The effect of dietary supplementation of coenzyme Q10 on reproductive variables of cadmium‐challenged male Japanese quails (Coturnix Japonica)

BACKGROUND: In recent decades, efforts to produce more efficient poultry products have increased due to its high demand. Meanwhile, some stressors have a negative impact on poultry efficiency and reproduction. Cadmium (Cd) is a toxic heavy metal with a high potential for inducing reactive oxygen species. On the other hand, coenzyme Q10 (CoQ10), with antioxidant properties, exerts a free radical‐neutralizing effect on biological systems under stressful conditions. OBJECTIVES: This study aimed to determine the effect of dietary CoQ10 supplementation on reproductive variables of Cd‐challenged male quails. METHODS: Two hundred and sixteen 42‐day‐old Japanese quails with a male‐to‐female ratio of 1:3 were randomly divided into three experimental groups (n = 72) and fed by experimental diets from 9 to 13 weeks of age (woa). Treatments included a negative control (NC): feeding basal diet; positive control (PC): feeding basal diet and Cd administration (1 mg per 100 g body weight at 10 and 11 woa); and CdQ10: dietary supplementation of CoQ10 (900 mg per kg diet) and Cd administration. At 10 and 13 woa, liver and testis, cloacal gland index, sera concentration of malondialdehyde (MDA) and testosterone, total antioxidant capacity (TAC), alanine aminotransferase (ALT), testicular histology, mRNA abundance of Hsp70 and fatty acid profile of testis, as well as hatchability and fertility, were measured. RESULTS: Liver and testis weights, cloacal gland index, serum concentration of testosterone, ALT, MDA, TAC, mRNA abundance of HSP70, hatchability, and fertility were not affected by the treatments. However, Cd administration decreased seminiferous tubule diameter and seminiferous epithelium thickness (SET) in the PC group compared to the NC group (p < 0.05). The proportion of saturated fatty acids (SFA) in testis tissue was increased, and the proportion of PUFA and n‐3 to n‐6 PUFA ratio was decreased in the PC group compared to the NC group (p < 0.05). In addition, CoQ10 supplementation ameliorated the effect of Cd on decreasing SFA and increasing n‐3 to n‐6 PUFA ratio proportions. CONCLUSIONS: In conclusion, Cd exerts several adverse effects on reproductive‐associated variables; some, but not all, of them are mitigated by CoQ10 supplementation.