Source: UNIVERSITY OF TENNESSEE submitted to NRP
METABOLIC CHANGES IN WETHERS CONSUMING ENDOPHYTE-INFECTED TALL FESCUE HAY SUPPLEMENTED WITH ARGININE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
ANIMAL HEALTH
Reporting Frequency
Annual
Accession No.
0201830
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2004
Project End Date
Sep 30, 2005
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF TENNESSEE
2621 MORGAN CIR
KNOXVILLE,TN 37996-4540
Performing Department
COMPARATIVE MEDICINE
Non Technical Summary
Other sources of arginine (corn gluten or cottonseed meal) may be more practical and functional to Tennessee producers as a viable source of arginine. The goal for the current study will be to perform research designed to identify viable feedstuff sources of arginine for supplementation during consumption of endophyte infected tall fescue, and to assess the alleviating effect on the usual clinical and metabolic signs of fescue toxicosis.
Animal Health Component
75%
Research Effort Categories
Basic
25%
Applied
75%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
31436101010100%
Knowledge Area
314 - Toxic Chemicals, Poisonous Plants, Naturally Occurring Toxins, and Other Hazards Affecting Animals;

Subject Of Investigation
3610 - Sheep, live animal;

Field Of Science
1010 - Nutrition and metabolism;
Goals / Objectives
Previous research has indicated that consumption of endophyte infected tall fescue causes a reduction in growth, reproduction, heat tolerance and serum arginine. A current study is evaluating the efficiency of arginine supplementation on growth and reproductive performance of yearling beef heifers. However, other sources of arginine (corn gluten or cottonseed meal) may be more practical and functional to Tennessee producers as a viable source of arginine. Findings from this proposal would greatly aid in identifying viable (practical) sources of arginine for producers to utilize in their animals as well as directing the PIs to viable funding opportunities within the feed industry.
Project Methods
24 intact wethers will be used in a randomized block design experiment to evaluate the efficacy of supplemental arginine supplied to wethers having free choice access to endophyte infected (E+) tall fescue hay and subjected to elevated ambient temperatures. Treatments will include: 1) a negative control, wethers will receive only E+ hay, 2) hay supplemented with a rumen protected purified arginine, 3) hay supplemented with corn gluten meal based supplement, and 4) hay supplemented with cotton seed meal based supplement. Wethers will be blocked by weight, randomly allotted to treatments, and housed in individual digestibility crates within an enclosed environmentally controlled facility with 12 hours of light and subjected to temperatures of 33C. Wethers will have continuous access to water and tall fescue hay harvested from guaranteed endophyte infected tall fescue. Hay will be weighed out daily to provided 115% of the average intake for the previous 3 d. Sixty percent of the forage will be fed and all the supplement will be fed at 0800 with the remaining forage being supplied at 2000. Feed refusals from the previous day will be determined before feeding. A trace mineral salt mix will be available. An intramuscular injection of vitamins A, D, and E will be administered to each lamb to safeguard against deficiency. All animals will consume the control treatment for at least 14 days prior to initiation of the experiment. During this period, wethers will be acclimated to the research facility and digestibility crates. Experimental periods will be 28 d. The first 18 d will be a treatment adaptation period. Dry matter intake will be measured daily, and intakes determined from forage and feed refusal samples collected on d 19 to 25. On d 22 to 28, total fecal collections will be conducted. A sub-sample of each daily fecal sample (10%; as-is basis) will be used to form a composite that will be lyophilized. On d -2, 0, 22, 25, and 28, rectal temperatures will be recorded and blood will be collected from the jugular vein 4 h after feeding and placed on ice, transported to the lab and allowed to coagulate and then centrifuged (2,500 x g, 4C, 20 min) to harvest serum and stored (-20C). Dry samples will be ground through a Wiley mill (1-mm screen). Samples of hay will be obtained by compositing one core sample (using Penn State Forage Sampler) from each bale fed. Total daily feed refusals will be collected for each wether and combined to form a single composite sample. Hay, supplements, feed refusals and fecal samples will be analyzed for dry matter, organic matter, neutral detergent fiber, acid detergent fiber, and nitrogen. Hay and supplement samples will be analyzed for arginine. Serum samples will be assayed for prolactin and arginine. Data will be analyzed as a completely randomized block design using the MIXED procedure of SAS. The model will include block and treatment. Least Squares Differences will be used to separate means. Response variables will include changes in serum prolactin and arginine concentrations, intake and digestibility of dry matter, organic matter, neutral and acid detergent fiber, and nitrogen, and arginine intake.

Progress 10/01/04 to 09/30/05

Outputs
The study to investigate metabolic changes in wethers consuming endophyte-infected tall fescue hay supplemented with arginine includes 4 treatment groups: 1) endophyte-infected (E+) hay only; 2) E+ hay and corn gluten meal; 3) E+ hay and cottonseed meal; and 4) E+ hay and soyhulls fed to match the energy level supplied by cottonseed meal in treatment 3. The design is a incomplete Latin square (4 treatments for 3 periods). Blood collections for arginine and prolactin determinations will be taken on day 1 of period, and the last day of periods 1, 2 and 3 for a total of 32 samples. This protocol builds on prior studies that indicated lack of success in protecting arginine from being degraded in the rumen of cattle. The amount of E+ hay available has limited numbers of wethers available for the study.

Impacts
Tall fescue toxicosis continues to be the most important grass-related disease in the U.S. in terms of economic loss to producers. Consumption of E+ tall fescue by herbivores leads to vascular changes and altered bloodflow in tissues, which contributes to reduced growth, reproduction and heat tolerance in these animals. Correction of serum arginine deficiency, by feeding arginine-rich protein, is expected to alleviate the above compromised production parameters that cost animal producers in the U.S. millions of dollars each year.

Publications

  • Oliver, J.W., H. Al-Tamimi, J.C. Waller, H.A. Fribourg, K.D. Gwinn, L.K. Abney and R.D. Linnabary. Effect of chronic exposure of beef steers to the endophyte fungus of tall fescue: Comparative effects on nitric oxide synthase activity and nitrite/nitrate levels in lateral saphenous veins. Proceedings Tall Fescue Toxicosis Workshop, SERAIEG-8. Chapel Hill, TN. Nov. 5-6, 2001. Pg 55.
  • Oliver, J.W., S.K. Cox, J.C. Waller, H.A. Fribourg, K.D. Gwinn, B.W. Rohrbach and R.D. Linnabary. Effect of chronic exposure of beef steers to the endophyte fungus of tall fescue: Comparative effects on serum arginine levels. Proceedings Tall Fescue Toxicosis Workshop, SERAIEG-8. Chapel Hill, TN. Nov. 5-6, 2001. Pg. 56.
  • Oliver, Jack W. Pathophysiologic response to endophyte toxins. In: Roberts, C.A., West, C.P. and Spiers, D.E. (Eds). Neotyphodium in Cool-Season Grasses. Blackwell Publishing , Ames, Iowa. Pp. 291-304, 2005.
  • Schuenemann, G.M., J.L. Edwards, F.M. Hopkins, N.R. Rohrbach, H.S. Adair, F. N. Scenna, J.C. Waller, J.W. Oliver, A.M. Saxton and F.N. Schrick. Fertility aspects in yearling beef bulls grazing endophyte-infected tall fescue pastures. Reprod., Fertil. & Develop., 17:479-486, 2005.