The consequences of introducing stochasticity in nutrient utilisation models: the case of phosphorus utilisation by pigs
| Autor: | Ilias Kyriazakis, Ilkka Leinonen, Vasilis Symeou |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Animal feed Swine Population Medicine (miscellaneous) chemistry.chemical_element Body weight 03 medical and health sciences Nutrient Animals education education.field_of_study Nutrition and Dietetics Phosphorus Simulation modeling Body Weight 0402 animal and dairy science 04 agricultural and veterinary sciences Models Theoretical 040201 dairy & animal science Animal Feed Diet 030104 developmental biology Variation (linguistics) chemistry Agronomy Phosphorus Dietary |
| Zdroj: | The British journal of nutrition. 115(3) |
| ISSN: | 1475-2662 |
| Popis: | Simulation models of nutrient utilisation ignore that variation in pig system components can influence the predicted mean and variance of the performance of a group of pigs. The objective of this study was to develop a methodology to investigate how variation in feed composition would (a) affect the outputs of a nutrient utilisation model and (b) interact with variation that arises from the traits of individual pigs. We used a P intake and utilisation model to address these characteristics. Introduction of stochasticity gave rise to a number of methodological challenges – for example, how to generate variation in both feed composition and pigs and account for correlations between ingredients when modelling variation associated with feed mixing efficiency. Introducing variation in feed composition and pig phenotype resulted in moderate decreases in mean digested, retained and excreted P predicted for a population of pigs and an increase in their associated CV. A lower percentage of pigs in the population were predicted to meet their requirements during the feeding period considered, by comparison with the no-variation scenario. Variation in feed ingredient composition contributed more to performance variation than variation due to mixing efficiency. When variations in both feed composition and pig traits were considered, it was the former rather than the latter that had the dominant influence on variability in pig performance. The developed framework emphasises the consequences of random variability on the predictions of nutrient utilisation models. Such consequences will have a significant impact on decisions about management strategies such as feeding that are subject to variation. |
| Databáze: | OpenAIRE |
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