This study explores offspring sex ratio alterations in rabbit and sheep populations, investigating genetic and environmental factors. It introduces a novel analytical approach (MUTj model) to detect new mutations affecting sex ratios. Results show significant variations in sex ratios over time, with strong evidence for seasonal and inbreeding effects. The analysis suggests the presence of new mutations primarily in Ripollesa sheep, originating several generations from the founders. This approach provides a valuable tool for mutation analysis within pedigree files, enhancing our understanding of sex ratio dynamics.
