Eight rumen-cannulated steers (initial wt 330kg) were adapted to a mixed alfalfa-grass hay diet for 30 d and abruptly changed to complete mixed diets of corn silage, snapped ear corn and a corn-based supplement to determine the effects of buffers on diet adaptation, digestion and ruminal metabolism. The diets contained: 1) no buffer, 2) .5% magnesium oxide (MgO), 3) 1.0% sodium bicarbonate (NaH...

UNLABELLED The first cause of death of dairy calves is often diarrhea which is mainly caused by pathogenic bacteria, which can result in excessive use of antibiotics. However, facing the increase concern by the industry and consumers, the use of antibiotics not only to control pathogens, but also to manipulate growth, has become a challenge. Alternative additives, such essential oils, have the ...

A digestion trial using cannulated lactating cows was conducted to evaluate the influence of barley grain processing on characteristics of ruminal fermentation and the site and extent of digestion. The experiment consisted in 4 periods and lasted 84 days. The total mixed rations contained 39.86% of grains and 42.90% of alfalfa hay and the rest of ration was composed mainly by cane molasses, fat...

Rumen epithelial Na(+)/H(+) exchanger (NHE) catalyzes the exchange of extracellular Na(+) for intracellular H(+). Thus, it is of importance in the maintenance of Na and pH homeostasis of rumen epithelial cells. We have tested the hypothesis that an increase in energy and protein intake induces alterations of NHE isoform 1, 2, and 3 (NHE1, NHE1, and NHE3, respectively) mRNA abundance in the rume...

This study was carried out to determine of the effects of monensin on ruminal fermentation parameters in Ghizel sheep. Sixteen male Ghizel sheep were used allocated in completely randomized design. The diet containing of 2.9 ME (Mcal/kg DM) and 150 g/kg DM CP was formulated based on NRC requirement consisting of 400 g kg-1DM alfalfa, 488 g kg-1 DM barley grain, 200 g kg-1 DM soybean meal, 589 g...

Feeding dairy cows for maximum milk production increases the risk of ruminal acidosis. Diets fed to high producing dairy cows in North America are typically highly digestible in the rumen and often lack sufficient physical fiber. Rapid fermentation of carbohydrates causes an accumulation of volatile fatty acids (VFA) in the rumen, leading to a drop in ruminal pH. Lack of sufficient physical fib...

Subacute Ruminal Acidosis (SARA) corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the ...

The objective of this study was to investigate the effect of the pattern of concentrate-rich feeding on subacute ruminal acidosis (SARA), its severity, and the corresponding changes in VFA concentration. Eight rumen-cannulated Holstein cows were assigned to a 2 × 2 crossover design with 2 SARA challenge models and 2 experimental runs ( = 8 per treatment). Each run lasted for 40 d, consisting of...

The ruminal biohydrogenation of c9,c12-18:2 can be affected by the fibre/starch ratio of the diet and the ruminal pH. The objectives of this study were to examine independently in vitro the effects of fermentation substrate (hay vs. corn starch) and buffer pH (6 vs. 7) on the biohydrogenation of c9,c12-18:2 carried out by grape seed oil, focusing on its t11 and t10 pathways, using 6-h ruminal i...

In a previous study, preparations of polyclonal antibodies (PAP) against Fusobacterium necrophorum (PAP-Fn) or Streptococcus bovis (PAP-Sb) were successful in decreasing ruminal counts of target bacteria and increasing ruminal pH in steers fed high-grain diets. The objective of this study was to evaluate the effects of feeding PAP-Fn or PAP-Sb on performance, carcass characteristics, and rumina...