Th is experiment compared linear relationships among end-products of rumen fermentation measured at the time (t1⁄2) at which a feed produces half of its asymptotic gas production) or at 48 h. Meadow hay and corn grain were incubated for t1⁄2 (16 and 9 h, respectively) or for 48 h into glass bottles. Each bottle (310 ml) was fi lled with feed sample (0.5 g) and 75 ml of buff ered rumen fl uid, a...

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 ruminally cannulated steers (BW 581 +/- 12.8 kg) were used in a crossover design to determine the effects of prolonged, moderate nutrient restriction on plasma ghrelin concentrations and to establish the relationship of plasma ghrelin concentrations with hormones and metabolites indicative of nutritional status and end products of rumen fermentation. A high-grain diet was offered at 240% o...

This study using the rumen simulation technique (RUSITEC) investigated the changes in the ruminal microbiota and anaerobic fermentation in response to the addition of different lipid supplements to a ruminant diet. A basal diet with no oil added was the control, and the treatment diets were supplemented with sunflower oil (2%) only, or sunflower oil (2%) in combination with fish oil (1%) or alg...

The dairy cow has a well-recognized natural daily pattern of feed intake and milk synthesis, but regulation of these circadian rhythms has not been well described in the literature or well considered in current dairy management. Even when a total mixed ration (TMR) is fed, ruminal fermentation varies due to circadian variation in feed consumption, resulting in more fermentable substrate in the ...

Although the protein requirement of domestic ruminants may be calculated from a simple one-compartment model, this approach ignores factors such as microbial fermentation in the rumen and the non-equality of feed proteins. By examining digestion in each of the functional compartments of the digestive tract of the ruminant, a model may be constructed of the complete process. In this review, we p...

The degradation and fermentation of cellulose filter paper were studied in axenic cultures of 3 species of rumen anaerobic fungi, Neocallimastix frontalis, Piromyces communis and Caecomyces communis, and in cocultures containing 1 of these fungal strains and Eubacterium limosum, a hydrogenotrophic rumen bacterial species. When E limosum was introduced into fungal cultures a slight decrease in f...

Six ruminally fistulated steers (average BW 317 kg) were used in a 5 X 5 + 1 Latin Square design to determine effects of humic/fulvic acid (HFA) on serum urea nitrogen (SUN), rumen pH, rumen ammonia nitrogen (RAN), and rumen VFA production in Holstein steers. Treatments included a control (0%), 0.5, 1.0 or 1.5% HFA, and a diet containing monensin (33 mg/kg). A quadratic feed intake response was...

The inhabitants of the rumen microbial eco-system, a complex consortium of different microbial groups living in symbiotic relationship with the host, act synergistically for the bioconversion of lignocellulosic feeds into volatile fatty acids which serve as a source of energy for the animals. The constraints, imposed by the host and the feed consumed by the animal, under which these microbes ha...

This study aimed to identify chemical composition of Thymus kotschyanus essential oil (TKEO) and to evaluate the effects of different doses of TKEO on in vitro gas production, fermentation parameters, acidosis and protozoal population using a completely randomized design with four replicates. Two diets (D1: 100% forage and D2: 30% forage+70% concentrate) were incubated with buffered rumen fluid...