfel, C. S. Dunkley, P. Y. Hester, T. D. Crenshaw, and S. C. Ricke, 2008. The effects of alfalfa-based molt diets on skeletal integrity of White Leghorns. Poultry Sci. 87: 2178–2185.
Fanatico, A. C., P. B. Pillai, P. Y. Hester, C. Falcone, J. A. Mench, C. M. Owens, and J. L. Emmert, 2008. Performance, livability, and carcass yield of slow- and fast-growing chicken genotypes fed low-nutrient or standard diets and raised indoors or with outdoor access. Poultry Sci. 87:1012-1021.