In Vitro Prediction of Phosphorus Availability in Feed Ingredients for Swine

Abstract

The percentage of phosphorus (P) dialyzability was determined in 10 plant-origin and 4 animal-origin feed ingredients using an in vitro procedure that simulates the digestive system of growing swine. The test feed ingredients included alfalfa meal, barley, canola meal, corn, grain sorghum, oats, rice bran, soybean meal, wheat, wheat bran, menhaden fish meal, meat and bone meal, spray-dried blood meal, and dry whey. Repeatability of the in vitro procedure was tested for each ingredient using quadruplicate samples. The in vitro P dialyzability percentages were correlated with published in vivo P availability values for swine. Results showed that P dialyzability with the in vitro procedure was highly repeatable (>96%). For the 10 plant-origin feed ingredients, significant correlations (r = 0.72−0.88) were found among the in vitro P dialyzability percentages and the published in vivo P availability values. For the four animal feed ingredients, however, the in vitro dialyzability percentages obtained were poorly correlated (r = −0.26 to 0.70, p > 0.3−0.7) with published in vivo P availability values. In conclusion, the in vitro P dialyzability procedure presented here is a valid alternative to conducting in vivo studies for ranking plant-origin feed ingredients in P availability. Fine grinding of the ingredients and the addition of acid phosphatase increased the validity of this in vitro procedure. Keywords: In vitro dialyzability; phosphorus; feed ingredients; swine

Carotenoids bioavailability from foods: From plant pigments to efficient biological activities

“…This approach, although highly valuable, is not sufficient for a detailed analysis of the effects of food matrix composition or other factors on each stage in the process of absorption. There were in vitro digestion models ready for the estimation of digestibility of minerals such as iron and phosphorus (Liu, Ledoux, & Veum, 1998;Miller, Schricker, Rasmussen, & van Campen, 1981), cholesterol (Fouad, Farrell, Marshall, & van de Voort, 1991) and hydrosoluble vitamins (Ekanayake & Nelson, 1986). These are static gastrointestinal models, simulating the transit through the human digestive tract, and reproducing the physiological conditions of gastric and intestinal digestion.…”

Animal production for efficient phosphate utilization: from optimized feed to high efficiency livestock

“…Model parameters governing these flows were derived from in vitro and in vivo literature data. A combined approach where in vitro systems are used to measure and estimate degradation parameters [18,19] and then convert it to an in vivo P digestibility equivalent was implemented. Such a model may eventually be used to find economically optimal diets.…”

Validation of an in vitro method for the estimation of apparent total tract digestibility of phosphorus in plant feed ingredients for pigs

“…The method is based on Liu et al (1998) and Bollinger et al (2004Bollinger et al ( , 2005. Relevant modifications were identified (Roulin et al, 2008): a preliminary soaking step was introduced to imitate initial in vivo pH decrease and enabling endogenous phytase activity when present; an enzymatic preparation was also included, mainly for the cleavage of polysaccharides (␤-glucanase and endo-xylanase), but also for its hemicellulase, cellulase and proteinase activities.…”

“…The access to a rapid and inexpensive analytical method (in vitro) to estimate the ATTD of P in feed ingredients may improve diet formulation. In vitro enzymatic methods to evaluate the ATTD of P in feed ingredients and feeds have been suggested (Liu et al, 1998;Bollinger et al, 2004Bollinger et al, , 2005Roulin et al, 2008), unfortunately without direct in vivo validation. a One phytase activity unit (FTU) is the amount of enzyme that liberates 1 mol of inorganic P per minute from 5.1 mmol/l solution of sodium phytate, at pH 5.5 and 37 • C.…”