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Browsing by Author "Torres-Henderson, Camille, committee member"

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    Investigating hepatic copper trafficking in beef cattle
    (Colorado State University. Libraries, 2020) Tillquist, Nicole, author; Engle, Terry, advisor; Coleman, Stephen, committee member; Nair, Mahesh Narayanan, committee member; Torres-Henderson, Camille, committee member
    To view the abstract, please see the full text of the document.
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    Propionibacteriaium acidipropionici CP 88 dose alters in vivo and in vitro ruminal fermentation characteristics
    (Colorado State University. Libraries, 2024) Levenson, Jonah, author; Engle, Terry E., advisor; Wagner, John J., committee member; Torres-Henderson, Camille, committee member
    Twelve steers, fitted with rumen canulae were used in a 4 x 4 Latin square design to examine the impact of the direct fed microbial Propionibacteria acidipropionici (PA) on rumen fermentation characteristics. All steers were housed together in one pen equipped with GrowSafe feed intake monitoring stations and one Greenfeed system used to estimate in vivo methane production. Steers were fed a corn silage-based diet throughout the experiment. Treatments consisted of PA administered at: 1) 0.0; 2) 1.0 x 108; 3)1.0 x 109; and 4) 1.0 x 1010 CFU∙animal-1∙day-1. Treatments were administered directly into the rumen as a single bolus dose daily. On day 7 and 14 of each period, rumen fluid was collected from each steer 2 h post treatment administration for VFA analysis and for determining in vitro fermentation characteristics. Following a 14-d washout period, animal treatments were switched, and the experiment repeated. Data were analyzed as a 4 x 4 Latin square design. In vivo propionic acid molar proportions (25.4 vs 23.6±0.24 mM) and total VFA concentrations (125.2 vs 121.3±1.87 mM) were greater (P < 0.05) in steers receiving PA when compared to controls. In vitro DM disappearance (P < 0.05; 63.3% vs 59.2%±1.12) and total VFA (P < 0.05; 147.9 vs 145.2±1.76 mM) were greater and methane (ml/g DMD) lesser (P < 0.04; vs 13.1 vs 15.6±0.11) in fermentation vessels incubated with rumen fluid from animals receiving PA when compared to controls. Dry matter disappearance (P < 0.03) and propionic acid (P < 0.04) increased linearly as dose of PA increased. In vitro total VFA tended (P < 0.08) to increase linearly and methane production tended (P < 0.09) to decrease quadratically in response PA dose. In vivo methane production was similar across treatments. In conclusion, PA addition improved in vivo and in vitro rumen fermentation, gas production, and rumen microbial manipulation.
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    The influence of propionibacteria on in vivo rumen fermentation characteristics and in vitro lactic acid clearance rate in fistulated steers fed moderately high concentrate diets
    (Colorado State University. Libraries, 2022) Gifford, Ryan J., author; Engle, Terry E., advisor; Wagner, John J., committee member; Torres-Henderson, Camille, committee member
    The objective of this experiment was to determine the impact of a direct fed microbial (DFM) supplementation on rumen fermentation characteristics and in vitro lactic acid clearance. Fistulated steers (n = 6) were sorted into two groups of three steers, randomly assigned to one of two treatments, and fed a moderately high concentrate diet (14.9% CP, 1.17 Mcal/kg NEg, and 28.3% NDF) for 21 d prior to beginning the experiment. Treatments consisted of: 1) Control (No DFM; carrier only) or 2) DFM (0.225g∙animal-1∙day-1 of 4.45x 1010 CFU/g of Propionibacteria acidipropionici - CP88). Treatments were administered daily, directly into the rumen via the cannula as a single bolus dose at the time of feeding. Immediately after treatment administration, the rumen contents were thoroughly mixed by hand. Two hours post feeding, rumen pH was determined, and rumen contents were sampled and analyzed for short chain fatty acids (SCFA), daily. On d 7 and 14, rumen fluid was collected from all steers and subjected to an in vitro lactic acid clearance challenge. Lactic acid and SCFA concentrations were determined at 0, 3, 6 and 9 h post-incubation. After d 14, all cattle received the basal diet for 21 d. On d 22, treatment crossover was implemented, and the experiment repeated. Data were analyzed by a mixed effects completely randomized block design (Proc Mixed, SAS Inst. Carey, NC). There were no treatment x block, treatment x time, or treatment x block x time interactions for any in vivo or in vitro rumen variables measured. Propionic acid concentrations were greater (P < 0.05) and total SCFA tended (P < 0.06) to be greater in rumen fluid from steers receiving DFM compared to controls. Other in vivo rumen fermentation characteristics were similar. D- and total lactic acid concentrations but not L+ lactic acid concentrations were lesser (P < 0.05) at 3 h post incubation in vitro, for steers receiving DFM. D-, L+, and total lactic acids concentrations were similar between control and DFM treatments at 0, 6, and 9 h post incubation. In vitro molar proportions of propionic acid and total SCFA concentrations were greater (P < 0.05) and acetic acid molar proportions were lesser (P < 0.05) in steers receiving DFM. Collectively, under the conditions of this experiment, these data indicate that the DFM test article (P. acidipropionici - CP88) used in this experiment alters rumen fermentation characteristics in vivo, and in vitro, and lactic acid utilization in vitro.