Palm Kernel Meal Protein Hydrolysates Enhance Post-Thawed Boar Sperm Quality

Abstract

Boar sperm is sensitive to particular conditions during cryopreservation, resulting in an extreme reduction in fertilizing ability due to damage to the sperm membranes. PKMPH contains bioactive peptides that have antioxidant and antimicrobial activities. There is no information on the use of palm-kernel-meal-derived bioactive peptides for boar semen cryopreservation. This study aimed to examine the effects of bioactive peptides from PKMPH on post-thawed boar sperm quality. Boar semen ejaculates (n = 17) were collected and divided into six equal aliquots based on PKMPH concentrations (0, 1.25, 2.5, 5, 10, and 15 µg/mL) in a freezing extender. Semen samples were processed and cryopreserved using the liquid nitrogen vapor method. Thereafter, the frozen semen samples were thawed at 50 °C for 12 s and evaluated for sperm motility using a computer-assisted sperm analyzer and for sperm viability, acrosome integrity, mitochondrial function, and lipid peroxidation by measuring the level of malondialdehyde (MDA). The results demonstrate that the supplementation of PKMPH with 2.5 µg/mL afforded superior post-thawed sperm qualities, such as increased total motility, viability, acrosome integrity, and mitochondrial function by 10.7%, 12.3%, 18.3%, and 12.7%, respectively, when compared to the control group. PKMPH at a concentration of 2.5 µg/mL showed the lowest level of MDA (40.6 ± 2.0 µMol/L) compared to the other groups. In conclusion, adding PKMPH peptides at 2.5 µg/mL to the freezing extender reduced the oxidative damage associated with cryopreservation and resulted in higher post-thawed sperm quality.

Camellia oil with its rich in fatty acids enhances post-thawed boar sperm quality

“…Progressive motility (PMOT) has been interpreted as the presence of a VCL ≥ 48 µm/s and a VSL < 10 µm/s. The total motility (MOT) is the summation of sperm motility subpopulations that were determined by VCL thresholds, including local motility (VCL ≥ 24 and < 48 µm/s), slow motility (VCL ≥ 48 and < 80 µm/s), and fast motility (VCL ≥ 80 µm/s) [ 16 ].…”

“…For the colorimetric assay, a 2 mM MDA standard was prepared and serially diluted for the standard curve. The levels of MDA were calculated from the MDA standard curve and expressed as µmol/L [ 16 ].…”

“…It has been reported earlier that those fatty acids from various sources, such as DHA from fish oil [ 11 – 13 ], DHA from different egg yolks, and olive oil, [ 14 ] influence fatty acids on the sperm plasma membrane and consequently improve post-thawed boar semen quality [ 15 ]. Besides supplementation of fatty acid into freezing extender, palm kernel meal protein hydrolysate with its bioactive peptides [ 16 , 17 ], curcumin [ 18 ], and resveratrol [ 19 ] have also been applied to improve frozen boar semen quality, such as total motility, progressive motility and viability as well as minimize lipid peroxidation.…”

Post-Thaw Storage Temperature Influenced Boar Sperm Quality and Lifespan through Apoptosis and Lipid Peroxidation

“…Another big challenge to deal with is the oxidative stress (OS) induced by the overproduction of reactive oxygen species (ROS) during the freezing and thawing process. Chemicals (myoinositol [ 11 ], dithiothreitol and glutathione [ 12 ], and quercetin [ 13 ]) or compounds (palm kernel meal protein hydrolysates [ 14 ], natural honey [ 15 ], and lipoproteins [ 16 ]) with antioxidant properties have been added to freezing or thawing extender to protect against OS-induced damages in sperm quality and functionality. The supplementation of antioxidants showed positive effects on post-thaw sperm quality by reducing OS and therefore, resulted in improved fertility [ 11 , 17 ].…”