Progress 02/01/09 to 01/31/12
Outputs
OUTPUTS: Extensive laboratory and data analyses were completed from a study in which 78 early lactation dairy cattle were treated with sodium salicylate or placebo to assess the impact of suppressing inflammation on measures of metabolic function and productivity. In addition to metabolic panels, hormonal assays, and gene expression analyses that are standard in our laboratory, collaborations with 2 other labs have allowed us to assess plasma salicylate concentrations resulting from our treatment protocol and also to analyze a panel of 14 eicosanoids involved in generating or resolving inflammation. Finally, feeding behavior for all animals over the first 21 days in milk was analyzed to assess treatment effects on meal patterns, and whole-lactation milk production responses were determined from Dairy Herd Improvement Records PARTICIPANTS: Dr. Barry Bradford, Principle Investigator: Designed and oversaw research and analysis. Dr. J. Ernest Minton, Co-Principle Investigator: Assisted with experimental design, interpretation. Dr. Laman Mamedova, Research Asst. Prof.: Coordinated and oversaw laboratory assays. Jaymelynn Farney, PhD student: Conducted salicylate study and associated laboratory work. Dr. Johann Coetzee, Veterinary Diagnostic and Production Animal Medicine Department, Iowa State University, Ames Dr. Lorraine Sordillo, Department of Large Animal Clinical Sciences, Michigan State University, East Lansing TARGET AUDIENCES: Target audiences include dairy scientists, veterinarians, dairy nutritionists, and dairy producers. Conference and extension presentations have put the central hypothesis of this project in front of a large segment of this audience. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
At calving, 78 cows (n = 39 primiparous [1P]; n = 24 2nd lactation [2P]; n = 15 ≥3 lactations [3P]) were alternately assigned to either control (CON) or SS treatment for 7 d and remained on study until 21 d postpartum. SS treatment was administered via individual water bowls at a concentration of 1.68 g/L, delivering a mean of 123.3 plus 5.5 g SS/d during the 7 d of treatment. Blood samples were collected weekly and liver biopsies were collected on d 4 and 21 postpartum. Data were analyzed using mixed models with repeated measures over time and significance was declared at P < 0.05 and interactions were investigated at P < 0.15. There were no overall treatment effects on daily intake of water or DM, and SS treatment resulted in plasma salicylate concentrations of 34.4 plus 15.0 micrograms/mL on d 7. Liver TNFα mRNA abundance was decreased by SS on d 4 (28% reduction). Plasma glucose concentration was decreased by SS on d 7, especially in 2P and 3P cows (51.7 vs. 40.7 plus 3.1 mg/dL); 3P cows treated with SS had a 49% reduction in glucose-6-phosphatase mRNA on d 4 and a 81% reduction (d 21) in mRNA abundance of CREBH, a positive regulator of gluconeogenesis induced by inflammatory pathways. Plasma BHBA concentration was elevated in SS cows on d 14 and 21 (977 vs. 749 plus 56 microM), and plasma NEFA was elevated in SS cows on d 21 (525 vs. 377 plus 36 microM). SS treatment significantly increased liver triglyceride content on d 4 (29% increase) but by d 21 concentrations were similar across treatments. Because the most dramatic responses were observed in 3P cows, plasma samples from this block were analyzed for 14 eicosanoids. An index comprised of 11 pro-inflammatory eicosanoids showed no differences on d 7, but were significantly elevated for SS on d 14 (150% increase). Therefore, responses to SS after d 7 may have been due to altered metabolic programming or to post-SS increases in inflammatory signals. In summary, SS suppressed liver inflammation but decreased plasma glucose, increased plasma ketones, and contributed to liver triglyceride accumulation. These findings suggest that interrupting inflammation during the first week after parturition alters the metabolic adaptations to lactation. Cows were followed through the lactation by monthly milk yield and component testing, and the effects of treatment on the risk of leaving the herd and on 305-day milk, fat, and protein yields were determined by Fisher's exact test and ANOVA, respectively. Treatment by parity interactions were detected for both 305-day milk yield and 305-day milk fat yield. Milk yield was 1,988 kg higher over the lactation in 3P SS cows (17% increase, P = 0.05). Furthermore, 3P SS cows produced 144 kg more milk fat over the lactation (34% increase, P < 0.001). A treatment by parity effect was also observed for the risk of leaving the herd. First parity cows treated with SS cows tended to have greater risk of leaving the herd than controls (30% vs. 6% risk, P < 0.10). Results indicate that sodium salicylate has long term effects on fat metabolism in aged cows, but has potential negative effects for young cows.
Publications
- Farney, J. K., L. K. Mamedova, B. H. Godsey, and B. J. Bradford. 2011. Technical note: Validation of an ELISA for measurement of tumor necrosis factor alpha in bovine plasma. J Dairy Sci. 94(7):3504-9.
- Schoenberg, K. M., K. L. Perfield, J. K. Farney, B. J. Bradford, and T. R. Overton. 2011. Effects of prepartum 2,4-thiazolidinedione on insulin sensitivity, plasma concentrations of tumor necrosis factor alpha and leptin, and adipose tissue gene expression. J Dairy Sci. 94(11):5523-32.
- Bradford, B. J. 2011. Inflammation and oxidative stress in transition cows. Proc. 73rd Annual Cornell Nutrition Conference, Oct. 18-20, 2011. Syracuse, NY.
- Bradford, B. J. 2011. Inflammation and immunity in transition cows. Proc. 44th Annual Conference of the American Association of Bovine Practitioners, Sept. 22-24, 2011. St. Louis, MO.
- Bradford, B. J. 2011. Inflammation and the liver. Proc. Large Herd Seminar, June 21-22, 2011. Wotton-under-Edge, UK.
- Bradford, B. J. 2011. The role of inflammation in metabolic disorders. Proc. Mid-South Ruminant Nutr. Conf., Apr. 20-21, 2011. Grapevine, TX.
- Bradford, B. J. 2011. Connecting transition cow physiology, behavior, and nutrition. Proc. 10th Western Dairy Manag. Conf., Mar. 9-11, 2011. Reno, NV.
- Bradford, B. J. 2011. Balancing the acute phase response during the transition period: Impacts on performance and health. Proc. Florida Rum. Nutr. Symposium, Feb. 1-2, 2011. Gainesville, FL.
- Farney, J. K., L. K. Mamedova, J. E. Minton, J. F. Coetzee, L.C. Hollis, and B. J. Bradford. 2011. Effects of sodium salicylate on productivity of postpartum dairy cows. Dairy Research 2011, Kansas State University. Pp 26-30.
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Progress 02/01/10 to 01/31/11
Outputs
OUTPUTS: An enzyme-linked immunosorbent assay (ELISA) developed for determination of basal bovine TNFα concentrations was further validated. Additionally, an assay previously reported for use with bovine samples was demonstrated to detect off-target proteins in bovine plasma. In a collaborative effort with scientists at Cornell University, plasma samples from 31 periparturient dairy cows were assayed for TNFα concentrations covering a 10-week period throughout the transition from gestation to lactation. In addition to evaluating changes over time during this transition period, this analysis provided insight into the effects of 2,4-thiazolidinedione on TNFα concentrations. A study was initiated to evaluate responses to water-delivered sodium salicylate treatment in transition cows. The study will include at least 80 cows when it is completed, and will measure liver triglyceride, plasma metabolite, feed intake, disease incidence, and milk production responses to 0 or 5 g/L concentrations of sodium salicylate in drinking water during the first 7 days in lactation. PARTICIPANTS: Dr. Barry Bradford, Principle Investigator: Designed and oversaw research and analysis. Dr. J. Ernest Minton, Co-Principle Investigator: Assisted with experimental design, interpretation. Dr. Laman Mamedova, Research Asst. Prof.: Coordinated and oversaw laboratory assays. Cynthia Martel, PhD student: Conducted animal work and laboratory assays. Jaymelynn Farney, PhD student: Developed TNFα ELISA, conducted animal work. Chad Mullins, PhD student: assisted with animal work. Collaborators: Dr. Johann Coetzee, Department of Clinical Sciences, Kansas State University, Manhattan Dr. Meredyth Jones, Veterinary Medical Teaching Hospital, Kansas State University, Manhattan Dr. Tom Overton, Department of Animal Science, Cornell University, Ithaca, NY, Dr. Katie Schoenberg, Department of Animal Science, Cornell University, Ithaca, NY, Dr. Jeff Carroll, Livestock Issues Research Unit, ARS-USDA, Lubbock, TX. Training: Brian Godsey, a veterinary research scholar, contributed to the development of the TNFα ELISA during a summer program. TARGET AUDIENCES: Target audiences include dairy scientists, veterinarians, dairy nutritionists, and dairy producers. Conference and extension presentations as well as the electronic article posted on Dairy eXnet have put the central hypothesis of this project in front of a large segment of this audience. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A tumor necrosis factor alpha enzyme-linked immunosorbent assay (ELISA) for use with cell culture supernatant was modified for use with bovine plasma by optimizing antibody concentrations, incubation times and temperatures, and standard diluents. The coating antibody concentration was decreased from 10 ug/mL to 6.8 ug/mL, while the detection antibody concentration remained 2.5 ug/mL. Sample incubation was increased from 1 hour at room temperature to an overnight incubation at 4 degrees C, which increased the sensitivity of the assay. Multiple matrices were tested for dilution of standards and were assessed by determining recovery of bovine TNFα spiked into bovine serum and plasma. Standard curve matrices were fetal bovine serum (FBS), dialyzed FBS, lyophilized human serum (rehydrated), and phosphate-buffered saline (PBS) with 4% bovine serum albumin. Recoveries were <50% when quantified with standards diluted in PBS, FBS, or dialyzed FBS. However, recoveries were acceptable in both bovine serum and plasma (85-120%) when quantified with standards diluted in lyophilized human serum. The modified bovine TNFα ELISA offers a detection range of 2 to 250 pg/mL. This detection limit is at least an order of magnitude lower than previously reported, and will allow for greater precision in determining basal TNFα concentrations in bovine plasma. Holstein cows (n = 31) entering their second or greater lactation were administered 0, 2.0, or 4.0 mg TZD/kg BW by intrajugular infusion once daily from 21 d before expected parturition until parturition. Plasma samples were analyzed for TNFα on d -14, -3, -1, 1, 3, 7, 35, and 49 relative to parturition via a recently developed bovine TNFα enzyme-linked immunosorbent assay (ELISA). Results were analyzed with a mixed model including repeated measures over time and a covariate sample collected at d -22. Data transformation was required to meet assumptions of normality for statistical analysis and values reported are back-transformed. Independent of day, plasma TNFα was increased linearly by increasing TZD dose (2.63, 3.72, 3.95 pg/mL; P = 0.01). The temporal pattern (effect of day; P < 0.01) for plasma TNFα was such that it lowest (2.85 pg/mL) during the postpartum period (d + 7 to d + 49), highest (4.18 pg/mL) during the prepartum period (d -14) and intermediate (3.32 pg/mL) during the transition period (d -3 to +3). Contrasts of the effect of period showed that prepartum values were significantly different from both the transition period (P < 0.01) and the postpartum period (P < 0.001). These results suggest that TNFα may be an important metabolic regulator during the transition period.
Publications
- Bradford, B. J. 2010. Interactions of the immune system with nutrient metabolism. Proc. Elanco Science Symposium, Oct. 27-29. Indianapolis, IN.
- Bradford, B. J. 2010. Regulation of glucose production in the transition dairy cow. Proc. Pacific Northwest Animal Nutrition Conference, Oct. 5-7. Vancouver, Canada.
- Bradford, B. J. and J. K. Farney. 2010. Influence of inflammation on metabolism in transition cows. Proc. Southwest Nutrition and Management Conference, Feb. 25-26. Tempe, AZ.
- Farney, J. K., L. K. Mamedova, and B. J. Bradford. 2010. Modification and validation of a bovine TNFα enzyme-linked immunosorbent assay with improved sensitivity. J Dairy Sci. 93 (E-Suppl. 1): 404 (Abstr.).
- Martel, C. A., L. K. Mamedova, E. J. Minton, M. L. Jones, J. A. Carroll, and B. J. Bradford. 2010. Effects of continuous infusion of tumor necrosis factor-alpha (TNFα) into adipose tissue on glucose and fatty acid metabolism in lactating dairy cattle. J Dairy Sci. 93 (E-Suppl. 1): 503 (Abstr.).
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Progress 02/01/09 to 01/31/10
Outputs
OUTPUTS: An experiment was conducted to investigate the metabolic effects of continuous infusion of tumor necrosis factor alpha (TNFα) into adipose tissue. Twenty-eight late-lactation cows were used in a randomized complete block design with 3 treatments: control, TNFα infusion, and pair-fed control. To mimic a low-grade inflammatory state, 2 microgram/kg TNFα per day was continuously infused over 7 days through 2 osmotic pumps inserted in the adipose layer in the tailhead region. Throughout the 7-day treatment period, feed intake, milk yield, and milk component yield were measured daily to characterize treatment effects on energy balance. On each treatment day, a blood sample was collected for analysis of glucose, beta-hydroxybutyrate, and non-esterified fatty acid concentrations. Plasma glucose turnover rate was measured by disappearance of a U-13C-glucose bolus on day 7. At the end of day 7, liver samples were collected by puncture biopsy for analysis of triglyceride content, TNFα protein abundance, and mRNA abundance of several key metabolic genes. An enzyme-linked immunosorbent assay (ELISA) was developed and validated for determination of basal bovine TNFα concentrations. Although bovine TNFα has been reported in the literature, common methods are not precise enough to accurately measure low concentrations of TNFα in plasma of relatively healthy animals. Concentrations of coating and detection antibodies were varied to improve assay precision, and matrix effects were assessed and controlled by testing various diluents for standards. PARTICIPANTS: Dr. Barry Bradford, Principle Investigator: Designed and oversaw research and analysis. Dr. J. Ernest Minton, Co-Principle Investigator: Assisted with experimental design, interpretation. Dr. Laman Mamedova, Research Asst. Prof.: Coordinated and oversaw laboratory assays. Cynthia Martel, PhD student: Conducted animal work and laboratory assays. Jaymelynn Farney, PhD student: Developed TNFα ELISA. Collaborators: Dr. Johann Coetzee, Department of Clinical Sciences, Kansas State University, Manhattan. Dr. Meredyth Jones, Veterinary Medical Teaching Hospital, Kansas State University, Manhattan. Dr. Tom Overton, Department of Animal Science, Cornell University, Ithaca, NY. Dr. Jeff Carroll, Livestock Issues Research Unit, ARS-USDA, Lubbock, TX. Training: Brian Godsey, a veterinary research scholar, contributed to the development of the TNFα ELISA during a summer program. TARGET AUDIENCES: Target audiences include dairy scientists, veterinarians, dairy nutritionists, and dairy producers. Conference and extension presentations as well as the electronic article posted on Dairy eXnet have put the central hypothesis of this project in front of a large segment of this audience. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Continuous low-level infusion of TNFα into adipose tissue did not alter adipose or liver TNFα mRNA abundance, plasma TNFα, IL-4, IL-6, or interferon-γ concentrations, feed intake, or rectal temperature. Milk fat and lactose concentrations decreased with TNFα (P < 0.05), but milk yield remained unchanged and treatments did not alter the proportion of short vs. long-chain FA in milk on day 7. Treatments did not alter plasma NEFA concentration, liver triglyceride content, or adipose mRNA abundance for hormone-sensitive lipase or perilipin. Plasma glucose turnover rate was not altered by treatment, nor was liver mRNA abundance for phosphoenolpyruvate carboxykinase or pyruvate carboxylase. Metabolic and transcriptional responses to continuous TNFα infusion in adipose tissue differed dramatically from previous responses to daily subcutaneous TNFα injections. This TNFα delivery protocol failed to induce inflammation, which may account for the lack of metabolic responses. These results may also suggest that chronic adipose-derived TNFα is less likely to induce inflammation than other sources, although it is possible that visceral adipose tissue may be more critical for delivery of TNFα to the liver than subcutaneous depots.
Publications
- Bradford, B. J. 2009. Inflammation and transition cow disorders. Proc. Four-State Dairy Nutrition and Management Conference, June 10-11, Dubuque, IA.
- Bradford, B. J. 2009. Inflammation and transition cow disorders. eXtension Dairy Resource Area, available at http://www.extension.org/pages/Inflammation_and_Transition_Cow_Disord ers, posted Sept. 22.
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