Vaccination against foot-and-mouth disease (FMD) deteriorates sperm quality for a substantial duration post-vaccination and alters the abundance of fertility-related mRNA transcripts in Murrah Buffalo bulls spermatozoa
Authors: Dewry Raju Kumar , Mohanty Tushar Kumar , Nath Sapna , Bhakat Mukesh , Yadav Hanuman Prasad , Nain Dipti , Upadhyay Vishwa Ranjan , Abedin Sayed Nabil , Yadav Dileep Kumar , Gupta Vinod Kumar , Kumar Pratyush 
Published: November 2024

Male fertility is the ability of sperm to fertilize the egg, sustain embryo development, and produce viable offspring. Several factors determine the fertilizing capacity of mammalian sperm, including season and vaccination of breeding bulls. The current study aimed to investigate the effect of FMD vaccination on semen quality and sperm fertility markers in Murrah buffalo bulls. Eight (8) Murrah buffalo bulls were selected based on data from 2010 to 2018 and adjusted conception rates (CR) obtained from the farm. These bulls were divided into two groups based on CR: high fertility (n = 4; CR > 50%) and low fertility (n = 4; CR < 40%). The selected bulls were immunized with Raksha OVAC trivalent against FMD(IIM, India). Six (6) ejaculates were collected from each bull 15 days before vaccination and at 15-day intervals post-vaccination until the 60th day and evaluated for fresh sperm parameters. Samples meeting minimum standards were processed for cryopreservation. These cryopreserved samples underwent advanced in-vitro sperm function tests, including sperm membrane integrity, acrosome integrity, sperm protamine deficiency, sperm apoptosis, and capacitation status using the CTC assay, lipid peroxidation (LPO), and sperm kinematic parameters. Fresh semen samples were processed for RNA isolation, quantification, and identification of transcripts associated with fertility, such as CRISP2, PRM1, AQP7, CCT5, and CCT8. The effect of FMD vaccination on routine and advanced sperm functions test, in-vitro sperm capacitation, and sperm kinetic parameters differed significantly (p < 0.05) in high and low fertile bulls and pre and post-vaccination. Most of the seminal attributes significantly (p < 0.05) decreased, and sperm abnormalities showed a significant (p < 0.05) increase on the 15th day post-vaccination. The in-vitro sperm function tests significantly (p < 0.05) declined 15th day post-vaccination. Lipid peroxidation (LPO) levels were significantly (p < 0.05) higher 15th day post-vaccination as compared to pre-vaccination. Sperm kinematic parameters were also significantly (p < 0.05) reduced 15th days post-vaccination and restored to normal levels 60 days post-vaccination. CRISP2 and PRM1 gene expression gradually increased post-vaccination up to 60th days in both high and low-fertile Murrah bulls. The expression of the CCT5 and CCT8 genes was significantly (p < 0.05) up-regulated during the post-vaccination period on the 15th day and gradually decreased in both high and low-fertile bulls. In conclusion, FMD vaccination in Murrah buffalo bulls had significantly impacted semen quality, with notable declines in sperm parameters and alterations in fertility-related gene expression. These findings underscore the complex relationship between vaccination, sperm function, and genetic markers, highlighting potential implications for male fertility in Murrah buffalo bulls.