Genetic Variants of Kappa Casein in Tunisian Native Goats

Introduction: The nutritional qualities of goat milk are affected by both environmental factors and genetic variations within casein genes. This study aims to assess the genetic polymorphism of the Kappa Casein (CSN3) gene in a goat population from Southeast Tunisia. This population is known for its exceptional resilience to harsh conditions, including limited feed and water scarcity. Materials and methods: The PCR-RFLP was used to analyze the genomic DNA of 48 blood samples belonging to unrelated individuals from the Tunisian goat population for the CSN3 casein gene variability, at positions 166 and 448 bp. Results: The analysis revealed a high prevalence of the GG genotype at position 166 and the TT genotype at position 448. Interestingly, the frequency of alleles from group I (A, B, E, F, H, J, and K) in the studied goat population of the present work is quite high; the alleles belonging to this group were known as associated with higher milk protein content. These findings suggest that these goats possess genetic traits that may improve milk protein production, which is crucial for ensuring the survival and well-being of their offspring. Conclusion: The prevalence of alleles within the CSN3 gene, which is associated with high milk protein content, is a notable finding in this study. These genetic characteristics help mitigate the negative impacts of restricted feed and water on the growth and development of the offspring. The present study displays one of several adaptative features of this goat population which may highlight also the importance of these traits for sustainable goat breeding and milk quality improvement.