# Optimal Choice by Mathematical Modelling and Optimization of Protein Addition to the Starter of Broiler Chickens

N. TAKUCHEV and MOHAMED NAIM SHARIF

*Trakia University, BG - 6000 Stara Zagora, Bulgaria *

### Abstract

TAKUCHEV, N. and MOHAMED NAIM SHARIF, 2004. Optimal choice by mathematical modelling and optimization of protein addition to the starter of broiler chickens.** ***Bulg. J. Agric. Sci.,* 10: 131-136

Three groups of mathematical models are built on the basis of data from an experiment with chickens nutrition, each with one out of three protein additions to soybean meal - peas, chickpeas and broad beans. Each group consists of three functions, with dependent variables - the relative chicken mass increase, the metabolizable energy and the crude protein, respectively. The relative masses of the components in the starter - soybean meal, maize, DL-methionine, animal fat (lard) are independent variables.

The maxima in the relative chicken mass increase for each group of models are obtained. The models of the metabolizable energy and the crude protein are constraints. Other constraints are the variation limits of the independent variables. The optimal ratio between the components in the starter, determining the respective maximum, is calculated, too.

The biggest is the maximum for the models with broad beans - 551 g/kg and ratio between broad beans and soybean meal of 23 %, followed by the maximum for the model with peas - 520 g/kg and ratio between peas and soybean meal of 31 %, and by the maximum for the model with chickpeas - 472 g/kg and ratio between chick-peas and soybean meal of 16 %.

The results show the most economically acceptable variant of addition to the soybean meal in the starter in case of relatively equal addition prices - with peas (30 %), which reduces the price significantly, without significant decrement of the mass increase.

*Key words: *optimal starter, mathematical modelling, optimization, nutrition