for induction of ruminal acidosis, 10 clinically healthy three years old non pregnant female sheep were selected. prior to the infusion of sucrose (0 hour), rumen and blood samples were obtained in order to determine baseline rumen and blood ph, respectively. electrocardiogram (ecg) was also recorded. acute ruminal acidosis was induced experimentally with sucrose at a dose of 18g kg-1 body weig...

Mertens (1997) defined physically effective NDF (peNDF) as the fraction of NDF that stimulated chewing and contributed to a ruminal digesta mat. He also proposed a standard laboratory method for measuring peNDF that involved dry sieving and measuring the fraction of sample NDF retained on the ≥1.18-mm sieve. This large particle pool requires rumination and has a high resistance to escape from t...

Omasal contents were collected from slaughtered cattle (n = 54), bison (n = 15), and sheep (n = 40) to determine numbers and generic distribution of ciliated protozoa. Total protozoan numbers were significantly lower in omasal contents than in ruminal contents of all three species, but the percent composition of all protozoan genera was similar between omasal and ruminal populations. The highes...

Binding of IgG antibodies to Entodinium spp. in the rumen of sheep (Ovis aries) was investigated by adding IgG, purified from plasma, directly into the rumen. Plasma IgG was sourced from sheep that had or had not been immunized with a vaccine containing whole fixed Entodinium spp. cells. Ruminal fluid was sampled approximately 2 h after each antibody dosing. Binding of protozoa by a specific an...

The current study was undertaken to investigate the effect of feeding diets varying in sugar concentration to postpartum transition cows on productivity, ruminal fermentation, and nutrient digestibility. We hypothesized that the high-sugar diet would increase dry matter intake and lactation performance. The secondary objective was to characterize changes in ruminal fermentation and nutrient dig...

The objective of this study was to determine the effects of organic acids and monensin on the in vitro fermentation of cracked corn by mixed ruminal microorganisms. Ruminal fluid was collected from a steer fed 36.3 kg of wheat silage and 4.5 kg of concentrate supplement once daily. Mixed ruminal microorganisms were incubated in anaerobic media that contained 20% (vol/vol) ruminal fluid and .4 g...

Continuous recording of ruminal pH in cannulated cattle has been practiced to study rumen metabolism. However, most systems reported did not permit animal mobility during pH recording. Therefore, the objective of this study was to develop a continuous rumen pH data acquisition system that permitted animal mobility during data acquisition. A further objective was to compare the pH readings obtai...

The aim of this study was to evaluate the nutrient digestibility, ruminal fermentation and microbial protein synthesis of mid-lactating cows fed high dietary levels of monensin. Twelve Holstein cows were distributed into four 3 × 3 latin squares and assigned to the following treatments: control (CON), monensin 24 (M24, addition of 24 mg monensin/kg diet DM) and monensin 48 (M48, addition of 48 ...

The aim of this study was to evaluate the accuracy and precision of indwelled wireless sensors relative to intrareticuloruminal differences in dairy cows transitioned from a forage to a high-concentrate diet. A feeding trial was performed with 8 rumen-cannulated Holstein cows. The cows were stepwise switched from 0 to 60% concentrate in the diet and fed 5 wk. Samples from the free ruminal liqui...

Two experiments were conducted to study the effects of methionine supplementation on ruminal fermentation and digesta kinetics. In Exp. 1, nine ruminally cannulated beef heifers (average initial BW = 527 kg) in a crossover design were fed low-quality grass hay and cottonseed meal with or without 11.4 g of supplemental methionine (polysaccharide-coated). Particulate and fluid kinetics, rate of D...