The formation of hydroxystearic acid (HSA) and ketostearic acid (KSA) from oleic acid transformation has been documented in a variety of microbial species, including several isolated from the rumen of domesticated ruminant species. However, their ruminal production rates have not been established as influenced by fatty acid source. Dosing continuous cultures of mixed ruminal microorganisms with...

Ruminal amino acid degradation is a nutritionally wasteful process that produces excess ruminal ammonia. Monensin inhibited the growth of monensin-sensitive, obligate amino acid-fermenting bacteria and decreased the ruminal ammonia concentrations of cattle. 16S rRNA probes indicated that monensin inhibited the growth of Peptostreptococcus anaerobius and Clostridium sticklandii in the rumen. Clo...

Ruminal bacteria or fungi were selected by the addition of cycloheximide or streptomycin and penicillin, respectively, to ruminal fluid, and the weakening and degradation of lignified tissues in alfalfa and Bermuda grass stems by these treatments and whole ruminal fluid were evaluated in vitro. Dry weight loss in alfalfa was similar for whole ruminal fluid and streptomycin-penicillin treatment,...

Six crossbred steers (315 kg) with cannulas in the rumen, proximal duodenum and distal ileum were used to study the influence of level and source of dietary fat on characteristics of digestion. Dietary treatments consisted of a steam-rolled barley-based finishing diet containing 1) no supplemental fat; 2) 4% yellow grease (YG); 3) 4% blended animal-vegetable fat (BVF); 4)8% YG; 5) 8% BVF or 6) ...

Oxalic acid (OA) is a secondary compound occurring in a wide range of plants consumed by ruminants, especially in saline lands or in arid and semi-arid regions. However, its impact on the rumen microbial community and its changes over time, as well as the potential consequences on ruminal function, remain unknown. To examine this impact, five ewes fitted with a ruminal cannula and fed low-quali...

This study investigated the effect of Rumex Sc (commercial product which includes of Saccharomyces cervisiae, saponin and essential oils) on rumen fermentation, blood glucose, urea, milk yield and milk composition. Animals were offered a basal diet containing alfalfa hay (15.5%), corn silage (24%), beet pulp (7%) and concentrate (53.5%). Additionally, Rumex Sc was included in the experimental d...

A study was conducted to characterize the carbohydrate and protein fractions of barley-based distillers grains (BDG) derived from a mix of 70% barley, 20% wheat and 10% rye/triticale. Amino acid composition, ruminal escape protein and amino acid values, and ruminal nutrient degradability of BDG were determined relative to wheat-based distillers' grains (WDG) derived from 100% wheat. On a dry ma...