A review of antioxidant strategies to improve reproduction in aging male broiler breeders

Abstract

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Keywords: Fertility; Oxidative stress; Reproductive senescence; Roosters; Sperm.

Fig. 1

A high proportion of polyunsaturated fatty acids (PUFAs) in the sperm plasma membrane, the main PUFA in the rooster semen (22:4n-6, docosatetraenoic acid) being most susceptible to peroxidation, plus age-related reductions in seminal antioxidant capacity, make the plasma membrane of avian sperm susceptible to lipoperoxidation once exposed to reactive oxygen species

Fig. 2

Effects of age on roosters’ fertility potential. Age-related reductions in sperm quality, hormonal balance, and testicular histology. LH, luteinizing hormone; FSH, follicle-stimulating hormone

Fig. 3

Antioxidants improve the reproduction potential of aging roosters; they are ROS “scavengers “ that promote oxidant/antioxidant balance, thereby improving sperm quality, reproductive performance, and fertility. ROS, reactive oxygen species

Fig. 4

Classification of enzymatic and non-enzymatic antioxidants [155, 156]. SOD, superoxide dismutase; CAT, catalase; GPX, glutathione peroxidase; GR, glutathione reductase; G6DPH, glucose-6-phosphate dehydrogenase