Development of equations for predicting metabolisable energy concentrations in compound feeds for pigs.

In 2006 in Germany new recommendations for the supply of energy and nutrients to pigs were published, including a modification of the energy evaluation on the basis of metabolisable energy for pigs (MES). It was the objective of this meta-analysis to calculate equations that can be used for predicting MES in compound feeds for pigs on the basis of their nutrient concentrations. Data from digestibility studies with a total of 290 compound feeds were provided by different research institutions. Feeds for both piglets and growing-finishing pigs were contained in the data set. The MES concentration ranged from 10.4-16.6 MJ/kg DM, with the majority of data ranging between 15 and 16 MJ/kg DM. The data were processed with a cross validation method and a multiple regression approach by using MES as the independent variable. A corrected Akaike-Information-Criterion (AIC_ cor) was used for model evaluation. Various models were developed and validated independently. Calculations were made both for piglet and growing-finishing pig feeds, separately and together, for all feeds. It was shown that the MES concentration in compound feeds can be predicted with good accuracy if the concentrations of crude protein, crude fat, crude fibre, and starch are known. Prediction equations were presented. The lack of data for highly fibrous feeds as well as the analysis of different fibre fractions was identified as a challenge for further improvement of the prediction equations.