Metabolizable energy (ME) equations Broiler 2019
Energy is the first and most expensive constraint in broiler feed production. The energy content in the feed drives intake and therefore sets the bar for nutrient intake. The central Database (CDB) of Nutreco was established in 2007 with CVB data. The CDB had improved and evolved over years with the implementation of own data together with CVB data.
The broiler nutrient equations in Central database are the following
- MEbroiler based on CVB 2021 system which is based on ME broiler 2007 equation.
- MEbroiler Nutrix based on Nutrix upgrade of MEbroiler to include starch, sugars, and residual Nitrogen free extract (rNFE) fraction.
- AME broiler INRA equations
- The new MEbroiler 2019 based on the Broiler 2019 feeding requirements published by CVB
This MEbroiler equations are based on the results of a multiple regression analysis on the studies conducted and literature reviewed over time. The components of the equation, the amounts of digestible crude protein (CP), crude fat (CF) and carbohydrates were included in the regression model as explanatory variables (or digestibility (D) coefficients corrected to N-balance if regression data is not available).
ME Broiler 2007 (MJ/kg) = (15.56 x DCP+ 38.83 x DCFATh + 17.32 x DNFE + 14.55 x Lactic acid) / 1000, the contents DCP, DCFh, DNFE and LA in gram per kilogram.
The central database ME broiler CVB equation up to 2021 has the 15.56 as ME coefficient for ME value calculation of Crude Protein value of feed material. Since the introduction, MEbroiler 2007 equation was always debated for the correctness of the energetic coefficient for CP in the formula due to lack of physiological explanation.
The complete metabolism of CP into water, carbon dioxide, uric acid (and urea) yields a gross energy value of 23.6 MJ/kg whereas the excretion component uric acid (and urea) has a gross energy of uric acid of 5.6 MJ/kg. This makes the ME coefficient for protein to be approximately 18.03 MJ/kg not 15.56 as mentioned in MEbroiler 2007 equation. The roosters and layers had the ME coefficient for protein as 18.03 in the ME equations.
Regarding the carbohydrate fraction, the composition of starch, sugar and fiber components varies within different batches of the feed ingredients. Among the fractions of carbohydrates, starch and sugars have a (very) high digestibility, whereas the fiber fraction will be very low to negligible. If a fixed digestion coefficient for the carbohydrate fraction, however, means that the variation in the composition of the carbohydrates fraction is not considered at all. This means that better quality grain and grain byproducts with higher starch content are estimated better compared to previous 2007 system, but also the other way around, lower quality grains are will have a decreased ME value.
The Sugar fraction in feed ingredients consists of enzymatically digestible and fermentatively degradable sugars. Due to high digestibility, birds fed with a relatively high sugar rich feed ingredients have no sugar excreted in faeces. A negligible percentage of starch supplied via the feed ingredient is found in the excreta due to less digestibility. The caeca microbial breakdown of fermentable sugars and ileal undigested starch are absorbed completely or partially excreted via the excreta. In addition, some fermentation of some water-soluble components of the NSP fraction take place in the caeca. Based on these considerations, it was decided to increase the digestibility of the carbohydrate fraction in the ME 2019 broiler equation. The ME broiler 2019 equation is modified as follows:
ME Broiler 2019 (MJ/kg) = (18.03 x DCP + 38.83 x DCFATh h + 17.32 x D(Starch + Sugar) + 14.72 x * Lactic Acid in DM / 1000 , the contents DCP, DCFh, sugar , starch and LA in gram per kilogram.
Finally, two new nutrients are introduced in NutriOpt and the formulation programs Bestmix and Faas:
MEbroiler 2019 (kCal) 594
MEbroiler 2019 (MJ) 593
To summarize the other most important changes in MEbroiler 2019 compared to MEbroiler 2007:
- Higher energy level for Crude Protein nutrient
- Better prediction of the grains and grain byproducts due to the use of Starch in the equation and no longer using NFE as a total