Browsing by Author "Richeson, John T."
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Item Dogs' ability to detect an inflammatory immune response in cattle via olfaction(2024) Juge, Aiden E.; Hall, Nathaniel J. (TTU); Richeson, John T.; Cooke, Reinaldo F.; Daigle, Courtney L.Introduction: Canine olfaction is a potential means for detection of respiratory disease in beef cattle. In a prior study, two dogs were trained to discriminate between nasal swabs from healthy cattle and cattle that developed Bovine Respiratory Disease. Dogs had some ability to identify samples from BRD-affected cattle, but results were ambiguous. The purpose of this study was to evaluate more dogs using better-controlled training and testing procedures. Methods: Nasal and saliva swabs were collected from 96 cattle before and after administering a vaccine to induce an inflammatory immune response. Samples were stored at −80°C for up to 11 months before use, and samples from animals with an elevated body temperature at baseline were omitted. An automated olfactometer apparatus was constructed to improve blinding procedures and reduce opportunities for odor contamination. Four dogs were trained to distinguish between swabs from healthy and sickness-model cattle, including the two dogs from the previous study (“Runnels” and “Cheaps”) and two inexperienced dogs (“Molokai” and “Amy”). During a seven-month training period, dogs were exposed to samples from 28 animals. Dogs were tested on 59 sets of unfamiliar samples. Results: Performance varied among dogs (χ2 = 10.48, p = 0.02). Molokai's performance was above chance (0.73 ± 0.06, p = 0.0006), while Amy (0.44 ± 0.06, p = 0.43), Cheaps (0.53 ± 0.07, p = 0.79), and Runnels (0.56 ± 0.06, p = 0.43) did not respond correctly at a rate different from chance. Accuracy did not differ between nasal swabs (0.63 ± 0.08) and saliva swabs (0.53 ± 0.08, χ2 = 0.81, p = 0.37). Discussion: The results of this study indicate that canine olfaction may be an effective means of detecting illness in beef cattle. However, individual dogs' aptitude for this detection task varies.Item Effects of Bacillus subtilis PB6 and/or chromium propionate supplementation on serum chemistry, complete blood count, and fecal Salmonella spp. count in high-risk cattle during the feedlot receiving and finishing periods(2020) Smock, Taylor M.; Samuelson, Kendall L.; Wells, Jim E.; Hales, Kristin E. (TTU); Hergenreder, Jerilyn E.; Whitney Rounds, P.; Richeson, John T.The study objective was to determine the effects of Bacillus subtilis PB6 and/ or chromium propionate supplementation on serum chemistry, complete blood count, and fecal Salmonella spp. count in high-risk beef cattle during a 56-d feedlot receiving period and the subsequent finishing period. Four truckload blocks of crossbred beef bulls (n = 300) and steers [n = 84; total n = 384; average initial body weight (BW) = 220 ± 16.2 kg] were sourced from regional auction markets and assigned randomly to treatments arranged in a 2 × 2 factorial. Blood samples were collected from two bulls nearest to the median BW on arrival in each pen (n = 96) and fecal samples were collected from cattle in block 3 (n = 96). The generalized complete block design consisted of 12 pen replications per treatment with pen as the experimental unit. Treatments were: 1) negative control (CON); 2) 13 g per animal daily of prepared B. subtilis PB6 product (CST); 3) 450 ppb dry matter (DM) chromium propionate (CHR); and 4) 13 g per animal daily of prepared B. subtilis PB6 product and 450 ppb DM chromium propionate (CST + CHR). Treatments were top dressed in feed bunks daily using 0.45 kg per animal ground corn carrier immediately following feed delivery. Data were analyzed using mixed models with repeated measures. Day affected all serum chemistry variables (P ≤ 0.03) except total CO2 (P = 0.34) and all complete blood count variables during receiving (P ≤ 0.02) except percentage basophils (P ≥ 0.12). During the overall receiving period, serum calcium was decreased (P = 0.02) by CHR. Cattle fed CHR had greater total leukocyte count (P = 0.04) and neutrophil count (P = 0.02) during the overall receiving period. Fecal Salmonella spp. count was markedly reduced in cattle fed CST on day 28 (P = 0.01) and overall (P = 0.07). Overall, these data provide metabolic and hematologic insight into the unique challenges presented by lightweight, high-risk feeder cattle. Notably, CST was found to be effective in mitigating fecal enumeration and presumably replication of Salmonella spp. in the gastrointestinal tract.Item Immune responses and performance are influenced by respiratory vaccine antigen type and stress in beef calves(2020) Hudson, Rachel E.; Tomczak, Dexter J.; Kaufman, Emily L.; Adams, Ashlee M.; Carroll, Jeffery A.; Broadway, Paul R.; Ballou, Michael A. (TTU); Richeson, John T.The study objective was to determine if a combined weaning and transportation stress model affected performance, antibody, endocrine, or hematological responses to modified-live virus (MLV) or killed virus (KV) respiratory vaccination in beef steers. In total, 48 calves (Day 0 BW = 226 ± 6.2 kg) from a single origin were used in a 2 × 2 factorial to evaluate main effects of stress model, vaccine type, and their interaction, resulting in four treatments (n = 12/treatment) including nonstress control (C) with KV (CKV), C with MLV (CMLV), stress model implementation (S) with KV (SKV), and S with MLV (SMLV). The C calves were weaned at the origin ranch on Day −37 and transported 472 km to the study site on Day −21 to allow acclimation. The S calves were weaned on Day −3, transported 460 km to a research facility on Day −2, held overnight, and transported 164 km to the study site on Day −1 to mimic the beef cattle marketing process. Vaccines were administered on Day 0 and KV was revaccinated on Day 14. The animal was the experimental unit and dependent variables were analyzed using PROC MIXED with repeated measures (day). A stress model effect (p = 0.01) existed for DMI from Day 0 to Day 7 with greater DMI for C (6.19 vs. 4.64 kg/day) when compared to S. The MLV groups had reduced (p = 0.05) ADG from Day 0 to Day 56, compared to KV. There was a vaccine type × day (p < 0.01) interaction with increased (p ≤ 0.01) PI3V- and IBRVspecific antibody titers for KV on Day 21; conversely, MLV had increased (p ≤ 0.01) BVDV titers on Days 14, 28, 35, 42, 49, and 56. Increased (p ≤ 0.05) BRSV titers were observed in a stress model × day (p < 0.01) interaction for S on Days 21, 28, 36, and 42; however, C exceeded S in BVDV-specific antibody concentration on Days 21, 28, and 49. A day effect (p < 0.01) was observed for serum haptoglobin with the greatest (p < 0.01) concentration on Day 3. Serum cortisol concentration was greater (p ≤ 0.04) for C vs. S on Days −2, 0, 1, 3, and 5. Total leukocytes were decreased for C vs. S on Days 0, 1, 3, 5, 7, 14, and 21 (p ≤ 0.02). A reduction (p ≤ 0.04) in total leukocytes was observed for MLV on Days 5, 7, and 14 vs. KV. Neutrophils and neutrophil:lymphocyte were markedly increased (p ≤ 0.01) for S on Day −2, whereas neutrophils were decreased (p ≤ 0.01) on Days 1 and 21 for S. Monocytes were decreased on Days 1, 5 and 7 for MLV (p ≤ 0.04) and Days −2 to 14 for S (p ≤ 0.03). Eosinophils were reduced (p = 0.007) for S vs. C on Day −2, yet a distinct rebound response (p = 0.03) was noted for S on Day 0. The results indicate that S and MLV vaccination more profoundly induced immunomodulation in beef calves.Item Modulation of the metabolic response using dexamethasone in beef steers vaccinated with a multivalent respiratory vaccine1(2020) Sanchez, Nicole C.Burdick; Carroll, Jeffery A.; May, Nathan D.; Hughes, Heather D.; Roberts, Shelby L.; Broadway, Paul R.; Ballou, Michael A. (TTU); Richeson, John T.Available energy plays a critical role in the initiation and maintenance of an immune response to a pathogen, a process that is further altered by activation of the stress system. This study was designed to determine the effect of an acute vs chronic stress model on the metabolic response to vaccination in naive beef steers. Steers (n = 32; 209 ± 8 kg) were blocked by body weight (BW) and randomly assigned to one of three treatments: 1) Chronic stress (CHR), 0.5 mg/kg BW dexamethasone (DEX) administered i.v. at 1000 h on day 3 to day 0; 2) Acute stress (ACU), 0.5 mg/kg BW DEX administered i.v. at 1000 h on day 0 only; or 3) Control (CON), no DEX. On day-4, steers were fitted with jugular vein catheters and moved into individual bleeding stalls in an environmentally-controlled facility. Blood samples were collected at-74,-50, and-26 h, at 0.5-h intervals from-4 to 6 h, and at 12, 24, 36, 48, and 72 h relative to vaccination with a combination vaccine (Pyramid 5 + Presponse SQ, Boehringer Ingelheim Animal Health USA, Duluth, GA) at 1200 h on day 0. Data were analyzed by the MIXED procedure of SAS specific for repeated measures. There was a treatment × time interaction (P < 0.001) for serum glucose concentrations. Specifically, glucose concentrations increased at-50 h in CHR steers and at 1200 h in ACU steers and remained elevated through 72 h postvaccination period in these two treatments compared to CON steers. The change in nonesterified fatty acid (NEFA) concentrations relative to baseline values was affected by treatment and time (P < 0.001) such that the change in NEFA was greater in CHR (0.06 ± 0.01 mmol/L), followed by CON (-0.01 ± 0.01 mmol/L) and ACU steers (-0.04 ± 0.01 mmol/L). There was a tendency (P = 0.08) for a treatment × time interaction for change in serum NEFA concentrations. Serum urea nitrogen (SUN) was affected by treatment and time (P < 0.001) such that SUN concentrations were greatest in CHR (12.0 ± 0.1 mg/dL) followed by ACU (10.4 ± 0.1 mg/dL) and CON steers (9.6 ± 0.1 mg/dL); however, the treatment × time interaction was not significant (P = 0.12). These data demonstrate that activation of the stress and immune axes using an acute or chronic stress model can increase energy mobilization prior to and following vaccination in naive steers, potentially affecting available energy needed to mount an adequate antibody response to vaccination.Item Using Canine Olfaction to Detect Bovine Respiratory Disease: A Pilot Study(2022) Juge, Aiden E.; Hall, Nathaniel J. (TTU); Richeson, John T.; Daigle, Courtney L.Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in feedlot cattle and is a major welfare and economic concern. Identification of BRD-affected cattle using clinical illness scores is problematic, and speed and cost constraints limit the feasibility of many diagnostic approaches. Dogs can rapidly identify humans and animals affected by a variety of diseases based on scent. Canines' olfactory systems can distinguish between patterns of volatile organic compounds produced by diseased and healthy tissue. In this pilot study, two dogs (“Runnels” and “Cheaps”) were trained for 7 months to discriminate between nasal swabs from cattle that developed signs of BRD within 20 days of feedlot arrival and swabs from cattle that did not develop BRD signs within 3 months at the feedlot. Nasal swabs were collected during cattle processing upon arrival to the feedlot and were stored at −80°C. Dogs were presented with sets of one positive and two negative samples and were trained using positive reinforcement to hold their noses over the positive sample. The dogs performed moderately well in the final stage of training, with accuracy for Runnels of 0.817 and Cheaps of 0.647, both greater than the 0.333 expected by chance. During a double-blind detection test, dogs evaluated 123 unique and unfamiliar samples that were presented as 41 sets (3 samples per set), with both the dog handler and data recorder blinded to the positive sample location. Each dog was tested twice on each set of samples. Detection test accuracy was slightly better than chance for Cheaps at 0.451 (95% CI: 0.344–0.559) and was no better than chance for Runnels at 0.390 (95% CI: 0.285–0.496. Overall accuracy was 0.421 (95% CI: 0.345–0.496). When dogs' consensus response on each sample set was considered, accuracy was 0.537 (95% CI: 0.384–0.689). Detection accuracy also varied by sample lot. While dogs showed some ability to discriminate between BRD-affected and healthy cattle using nasal swabs, the complexity of this task suggests that more testing is needed before determining whether dogs could be effective as a screening method for BRD.