Heritability Estimates of Body Weight and Linear Body Measurements in Goats Under Smallholder Farming Systems

CHAPTER ONE

1.1 Background to the Study

Goats are important livestock species that contribute to the livelihood of millions of rural farmers through meat, milk, and hide production. They are well adapted to harsh environments and require minimal input for maintenance (Yakubu et al., 2021). In Nigeria, smallholder farmers rear various goat breeds under traditional systems, but productivity remains low due to poor genetic improvement and management practices.

Estimating heritability of body weight and linear body measurements is a fundamental step in genetic improvement programs. Heritability provides an indication of how much of the variation observed in a trait is due to genetic rather than environmental factors (Falconer and Mackay, 2019). Understanding these genetic parameters enables breeders to make informed selection decisions for improved performance and productivity.

1.2 Statement of the Problem

The lack of accurate genetic information on local goat breeds has hindered their improvement and utilization. Most smallholder farmers rely on phenotypic selection, which is often less effective in achieving long-term genetic progress. Furthermore, limited record-keeping and inadequate breeding strategies have slowed productivity gains in goat production (Ojedapo et al., 2020). Hence, estimating heritability and other genetic parameters for growth traits is crucial for sustainable breed improvement.

1.3 Objectives of the Study

The objectives of this study are:

1. To estimate the heritability of body weight and linear body measurements in goats under smallholder farming systems.

2. To assess the relationship between body weight and linear body traits.

3. To identify the most reliable predictors of body weight among the measured traits.

1.4 Research Questions

1. What is the heritability of body weight and linear body measurements in local goat breeds?

2. Which linear body traits are most correlated with body weight?

3. How can heritability estimates guide genetic improvement among smallholder farmers?

1.5 Significance of the Study

The findings of this research will provide baseline genetic information useful for goat breeders, extension agents, and livestock policymakers. It will also enhance the design of selection programs aimed at improving growth performance in goats. This will contribute to poverty reduction, food security, and sustainable livestock production among smallholder farmers.

1.6 Scope of the Study

This study covers selected goat populations under smallholder systems. Traits such as body weight, body length, chest girth, and height at withers will be measured and analyzed using genetic models.

1.7 Definition of Terms

• Heritability: The proportion of total variation in a trait attributed to genetic factors.

• Linear Body Measurements: Physical dimensions of animals such as length, height, and girth.

• Smallholder Farming System: A low-input, family-based agricultural production system.