Today, the studies are limited on roles of insulin-like peptide 3 (INSL3), insulin-like peptide 7 (INSL7), and relaxin family peptide receptor 1 (RXFP1) which are synthesized by the testis. It is aimed to investigate the levels of the sex hormone as testosterone and the family of insulin-like proteins (relaxin family peptides), which are important in the puberty transition, in the testicular and liver tissues of male offspring born to female rats fed a zinc-deficient diet during the pregnancy, and in the changes in lipid peroxidation markers. The study was performed on 40 male offspring. In Group I: Control group, both male offspring and mothers were fed with standard rat chow. In Group II: Zinc deficient diet, both male offspring and mothers were fed a zinc-deficient diet (2.8 mg/kg zinc). In Group III: Normal diet, male offspring fed standard rat chow for 45 days (66th day) after being separated from their mothers with a maternal zinc-deficient diet. In Group IV: Zinc-supplemented diet, offspring fed with zinc supplemented (5 mg/kg/day intraperitoneal zinc sulfate, i.p.) in addition to standard rat chow after being separated from their mothers with maternal zinc deficiency until the termination of the study (66th day). Our study suggests that zinc-supplemented diets play an important role in the changes in INSL3, INSL7, RXFP1, and testosterone levels during spermatogenesis. INSL7, INSL3, and RXFP1 levels were higher in zinc-supplemented group than the zinc-deficient diet group. Liver levels of INSL3, INSL7, and MDA were significantly different in zinc-deficiency diet group than zinc-supplemented group.