the effect of d-aspartic acid on sperm quality of broiler breeder roosters

the aim of this study was to evaluate the effect of d-aspartic acid on semen characteristics of ross 308 roosters. thirty 60-wk-old ross 308 roosters were randomly assigned into 6 groups and individually caged. all groups fed the same basal diet and orally administered with different levels of d-aspartic acid: 0(a-0), 40 (a-40), 80 (a-80), 120 (a-120), 160 (a-160), and 200 (a-200) mg/kg bw per day as a single capsulated dose. seminal characteristics including ejaculate volume, motility, progressive motility, sperm concentration, abnormality, viability and hypo osmotic swimming test were studied following two weeks of adaptation period, and continued for up to six weeks. results of the experiment revealed that d-aspartic acid positively affected rooster sperm parameters with  all parameters being significantly improved with increasing the level of d-aspartic acid except for abnormality percentage that was not significantly affected by the treatment (p>0.05). taking all parameters into account, a-200 treatment exhibited the most optimal response in sperm parameters amongst all treatments. however, further studies including fertility and hatchability tests are needed to ascertain these results.