Ruminant Diets (ruminant + diet)

Distribution by Scientific Domains


Selected Abstracts


Effects of aromatic amino acids, phenylacetate and phenylpropionate on fermentation of xylan by the rumen anaerobic fungi, Neocallimastix frontalis and Piromyces communis

JOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2007
A.Y. Guliye
Abstract Aims:, Anaerobic fungi are important members of the fibrolytic community of the rumen. The aim of this study was to study their requirement for aromatic amino acids (AA) and related phenyl acids (phenylpropionic and phenylacetic acids) for optimal xylan fermentation. Methods and Results:,Neocallimastix frontalis RE1 and Piromyces communis P were grown in a defined medium containing oat spelts xylan as the sole energy source, plus one of the following N sources: ammonia; ammonia plus a complete mixture of 20 AA commonly found in protein; ammonia plus complete AA mixture minus aromatic AA; ammonia plus phenyl acids; ammonia plus complete AA mixture without aromatic AA plus phenyl acids. Both species grew in all the media, indicating no absolute requirement for AA. The complete AA mixture increased (P < 0·05) acetate concentration by 18% and 15%, sugar utilization by 33% and 22% and microbial yield by about 22% and 15% in N. frontalis and P. communis, respectively, in comparison with the treatments that had ammonia as the only N source. Neither the supply of aromatic AA or phenol acids, nor their deletion from the complete AA mixture, affected the fermentation rate, products or yield of either species. Conclusions:, AA were not essential for N. frontalis and P. communis, but their growth on xylan was stimulated. The effects could not be explained in terms of aromatic AA alone. Significance and Impact of the Study:, Ruminant diets should contain sufficient protein to sustain optimal fibre digestion by ruminal fungi. Aromatic AA or phenyl acids alone cannot replace the complete AA mixture. [source]


In vitro fermentative characteristics of ruminant diets supplemented with fibrolytic enzymes and ranges of optimal endo-,-1,4-glucanase activity

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2010
E. González-García
Summary Effectiveness of fibrolytic enzymes supplementing a range of forage to concentrate (F:C) diets was assessed with goat (G) or cow (C) inoculum using the gas production (GP) technique. Four F:C diets were evaluated: forage (1:0), high forage (0.7:0.3), medium forage (0.5:0.5) and low forage (0.3:0.7) diets, supplemented or not with PromoteTM (PRO) at 1 or 2 ml/kg dry matter (DM). The GP kinetic was different between F:C (1:0 < 0.7:0.3 < 0.5:0.5 < 0.3:0.7) and inoculum. Responses to enzyme were positively related to forage level and differed with inoculum. The neutral detergent fibre and acid detergent fibre degradation were depressed by the concentrate in the substrates fermented with C and were not altered or even enhanced in G sets. Results confirm that increasing starch proportion modified the pattern of microbial fermentation, while no influences were detected in the improvement of cell wall degradation with fibrolytic enzymes. Another in vitro experiment was conducted to investigate factors by which endo-,-1,4-glucanase activity (EA) of PRO is compromised in a factorial design (3 × 4 × 3) for three pH (4.0, 5.5 and 6.5), four temperatures (30, 40, 50 and 70 °C) and three doses (1, 2 and 3 ml/kg DM of substrate). Maximum EA were obtained for pH 4.0, 50 °C and 3 ml/kg DM. Optimal conditions for PRO proved to be outside the normal ranges in ruminal environment. [source]


In vitro effects of phlorotannins from Ascophyllum nodosum (brown seaweed) on rumen bacterial populations and fermentation

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2009
Yuxi Wang
Abstract BACKGROUND: Use of brown algae (seaweed) in ruminant diets is increasing, but the effects of its phlorotannins (PT) on rumen microbial ecology have not been determined. Mixed forage (50:25:25 ground barley silage,alfalfa hay,grass hay) was used as substrate in a batch culture ruminal incubation that included PT extracted from Ascophyllum nodosum, with and without polyethylene glycol. Principal ruminal bacteria were quantified using real-time polymerase chain reaction. RESULTS: At 500 µg mL,1, PT reduced growth of Fibrobacter succinogenes by 78%, 83% and 65% at 6, 12 and 24 h (P < 0.001), Ruminococcus albus at 24 h only (P < 0.01) and did not affect R. flavefaciens. Non-cellulolytic bacteria Selenomonas ruminantium, Ruminobacter amylophilus and Prevotella bryantii were increased (P < 0.001) by PT at 12 and 24 h. Effects of PT on fermentation products (gas production, volatile fatty acid profiles and ammonia accumulation) were consistent with alterations in rumen microbial populations. CONCLUSION: The effects of PT on ruminal bacteria were species-dependent, which suggests that diet may mediate PT effects on animal performance. The variation in sensitivity of ruminal bacteria to PT reflects previously reported effects of condensed tannins from terrestrial plants on microbial populations. Copyright © 2009 Crown in the right of Canada. Published by John Wiley & Sons, Ltd [source]


Silage preparation and nutritive value of Chinese yam by-product

ANIMAL SCIENCE JOURNAL, Issue 4 2009
Chuncheng XU
ABSTRACT The objective of this experiment was to determine the ensiling characteristics, nutrient composition and nutritive value of Chinese yam by-product (CYBP) silage treated without additive (Control), with lactic acid bacteria (LY), with dried beet pulp (BY), or with mixtures of lactic acid bacteria and dried beet pulp (LBY) for a fermentation period of 150 days. The nutritive value of CYBP silage was studied in an in vivo digestibility trial using wethers in a 4 × 4 Latin square design. Addition of lactic acid bacteria and/or dried beet pulp greatly improved fermentation quality of CYBP silage. The pH was reduced to below 4.0 and lactic acid was produced at above 4.6% on dry matter basis. There were no statistical differences among treatments in the digestibilities of dry matter, organic matter, crude protein and energy in the silages, but neutral detergent fiber and acid detergent fiber digestibility were higher (P < 0.001) in wethers fed BY and LBY silages compared to the control and LY silages. It was estimated that total digestible nutrient and digestible energy in the CYBP silage averaged 79.1% and 14.3 MJ/kg on dry matter basis. The study suggests that CYBP can be well preserved by making a silage and it is a good potential energy source for ruminant diets. [source]