Effects of castration on growth performance and pineal gland function of Hu sheep

Castration, as a veterinary procedure, can enhance carcass quality, significantly influencing the development of male animals. This study aimed to assess the effect of castration on growth performance and pineal gland function in Hu sheep lambs. Six healthy male Hu sheep were selected and randomly assigned to two groups. Three lambs underwent castration at 3 days of age (CAS), whereas the control group (CK) remained uncastrated. All lambs were housed indoors. Results indicated that the CAS group's body weight was significantly lower than that of the CK group (p < 0.05). However, the feed conversion ratio was significantly higher in the CAS group than in the CK group (p < 0.05). Serum testosterone, growth hormone and melatonin levels in the CK group were significantly elevated compared with those in the CAS group (p < 0.05). Pineal glands were harvested for RNA sequencing, which revealed 537 differentially expressed genes in the CAS group compared with CK, comprising 174 upregulated and 363 downregulated genes. The Kyoto Encyclopedia of Genes and Genomes pathway analysis highlighted significant enrichment in the neural ligand-receptor interactions, and autoimmune thyroid disease. The results demonstrated that castration could significantly influence the growth and development of lambs and affect the function of the pineal gland.