Authors
1
Animal Science Research Institute of Iran (ASRI), Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran.
2
Assistant Professor, Department of Animal and Poultry Physiology, Faculty of Animal Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
3
PhD graduated of Animal Physiology, Department of Animal Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
4
Assistant Professor of Animal Science Research Institute of Iran (ASRI), Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
Abstract
Abstract
Background and objectives: Goat is one of the first animals that was domesticated by humans, and according to the available evidence, the origin of domestication of this animal is considered to be in the country of Iran. Considering the hot and dry climate developing in Iran, the reproduction management of this valuable livestock can improve livestock production in the country. One of the technologies that help reproductive management is artificial insemination. In this method, superior genes of animals with high genetic value are rapidly developed in the herd. In the first stage, for successful artificial insemination, suitable sperm is needed for insemination. One of the ways to preserve sperm is its long-term preservation by freezing. Osmotic, chemical, and mechanical stresses during freezing processes are the most sources that include ultrastructural, biochemical, and functional changes that can reduce sperm fertility. Peroxidation of membrane lipids is one of the most important chemical factors in freezing-thawing process. L-carnithine is needed for the beta oxidation of long-chain fatty acids in the mitochondria, and by providing the energy required by the sperm, it has a positive effect on the metabolism, maturation and motility of the sperm. Therefore, the purpose of this research was to investigate the effect of different levels of L-carnitine during the freezing process to maintain the quality of goat semen.
Materials and methods: In this experiment, 5 Saanen goat were used. After semen collection and primary evaluation, semen samples were pooled in order to eliminate individual differences. Semen was added to the extenders containing 0, 1, 2, 5 and 10 mM L-carnitine and were frozen. Microscopic evaluation of spermatozoa was done after thawing and quality parameters including motility characteristics, lipid peroxidation, membrane functionality, abnormal morphology, mitochondrial activity, acrosome integrity, viability, apoptotic-like changes and DNA fragmentation were assessed.
Results: Samples supplemented with 5 mM L-carnitine showed higher (P ≤ 0.05) total motility, progressive motility, membrane functionality, mitochondrial activity, acrosome integrity, viability, and lower (P ≤ 0.05) apoptotic-like changes, DNA fragmentation and lipid peroxidation. Addition of L-carnitine to the cryopreservation extender had no effect (P > 0.05) on velocity parameters and abnormal morphology. The data obtained from testing different levels of L-carnitine in the form of a completely randomized design were analyzed using Proc GLM by SAS statistical software and the significance level was considered P<0.05. Comparison of means was done using Tukey's method.
Conclusion: The supplementation of buck’s freezing medium with L-carnitine significantly preserves the quality of buck sperm after cryopreservation process.
Keywords: L-carnithine, Sperm, Freezing, Goat
Keywords
Main Subjects
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