**Abstract**

In the era of genomic selection, basic animal breeding methods are still playing a very important role in animal selection and their improvement. Animal Breeding involves the selective breeding of domestic animals with the intention to improve desirable and heritable qualities in the next generation. An animal's overall performance is mostly influenced by genetic potential acquired from its parents, as well as the environment, which includes nutrition, health, management, and other factors. This chapter covers a brief outline of traditional breeding methods for the selection of animals and their improvement.

**Keywords:** criteria, methods, selection, improvement, breeding value, inbreeding

### **1. Introduction**

Selection is one of the important processes for any improvement in farm animals. The breeding merit animal is not often determined by a single character, but more often based on many characters simultaneously. The purpose of selection is to produce elite breeding stocks which act as parents of future generations. The system of selection allows the best animals to act as parents of future generations and culling of undesirable animals from the herd. The animals retained have certain acceptable traits which make them produce more. The breeding of animals is underneath human control, and the breeders decide which individuals shall produce the subsequent generation [1, 2]. The breeding of animals is based upon the fact that certain qualities are genetic; hence valuable qualities are passed on from parents to offspring's. Due to selection, the qualities of animals can be maintained or improved in the next generation [3]. The purpose of selection is to enhance the frequency of desirable alleles and reduce the frequency of unwanted alleles from the herd which in the long run consequences genetic improvement in livestock. The overall performance of an animal is mainly influenced by the genetic potential that is inherited from its parents and the environment which particularly encompass feeding, health, management and so forth.

## **2. Methodology**

Breeding for increased productivity over the past few decades has been very successful in terms of improvement of growth, production and reproduction traits; however, it has also had negative consequences on behavior and welfare [4]. Breeding and genetics are playing an important role in the improvement of domestic animals. Therefore, a broad approach is needed that encompasses both production and welfare traits, even though welfare may not be a primary breeding goal of

the selection scheme. Now, in the era of genomics, breeders have lots of opportunities to collect more precise information on the biological impact of certain breeding decisions. This might help breeders to make more accurate decisions in their selection programs. Genomic tools could also facilitate selection for complex traits, which are frequently not possible to measure on a large number of animals. Looking to this the salient features about selection criteria and methods of selection have been discussed in this chapter.

#### **2.1 Types of selection**

**Figure 1** is showing the different type criteria and methods of selection that are applied for the selection of animals for a single trait or multiple traits in animal breeding [5, 6].

### **2.2 Selection for improvement of animals**

The manmade selection with certain desirable goal plays important role in the improvement of animal. The different types of artificial selection have been discussed in this chapter along with their merits and demerits. The selection, breeding and propagation of animals by breeders are known as artificial selection. There are two approaches for artificial selection. First is the traditional "breeder's approach" in which the breeder applies "a known amount of selection to a single phenotypic trait" by examining the selected trait and selecting to breed only those that show superior values" of the trait under selection [7]. The second is called "controlled natural selection," which is actually natural selection in a controlled environment [8]. The main purpose of animal breeding is not just to improve individual animals genetically but also to improve the future generation of the animal population [9]. The technique or method used by the breeder to make longterm changes in animals is called selection. Selection is the process in which certain individuals in a population are given an opportunity to produce progeny while others are denied this opportunity [10]. It also decides about how many progenies it should produce and how long they should remain in the breeding population. Selection is an important tool for changing gene frequencies to better-fit individuals for a particular purpose. Selection is not an invention of modern man. It has been going on in nature since life existed in the world. Selection is choosing individuals

**Figure 1.** *Different types of selection [5, 6].*

### *Basic Animal Breeding Methods DOI: http://dx.doi.org/10.5772/intechopen.104136*

that will be parents of the next generation. The effectiveness of selection depends on the ability to recognize those animals, which possess superior inheritance [11]. Those superior animals must be mated together for the production of offspring. The aids available to estimate the breeding value of an animal is through the phenotype of an animal or its relatives.

### **2.3 Basis of selection for single traits**

**Figure 2** is showing the different basis of selection that are commonly used to estimate the probable breeding for the selection of animals for a single trait [3, 5, 6].

## *2.3.1 Individual selection/performance testing*

Individual selection is most commonly used as a basis for selective improvement in livestock. Individual selection is based on the performance of individual or individual phenotypic value. These animals are selected based on their own phenotype. Individual selection is more effective when the heritability of traits is high, but the effect decreases with falling heritability. It is the simplest, more rapid and most commonly used basis of selection. If proper performance records are maintained then, the traits like body weight, growth rate, fleece production and other parameters of similar nature can be evaluated directly from the performance of individual animals [10, 12].
