Ruminal phosphorus availability from several feedstuffs measured by the nylon bag technique

Abstract

-The present study was aimed at determining rumen phosphorus availability of some feedstuffs assessed with the nylon bag technique: forage (alfalfa), cereals (control-C wheat, formaldehyde treated-FT wheat, barley, corn), cereal by-products (wheat bran, wheat distillers, corn distillers) and meals (C and FT soya bean meals, rapeseed meals and sunflower meals). Rumen phosphorus availability was not uniform amongst the feedstuffs, varying from 33.1% (FT rapeseed meal) to 84.7% (C wheat). Alfalfa phosphorus release kinetics showed high bacterial phosphorus contamination. Technological treatments affected phosphorus content of by-products by either increasing (wheat bran and distillers) or decreasing (corn distillers) after germ extraction from the seed. Formaldehyde treatment decreasing rumen phosphorus availability (from 77.2% vs. 89.4% for wheat to 33.1% vs. 64.4% for the rapeseed meal) may depreciate the phosphorus nutritional value of FT meals. availability / feedstuff / phosphorus / rumenRésumé -Disponibilité ruminale du phosphore de certaines matières premières mesurée à l'aide de la méthode des sachets nylon. Cet article décrit la détermination, par la méthode des sachets nylon, de la disponibilité ruminale du phosphore d'un fourrage (luzerne déshydratée), de céréales (blé, blé tanné, orge, maïs), de sous-produits de céréales (son et drêches de blé, drêches de maïs) et de tourteaux (soja et soja tanné, colza et colza tanné, tournesol et tournesol tanné). La disponibilité ruminale du phosphore est très variable : de 33,1 % (tourteau de colza tanné) à 84,7 % (blé). La cinétique de libération du phosphore de la luzerne indique une importante contamination par le phosphore bactérien. Les traitements technologiques influencent la teneur en phosphore. L'extraction du germe enrichit (son et drêches de blé) ou appauvrit (drêche de maïs) en phosphore les sous-produits par rapport à la céréale. Le tannage au formol, diminuant la disponibilité ruminale du phosphore (de 77,2 % vs. 89,4 %, blé à 33,1 % vs. 64,4 %, tourteau de colza), semble pénaliser la valeur nutritionnelle du phosphore des tourteaux tannés. disponibilité / matière première / phosphore / rumen

In situ ruminal phosphorus degradation of selected three classes of feedstuffs in goats

“…The in situ ruminal degradation of P was inconsistent to the previous study on wheat (a = 61.4%, b =38.9%) (Bravo et al, 2000). The variation might be related to the differences in washing in the in situ procedure, animal diet and differences in sample preparation (Vanzant et al, 1998;Schwab et al, 2003).…”

“…It is accepted that phytate P is poorly absorbed by monogastric animals, but could be efficiently utilized by ruminants, due to the high phytase activity of ruminal microorganisms (Konishi et al, 1999). Furthermore, P content and rumen solubilization vary greatly depending on the feedstuffs (Bravo et al, 2000). In addition, concerning the current challenge of reducing P pollution in animal husbandry, it is urgent to decrease dietary P rations of ruminants by reducing the safety margin of excess P (Jonker and Kohn, 1999;Valk and Sebek, 1999;Wu et al, 2000).…”

Utilisation of phytate phosphorus by rumen bacteria in a semi-continuous culture system (Rusitec) in lactating goats fed on different forage to concentrate ratios

“…The variations observed in phytate phosphorus release in the rumen among feedstuffs [1,18] probably indicate that different phytic acid salts are not hydrolysed with the pH, N-NH 3 and total SCFA could indicate that the microbial fermentation activity was not affected by our experimental conditions. The P supply in an inorganic as well as in an organic form, was adequate to meet bacterial requirements [2,6].…”

Treatment of grain with organic acids at 2 different dietary phosphorus levels modulates ruminal microbial community structure and fermentation patterns in vitro

“…In contrast to monogastric animals, the InsP 6 is completely available for ruminants, due to a high phytase activity of ruminal microbes (Clark et al, 1986;Morse et al, 1992;Feng et al, 2013). However, other studies have shown that the rumen degradation of InsP 6 may be incomplete (Park et al, 2000;Jarrett et al, 2014), whereby various factors such as feed physical properties, short ruminal retention time Jarrett et al, 2014), and processing of feedstuffs with formaldehyde or heat (Konishi et al, 1999;Park et al, 2000;Bravo et al, 2000) seem to play a role. Newer research data indicate that ruminal degradability of InsP 6 is increased by supplementing exogenous phytase to dairy cow diets, resulting in a higher P availability for ruminal microbiota and the host Brask-Pedersen et al, 2013;Jarrett et al, 2014).…”