**4. Informal way of creating breed of chicken. (how novices can create breeds of chickens)**

### **4.1 Things a novice must do after arrival**

Beeken [66] has shown that novices can develop a new breed following the methods below.


### **4.2 Conventional breeding methods**

The moment a breeder sets out to create a meat-type (broiler) or an egg-type (Layer) breed, it has an intention of changing the genetic composition of the population. This implies change of gene and genotypic frequency of that population. It can also be explained as changing the gene frequency of a superior gene from a low value (0.1 to 0.5) to a high value or fixation (1). Firstly, the breeder carefully considers the appropriate genetic model. The breeder examines the causal effects of the population variance to enable him determine the genetic parameters, consisting of heritability,

repeatability, and genetic correlations. Genetic parameters further illuminates the breeders decision on best selection option that is necessary for improved performance or genetic progress. The result of heritability estimates provides the framework for evaluation of the performance of individuals, popularly known as the breeding values. The breeding values ultimately reveal individuals of superior genotype that must be selected for necessary improves performance of genetic progress among the progenies.

### **4.3 Genetic gain or response (R)**

• **Genetic Gain or response (R)** is simply a product of heritability and selection differential expressed in the following equation;

$$\mathbf{R} = \mathbf{h}^2 \,\mathbf{S} \tag{1}$$


### **4.4 Computation of a selection index**

A statement of the breeding goal is the first information needed. The concept of merit based on a single trait must be replaced by merit based on combination of traits which are economically important and which have sufficient additively genetic variance to give a reasonable response to selection.

The worth, W, or value of an individual or group is defined as

$$\mathbf{W} = (\mathbf{W} - \mathbf{W}) = \mathbf{W} = (\mathbf{W} - \mathbf{W}) = \mathbf{W} + \mathbf{a}\_1 \mathbf{x}\_1 + \mathbf{a}\_2 \mathbf{x}\_2 + \dots \mathbf{a}\_n \mathbf{x}\_n = \{\mathbf{a} \mathbf{i} \mathbf{i} \mathbf{i}\} \tag{2}$$

where ai are the relative increases in net worth expected from one unit of improved merit in the trait X, independent of the improvement in the other traits in w.

The additive genetic value for worth then becomes gw in contrast to g for the I trait and it can be defined as

$$\mathbf{g}\_{\mathbf{w}} = \mathbf{a}\_{i}\mathbf{g}\_{i} + \mathbf{a}\_{2}\mathbf{g}\_{2} + \dots + \mathbf{a}\_{n}\mathbf{g}\_{n} = \{\mathbf{a}\_{i}\mathbf{g}\mathbf{i}\}\tag{3}$$

### **4.5 Development of breeding goals and breeding plans**

In the words of Legates and Warwick, any breeder with the intention of developing or improving livestock must be able to mesh together the fundamental principles tampered with livestock experience and economic realities of animal production. Many early breeders like Babcock have confirmed this as the created purebred without academically specializing in genetics and animal breeding. Beeken [66] in his writings showed that even novice can create a pureline. Demonstrating the prerequisites for genetic improvement aided us to understand the reason behind the failure of Nigerian farmers, animal breeders, and animal scientists.

### **4.6 Prerequisites for genetic improvement**

Two major conditions were underscored by the following.

Firstly, be able to assess the genetic merit of our present animals by keeping accurate records of performance of known ancestry.

Secondly, the influence of the animals with the desired genes must be extended and made available especially through AI and Embryo transfer.

Thirdly, developing a breeding goal embodied in an efficient Selection index, laying emphasis on the following factors,

i. Consumer choice.

ii. Prediction of population in future.

