Cholesterol Enhances Post-Thaw Semen Quality in Buffaloes (Bubalus bubalis)

The objective of the present study was to determine if addition of cholesterol in semen extender has a beneficial effect on its post-thaw semen quality in buffalo bulls. Cholesterol was added to Tris-citric acid semen extender in the form of cholesterol-loaded cyclodextrin (CLC). Split pooled ejaculates (n=7) from four buffalo bulls were diluted in extender containing CLC either 3 mg (LOW), 4 mg (MED), 5 mg (HIGH) /ml or without CLC, i.e., control (CON). Motility before freezing (MBF), post-thaw motility (PTM), live percentage (LP), plasma membrane integrity (PMI), normal acrosomes (NA) and morphological abnormalities (MA) were assessed by using Phase contrast microscope and hypo osmotic swelling assays. Analysis of variance revealed that PTM & PMI from semen samples containing MED concentration of CLC were the highest (P<0.05) followed by LOW, HIGH and CON semen samples, respectively. Live percentage (LP) was the highest (P<0.05) in MED followed by LOW, HIGH and CON semen samples, respectively. Percent normal acrosomes (NA) values from semen samples containing MED concentration of CLC was the highest followed by LOW, HIGH and CON, respectively. Mean NA values in all the groups differed significantly (P<0.05) except LOW and MED which differed non-significantly with each other. Mean MA values were the highest in CON followed by HIGH, LOW and MED semen samples. Mean values for MA amongst all the groups differed significantly (P<0.05) except HIGH and CON which differed non-significantly. It is concluded that addition of cholesterol in MED concentration to buffalo bull semen can improve post-thaw semen quality.