Supplementation and monensin effects on digesta kinetics. I. Cattle grazing summer range
Issue Date
1990-09-01Keywords
steersdigestibility
crude protein
digesta
kinetics
dietary supplements
pH
transit time
barley
feed supplements
natural grasslands
summer
cattle feeding
monensin
feed grains
diets
cattle
rumen fermentation
Montana
grazing
feed intake
Metadata
Show full item recordCitation
Ward, M. G., Adams, D. C., Wallace, J. D., Galyean, M. L., & Knapp, B. W. (1990). Supplementation and monensin effects on digesta kinetics. I. Cattle grazing summer range. Journal of Range Management, 43(5), 378-382.Publisher
Society for Range ManagementJournal
Journal of Range ManagementDOI
10.2307/3898994Additional Links
https://rangelands.org/Abstract
Sixteen ruminally cannulated beef steers grazing native summer range in the Northern Great PIains were assigned to 4 treatments in a 2 X 2 factorial arrangement. Main effects were barley grain and monensin. Rolled barley (RB) containing 7.5% molasses was fed at 0 and 1.36 kg head-1 day-1. Steers received no monensin (M) or M released at 101 mg/d via a ruminal delivery device. Forage intake and digestibiIity, ruminal fermentation, and ruminal passage rate were measured during trials in: (1) June, (2) July, and (3) August. Diet samples were collected from esophogeally fistuIated steers during each trial. Dietary crude protein was greater (P<0.05) during trials 1 (15.2%)and 3 (14.3%) than in trial 2 (10.2%). In vivo organic matter (OM) digestibiiity, ruminal fluid passage rate, and fermentation variables varied by trial (P<0.01). Forage OM intake was reduced (P<0.10) by RB, but was not influenced (P>0.10) by M or the M and RB combination. In vivo OM digestibility was increased (P<0.05) by M, while RB had no effect. Particulate passage was not affected by M or RB but gastrointestinal tract fill was reduced by monensin (P<0.05). Ruminal fluid passage rate was affected by the RB X M X Trial interaction (P<0.05). Within June and July, fluid passage rate was similar among treatments and ranged from 14.0 to 11.3 %/h, respectively. During trial 3, a RB X M interaction (P<0.05) increased fluid passage rate. Ruminal ammonia-N concentration was similar among treatments. Barleey lowered (P<0.05) ruminal pH and increased (P<0.10) total volatile fatty acids. A RB X M X Trial interaction (P<0.05) was noted for molar proportions of acetate, propionate, and butyrate. Within trials, RB, M, and their combination affected (P<0.01 to P<0.10) acetate, propionate, and butyrate. We conclude that barley, monensin, and forage quality infiuence ruminal fermentation, passage rate, and intake traits of steers grazing summer range.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/3898994