Abstract
Glyphosate-based herbicides (GBHs) such as RoundUp® are a staple of modern crop production, and as a result, residues of their ingredients are typically found in animal feeds. GBH ingredients have repeatedly been shown to impact the male reproductive health of various animals, but at present, the impact of GBH exposures on reproductive health have not been investigated in broiler breeder roosters. This study sought to determine the effect of these exposures on roosters as well as the ability of humic acids (HA) to counteract the effect of GBH exposure. Through 18 weeks of treatment with Roundup®-added or HA-added feeds compared against a common broiler breeder mash, negative effects of Roundup® exposure were seen on testis morphology as well as sperm quality. Increased exposure to Roundup® ingredients resulted in increased vacuolation of seminiferous tubule epithelium. Exposure to Roundup® impacted assessments of sperm quality including sperm mobility, viability and count during the experimental trail. HA supplementation served as a promising adsorptive additive by improving both morphology and sperm quality during the trial. Roundup® exposure was shown to have a negative influence on broiler breeder rooster reproductive health while HA improved reproductive health. The use of HA as an absorbent additive in broiler breeder feeds shows promise in improving reproductive efficiency in broiler breeders.