Influence of alkaloid concentration of tall fescue straw on the nutrition, physiology, and subsequent performance of beef steers
| Autor: | S. D. Brandyberry, Timothy DelCurto, M. M. Stamm, M. R. Horney, R. K. Barton |
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| Rok vydání: | 1994 |
| Předmět: |
Dietary Fiber
Male Rumen Poaceae Endophyte Ergovaline Body Temperature Random Allocation Animal science Heart Rate Botany Genetics Animals Thyrotropin-Releasing Hormone biology Acremonium Chemistry Alkaloid Respiration General Medicine Straw biology.organism_classification Prolactin Ergotamines Fermentation Animal Science and Zoology Nutrition physiology Animal Nutritional Physiological Phenomena Cattle Digestion Food Science |
| Zdroj: | Journal of animal science. 72(4) |
| ISSN: | 0021-8812 |
| Popis: | Two experiments were conducted to evaluate digestion, performance, and physiological responses to Acremonium coenophialum-infected tall fescue straw offered to vary ergovaline concentrations. In Exp. 1, 16 Hereford x Angus ruminally cannulated steers (370 k 12 kg BW, mean k SEI were blocked by age and BW and, within block, randomly assigned to one of four treatments containing graded concentra- tions of ergovaline in the diet: 1 ) 0 ppb, 2 1 158 ppb, 3 ) 317 ppb, and 4) 475 ppb. Alkaloid concentrations were produced using various mixtures of two varieties of tall fescue straw that had similar genetic and phenotypic characteristics but differed in degree of endophyte incidence and associated concentrations of alkaloids. In the 36-d digestion study, feed intake, apparent DMD, and total tract NDF digestion were not influenced by alkaloid concentration (P > .lo). Differences were observed with digesta kinetics; spe- cifically indigestible ADF (IADF) fill and outflow decreased linearly with increasing alkaloid concentra- tion (P .lo). Concentration of serum prolactin measured weekly tended ( P .lo) between alkaloid concentrations of the basal diet (P > .lo>. In Exp. 2, 84 Hereford x Angus weaned steer calves (220 f 15 kg BW) were sorted into three BW blocks (heavy, medium, and light) and, within blocks, were assigned randomly to the same treatments as in Exp. 1 for an 84-d feeding period. Feed intake tended (P .lo) among alkaloid concentrations. In conclusion, the endophyte-produced alkaloids as- sociated with feeding tall fescue straw during the winter months did not cause health problems or reductions in animal performance. However, decreases in circulating prolactin with increasing alkaloid con- centration of the diet suggest a possible subclinical effect. |
| Databáze: | OpenAIRE |
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