The aquaculture sector is facing a lack of natural resources and new challenges (decline of fishmeal, lack of water in extensive production, replacement of non-renewable energy sources, reducing of ecological footprint, monitoring of fish meat quality, reduction of pathogens, etc.). Common carp is one of the most cultured freshwater species in Europe and worldwide as well. Nowadays, it is difficult to predict the success of common carp propagation. In some cases, a variable or low individual fertilization capacity in breeders is observed. Alternative feed additives (such as algae, vitamins etc.) can increase gamete quality and stabilize the propagation success.
The aim of our study was to investigate sperm quality in common carp male broodstock following a 1% algae supplemented feeding regime (Chlorella spp , Scenedesmus spp , Coelastrella spp , Acutodesmus spp). The individuals were fed with experimental and control ( carp broodstock feed, Haltáp Ltd., Szarvas, Hungary) feed in two different earthen ponds for one month prior to the spawning season. Six-six male was sampled at three different period (water temperature: 16, 20.5 and 22 °C ) from both experimental and control group during the spawning season. Common sperm quality parameters (total volume, volume per body weight, motility parameters, osmolality , pH, concentration, total sperm production and total sperm production per body weight), glucose and ion content (glucose, fructose, sodium, potassium, calcium, magnesium), and fatty acid content of sperm (total, saturated, unsaturated, poly unsaturated, omega-3 and -6 fatty acids) were comprehensively analysed in both groups at each sampling period.
Significantly lower result was recorded only in pH and curvilinear velocity (kinetic sperm parameter) by the experimental group in comparison with the control. No significant difference was observed between the two groups in the glucose, ion and fatty acid content. The water temperature (sampling period) had significant effect on various common sperm quality parameters, glucose and ion content. In contrast, fatty acid content of sperm was not affected by the water temperature. This comprehensive sperm quality study highlighted the future opportunity of algae supplementation in the feeding regime of common carp male broodstock prior to the spawning season. However, the water temperature can affect notably several quality parameters.
The study was supported by the project 2020-1.1.2-PIACI-KFI-2020-00161 and the project “Support for talent management programmes in colleges” (NTP-SZKOLL-23-0043), commissioned by the Ministry of Culture and Innovation and funded by the National Cultural Fund of Hungary . Our work was also co-financed by the project 2022-1.2.6-TÉT-IPARI-TR-2022-00002 within the framework of the National Research, Development and Innovation Fund announced by the Ministry of Culture and Innovation. The experiments were also funded by the ÚNKP-22-3 New National Excellence Program of the Ministry of Culture and Innovation from the source of the National Research, Development and Innovation Fund.