Effect of ostrich egg lipoproteins and hen egg yolk on the quality of dog sperm during liquid storage at 5°C

The objective of this study was a comparative analysis of the impact of the addition of lipoproteins from ostrich egg yolk (LPFo) and hen egg yolk (HEY) to a Tris-citric acid-fructose (TCF) extender on the quality of dog sperm preserved at 5°C for 7 days. The sperm-rich fraction of the ejaculate was manually collected and extended using the following extenders: control (TCF), TCF+ 5% addition of LPFo (TCF-LPFo) and TCF+ 20% of addition HEY (TCF-HEY). The analysis of quality included: sperm motility parameters (TMOT, PMOT, VAP, VSL, VCL, ALH, BCF, STR, LIN), normal apical ridge acrosome (NAR), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), and ATP content. The addition of LPFo and HEY to the TCF extender had a beneficial effect on all quality parameters of the stored sperm compared with the TCF extender. However, the analysis of sperm motility parameters revealed differences (P≤0.05) between TCF-LPFo and TCF-HEY extenders as affected by storage day. Semen extended in TCF-LPFo was characterized by lower values of TMOT and VAP on Day 5 and by lower values of TMOT and VCL on Day 7, compared to that extended in TCF-HEY. The analysis of PMOT, VSL, ALH, BCF, STR, LIN, PMI, MMP and ATP content showed no differences (P≥0.05) between TCF-LPFo and TCF-HEY extenders. The results suggest that TCF extender supplementation with LPFo or HEY improves the quality of dog sperm stored at 5°C. Both LPFo and HEY protect motility, membrane integrity and can contribute to the improvement of the energy status of stored dog sperm. LPFo can be alternatively used instead of HEY for dog semen preservation in the liquid state.