Progress 09/15/00 to 09/14/03
Outputs
Toxicity of Se for ruminants is unknown and estimates using monogastric species are likely off by more than a factor of 2-3. Biovailability and tolerance trials are using wether and ewe sheep fed different levels of sodium selenite. Blood samples were collected and analyzed for Se periodically and tissue samples at termination of the experiment. Sodium selenite was added to provide 0.2, 2, 4, 6, 8 and 10 ppm Se to a basal diet. Tolerance of Se as sodium selenite was not toxic to wether sheep for one year even at 10 ppm. Two additional trials were undertaken with either ewes (1.5 yr) or wether sheep (2 yr) to test the effect of higher dietary concentrations of Se, 4 to 20 ppm in ewes and 20-40 ppm for wethers. For the ewe experiment it was possible to evaluate placental transfer of Se to lambs as affected by treatment. To accomplish this blood was collected from lambs prior to nursing. For the last two sheep trials, samples are currently being analyzed and raw data
indicate that Se from an organic source is more effective than inorganic Se at increasing serum Se levels. Three new products are now available for Se supplementation: 1) barium selenate as a fertilizer source, 2) barium selenate as a long term injectable product and 3) organic-Se (yeast product). Principal objectives of experiments are to evaluate methods of Se supplementation for grazing ruminants (free-choice, injectable, and fertilizer application). Selenium as sodium selenate and barium selenate has been sprayed on specific tropical forages species from Puerto Rico at the rates of 0, .25, .75 and 1.0 kg/ha. Analysis are pending. Also from Puerto Rico, injectable barium selenate was given to half a crossbred herd of cattle. For cows receiving the injectable Se, there were significantly higher Se levels in plasma, liver and calf plasma. In a second cattle experiment forty-three 2-3 year old Angus cows were used in a 52-week experiment to compare effects of different methods of
selenium supplementation on Se levels in serum, whole blood, colostrum, and milk. Cows received either no Se supplementation (control), injectable sodium selenite, injectable barium selenate, inorganic Se via free-choice mineral (26 mg/kg Se), or organic Se via free-choice mineral (26 mg/kg Se). Serum, whole blood (from cow/calf), colostrum, and subsequent milk were collected at parturition, 30, 90, and 180-d post-calving. Samples from this experiment are currently being analyzed.
Impacts
Better methods of Se supplementation are needed to improve productivity of ruminant livestock. Pasture fertilization of Se and use of organic Se (i.e. selenomethionine) and injectable barium selenate are effective methods of supplementation. The tolerance or toxicity of Se is more than 10 ppm for sheep fed this level for one year.
Publications
- Arizmendi-Maldonado, D., McDowell, L.R., Sinclair, T.R., Mislevy, P., Martin, F.G. and Wilkinson, N.S. 2003. Alpha-tocopherol and beta-carotene concentrations in three tropical grasses as affected by increasing daylength. Commun. Soil Sci. Plant Anal. 34(3&4):519-530.
- Hidiroglou, N., Toutain, P.L. and McDowell, L.R. 2003. Influence of sources and dietary vitamin E on the maternal transfer of alpha tocopherol to fetal and neonatal guinea pigs using a stable isotopic technique. Brit. J. Nutr. 89:455-466.
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2003. Selenium status of beef calves from dams receiving selenium supplementation. J. Anim. and Vet. Adv. 2(6):338-342.
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2003. Effects of supplementing selenium to a beef cattle cow-calf herd on tissue selenium concentration. J. Anim. and Vet. Adv. 2(3):126-132.
- Arizmendi, D., McDowell, L.R., Sinclair, T.R., Mislevy, P., Martin, F.G. and Wilkinson, N.S. 2003. Mineral, alpha-tocopherol and beta-carotene concentrations in tropical grasses as affected by increasing daylength. Tropical and subtropical agrosystems. 3:547-549.
- Cristaldi, L.A., McDowell, L.R., Buergelt, C.D., Wilkinson, N.S. and Martin, F.G. 2003. Tolerance of inorganic selenium in wether sheep. J. Anim. Sci. 81(Suppl. 1):279 (abstr.).
- McDowell, L.R. 2003. Minerals in Animal and Human Nutrition, 2nd Ed., editor and sole author of 19 chapters, 664 pp. Elsevier Sci.
- Carvalho, F., Barbosa, F. and McDowell, L.R. 2003. Nutricao de Bovinos a Pasto. Mineral Bulletin. Matsuda, Brazil and Florida Department of Animal Sciences, Presidente Prudente, Brazil. 428 p.
- McDowell, L.R. and Marshall, T. (eds.). 2003. Florida 2003 Beef Report, University of Florida, Gainesville, FL.
- McDowell, L.R. 2003. Providing minerals to grazing ruminants. Feedstuffs. 75(47):12-14.
- McDowell, L.R. 2003. Free-choice mineral supplements for grazing sheep. Conference 'Meat Sheep Alliance of Florida' 14 pp Handout, Ocala, FL.
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Progress 10/01/01 to 10/01/02
Outputs
In the lay press, and even among many scientists, Se is most noted as a toxic element. Tolerance of Se for ruminants is unknown and estimates using monogastric species are too conservative by a factor of 2. Since supplemental dietary Se level is controlled (FDA), it is important to: 1) establish the most bioavailable forms (inorganic vs organic), 2) tolerance level of Se, and 3) most economical methods of supplementation. Three new products are now available for Se supplementation: 1) barium selenate as a fertilizer source, 2) barium selenate as a long term injectable product and 2) organic-Se (yeast product). Principal objectives of experiments are: 1) study tolerance of Se and 2) evaluate methods of Se supplementation for grazing ruminants (free-choice, injectable, and fertilizer application). Bioavailability and tolerance trials are using wether and ewe sheep fed different levels of sodium selenite. Blood samples will be collected and analyzed for Se periodically
and tissue samples at termination of the experiment. Sodium selenite was added to provide 0.2, 2, 4, 6 and 8 ppm Se to a basal diet. Increased dietary concentrations of Se increased the element in blood and tissues of sheep. Tolerance of Se as sodium selenite was not toxic to wether sheep for one year even at 10 ppm. Other experiments with cattle are evaluating methods of supplemental Se administration (sodium selenite, barium selenate and free-choice). Liver (biopsy) blood (cows and calves) and milk are being analyzed for Se content. Selenium as sodium selenate and barium selenate will be sprayed on specific tropical forages species at the rates of 0, .25, .75 and 1.0 kg/ha. Use of the organic Se resulted in higher levels of Se in blood of cows, liver, colostrum and blood of calves. The long-term injectable product Deposal also significantly increased Se concentrations in blood, liver and colostrum of cows. Selenium as fertilizer was more effective for fescue than bahiagrass.
Topdressed Se was more effective than sprayed administration. Forage Se was more than adequate 22 weeks after application.
Impacts
Selenium deficiency is severely limiting grazing livestock production and the better methods of supplementation will improve productivity of ruminant livestock. Continuous Se provided in a free-choice mixture as seleomethionine resulted in highest tissue Se concentrations. The tolerance or toxicity of Se is more than 10 ppm for sheep.
Publications
- McDowell, L.R. 2001. Vitamin nutrition of livestock species. Nutrition Abstract and Review, series B 71(no. 11). 71:33R-41R (not available until 2002).
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2001. Supplementing organic and inorganic selenium on yearling cattle performance and tissue selenium concentrations. Inter. J. Anim. Sci. 16:283-289 (not available until 2002).
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2001. Effect of selenium supplementation on thyroid hormone of growing beef calves. Inter. J. Anim. Sci. 16:277-281 (not available until 2002).
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2002. Selenium concentration of fescue and Bahia grasses after applying a selenium fertilizer. Commun. Soil. Sci. Plant Anal. 33 (9 and 10):1461-1472.
- Tiffany, M. E., McDowell, L.R., O'Connor, G.A., Martin, F.G., Wilkinson, N.S. and Katzowitz, N.A. 2002. Effects of residual and reapplied biosolids on performance and mineral status of grazing beef steers. J. Anim. Sci. 80:260-269.
- Arizmendi-Maldonado, D., McDowell, L.R., Sinclair, T.R., Mislevy, P., Martin, F.G. and Wilkinson, N.S. 2002. Mineral concentrations in four tropical forages as affected by increasing day length. J. Anim. Sci. 80(Supp. 1): 333 (Abstr.).
- Valle, G., McDowell, L.R., Davis, P.A., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2002. Selenium status of beef calves from dams receiving different forms of selenium supplementation. J. Anim. Sci. 80(Supp. 1): 367. (Abstr.).
- Valle, G., McDowell, L.R., Davis, P.A., Prichard, D.L., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2002. Selenium status of beef calves from dams receiving different forms of selenium supplementation. Alltech's Seventh Annual North American University Seminar Series, p. 47, Nicholasville, KY (Abstr.).
- McDowell, L.R., Valle, G., Cristaldi, L.A., Davis, P.A., Rosendo, O. and Wilkinson, N.S. 2002. Selenium availability and methods of selenium supplementation for grazing ruminants, Thirteenth Annual Florida Ruminant Nutrition symposium. P. 86-101, Gainesville, FL.
- McDowell, L.R., Valle, G., Cristaldi, L.A., Davis, P.A., Rosendo, O. and Wilkinson, N.S. 2002. Mineral supplementation for ruminants in tropical regions emphasizing organic selenium. Proc. Alltech's Eighteenth Annual Symposium (Lyons, T.P. and Jacques, K.A. eds.), p. 193-207, Nottingham University Press, United Kingdom.
- Arizmendi-Maldonado, D., McDowell, L.R., Sinclair, T.R., Mislevy, P., Martin, F.G. and Wilkinson, N.S. 2002. Mineral concentrations in four tropical forages as affected by increasing daylength. II. Microminerals. Commun. Soil Sci. Plant Anal. 33(11 and 12):2001-2009.
- Valle, G., McDowell, L.R., Prichard, D.L., Davis, P.A., Chenoweth, P.J., Wright, D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2002. Effects of supplementing selenium to a beef cattle cow-calf herd on tissue selenium concentrations. J. Anim. Sci. (Suppl. 2) p. 24. (Abstr.).
- McDowell, L.R., Valle, G., Cristaldi, L.A., Davis, P.A., Rosendo, O. and Wilkinson, N.S. 2002. Selenium availability and methods of selenium supplementation for grazing ruminants. Proc. Alltech's Eighteenth Annual Symposium (Lyons, T.P. and Jacques, K.A. eds.), p. 1-3, Nottingham University Press, United Kingdom.
- Tiffany, M.E., McDowell, L.R., O'Connor, G., Martin, F.G., Wilkinson, N.S. and Rabiansky, P. 2003. Effects of pasture-applied biosolids (Municipal sewage sludge) on performance and mineral status of grazing beef heifers. Florida 2003 Beef Report, p. 9-10, Department of Animal Sciences, Gainesville, FL.
- Valle, G., McDowell, L.R., Prichard, D.L., Chenoweth, P.J., Wright. D.L., Martin, F.G., Kunkle, W.E. and Wilkinson, N.S. 2003. Selenium concentration of fescue and Bahiagrass after applying a selenium fertilizer. Florida 2003 Beef Report, p. 37-39, Department of Animal Sciences, Gainesville, FL.
- Tiffany, M.E., McDowell, L.R., O'Connor, G.A., Martin, F.G., Wilkinson, N.S. and Nguyen, H.Q. 2001. Pasture applied biosolids as related to copper status of grazing beef steers. J. Anim. Sci. 79(Suppl.1):291 (Abstr).
- Piaggo, L., Uriarte, G., Garcia, P., Cuenca, L., Podesta, C. and McDowell, L.R. 2001. Characterization of natural pastures on cretaceous soil as a basis for the formulation of mineral supplements: herbage mass, quality and mineral composition. World Buietries Proc. p. 1-6. Punta del este, Uruguay.
- Uriarte, G., Cuenca, L., Garcia, P., Piaggo, L., Podesta, C. and McDowell, L.R. 2001. Effects of mineral supplementation of animal performance and reproductive efficiency in beef cattle herds grazing on natural pasture. World Buietries Proc. p. 7-12, Punta del este, Uruguay.
- Uriarte, G., Podesta, C., Cuenca, L., Piaggo, L., Garcia, P. and McDowell, L.R. 2001. Effects of mineral supplementation on blood biochemistry of beef cattle in extensive grazing conditions. World Buietries Proc. p. 13-19. Punta del este, Uruguay.
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Progress 10/01/00 to 10/01/01
Outputs
Nutritional deficiencies, including Se, severely restrict the production of ruminant animals in Florida as well as developing countries, including those of the Carribean Basin. For ruminants, signs of Se deficiencies include white muscle disease, reproductive failure, retained placenta, mastisis and immune system responsive diseases (e.g., diarrhea and respiratory conditions). In the lay press, and even among many scientists, Se is most noted as a toxic element. Toxicity tolerance of Se for ruminants is unknown and estimates using monogastric species are too conservative by a factor of 2. Since supplemental dietary Se level is controlled (FDA), it is important to: 1) establish the most bioavailable forms (inorganic vs organic), 2) tolerance level of Se, and 3) most economical methods of supplementation. Three new products are now available for Se supplementation: 1) barium selenate as a fertilizer source, 2) barium selenate as a long term injectable product and 2)
organic-Se (yeast product). Principal objectives are: 1) study tolerance of Se and 2) evaluate methods of Se supplementation or grazing ruminants (free- choice, injectable, and fertilizer application). Bioavailability and tolerance trials are using wether and ewe sheep fed different levels of sodium selenate. Blood samples will be collected and analyzed for Se periodically and tissue samples at termination of the experiment. Other experiments with cattle will evaluate methods of supplemental Se administration (sodium selenite, barium selenate and free-choice). Liver (biopsy) blood (cows and calves) and milk are being analyzed for Se content. Selenium as sodium selenate and barium selenate will be sprayed on specific tropical forages species at the rates of 0, .25, .75 and 1.0 kg/ha. Use of the organic Se resulted in higher levels of Se in blood of cows, liver, colosstrum and blood of calves. The long-term injectable product (Deposal) also significantly increased Se concentrations in
blood, liver and colostrum of cows. Selenium as fertilizer was more effective for fescue than bahiagrass. Topdressed Se was more effective than sprayed administration. Forage Se was more than adequate 22 weeks after application. Up to 10 ppm dietary Se for wether lambs for 1 year did not affect productivity.
Impacts
Selenium is severely limited for grazing livestock and the better methods of supplementation will improve productivity of ruminant livestock. A number of Se supplementation methods are available (organic Se, injectable products and fertilization) and effective to improve Se status. The tolerance of toxicity of Se for ruminants would appear to be considerably higher than 2 ppm (dry basis).
Publications
- Cuesta, P.A., McDowell, L.R., Kunkle, W.E., Bullock, F., Drew, A., Wilkinson, N.S., and Martin, F.G. 2001. Seasonal variation of soil and forage mineral concentrations in north Florida. Florida Beef Cattle Research Report, p. 25-28, Gainesville.
- McDowell, Lee R. 2001. Recent advances in minerals and vitamins on nutrition of lactating cows. Milk Production Symposium, Universidad e Federalde Lavras, p. 50-76, Lavaras, Brazil.
- Merkel, R.C., McDowell, L.R., Wilkinson, N.S., and Popenoe, H.L. 2001. Mineral status comparisons between water buffalo and Charolais cattle in Florida. Florida Beef Cattle Research Report, p. 22-24, Gainesville.
- Tiffany, M. E., McDowell, L.R., O'Connor, G.A., Nguyen, H., Martin, F.G., Wilkinson, N.S., and Katzowitz, N. A. 2001. Effects of residual and reapplied biosolids on forage and soil concentrations over a grazing season in North Florida. II. Microminerals. Commun. Soil Sci. Plant Anal. 32(13 & 14):2211-2226.
- McDowell, L.R. Mineral deficiencies in Florida. 2000. Mineral deficiencies in Florida. The Florida Cattlemen. Sept. pp. 99.
- Ramos, S.R. and McDowell, L.R. 2000. Agronomic comparison of six Bermuda grasses from Southern USA with five tropical grasses in Central Puerto Rico, J. Plant Nutrition. 26:711-717.
- Spalding, M.G., Frederick, P.C., Lynch, H., Bouton, S.N., Burnett, F., and McDowell, L. 2000. Effects of methyl mercury on growth, appetite and tissue contamination of captive great Egret nestlings. J. Wildlife Dis. 36:411-422.
- Tiffany, M.E., McDowell, L.R., O'Connor, G.A., Martin, F.G., Wilkinson, N.S., Cardoso, E.C., Percival, S.S., and Rabiansky, P.A. 2000. Effects of pasture applied biosolids on performance and mineral status of grazing beef heifers. J. Anim. Sci. 78:1331-1337.
- Tiffany, M.E., McDowell, L.R., O'Connor, G.A., Nguyen, H., Martin, F.G., Wilkinson, N.S., and Katzowitz, N.A. 2000. Effects of pasture applied biosolids on forage and soil concentrations over a grazing season in North Florida. II. Microminerals. Commun. Soil Sci. Plant Anal. 31:215-227.
- Tiffany, M.E., McDowell, L.R., O'Connor, G.A., Nguyan, H., Martin, F.G., and Wilkinson, N.W. 2000. Effects of residual and reapplied biosolids on forage and soil mineral concentrations in Florida. J. Anim. Sci. 78:112-112. (Abstr.)
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