Effect of Dietaryn‐3Source on Rabbit Male Reproduction

Abstract

In the last two decades, the human sperm count linearly decreased in Western countries. Health problems, lifestyle, pollutants, and dietary behaviours are considered as the main risk factors, and the unbalance of dietary n‐6/n‐3 fatty acids is one of the most relevant. The aim of the present research is to study the effect of different dietary sources of n‐3 polyunsaturated fatty acids (PUFA) on reproductive traits using rabbit buck as the animal model. Fifteen rabbit bucks were assigned to three experimental groups: the control group, the FLAX group fed 10% extruded flaxseed, and the FISH group fed 3.5% fish oil for 110 days (50-day adaptation and 60-day experimental periods). Semen samples were collected weekly, whereas blood was collected every two weeks for the analytical determination of semen traits, oxidative status, fatty acid profiles, isoprostanes, neuroprostanes, and the immunocytochemistry of docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) acid. At the end of the trial, the rabbits were killed and the testes were removed and stored for the analysis of fatty acid profile and immunocytochemistry. Results showed that dietary administration of n‐3 PUFA improved the track speed of the sperm and increased the n‐3 long-chain PUFA mainly confined in the sperm tail. Seminal plasma increased the thiobarbituric reactive substances (TBARs) by three times in the groups fed supplemental n‐3, whereas the F2-isoprotanes (F2-IsoPs) and F4-neuroprostanes (F4-NeuroPs) were lower and higher, respectively, in both supplemented groups than in the control. The testes and sperm showed a higher DHA and EPA distribution in rabbits from the n‐3 supplemented groups compared with the control. In conclusion, supplemental dietary n‐3 PUFA improved sperm motion traits and resulted in an enrichment of membrane fatty acid in the sperm and testes of the rabbits. However, such an increased amount of PUFA negatively affected the sperm oxidative status, which was mainly correlated with the generation of F4-NeuroPs with respect to F2-IsoPs. Accordingly, the latter cannot be considered a good marker of oxidation when diets rich in n‐3 PUFA are provided.

Relevance of Fatty Acids to Sperm Maturation and Quality

“…Studies on a rabbit model showed that the dietary supplementation of n-3 PUFAs and antioxidants [99,100] largely altered the sperm membrane and improved the motility rate and the sperm speed. Moreover, rabbits treated with a diet supplemented with 10% of extruded flaxseed or 3.5% of fish oil showed a higher distribution of DHA and EPA in the testes and sperm membranes compared to controls [101].…”

Tissue Antioxidant Status and Lipid Peroxidation Are Related to Dietary Intake of n-3 Polyunsaturated Acids: A Rabbit Model

“…A higher LCPn-3 content was recorded in the liver and brain only when fish oil was administered, whereas the testis did not show any significant differences in LCPn-3 with any dietary plan. This trend was probably due to the specific cell membrane composition of the rabbit testis, where LCPn-6 are the main FAs (22:5n-6 was the primary one [ 1 , 22 ]). Furthermore, highly productive rabbit strains show greater conversion of LA into ARA than ALA into LCPn-3 [ 59 ].…”

“…Castellini et al [ 22 ] demonstrated that the dietary administration of n-3 PUFA, both as LCPs (fish oil) or precursor (flaxseed), determined an enrichment in such fatty acids (FAs) in rabbit testes. Furthermore, the same authors reported that, although the liver is the main metabolic centre for LCP synthesis, reproductive tissues (i.e., ovaries) have a noticeable role in LCP generation [ 23 ].…”

Impact of Algerian date palm pollen aqueous extract on epididymal and ejaculated rabbit sperm motility duringin vitroincubation

“…During sperm storage, the membrane lipid peroxidation caused by an excess level of ROS, negatively affect negatively sperm lipids stability, proteins, nucleic acids and also sugars (Bansal and Bilaspuri 2011;Kim et al 2011). Rabbit sperm is particularly rich in long chain PUFA (Castellini et al 2019;Rodr ıguez et al 2019) and consequently shows a higher susceptibility to the peroxidation.…”