Assessment of deep morphology and cryodamage in spermatozoa of indigenous and exotic pig breeds from the Northeast Indian Himalayas using scanning electron microscopy (SEM).

Background: Sperm morphology assessment is related to the ejaculate quality, which varies in males and breeds. Routine microscopy does not accurately assess deeper morphological or cryodamage. Comparative quality assessment of indigenous and exotic breed spermatozoa is yet to be characterized under high-resolution microscopy. Aim: This study aimed to identify dimensional, deeper morphological, and cryodamage differences in the fresh and frozen sperm of Indian and exotic pig breeds. Methods: Fresh and frozen-thawed boar spermatozoa of indigenous (Ghungroo) and exotic (Large White Yorkshire) breeds were used to estimate the deep morphological abnormalities, morphometry, and cryodamage using scanning electron microscopy (SEM). Analysis of variance followed by Tukey's post hoc test was used for data analysis. Results: Under phase contrast microscopy, the quality parameters of fresh semen were found to be within acceptable limits, showing no significant differences ( Conclusion: SEM is better for assessing deeper sperm morphological abnormalities or cryodamage. Indigenous breed spermatozoa were similar to their exotic counterparts in terms of morphometric dimensions, structural integrity, and cryoresilience. This study opened newer opportunities in semen testing for the early detection of fertility or subfertility for the evaluation of boar breeding soundness.