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Your search keyword '"Korver, Doug R."' showing total 9 results
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9 results on '"Korver, Doug R."'

2. Lysine requirements of pre-lay broiler breeder pullets: determination by indicator amino acid oxidation

Author

Coleman, Russell A., Bertolo, Robert F., Moehn, Soenke, Leslie, Michael A., Ball, Ronald O., and Korver, Doug R.

Subjects
Lysine -- Health aspects, Food/cooking/nutrition
Abstract

The indicator amino acid oxidation (IAAO) method allows the determination of amino acid requirements under conditions of low growth rate as found in pre-laying broiler breeder pullets. Cobb 500 breeder pullets (20 wk old; 2290 [+ or -] 280 g, n = 4) were adapted (6 d) to a pelleted, purified control diet containing all nutrients at [greater than or equal to] 110% of NRC recommendations. After recovery from surgery for implantation of a jugular catheter, each bird was fed, in random order, test diets containing one of nine levels of lysine (0.48, 0.96, 1.92, 2.88, 3.84, 4.80, 7.68, 9.60 and 14.40 g/kg of diet). Indicator oxidation was determined during 4-h primed (74 kBq/kg body), constant infusions (44 kBq * [h.sup.-1] * kg [body.sup.-1]) of L-[1-[sup.14]C]phenylalanine. Using the breakpoint of a one-slope broken-line model, the lysine requirement was determined to be 4.88 [+ or -] 0.96 g/kg of diet or 366 [+ or -] 72 mg * [hen.sup.-1] * [d.sup.-1] with an upper 95% CI of 6.40 g/kg of diet or 480 mg * [hen.sup.-1] * [d.sup.-1]. IAAO allows determination of individual bird amino acid requirements for specific ages and types of birds over short periods of time and enables more accurate broiler breeder pullet diet formulation. KEY WORDS: * individual requirement * maintenance requirement * broiler breeder pullet * indicator amino acid oxidation * continuous infusion

Published
2003

4. Detection, characterization, and in vitro and in vivo expression of genes encoding S-proteins in Lactobacillus gallinarum strains isolated from chicken crops

Author

Hagen, Karen E., Le Luo Guan, Tannock, Gerald W., Korver, Doug R., and Allison, Gwen E.

Subjects
Lactobacillus -- Genetic aspects, Broilers (Poultry) -- Genetic aspects, Genetic code -- Research, Genetic research, Biological sciences
Abstract

Thirty-eight isolates of Lactobacillus gallinarum cultured from the crops of broiler chickens are screened for the presence of genes encoding S-layer proteins. The results provide a basis for the investigation of gene duplication and sequence variation as mechanisms by which bacterial strains of the same species can share the same habitat.

Published
2005

5. Detection and identification of Lactobacillus species in crops of broilers of different ages by using PCR-denaturing gradient gel electrophoresis and amplified ribosomal DNA restriction analysis

Author

Le Luo Guan, Hagen, Karen M., Tannock, Gerald W., Korver, Doug R., Fasenko, Gaylene M., and Allison, Gwen E.

Subjects
Lactobacillus -- Identification and classification, Lactobacillus -- Research, Broilers (Poultry) -- Research, Nucleotide sequencing -- Research, Biological sciences
Abstract

The microflora of the crop was investigated throughout the broiler production period using PCR combined with denaturing gradient gel electrophories and selective bacteriological culture of lactobacilli followed by amplified ribosomal DNA restriction analysis. The results provide knowledge of the Lactobacillus microflora in the crops of birds of different ages nucleic acid-based methods of detection and identification.

Published
2003

9. Leukocytic Cytokines Regulate Growth Rate and Composition Following Activation of the Immune System

Author

Klasing, Kirk C. and Korver, Doug R.

Abstract

When an immune response is triggered by an infectious challenge the pro-inflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor-α (TNFα) are released. These cytokines mediate a stress response consisting of specific behavioral, cellular, and metabolic changes that alter the partitioning of nutrients away from growth and toward processes that support the immune and inflammatory responses. They act directly on most tissues of the body through specific receptors, and they induce distinct endocrine changes that further impair growth, including increased glucocorticoids and decreased insulin like growth factor-I. Anorexia induced by pro-inflammatory cytokines accounts for 70% of the growth reduction in young chicks, with the remainder due to tissue-specific changes in metabolism. In chick skeletal muscle, IL-1 and TNFα act synergistically to increase the rate of protein degradation. In vivo, IL-1 induces the release of corticosterone that decreases the rate of skeletal muscle protein synthesis and further slows skeletal muscle accretion. Conversely, pro-inflammatory cytokines and corticosterone elevate liver protein synthesis due to increased secretion of acute-phase proteins. Thus, an inflammatory response orchestrates a change in both the rate and the composition of growth in a manner that varies directly with the amount of pro-inflammatory cytokines released. Endogenous mediators that block the release or action of pro-inflammatory cytokines ameliorate the growth suppression that accompanies an immune response. These include the IL-1 receptor antagonist and solubilized receptors. The ratio of dietary (n-3) to (n-6) fatty acid also modulates the growth depression induced by an inflammatory response. An unanswered question is the degree to which specific (adaptive) immune responses impair growth. The profiles of cytokines released allow speculation that inflammatory and TH1 responses are most growth suppressive and TH2 responses are more benign.

Published
1997
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