BACKGROUND The prevalence of subacute ruminal acidosis (SARA) in dairy cows is high with large impact on economy and welfare. Its current field diagnosis is based on point ruminal pH measurements by oral probe or rumenocentesis. These techniques are invasive and inaccurate, and better markers for the diagnosis of SARA are needed. The goal of this study was to evaluate clinical signs of SARA and...

Subacute ruminal acidosis (SARA) was induced by replacing 25% of the total mixed ration intake [dry matter (DM) basis] with pellets consisting of 50% wheat and 50% barley. This reduced dietary forage content (DM basis) from 39.7 to 29.8% and increased the dietary concentrate content from 60.3 to 70.2%. Induction of SARA reduced the 24- and 48-h in situ neutral detergent fiber (NDF) degradabilit...

The objective of this study was to determine how duration of time that cattle are fed a high-grain diet affects feed sorting, both before and after an episode of acute ruminal acidosis. Sixteen Angus heifers (261 ± 6.1 kg; BW ± SEM) were assigned to 1 of 4 blocks and fed a backgrounding (BG) diet (60% forage, DM basis). Within block, heifers were randomly assigned to 1 of 2 treatments differing...

The impact of a long-term subacute rumen acidosis (SARA) on the bovine epimural bacterial microbiome (BEBM) and its consequences for rumen health is poorly understood. This study aimed to investigate shifts in the BEBM during a long-term transient SARA model consisting of two concentrate-diet-induced SARA challenges separated by a 1-week challenge break. Eight cows were fed forage and varying c...

Corresponding Author: O. ALZahal Department of Animal Biosciences, University of Guelph, Ontario, Canada N1G 2W1, Canada Email: [email protected] Abstract: The objective of this experiment was to examine the effect of Subacute Ruminal Acidosis (SARA) on milk fatty acid (FA) profiles with emphasis on odd-chain and branched-chain FA. Sixteen multiparous Holstein dairy cows (618±35 kg of body w...

The relationship between SARA and milk fat depression is inconsistent and complex. It can be surprisingly difficult, at times, to determine if a herd really has a low milk fat test or not. Normal milk fat percentage depends greatly on breed, season, and days in milk. Nutritional causes of milk fat depression (which may include SARA) only become a concern when these three major factors have alre...

Laminitis often follows lactic acidosis and is accompanied by increased blood and rumen histamine. However, since histamine is poorly absorbed and absorbed histamine is rapidly metabolized, and since high levels of oral histamine have not produced laminitis, it is unlikely that ruminal histamine causes laminitis. Lactic acidosis leads to rumenitis, which, in turn, leads to liver abscesses becau...

Thiopeptin, thiopeptin-like antibiotics and penicillin were shown previously to be highly active in vitro against Streptococcus bovis, the microorganism believed to be responsible for the initiation of ruminal lactic acidosis. The purpose of this work was to determine the efficacy of these antibiotics in preventing lactic acidosis in lambs challenged by intraruminal administration of ground whe...