Liu JH, Xu TT, Liu YJ, Zhu WY, Mao SY. A high-grain diet causes massive disruption of ruminal epithelial tight junctions in goats. Am J Physiol Regul Integr Comp Physiol 305: R232–R241, 2013. First published June 5, 2013; doi:10.1152/ajpregu.00068.2013.—Alterations in rumen epithelial tight junctions (TJs) at the tissue and molecular levels during high-grain (HG) diet feeding are unknown. Here,...

Lambs (29 +/- 2.5 kg) were fed three diets at various intakes to determine whether diet composition or level of intake was reflected in changes in diet digestibility or ruminal fluid characteristics. In Exp. 1, a 90% concentrated, pelleted diet or a whole shelled corn diet with a pelleted protein supplement was fed at three levels of intake: ad libitum and 92.5 and 85% of ad libitum (n = 15). E...

________________________________________________________________________________ Abstract Diet composition has been suggested as a factor that influences the variability of responses when Saccharomyces cerevisiae (SC) is fed to ruminant animals. Diets based on lucerne hay (462 g/kg DM) and maize silage (488 g/kg DM) were fed to determine the effects of 0 or 5 g SC 47 (8×10 cfu/g) on ruminal dig...

Alimet (Novus Inter., Inc., St. Louis, MO) feed supplement (an 88% aqueous solution of 2-hydroxy-4-(methylthio) butanoic acid; HMB) is a source of L-Met commonly used in nonruminants and ruminants. The absorption of HMB across ovine omasal and ruminal epithelia was evaluated in this study. Ruminal and omasal epithelia were collected from eight lambs (BW = 67.6 kg +/- 9.1) and mounted in parabio...

A model rumen system, dual-flow continuous culture fermenters, was evaluated by two comparative criteria in two experiments using ribosomal (r)RNA-targeted DNA probes to compare key microbial groups in samples. The initial experiment measured temporal changes in population structure during adaptation of ruminal microbial populations in fermenters over 240 h. The fermenter inoculum contained 34....

The amino (AA) profile of eight feedstuffs (two samples of fishmeal, soybean meal [SBM], formaldehyde-treated SBM, sopralin, cotton-seed meal [CSM], rapeseed meal [RSM], corn distillers grains [CDG], and corn gluten feed [CGF]) was determined before and after ruminal incubation for 8 and 12 h in three lactating Friesian cows using nylon bags. The profile of AA disappearing during intestinal pas...

Five ruminally and duodenally cannulated steers (491 +/- 21 kg BW) were used in an incomplete 5 x 4 Latin square with four 24-d periods to determine the influence of supplemental nonprotein N (NPN) source and supplementation frequency (SF) on the dynamics of ruminal fermentation in steers consuming low-quality grass straw (4% CP). Treatments (TRT) included an unsupplemented control (CON) and a ...

Rations containing approximately 85% ground high-moisture, ensiled corn were fed to steers in such a way as to produce lactic acid acidosis, and three dietary buffers were evaluated in regard to their effect on ruminal and systemic acidosis. The buffers consisted of (1) 2% sodium bentonite, (2) 1% sodium bentonite plus 1% dolomitic limestone, and (3) 1% sodium bentonite plus 1% potassium bicarb...

The efficiency of feedstuff utilization by ruminal microorganisms and the cow’s genetic ability to convert feed nutrients into milk and milk components are major factors that influence the profitability of a dairy herd. Monensin’s ability to modify the movement of ions across biological membranes leads to alterations in bacterial populations and subsequent changes in the proportion of volatile ...

The rumen typically operates as an energy-limited, nitrogen-excess system, but diets can be so low in degradable crude protein that microbial growth is limited by N. Ruminal bacteria respond differently to N sources and N-limitation. Cellulolytic ruminal bacteria need ammonia as an N source, have little capacity to utilize amino-N, are unable to ferment fiber when ammonia is depleted, and do no...