<![CDATA[Goat reproductive efficiency is largely determined by fertility, which influences litter size and overall productivity. The Bone Morphogenetic Protein Receptor 1B (BMPR-1B) gene is a major candidate gene associated with prolificacy in goats. This study aimed to identify single nucleotide polymorphisms (SNPs) in the BMPR-1B gene and evaluate their association with reproductive performance in Saanen goats maintained at the Indonesian Saanen Dairy Goat Breeding Center (BBPTU-HPT Baturraden). A total of 120 Saanen does with at least two kidding records were selected using purposive sampling. Reproductive traits included gestation length, litter size, birth weight, and weaning weight. Genomic DNA was amplified by PCR using primers targeting a 240 bp fragment of the BMPR-1B gene, followed by DNA sequencing for SNP identification. Genotype and allele frequencies were estimated, Hardy-Weinberg equilibrium was tested using the Chi-square test, and associations between genotypes and reproductive traits were analyzed using one-way ANOVA. PCR amplification successfully produced the expected 240 bp fragment in all samples. Sequence analysis identified four SNPs, c.29T>C, c.38A>G, c.72T>C, and c.83C>T, which were consistently detected in the population. The BMPR-1B locus deviated from Hardy-Weinberg equilibrium. These nucleotide substitutions caused amino acid changes, reducing the predicted protein length from 153 to 120 amino acids and the molecular weight from 13,051.33 to 10,325.36 Da. The proportions of Ala, Cys, Gly, and Thr residues also decreased. Only heterozygous genotypes (TC, AG, and CT) were detected, with an average litter size of 1.0 ± 0.52 kids and a twinning rate of 28.7%. No significant associations were found between BMPR-1B genotypes and gestation length, litter size, birth weight, or weaning weight. These findings indicate that the BMPR-1B gene was monomorphic in this Saanen goat population, and the detected heterozygous SNPs were not associated with reproductive performance or increased litter size.]]>
