Germinated Wheat as a Potential Natural Source of Antioxidants to Improve Sperm Quality: A Canary Trial

The present study was carried out to determine the effects of germinated wheat on some spermatological parameters (motility, abnormal spermatozoa, hypo-osmotic swelling test (HOST), and viability) in male Gloster canaries. For this purpose, the canaries were divided into two groups, each consisting of six canaries, one control (C), and the other experimental group (GW). Group C was fed commercial canary feed. The GW group was fed germinated wheat (germinated for 5 days) and commercial canary feed. The canaries were kept individually in four-storey cages (60 cm × 50 cm × 40 cm). In this study, which lasted 2 months, feed/water was provided ad libitum and lighting was applied daily for 16 h (turned on at 05:30 and turned off at 21:30). At the end of the experiment, the sperm samples obtained from the canaries were examined in terms of the aforementioned parameters. The effects of germination time × concentration, germination time, and solvent rate on DPPH radical scavenging activity and phenolic compounds in germinated wheat were significant (p < 0.001). The highest DPPH (2, 2-diphenyl-1-picryl hydrazyl) radical scavenging activity (86.06%) and phenolic content (316.25 mg GAE/g) in germinated wheats were obtained on the fifth day (90% solvent rate) of germination. It was determined that germinated wheat did not significantly affect abnormal sperm and HOST values (p > 0.05). However, it significantly affected the motility and viable sperm rates (p < 0.05). As a result, it is thought that germinated wheat can be used as a natural antioxidant source to increase motility and vitality in canary sperm.

Biophysical Determinants and Constraints on Sperm Swimming Velocity

Over the last 50 years, sperm competition has become increasingly recognised as a potent evolutionary force shaping male ejaculate traits. One such trait is sperm swimming speed, with faster sperm associated with increased fertilisation success in some species. Consequently, sperm are often thought to have evolved to be longer in order to facilitate faster movement. However, despite the intrinsic appeal of this argument, sperm operate in a different biophysical environment than we are used to, and instead increasing length may not necessarily be associated with higher velocity. Here, we test four predictive models (ConstantPower Density, Constant Speed, Constant Power Transfer, Constant Force) of the relationship between sperm length and speed. We collated published data on sperm morphology and velocity from 141 animal species, tested for structural clustering of sperm morphology and then compared the model predictions across all morphologically similar sperm clusters. Within four of five morphological clusters of sperm, we did not find a significant positive relationship between total sperm length and velocity. Instead, in four morphological sperm clusters we found evidence for the Constant Speed model, which predicts that power output is determined by the flagellum and so is proportional to flagellum length. Our results show the relationship between sperm morphology (size, width) and swimming speed is complex and that traditional models do not capture the biophysical interactions involved. Future work therefore needs to incorporate not only a better understanding of how sperm operate in the microfluid environment, but also the importance of fertilising environment, i.e., internal and external fertilisers. The microenvironment in which sperm operate is of critical importance in shaping the relationship between sperm length and form and sperm swimming speed.