Ardacin for steers grazing endophyte-free fescue pasture: effects on live weight gain, forage intake, nitrogen and fiber digestion, ruminal fluid kinetics, ruminal fermentation, and serum hormones and metabolites
| Autor: | M A Branine, Bret W. Hess, M B Judkins, L J Krysl, D W Holcombe, J D Hess |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Blood Glucose
Dietary Fiber Male Thyroid Hormones Rumen Time Factors Nitrogen Randomized block design chemistry.chemical_element Forage Weight Gain Endophyte Pasture Zea mays Blood Urea Nitrogen Eating Animal science Grazing Genetics Animals Insulin Insulin-Like Growth Factor I chemistry.chemical_classification geography geography.geographical_feature_category biology Body Weight General Medicine Hydrogen-Ion Concentration biology.organism_classification Anti-Bacterial Agents Diet Rats Aminoglycosides Agronomy chemistry Growth Hormone Fermentation Food Fortified Propionate Animal Science and Zoology Cattle Digestion Food Science |
| Zdroj: | Journal of animal science. 75(4) |
| ISSN: | 0021-8812 |
| Popis: | Growth and digestion studies were conducted to evaluate the use of ardacin as a feedgrade antibiotic for enhancing digestive function and growth in grazing steers. In Exp. 1, 90 yearling steers (average initial BW of 248 kg) used in a randomized complete block design (block = weight group) grazed fescue pasture without supplementation (CON) or with daily supplements (DM basis) of .4% of BW supplemental ground corn (CRN) or .4% of BW supplemental corn supplying 120 mg of ardacin (ARD). In Exp. 2, 12 ruminally and duodenally cannulated steers and three ruminally cannulated steers (Hereford x Angus; average BW of 347 kg) were used to evaluate the effects of the same supplements used in Exp. 1 on ruminal fermentation and digestion. In Exp. 1, ARD-supplemented steers weighed more (P.01) at the conclusion of the study than CRN steers, which together weighed more (P.01) than CON steers. Average daily gain was greater (P.10) in supplemented than in CON steers; ARD steers had greater (P.01) ADG than CRN steers. In Exp. 2, forage intake and harvesting efficiency did not vary (P.10) with supplementation or type of supplement, but total intake reflected (P = .03) the addition of corn to the forage diet. Addition of ardacin increased (P = .02) ruminal pH compared with CRN steers. Ardacin decreased ruminal molar proportions of acetate and increased (P = .01) propionate proportions when compared with CRN steers. Total tract N digestibility was affected (P.10) by supplementation and by addition of ardacin to the diet. Addition of ardacin to the ground corn supplement increased ADG, in part by enhancing acetate:propionate ratios and increasing N digestion. |
| Databáze: | OpenAIRE |
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