Browsing by Author "Ribeiro, Flavio R.B."
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Item Chromium propionate enhances adipogenic differentiation of bovine intramuscular adipocytes(2015) Tokach, Rebecca J.; Ribeiro, Flavio R.B.; Chung, Ki Yong; Rounds, Whitney; Johnson, Bradley J.In vitro experiments were performed to determine the effects of increasing concentrations of chromium propionate (CrPro) on mRNA and protein abundance of different enzymes and receptors. Intramuscular (IM) and subcutaneous (SC) preadipocytes and bovine satellite cells were isolated from the longissimus muscle to determine the effect of treatment on glucose transporter type 4 (GLUT4) and peroxisome proliferator-activated receptor γ mRNA and GLUT4 protein abundance. Preadipocyte cultures were treated with differentiation media plus either sodium propionate or different concentrations of CrPro for 96, 120, and 144 h before harvest. This study indicated that adipogenesis of the bovine IM adipocytes were more sensitive to the treatment of CrPro as compared to SC adipocytes. Enhancement of adenosine monophosphate-activated protein kinase and GLUT4 mRNA by CrPro treatment may enhance glucose uptake in IM adipocytes. CrPro decreased GLUT4 protein levels in muscle cell cultures suggesting that those cells have increased efficiency of glucose uptake due to exposure to increased levels of CrPro. In contrast, each of the two adipogenic lines had opposing responses to the CrPro. It appeared that CrPro had the most stimulative effect of GLUT4 response in the IM adipocytes as compared to SC adipocytes. These findings indicated opportunities to potentially augment marbling in beef cattle fed CrPro during the finishing phase.Item Effect of Direct-Fed Microbial Supplementation on Pathogenic Escherichia coli Fecal Shedding, Live Performance, and Carcass Characteristics in Feedlot Steers(2020) Thompson, Alex; Calle, M. Alexandra; Ribeiro, Flavio R.B.; Pond, Ansen R.; Kreikemeier, Wanda M.; McDonald, Allen; Johnson, Edward G.; Edmonds, Matthew D.; Loneragan, Guy H.; Brashears, Mindy M.; Johnson, Bradley J.Three experiments were conducted to evaluate direct-fed microbial (DFM) supplementation on live performance, carcass characteristics, and fecal shedding of E. coli in feedlot steers. In Exp. 1, 400 steers (BW = 348 kg) were assigned to treatments: CON = lactose carrier only, BOV = P. freudenreichii (NP24) + L. acidophilus (NP51), BOVD = P. freudenreichii (NP24) + L. acidophilus (NP51), and COMB = BOV fed for the first 101 d on feed, followed by BOVD for the final 28 d prior to harvest. In Exp. 2 (n = 1800; BW = 354 kg) and Exp. 3 (n = 112; BW = 397 kg), steers were utilized in a randomized complete block design and assigned to DFM treatments using low dose and high dose, respectively. Fecal samples were collected prior to harvest and analyzed for E. coli serogroups. In Exp. 1, DFM reduced (P < 0.01) the concentration of E. coli O157. Prevalence of O157 was reduced by BOVD supplementation in Exp. 2 and 3 (P < 0.01 and P = 0.08, respectively), and concentration of E. coli O157 in positive samples was reduced in both experiments where enumeration was performed (P ≤ 0.02). Weighted mean differences across the three experiments were equal to a 33% reduction in the prevalence of E. coli O157:H7 in BOVD treated cattle. A significant reduction in prevalence of O26, O45, O103, and O121 was observed in Exp. 2 (P ≤ 0.03). These results indicate that high levels of L. acidophilus (NP51) may represent an effective pre-harvest food safety intervention to reduce fecal shedding of several E. coli serogroups.Item Ractopamine Hydrochloride and Estradiol + Trenbolone Acetate Implants Alter Myogenic mRNA, β-Adrenergic Receptors, and Blood Metabolites(2020) Harris, T.L.; Smith, Zachary K.; Ribeiro, Flavio R.B.; Jennings, M.A.; Vogel, G.J.; Johnson, Bradley J.Two commonly used growth promotants in the United States beef industry are β-agonists and anabolic steroid hormones. Each has been shown to increase lean muscle deposition in cattle provided treatments of each growth technology, but much is still unknown of how steroidal implants and β-agonists work in combination. It was our goal to determine the effect of implant strategy and β-agonist administration in beef feedlot heifers (n = 264). A 3 × 2 factorial randomized complete block design was used with 2 levels of OPT and 3 different durations of terminal implant (TI) windows for a total of 6 treatment groups with 9 replications. Terminal implants (20 mg estradiol/200 mg trenbolone acetate implant, Component TE-200) were provided to heifers 140 d from slaughter (TI140), 100 d from slaughter (TI100), or 60 d from slaughter (TI60). Animals receiving the later two TI being first implanted on day 0 (8 mg estradiol/80 mg trenbolone acetate implant, Component TE-IH). The second treatment of the cattle received was the orally active beta adrenergic agonist, ractopamine-hydrochloride (RH) in the form of Optaflexx®(OPT; 0 (NO) or 200 (YES) mg/hd·d-1) over the final 28 days of the trial. Thirty animals were subjected to longissimus muscle (LM) biopsies on d 0, 40, 80, 112, and at slaughter on d 140 to view mRNA levels of myogenic related genes and protein quantities of the β1-adrenergic receptor (β1 AR) and β2-adrenergic receptor (β2 AR). On the same days, blood samples were taken from 108 animals to assess changes in plasma blood urea nitrogen (BUN), non-esterified fatty acids (NEFA) and progesterone due to treatments. Relative mRNA levels of myosin heavy chain IIX (MHC IIX), AMPKα, and IGF-I were increased (P < 0.05) in animals receiving a TI100 over the other two implant dates after OPT was fed to animals. After OPT administration myosin heavy chain IIA (MHC IIA) mRNA levels tended to decrease (P = 0.09) due to OPT. An interaction between TI d and OPT administration caused an increase (P < 0.05) in MHC IIA mRNA level in the TI60/Yes treatment group over all other treatments except the TI100/No treatment group. Protein intensity of the β2 AR was decreased (P < 0.05) by the latest TI d (TI60) during OPT feeding, while β1 AR protein intensity tended to be lower (P < 0.10) in animals fed OPT. Plasma BUN levels were reduced (P < 0.05) after terminal implants and OPT feeding; while progesterone was decreased (P < 0.05) by OPT alone. Neither growth promotant affected NEFA levels in plasma. Collectively, these data indicate that ractopamine hydrochloride and estradiol + trenbolone acetate implants alter myogenic mRNA, β-adrenergic receptors, and blood metabolites in finishing beef heifers.Item Review: the effects of dust on feedlot health and production of beef cattle(2021) Urso, Phil M.; Turgeon, Abe; Ribeiro, Flavio R.B.; Smith, Zachary K.; Johnson, Bradley J.Dust in feedlots is detrimental to optimal cattle performance. Contributors such as climate, manure production, and animal behaviour can affect dust production and ultimately, cattle health. Bovine respiratory disease (BRD) and acute interstitial pneumonia (AIP) represented to 68% of death loss across 30 feedyards from 2015 to 2017. Bovine respiratory disease specifically costs producers between $800 and $900 million each year with the cost per animal varying based on number of treatments, occurrence, and performance differences. Altering feeding schedule, stocking density, and sprinkler systems have decreased dust concentrations. By using these methods, cattle feeders can limit dust production and promote animal health. This paper serves to consolidate previous research and data discussing the effects of dust on cattle health.