TwitterLinkedinWhatsAppTelegramTelegram
0

Modeling the fate of dietary phosphorus in the digestive tract of growing pigs

A mathematical model serves as a tool to study phosphorus digestibility for different feedstuffs and feeding strategies.

29 December 2011
TwitterLinkedinWhatsAppTelegramTelegram
0

Environmental effects of excess phosphorus (P) from manure and the soaring price of phosphates are major issues in pig production. To optimize P utilization, it is crucial to improve our capacity to predict the amount of P absorbed, while taking into account the main factors of variation. Mathematical modeling can represent the complexity of the processes and interactions in determining the digestive utilization of P in growing pigs. This paper describes and evaluates a model developed to simulate the fate of the dietary forms of P in the digestive tract of growing pigs, with particular emphasis on the effect of dietary Ca and exogenous phytase on P digestive utilization. The model consists of 3 compartments associated with specific anatomical sections: stomach, proximal small intestine, and distal small intestine. The main metabolic processes occurring in these sections are, respectively, P solubilization/insolubilization and phytate P hydrolysis, and P absorption and P insolubilization. Model parameters governing these flows were derived from in vitro and in vivo literature data.

The sensitivity analysis revealed that the model was stable within a large range of model parameter values (± 1.5 SD). The model was able to predict the efficacy of Aspergillus niger microbial phytase in accordance with literature values, as well as the decreased efficacy of plant phytase compared with microbial phytase. The prediction capabilities of the model were assessed by comparing actual and simulated P and Ca apparent total-tract digestibility (ATTD) based on published pig data not used for model development. Prediction of P digestibility across 66 experiments and 281 observations was adequate [P ATTD observed = 0.24 (SE, 0.943) + 0.98 (SE, 0.0196) × P ATTD predicted; R2, 0.90; disturbance error (ED), 96.5%], whereas prediction of Ca digestibility across 47 experiments and 193 observations was less accurate (Ca ATTD observed = 11.1 + 0.75 × Ca ATTD predicted; R2, 0.78; ED, 20.4%). A lack of agreement between experimental and simulated Ca digestibility was found.

This model is, therefore, useful in evaluating P digestibility for different feedstuffs and feeding strategies. It can also be used to provide insight for improving dietary P utilization, especially from plant sources, by quantifying the effect of the mean sources of variation affecting P utilization.

MP Letourneau-Montminy, A Narcy, P Lescoat, M Magnin, JF Bernier, D Sauvant, C Jondreville and C Pomar, 2011. Journal of Animal Science, 89: 3596-3611.
http://dx.doi.org/10.2527/jas.2010-3397

Article Comments

This area is not intended to be a place to consult authors about their articles, but rather a place for open discussion among pig333.com users.
Leave a new Comment

Access restricted to 333 users. In order to post a comment you must be logged in.

Related articles

Netherlands - Less phosphorus in pig feed; Macro-effects, opportunities and barriers

26-Apr-2011
The Ministry of Economics, Agriculture and Innovation asked LEI to investigate the macro-economic effects of reduced-phosphorous feed. This request was translated into research into the influence of reduced phosphorous feed on the price of pig feeds, the influence on the manure surplus in kilos of phosphate, the effect on the necessary processing capacity of pig manure and the costs savings that this achieves. In addition, the research looked into the risks perceived by the animal feed industry, both for the industry itself and for pig farmers.