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

CHAPTER ONE

1.1 Background to the Study

Goat production plays a crucial role in the livelihood of rural households in sub-Saharan Africa. Goats are valued for their adaptability, low maintenance requirements, and ability to thrive under harsh environmental conditions (Devendra, 2012). In Nigeria, smallholder farmers rear goats primarily for meat, milk, and income generation.
Genetic improvement of goats through selection requires an understanding of heritability, which measures the proportion of variation in a trait due to genetic factors (Falconer & Mackay, 1996). Body weight and linear body measurements are important indicators of growth performance and are often used to predict body size and productivity (Yakubu et al., 2010). Estimating heritability helps breeders identify traits that can respond effectively to selection.

1.2 Statement of the Problem

Despite their economic importance, goats under smallholder systems have not benefited much from structured breeding programs. Most breeding decisions are based on physical appearance rather than genetic merit. Lack of data on heritability of key growth traits limits the potential for genetic improvement (Ogah, 2011). This study addresses this gap by estimating heritability values for body weight and linear measurements.

1.3 Objectives of the Study

The objectives of this study are to:

1. Determine the heritability of body weight in goats under smallholder systems.

2. Estimate heritability for selected linear body measurements.

3. Identify relationships between body measurements and growth performance.

1.4 Research Questions

1. What is the heritability estimate of body weight in goats under smallholder systems?

2. How are linear body traits related to growth performance?

3. Which traits are most suitable for selection in breeding programs?

1.5 Significance of the Study

The findings will provide baseline information for genetic improvement of goats through selection. Understanding heritability values will help breeders focus on traits that can yield sustainable productivity gains, thereby improving household income and food security.

1.6 Scope and Limitation of the Study

The study will be conducted among smallholder goat farmers. Limitations may include incomplete performance records and varying environmental conditions that affect accuracy.

1.7 Definition of Terms

• Heritability: The proportion of phenotypic variation attributed to genetic factors.

• Linear Body Measurements: Measurements that describe animal body conformation such as height, length, and girth.

• Smallholder Farming: A low-input farming system practiced by small-scale farmers.

References
Devendra, C. (2012) Goat production and climate change: Adaptation and resilience. Animal Frontiers, 2(2), 60–65.
Falconer, D. S. and Mackay, T. F. C. (1996) Introduction to Quantitative Genetics. Longman.
Ogah, D. M. (2011) Estimation of genetic parameters for body measurements in Nigerian goats. Livestock Research for Rural Development, 23(5), 112.
Yakubu, A., Salako, A. E. and Imumorin, I. G. (2010) Multivariate analysis of morphostructural characteristics in Nigerian goats. International Journal of Morphology, 28(3), 879–886.