We used six ruminally cannulated Texel wethers to study the relative role of protozoa and lactate-metabolizing bacteria in ruminal fermentative patterns during an induced latent acidosis. The sheep were fed an alfalfa hay diet (H) and latent acidosis was induced, following a short transition period of one week, with a grain-rich acidotic diet (W, 60% wheat + 40% alfalfa hay). Ruminal pH, rumina...

As a primary energy source for ruminants, volatile fatty acids (VFA) have been estimated to provide up to 75% of the total metabolizable energy (Bergman, 1990). Thus, it is not surprising that diets promoting fermentation and greater production of VFA also promote greater levels of productivity (e.g. milk production) than less fermentable diets (Kolver and de Veth, 2002; Oba and Allen, 2003a,b)...

Unlike other nutrients, such as protein and calcium, where requirements are provided in grams per cow per day for specific body weight and milk production levels, fiber “requirements” are merely minimum guidelines (NRC, 2001) aimed at maintaining normal ruminal pH, fiber digestion and milk fat test and preventing sub-acute rumen acidosis (SARA), laminitis and displaced abomasums (LDA). NRC (200...

Rumen-derived lipopolysaccharide (LPS) is translocated from the rumen into the bloodstream when subacute ruminal acidosis (SARA) occurs following long-term feeding with a high-concentrate (HC) diet in dairy cows. The objective of this study was to investigate the mechanism of inflammatory responses in the liver caused by HC diet feeding. We found that SARA was induced in dairy cows when rumen p...

Our objective was to determine if the severity of short-term feed restriction (FR) affects the timeline for recovery of the absorptive function of the reticulo-rumen and barrier function of the total gastrointestinal tract in beef cattle. Eighteen ruminally cannulated and ovariectomized Angus × Hereford heifers were housed in individual pens. Heifers were blocked by initial BW into 3 blocks and...

To meet the nutrition requirements of lactation, dairy cows are usually fed a high concentrate diet (HC). However, high-grain feeding causes subacute ruminal acidosis (SARA), a metabolic disorder that causes milk protein depression. This study aimed to investigate the effect of lipopolysaccharide (LPS) released in the rumen on inflammatory gene expression and casein synthesis in mammary glands ...

Ruminal pH in dairy cows follows a diurnal fluctuation; low values are indicative of subacute ruminal acidosis and associated with alterations rumen fatty acids concentrations. The objective the present study was to prospectively associations between fluid concentrations short, medium, long chain acids, under field conditions during first half lactation 53 Holstein farm. obtained by rumenocente...