BACKGROUND The behaviour of perfluoroalkyl acids (PFAAs) in tissues of ruminants has been shown to differ from that of monogastrics (J Agric Food Chem 61(12):2903-2912 doi:10.1021/jf304680j, 2013; J Agric Food Chem 62(28):6861-6870, 2014). This may be a consequence of the complex microbial ecosystem in the rumen. To evaluate this hypothesis, the recovery of PFAAs was studied using the rumen sim...

The effects of rumen buffer agents on ruminal fermentation parameters and bacterial community composition were determined using in vitro vivo experiments three rumen-cannulated, high-concentrate fed Holstein Friesian dairy cows. Experiment 1 treatments included bentonite, calcium carbonate, oxide, sodium bicarbonate, sesquicarbonate, processed coral, unbuffered samples served as the control. 2 ...

The primary growth of lucerne (Medicago sativa) was ensiled after treatment with either formic acid alone (4.1 litres/t; silage F) or with formic acid and either formaldehyde (30.5 g/kg crude protein (nitrogen X 6.25; CP); silage FF), glutaraldehyde (44.2 g/kg CP; silage FG) or a mixture of the two aldehydes at approximately half their individual application rates (silage FFG). Compared with fo...

1. Responses to twice-weekly oral supplementation with 4.0 g methionine were measured with lambs (27 kg) grazing kale (Brassica oleracea) for 10 weeks (Expt 1). In a second experiment with sheep fed on kale at hourly intervals, rumen fractional outflow rates of CrEDTA and ruthenium Tris(1,10 phenanthroline) markers were measured from the rates of decline in their concentrations. Rumen turnover ...

Bacteria, fungi and protozoa inhabiting the rumen, the largest chamber of the ruminants' stomach, release large quantities of hydrogen during the fermentation of carbohydrates. The hydrogen is used by coexisting methanogens to produce methane in energy-yielding processes. This work shows, for the first time, a fundamental possibility of using a hydrogen-rich fermentation gas produced by selecte...

In vitro gas production techniques simulate the rumen fermentation process and they have been used to evaluate the potential of feeds to supply nutrients to ruminants. Thus, effects of various levels of cobalt supplementation on gas production and rumen fermentation were investigated using an in vitro gas production technique. Ground samples (100 mg DM) of 70% wheat straw and 30% concentrate we...

The low intake and digestibility of low-quality roughages such as mature forages or crop residues often results in a digestible energy intake insufficient for a desired level of production. One alternative to increase digestible energy intake is to provide supplementary concentrates of high digestibility. ‘ Associative effects on forage fibre digestion may occur when roughage and concentrate ar...

The ability of rumen microbiota to incorporate inorganic sulfate into cystine and methionine was suggested by Loosli et al. (1949) and demonstrated by Block et al. (1951) through use of radioactive sodium sulfate. The significance of this incorporation as applied to ruminant nutrition has been discussed by Davis et al. (1954). Formation of microbial protein in the rumen of cattle is accompanied...

This experiment was designed to investigate the effect of lerak extract on the dynamic of rumen microbes in the in vitro fermentation of diet with different ratios of forage and concentrate. In vitro fermentation was conducted according to the method of Tilley and Terry (1963). The design of experiment was a factorial block design with 2 factors. The first factor was the ratio of forage and con...

The aim of this work was to determine whether reductive acetogenesis can provide an alternative to methanogenesis in the rumen. Gnotobiotic lambs were inoculated with a functional rumen microbiota lacking methanogens and reared to maturity on a fibrous diet. Lambs with a methanogen-free rumen grew well, and the feed intake and ruminal volatile fatty acid concentrations for lambs lacking ruminal...