Twelve ruminally cannulated Holstein calves (age, 12 ± 3 weeks) were used to identify the effect of a probiotic comprised of Lactobacillus plantarum, Enterococcus faecium and Clostridium butyricum on ruminal components. The calves were adapted to a diet containing a 50% high-concentrate (standard diet) for 1 week, and then, the probiotic was given once daily for 5 days (day 1-5) at 1.5 or 3.0 g...

The objective of this study was to determine the effects of diets having different fermentability on blood gases, blood metabolites and ruminal fermentation parameters in Holstein dairy cows. Four multiparous Holstein dairy cows (665 ± 25 kg BW, 170 ± 7.0 DIM and 15±1.5 kg of milk yield), fitted with rumen cannulae, were used in a 4×4 Latin Square design with 28-d periods. Corn starch and sucro...

BACKGROUND Ruminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were charact...

Seven ruminally and duodenally cannulated steers (264 +/- 8 kg BW) consuming low-quality forage (5% CP; 61% NDF; 31% ADF) were used to determine the influence of CP degradability and supplementation frequency (SF) on ruminal fermentation characteristics. Treatments included an unsupplemented control and degradable intake protein (DIP) or undegradable intake protein (UIP) provided daily, every 3...

Three experiments with factorial arrangements of treatments were designed to test the efficacy of avian-derived polyclonal antibody preparations (PAP) against Streptococcus bovis (PAP-Sb) or Fusobacterium necrophorum (PAP-Fn) in reducing ruminal counts of target bacteria in beef steers supplemented or not with feed additives (300 mg of monensin/d and 90 mg of tylosin/d; MT). Feeding increasing ...

Two trials were conducted to study ruminal lactic acid, histamine, tyramine and tryptamine concentrations following glucose engorgement in vitro and in vivo. Also, electrolyte changes in rumen fluid, blood plasma and urine during lactic acidosis were examined. Experiment 1 involved the addition of glucose to rumen fluid in vitro. After 30 hr of incubation, decreases in pH and increases in lacti...

To evaluate the influence of mass of ruminal contents on voluntary intake and ruminal function, five ruminally cannulated steers (550 kg) were fed an orchard grass hay diet ad libitum in a 5 x 5 Latin square experiment. The mass of ruminal contents was altered by adding varying weights of modified tennis balls to the rumen before the initiation of each 15-d experimental period. Treatments consi...

Two experiments were conducted to determine effects of sodium bicarbonate (NaHCO3) on nitrogen (N) balance, ruminal N metabolism and site and extent of nutrient digestion in sheep fed 75% concentrate diets. A 2 X 2 factorial arrangement of treatments was employed in both trials with experimental diets balanced for 10.5 or 12.0% crude protein and containing 0 or 3.5% NaHCO3. In experiment 1, 12 ...

BACKGROUND Acute ruminal lactic acidosis (ARLA) is a major nutritional and metabolic disorder usually characterized by excessive or non-adapted intake of diets rich in nonstructural carbohydrates. Feed additives that regulate the ruminal environment have been used to prevent ARLA, such as ionophores and, more recently, yeast culture. Thus, we aimed to compare the efficacy of a yeast-based cultu...