Browsing by Author "Edrington, T. S."
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Item Evidence supporting vertical transmission of Salmonella in dairy cattle(2016) Hanson, D. L. (TTU); Loneragan, G. H. (TTU); Brown, T. R.; Nisbet, D. J.; Hume, M. E.; Edrington, T. S.We set out to investigate whether Salmonella enterica could be recovered from various tissues of viable neonatal calves immediately following parturition. Eleven samples were aseptically collected from each of 20 calves and consisted of both left and right subiliac and prescapular lymph nodes (LN), mesenteric LN, spleen and liver, as well as intestinal tissue (including luminal contents) from the small intestine, caecum, spiral colon and rectum. In addition, a faecal sample was collected from 19 of the dams. Salmonella was recovered from at least one sample from 10 of the 20 neonates. Across all calves, Salmonella was recovered from 12.7% of all samples and from LN in particular, Salmonella was recovered from 10.0%, 5.0%, and 5.0% of subiliac, prescapular, and mesenteric LN, respectively. Within calves, Salmonella was recovered from 0% to 73% of samples and across tissues, estimates of Salmonella prevalence were greatest in the caecum (30%) but was never recovered from the right pre-scapular LN. These data provide evidence of vertical transmission from a dam to her fetus such that viable calves are born already infected and thereby not requiring faecal-oral exposure for transmission. This new knowledge ought to challenge - or at least add to - existing paradigms of Salmonella transmission dynamics within cattle herds.Item Toxicological evaluations of cyclopiazonic acid and ochratoxin A in broilers(1999) Gentles, A. (TTU); Smith, E. E. (TTU); Kubena, L. F.; Duffus, E.; Johnson, Paul; Thompson, J.; Harvey, R. B. (TTU); Edrington, T. S.The individual and combined effects of ochratoxin A (OA) and cyclopiazonic acid (CPA) were evaluated in Petersen x Hubbard broiler chickens from 1 d to 3 wk of age. The experimental design was a 2 × 2 factorial with treatments of 0 and 2.5 mg OA/kg feed and 0 and 34 mg CPA/kg feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was reduced (P < 0.05) by OA, CPA, and OA-CPA in combination at the end of 3 wk. Ochratoxin A significantly increased the relative weight of the kidney and serum concentrations of uric acid and triglycerides and decreased total protein, albumin, and cholesterol. The toxicity of CPA was expressed primarily through increased relative weights of the proventriculus and increased activity of creatine kinase. Exposure to OA-CPA was characterized by increased relative weights of the liver, kidney, pancreas, and proventriculus; decreased concentrations of serum albumin, total protein, and cholesterol; increased activity of creatine kinase; and increased concentrations of triglycerides and uric acid. Postmortem examination revealed that the chickens fed CPA or OA-CPA had thickened mucosa and dilated proventricular lumen. Data from this study demonstrate that OA, CPA, and the OA-CPA combination can limit broiler performance and adversely affect broiler health. The interaction of the compounds was primarily additive or less than additive in the parameter in which the interaction occurred.