This experiment was conducted to determine the effects of castration on some meta¬bolic alterations concerning proteins, lipids and minerals metabolism in both immature and mature rabbits. Twenty male New Zealand White rabbits (10 immature and 10 ma¬ture) were used. Blood samples were collected from the immature and mature intact animals (control non castrated). Moreover, the castrated animal groups (immature and mature) were sampled at 2, 4, 6 and 8 weeks after castration. The obtained results re¬vealed that, castration caused a significant decrease in serum total protein, albumin, a,-globulins and a2-globulins concentrations. Meanwhile, -/-globulins level was decrea¬sed temporarily at 2 weeks after castration in mature rabbits. 3-globulins level revea¬led non significant decrease at 2 weeks after castration in immature rabbits followed by a non significant increase. In mature rabbits (3-globulins level non significantly in¬creased. A significant decrease in serum total nucleic acid concentrations was obser¬ved after castration throughout the experimental periods, whereas the value of serum uric acid level markedly increased after castration. Serum lipids concentrations (total lipids, total cholesterol, phospholipids and non esterified fatty acids) were increased after castration. The value of serum trace elements including copper, iron, zinc and manganese concentrations showed a significant decrease after castration. The de¬crease in serum copper and zinc levels were markedly observed in mature castrated rabbits. Also, serum sodium and potassium concentrations were decreased after ca¬stration. Testosterone propionate administration in mature castrated rabbits restored most of the investigated serum blood parameters to the levels of intact non castrated mature rabbit.
It could be concluded that castration (deficiency of testosterone) induced marked decrease in protein synthesis and increased protein degradation, but serum lipids mar¬kedly elevated after castration in both immature and mature animals. Also, castration caused a marked decrease in some serum minerals and trace elements.