Accuracy and Response to Selection of Developed Breeding Objectives and Selection Indexes for Dairy Goats in Intensive Production Systems

Abstract

Enhancing milk production and overall performance of dairy goats through well-defined breeding objectives and selection indexes can significantly contribute to improved food security and the standard of living among dairy goat raisers. This study aimed to develop breeding objectives and selection criteria with estimated response due to selection for dairy goats in intensive production systems. Data were gathered through formal interviews, farm visits and actual animal data and were analyzed using descriptive statistics, the Wilcoxon rank-sum test, and the Restricted Maximum Likelihood (REML) procedure. Heritability estimates for most traits ranged from 0.21 to 0.51, indicating moderate to high genetic potential for improvement, except for lactation length (0.08) and kidding interval (0.07), which were low. Four breeding objectives were identified: three based on actual traits directly affecting farm profit, and one incorporating potential traits not yet widely utilized but with strong revenue-generating potential. Five selection indexes (SI) were developed using actual and potential traits from Saanen and Anglo-Nubian goats raised under intensive systems. Among these, Selection Index V_Php = 130.86MP + 3.89LL – 3.34AFK – 3.98KI + 0.41%MPROT + 0.28%MFAT + 0.11SCS + 1.96PROTY + 3.76FATY showed the highest selection accuracy of 0.996. The predicted genetic gains per generation included increases of 73.41 L/doe/lactation (MP), 161.45 days (LL), 0.85% (%MPROT), 0.65% (%MFAT), 0.30 cells/mL (SCS), 8.84 kg (PROTY), and 19.18 kg (FATY), while decreases of –7.11 and –146.06 days were observed for AFK and KI, respectively. Given the increasing demand for high-quality milk and the potential for differentiated pricing based on quality, Selection Index VPhp is recommended to maximize productivity and farm profitability.