Highly fermentable diets are rapidly converted to organic acids [i.e., short-chain fatty acids (SCFA) and lactic acid] within the rumen. The resulting release of protons can constitute a challenge to the ruminal ecosystem and animal health. Health disturbances, resulting from acidogenic diets, are classified as subacute and acute acidosis based on the degree of ruminal pH depression. Although i...

Knowledge of the nitrogen compounds utilized for growth of ruminal cellulolytic bacteria is of considerable importance to an understanding of the nitrogen economy of ruminants and of factors affecting ruminal cellulose digestion. Work with mixed cultures of bacteria from the rumen has shown that cellulose digestion occurs with ammonia or urea, which rapidly yields ammonia, as the sole source of...

This study evaluated 8 empirical models for their ability to accurately predict mean ruminal pH in beef cattle fed a wide range of diets. Models tested that use physically effective fiber (peNDF) as a dependent variable were Pitt et al. (1996, PIT), Mertens (1997, MER), Fox et al. (2004, FOX), Zebeli et al. (2006, ZB6), and Zebeli et al. (2008, ZB8), and those that use rumen VFA were Tamminga a...

the aim of the current study was to evaluate the replacement effect of soybean meal (sbm) at different levels (0 as d1, 33 as d2, 67 as d3 and 100% as d4 based on crude protein (cp) content) by guar meal (gm) on ruminal gas production kinetics, ruminal digestibility and fermentation characteristics of a fattening diet for lambs. three experiments were conducted. the first experiment of 144-h in...

Ten ruminally and duodenally cannulated (326 _+ 28 kg) and four esophageally fistulated (394 k 23 kg) steers grazing cool-season pasture throughout the growing season were used to evaluate the influence of Aspergillus oryzae fermentation extract (AO) supplementation on intake, forage nutrient utilization, and duodenal amino acid flow. Steers grazed a predominately smooth brome (Bromus inermis L...

Four Luxi beef cattle (400±10 kg) fitted with ruminal, duodenal and ileal cannulas were used in a 4×4 Latin square to assess the effects of soybean small peptide (SSP) infusion on rumen fermentation, diet digestion and flow of nutrient in the gastrointestinal tract. The ruminal infusion of SSP was 0 (control), 100, 200 and 300 g/d. Ruminal SSP infusion linearly (p<0.01) and quadratically (p<0.0...

Four crossbred wether Iambs (38 kg) with permanent ruminal and abomasal cannulae were used in a 4 • 4 Latin square arrangement of treatments to determine the effect of feeding frequency (FF) on forage fiber and N utilization. Lambs were offered 900 g of good quality (vegetative) Kentucky-31 tall fescue hay in equal portions either 2, 4, 8 or 16 times daily. Water consumption increased (P<.OS; l...

Essential oils have been shown to favorably effect in vitro ruminal fermentation, but there are few in vivo studies that have examined animal responses. The objective of this study was to evaluate the effects of thyme (THY) and cinnamon (CIN) essential oils on feed intake, growth performance, ruminal fermentation and blood metabolites in feedlot calves fed high-concentrate diets. Twelve growing...

BACKGROUND The nature and amount of dietary medicinal plants are known to influence rumen fermentation and nutrient digestibility in ruminants. Nonetheless, changes in nutrient digestibility and rumen metabolism in response to dietary Andrographis paniculata (AP) in goats are unknown. This study examined the effects of dietary supplementation of leaves and whole plant of AP on nutrient digestib...