Regression Models and Correlation Analysis for Predicting Body Weight of Female Ettawa Grade Goat using its Body Measurements

Akhmad Dakhlan,Angga Saputra,Sulastri Sulastri,Muhammad Dima Iqbal Hamdani

doi:10.17582/journal.aavs/2020/8.11.1142.1146

Abstract

Abstract | This research aimed to analyse the correlation and regression model and also to find the best regression model for predicting body weight of female Ettawa Grade (EG) goat using its body measurements. This research used 41 female EG goat aged 3–4 years. The method used was a survey with data collection by census, all female EG goats aged 3-4 years in research location were collected. Body weight (BW ) data were regressed and correlated to body measurements (body length = BL, chest girth = CG and shoulder height = SH) using linear and multiple linear regression using R program. Pearson correlation was used to calculate correlation coefficient (r). Coefficient of determination (R2), adjusted R2, residual standard error (RSE), Akaike information criterion (AIC), Bayesian information criterion (BIC) and step wise regression analysis were used to analyse and find the best and parsimonious model for predicting BW. The results showed that body measurements had positive correlation with the BW, which CG had the highest correlation (0.838); followed by BL (0.744) and SH (0.543). Results also showed that CG was the best predictor for BW compared to BL and SH if using single predictor. Combination of CG and BL resulted in the fittest prediction of BW with model regression BW = -67.86 + 0.87*CG + 0.51*BL with the highest correlation coefficient (r = 0.87), R2 (0.76), adjusted R2 (0.75) and the lowest RSE (2.795), AIC (205.51) and BIC (212.36). The results of this study suggested that CG and BL could be used as predictor for body weight and as indicator of indirect selection to improve genetic merit in body weight of EG goat. Keywords | Ettawa grade goat, Correlation and regression model analysis, Body weight, Body Measurements

Highlights

Goat raising is one of the common livestock business carried out either as a side job or as a main job by smallholder farmers
Statistics and distribution of body weight and body measurements including body length, chest girth, and shoulder height can be seen in Table 1 and Figure 1
The method used in this study was a survey and data collection were done by census, all female Ettawa Grade (EG) goats aged 3-4 years in the location were collected

Summary

Introduction

Goat raising is one of the common livestock business carried out either as a side job or as a main job by smallholder farmers. This business of goat keep on rising year after year. Based on statistics from the Directorate General of Animal Husbandry and Health of Republic Indonesia (2018), the population of goats in Lampung Province has increased from 1,326,103 heads in 2016 to 1,386,009 heads in 2018. While Pesawaran Regency is a district in the province of Lampung which has a very large population of goats. Population of goats in Pesawaran Regency reached 44,150 heads, most of which are Ettawa Grade (EG) goats (Department of Animal Husbandry and Animal Health of Lampung Province, 2017)

Objectives

Methods

Results

Discussion

Conclusion