Effect of different dietary zinc sources on the semen quality, testicular histology and sex hormone concentration in broiler breeder roosters

Abstract

The aim of the present study was to evaluate the effect of different dietary zinc sources (ZnSO4, Zinc-amino acid and Zn5(OH)2Cl2H2O), on hormone levels, testicular histology and sperm quality in broiler breeder roosters. Twenty, 54-week-old broiler breeder roosters (Ross 308) were reared in individual cages. Dietary treatments were T1: a basal diet without any addition of zinc (0 Zn) (Control), T2: control diet supplemented with 110 mg Zn (sulphate)/kg, T3: control diet supplemented with 110 mg Zn (organic)/kg and T4: control diet supplemented with 110 mg Zn (hydroxide)/kg. The traits measured included blood serum IGF- and testosterone, motility, concentration, viability, and membrane integrity of sperm and testicular histology. The results indicated that, significant differences between the experimental treatments in terms of serum levels of IGF and testosterone in the 32nd and 45th weeks (p < .05). The highest levels of IGF and testosterone were observed in the organic zinc treatment (T3). The results of testicular histology, fertility and sperm quality showed that there was a significant difference between experimental treatments in terms of diameter of seminiferous tubules, spermatogonia and the motility, integrity, morphology, viability and concentration of sperm (p < .05). The highest levels of these traits were observed in the organic zinc treatment (T3) and the lowest in the control treatment. In conclusion, organic zinc compared to other forms of zinc supplement can be used as an efficient feed additive for improving the fertility status of the flock of broiler breeder roosters. HIGHLIGHTS Mineral resources are used in various ways in poultry feed. Zinc is one of the most important mineral sources in poultry nutrition. Organic zinc has been shown to perform better than other sources of zinc.