Back to Search
Start Over
Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers.
- Source :
-
Journal of animal science [J Anim Sci] 1997 May; Vol. 75 (5), pp. 1393-9. - Publication Year :
- 1997
-
Abstract
- Five Angus x Hereford steers with ruminal and duodenal fistulas were used in a 5 x 5 Latin square to determine effects of increasing the proportion of urea in supplemental degradable intake protein (DIP) on intake, fermentation, and digestion. Steers had ad libitum access to low-quality, tallgrass-prairie forage (2.4% CP, 76% NDF). Supplemental DIP (380 g/d) was from sodium caseinate and(or) urea and was balanced with cornstarch to provide a final supplement (approximately 939 g DM/d) that contained 40% CP. The percentages of supplemental DIP from urea were 0, 25, 50, 75, and 100%. Intake of forage OM was not affected (P > or = .30) by urea level. Ruminal and total tract digestibilities of OM and NDF generally responded in a quadratic manner (P < or = .09) to increasing urea, with the lowest values observed at the highest urea level. As a result, digestible OM intake (DOMI) declined (linear, P = .03) with increasing proportions of urea and tended (quadratic, P = .14) to exhibit the largest proportional decline at the highest urea level. The effects of increasing urea on duodenal N flow, microbial efficiency, ruminal contents, and fluid dilution rate were minimal. Ruminal ammonia N and molar percent acetate increased linearly (P < or = .02), whereas most other VFA (except propionate) decreased (P < or = .05) with increasing urea. In conclusion, although forage OM intake was not altered, OM digestion, NDF digestion, and DOMI were lowest when all supplemental DIP was supplied as urea. Changes in fermentation characteristics reflected the change in source of available nitrogen.
- Subjects :
- Ammonia analysis
Animals
Diet veterinary
Dietary Proteins metabolism
Digestion drug effects
Digestion physiology
Duodenum microbiology
Eating physiology
Fatty Acids, Volatile analysis
Feces chemistry
Fermentation drug effects
Fermentation physiology
Food, Fortified
Hydrogen-Ion Concentration
Male
Nitrogen administration & dosage
Rumen chemistry
Cattle metabolism
Eating drug effects
Nitrogen analysis
Nitrogen pharmacology
Poaceae metabolism
Urea chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0021-8812
- Volume :
- 75
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Journal of animal science
- Publication Type :
- Academic Journal
- Accession number :
- 9159289
- Full Text :
- https://doi.org/10.2527/1997.7551393x