Spermatogonial stem cells from lamb testes were studied to see how different concentrations of fetal bovine serum and sucrose affect their viability before and after freezing. The cells were treated with varying levels of FBS and sucrose, then tested for viability. Results showed that using FBS at a lower concentration (10) led to higher cell viability compared to a higher concentration (20). Increasing sucrose levels did not improve cell viability. The study concluded that a freezing solution with dimethyl sulfoxide, FBS (10), and sucrose (0.07 M) is best for preserving lamb spermatogonial cells.