Browsing by Author "Crossland, Whitney L. (TTU)"

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Characterization of bacterial DNA identified in abscessed and non-abscessed bovine hepatic tissue at the time of harvest
(2021) Stotz, Miranda K. (TTU); Henry, Darren D.; Crossland, Whitney L. (TTU)
Bacteriological characterization of bovine liver abscesses has been accomplished by cultural methods but DNA methods are still needed, as many bacteria are not conducive to laboratory culture. In addition to this gap in research, there have been no studies which identify the bacterial presence within healthy, non-abscessed liver tissue. The objective of this study was to compare the bacteriome of both abscessed and non-abscessed bovine livers in an observational case–control study design. Fifty-six livers, obtained from Holstein steers, were scored according to a modified Elanco liver abscess score description where A− was partitioned into active abscesses or scarred where only scars were present. Parenchyma tissue was collected from non-abscessed livers (n = 22) and scarred livers (n = 7), and purulent material was collected from abscessed livers (n = 24), and DNA was extracted for 16s rRNA gene sequence-based bacterial analysis. Across liver samples, 21 total phyla were identified with a mean of 14. Predominant phyla, accounting for >98% of reads, were Fusobacteria (51.7%), Bacteroidetes (26.9%), Proteobacteria (8.03%), Firmicutes (5.39%), Cyanobacteria (3.85%), and Actinobacteria (2.21%). Proteobacteria, Cyanobacteria, and Firmicutes were greater in non-abscessed and scarred livers, whereas Fusobacteria and Bacteroidetes prevailed in abscessed livers. Non-abscessed livers shared 3,059 operational taxonomic units (OTU) with abscessed livers (total OTU of all livers = 4,167), but non-abscessed livers had greater richness and evenness, whereas abscessed livers had greater dominance (P ≤ 0.0014). Liver score affected the relative abundance of OTU (R = 0.463; P = 0.001) but abscessed livers shared ≥ 40% similarity and were not different from each other (P ≥ 0.370). Of the predominant OTU (top 10 as a % of reads), three OTU (Fusobacteria necrophorum, Bacteroides spp., and Trueperella pyogenes) were shared across both abscessed and non-abscessed livers. Fusobacterium necrophorum was the dominant OTU regardless of liver score, and the single most abundant OTU, even among non-abscessed livers. We describe bacterial DNA detected in non-abscessed bovine liver tissue for the first time, which indicates possible presence of viable bacteria with pathogenic potential in apparently healthy liver tissue.
Effect of exogenous melatonin on the cellular response of Holstein heifer calves during vaccination
(2024) Martin, Allie E. (TTU); Machado, Vinicius S. (TTU); Rathmann, Ryan J. (TTU); Crossland, Whitney L. (TTU)
Despite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in the calf sector of the dairy industry. Melatonin has modulated immune response in other mature animal species. We hypothesized that exogenous melatonin may improve the cellular response to vaccination in dairy calves. Our objective was to evaluate the effect of exogenous melatonin on polymorphonuclear leukocyte (PMN) function in Holstein heifer calves during immunization. Sixty neonatal Holstein heifers were enrolled by birth cohort (block) and randomized to one of four treatments: control (CON), vaccination of 0.5 mg ovalbumin on days 0 and 21 (VAC), implantation of 24 mg melatonin on day 0 (MEL), or both melatonin and vaccine treatments (MVAC). Jugular blood was collected on days 0, 21, 42, and 63 to measure circulating melatonin, anti-ovalbumin immunoglobulin-G, and PMN function. Calves implanted with melatonin had greater circulating melatonin than non-implanted on day 21 (P < 0.01). Anti-ovalbumin IgG was greater for vaccinated than non-vaccinated calves (P < 0.01). Anti-ovalbumin IgG was greater for MVAC than VAC calves on day 63. Percent of cells and mean florescence intensity of cells performing oxidative burst decreased from day 0 to day 63 (P < 0.01) but were not affected by treatment (P ≥ 0.26). There was a tendency (P = 0.10) for an interaction of melatonin, vaccination, and day for the mean florescence intensity of cells performing phagocytosis where MVAC was greater than all other treatments on d 42. Exogenous melatonin may alter PMN function of calves during vaccination. Further research is needed to define the effect of melatonin on development of antigen-specific IgG during programmed vaccination protocols.
Identification of blood-based biomarkers for detection of liver abscesses in beef × dairy heifers
(2024) Wilson, Reese A. (TTU); Johnson, Bradley J. (TTU); Sarturi, Jhones O. (TTU); Crossland, Whitney L. (TTU); Hales, Kristin E. (TTU); Rathmann, Ryan J. (TTU); Bratcher, Christy L. (TTU); Theurer, Miles E.; Amachawadi, Raghavendra G.; Nagaraja, T. G.; Speidel, Scott E.; Enns, R. Mark; Thomas, Milton G.; Foraker, Blake A.; Cleveland, Matthew A.; Woerner, Dale R. (TTU)
Objective: The objective was to determine the effects of liver abscesses on complete blood counts (CBC) and liver function and to identify blood-based biomarkers for detection of liver abscesses in feedlot cattle. Materials and Methods: Blood samples were collected on a subset of beef × dairy crossbred heifers with and without liver abscesses (n = 94; n = 113, respectively). From these blood samples, CBC and serum chemistry analytes related to liver health (alkaline phosphatase, gamma glutamyl transferase, bile acids, total bilirubin, and cholesterol) were analyzed to characterize animal health and model for liver abscesses. Abscess presence was predicted using logistic regression models and machine learning algorithms, with individual heifer serving as the experimental unit. Results and Discussion: In a binary system (abscessed or not), heifers with liver abscesses had lower concentrations of lymphocyte (LYM) and total white blood cell (WBC) concentrations but elevated platelet-to-LYM ratio. Serum chemistry measures were not affected by abscess presence or liver score (severity). In univariate, predictive modeling of CBC measures, only total WBC concentration was accurate (65.85%) at predicting liver abscess presence; however, this was not deemed an acceptable biomarker due to its poor specificity (54.79%). Using total WBC, basophils, red blood cells, and procalcitonin as variables to predict liver abscess condition, the Logit- Boost model produced the greatest accuracy (80.65%) and specificity (85.71%). An accurate blood test that allows for the detection of liver abscesses during the finishing phase may allow for therapeutic management or alternative marketing of cattle; however, the marginal accuracy demonstrated in this study combined with the impracticality and cost of analyzing a blood sample may not be feasible. Regardless, the most explanatory CBC variables in cattle with abscessed livers were suggestive of an immune response. Implications and Applications: Liver condition influenced the CBC of beef × dairy heifers but not serum chemistry. Multivariate predictive models showed potential for predicting liver abscess condition based on CBC. The results of this study warrant further investigation for biomarkers of the liver abscess condition. An antemortem indicator for liver abscesses could prove useful for making management decisions and in research applications, particularly in evaluating interventions.
Injecting Fusobacterium necrophorum into the peripheral circulation or hepatic portal vein of preruminant Holstein calves failed to induce liver abscesses*
(2024) Cox, Hannah E. (TTU); Menta, Paulo R. (TTU); Nagaraja, T. G.; Crossland, Whitney L. (TTU); Hales, Kristin E. (TTU); Henry, Darren D. (TTU); Strieder-Barboza, Clarissa (TTU); Broadway, Paul R.; Carroll, Jeffery A.; Ballou, Michael A. (TTU); Machado, Vinicius S. (TTU)
Objective: Our goal was to determine whether admin- istration of Fusobacterium necrophorum ssp. necrophorum into the jugular or portal vein will induce liver abscesses in preruminant calves. Materials and Methods: The study was performed as 2 experiments according to the inoculation site: jugu- lar vein or hepatic portal circulation. Experiment 1 was performed in 18 calves randomly assigned to receive intra- jugular infusion of saline (CONIV), or 107 (FUSOIV7), 109 (FUSOIV9), and 1011 (FUSOIV11) of F. necrophorum. In experiment 2, 20 calves were assigned to receive intrapor- tal infusion of saline or 106 (FUSOPV6), 108 (FUSOPV8), and 1010 (FUSOPV10) of F. necrophorum. Blood samples were collected on d 0, 1, 3, 5, 7, and 14 for hematology. Calves were slaughtered 14 d after inoculation and exam- ined for liver gross pathology. Results and Discussion: Neither model produced liver abscesses. However, in experiment 1, inoculation increased monocyte counts in FUSOIV11 calves versus CONIV, FUSOIV7, and FUSOIV9 on d 3 and 5 postchal- lenge. The neutrophil-to-lymphocyte ratio was greater for FUSOIV11 than CONIV and FUSOIV9 on d 7 postchallenge. In experiment 2, inoculation increased monocyte and neutrophils counts in the FUSOPV8 group compared with calves in other groups. Implications and Applications: Contrary to previ- ous reports, intraportal and intrajugular inoculation with F. necrophorum did not produce liver abscesses in preru- minant calves. Further research is necessary to explore alternative methodologies to use preruminant calves in experimental disease models for liver abscesses in cattle.
The effects of a nutritional packet (live yeast, vitamins C and B1, and electrolytes) offered to steers in a calf-fed system on growth performance, nutrient digestion, feeding behavior, carcass characteristics, and ruminal variables
(2023) Rush, Camron J. (TTU); Sarturi, Jhones O. (TTU); Huerta-Leidenz, Nelson O. (TTU); Woerner, Dale R. (TTU); Crossland, Whitney L. (TTU); Henry, Darren D.; Silva, Kaliu G.S. (TTU); Lopez, Alejandra M. (TTU)
Effects of a nutritional packet strategically offered to calf-fed system steers on growth performance, nutrient digestibility, feeding behavior, ruminal variables, and carcass characteristics were evaluated. Angus crossbred steer-calves (N=60; body weight [BW]=234±4 kg) were used in a randomized complete block design (block=BW) and stratified into two treatments: 1) control; and 2) 30 g/steer-daily (dry matter [DM] basis) of a nutritional packet containing (steer-daily basis): Live yeast (Saccharomyces cerevisiae; 1.7×1010 CFU), vitamin C (Ascorbic acid, 162 mg), vitamin B1 (thiamin hydrochloride, 400 mg), sodium chloride (2.4 g), and potassium chloride (2.4 g). Animals were offered (electronic feed-bunks [SmartFeed, C-Lock Inc., Rapid City, SD]), a steam-flaked corn-based finishing diet to ad libitum (individual intake), once daily for 233 d. Treatments were offered during the first and last 60 days on feed (DOF). The GLIMMIX procedure of SAS was used, with steer as the experimental unit, treatment and phase (for feeding behavior and digestibility) as fixed effects, and BW-block as a random effect. Steers offered the nutritional packet had 14% less (P<0.01) intake and 18% greater (P=0.01) feed efficiency during the initial 30 DOF. Intake (days 0 to 233) was 6% greater (P=0.02) for steers offered the nutritional packet, while BW gain was not different (P≥0.44). Greater (P=0.02) dressing percent (61.1% vs. 62%) for steers offered the packet was observed, while other carcass variables were not different (P≥0.33). Digestibility of DM, organic matter, and fiber were greater (P<0.01) for steers offered the packet. Steers offered the packet spent 13% less time eating during the first 60 DOF, while during the last 60 DOF a 14% greater meal frequency and 12.3% smaller mean meal size (treatment×phase interaction, P<0.02) were observed. Steers offered the packet had a reduced (P≤0.01) mean meal duration during both phases. Regardless of treatment, a decreased rumination (P≤0.03) and chewing (P≤0.01) activities were observed for the last 60 DOF compared to the first 60 DOF. Ruminal papillae area was 30% greater (P=0.02) and the total volatile fatty acid (VFA) tended (P=0.09) to be greater for steers offered the nutritional packet. The nutritional packet offered to calf-fed steers improved feed efficiency during the initial 30 d after arrival, while inducing superior overall intake, nutrient digestibility, dressing percentage, ruminal papillae area, and total ruminal VFA.