Determination of Metabolizable Energy Value in Canola Meal with and without Enzymes Addition By Regression Method in Adult Leghorn Roosters

In addition to high protein content, canola meal can play a significant role in the energy supply of poultry feeds due to its relatively high amount of carbohydrates and crude fat. The value of AMEn in the NRC table for a canola meal is 2000 kcal/kg. The metabolizable energy value of canola meal has not been published in Iranian tables of feed composition published by the animal science research center. The evaluation of the feed is completed by determining nutrients followed by measuring its metabolizable energy content. There are different methods to determine the amounts of metabolizable energy in poultry feeds, and each of them has advantages and disadvantages. The regression method is one of the methods of determining metabolizable energy, which provides the possibility of studying the metabolizable energy content of a test ingredient in practical diets at different levels. The purpose of this experiment was to determine the apparent metabolizable energy values corrected to zero point of nitrogen balance (AMEn) of canola meal with and without enzyme by regression method in adult leghorn roosters.

Canola meal samples were obtained from poultry feed plants in Tabriz city and their chemical composition was measured according to standard methods. The number of 48 adult leghorn roosters were used with 6 replications in a completely randomized design in factorial order (2 × 4) (two levels of enzyme Zero and 375 units × four levels of canola meal, Zero, 7, 14, 21 percent) using the regression method by replacing canola meal in corn-soybean meal-based diet.

The average values of dry matter, ash, crude protein, ether extract, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were 88.5, 6.8, 34.4, 6.7, 34.5, and 20.5% respectively and gross energy value of canola meal was 4324 kcal/kg.By increasing the level of canola meal in the experimental diets, the values of ADMM, AOMM, AMEn and gross energy efficiency decreased significantly (p<0.05). The amount of AMEn decreased by 7.4%, equivalent to 244 kcal/kg in the diet containing 21% canola meal compared to the control diet without canola meal. Enzyme addition improved AMEn of diets containing of canola meal as much as 64 Kca/Kg. The equations for estimating AMEn of canola meal with and without enzyme showed high determination coefficients of 0.83 and 0.79, respectively. The AMEn of canola meal with and without enzyme by regression method was estimated 1985 and 1838 kcal/kg, respectively.

The obtained values for AMEn of canola meal with and without enzyme by regression method were lower compared to the corresponding values reported in NRC (1994). Therefore, formulating poultry diets with AMEn values reported here may be effective in predicting the bird’s performance.