International Journal of Molecular Veterinary Research, 2024, Vol.14, No.5, 211-218 http://animalscipublisher.com/index.php/ijmvr 214 programs (Aboshady et al., 2021). These molecular tools enable breeders to make informed decisions, accelerating the development of disease-resistant goat populations. Figure 2 Appearance of a goat infected with caprine arthritis encephalitis virus (advanced stage) in which the animal is hitting its head against the pen wall (left picture), is displaying depressive behavior (middle picture), and has joint inflammation (right picture) (Adopted from Schultz et al., 2020) 4.3 Genomic selection and its impact on breeding programs Genomic selection further revolutionizes breeding programs by incorporating comprehensive genomic information to predict the breeding value of individuals. This method leverages genome-wide data to enhance the accuracy of selection, particularly for complex traits like disease resistance. Studies have shown that genomic selection can significantly improve resistance to various diseases, such as Haemonchus contortus infections, by identifying loci with divergent allelic frequencies under selection6. Additionally, genomic insights into disease resistance, such as those provided by RNA-seq analysis, have identified key pathways and genetic variants that distinguish resistant from susceptible genotypes (Mandal et al., 2018; Aboshady et al., 2021. The integration of genomic selection into breeding programs holds the potential to rapidly advance the genetic improvement of disease resistance in goats, offering a sustainable solution to disease management challenges (Ricci et al., 2017). In summary, the integration of traditional breeding practices with molecular and genomic tools has significantly advanced the genetic selection for disease resistance in goats. These methods provide a robust framework for developing resilient goat populations, ultimately enhancing productivity and sustainability in goat farming. 5 Case Study: The Role of Genetic Selection in Resistance to Parasites (Haemonchus contortus) 5.1 Biology and impact of Haemonchus contortus ingoats Haemonchus contortus, a gastrointestinal nematode, is a significant parasite affecting goats worldwide, leading to severe health issues and economic losses in the small ruminant industry (Babar et al., 2015). This parasite thrives in warm, humid environments, making regions like the southern United States particularly vulnerable (Estrada-Reyes et al., 2019). The infection results in clinical diseases such as anemia and reduced productivity due to blood loss and nutrient deprivation3 6. The prevalence and intensity of infection can vary based on factors such as breed, age, and environmental conditions (Mpofu et al., 2022). 5.2 Genetic selection strategies for parasite resistance Genetic selection has emerged as a promising strategy to enhance resistance to Haemonchus contortus in goats. This involves identifying and breeding individuals with genetic traits that confer resistance to the parasite (Estrada-Reyes et al., 2019; Omar et al., 2019; Tsukahara et al., 2021). Studies have identified specific genes and single nucleotide polymorphisms (SNPs) associated with resistance, such as those involved in immune response pathways. Breeding programs often utilize phenotypic indicators like fecal egg count (FEC) and packed cell volume (PCV) to select resistant individuals. Additionally, molecular tools are being developed to facilitate the identification of resistant genotypes, focusing on genes related to immunoregulatory mechanisms (Shrivastava et al., 2018; Mpofu et al., 2022). 5.3 Outcomes and implications of breeding programs for parasite resistance Breeding programs aimed at enhancing resistance to Haemonchus contortus have shown promising results. For instance, certain goat breeds, such as the Spanish and Kiko, have demonstrated lower FECs and improved
RkJQdWJsaXNoZXIy MjQ4ODYzNA==