Singh Mahak, Celina Apanai, Katiyar Rahul, Deori Sourabh, Singh Ashwani, Singh Vinay, Singh G D, Rajoriya J S, Kalita H, Mishra V K
Animal Reproduction Laboratory, ICAR Research Complex for NEH Region, Nagaland Centre, Medziphema, Nagaland, India.
Division of Animal Health and Fisheries Science, ICAR Research Complex for NEH Region, Umiam, Meghalaya, India.
Front Vet Sci. 2025 Apr 17;12:1562988. doi: 10.3389/fvets.2025.1562988. eCollection 2025.
In temperate regions, boars experience environmental heat stress due to the subtropical climate, leading to their semen quality and fertility being severely compromised compared to indigenous breeds. Considering the above effect, the present study aimed to evaluate the effect of season on semen quality, seminal plasma antioxidant status, and fertility of crossbred boars of exotic (50%) and indigenous inheritance in a subtropical climate. A total of 14 Hampshire-Ghungroo crossbred boars were used for this investigation, which took place in both summer and winter. Sperm characteristics, namely motility, viability, abnormality, acrosomal integrity, and the hypo-osmotic swelling test (HOST) results, and mitochondrial membrane potential (MMP) were evaluated. Sperm kinematics parameters were assessed using computer-assisted semen analysis (CASA). Antioxidant biomarkers (glutathione peroxidase, GPx; catalase, CAT; and total antioxidant capacity, TAC) and lipid peroxidation (malondialdehyde, MDA) were analyzed in boars' seminal plasma. The summer season had a significant ( < 0.01) negative impact on reaction time and false mounts, whereas semen volume and sperm concentration were significantly ( < 0.01) higher in the winter season. Similarly, sperm abnormalities were significantly ( < 0.01) lower in the winter season. In the winter, sperm quality parameters, namely total motility, progressive motility, viability, acrosomal integrity, and HOST reactivity, were significantly ( < 0.01) improved. However, during the summer, sperm MMP was significantly ( < 0.01) lower in fresh samples and after 72 h of storage. Season had a significant ( < 0.05) effect on the following sperm kinematics parameters: average path velocity, straight-line velocity, curve linear velocity, amplitude of lateral head displacement, and beat cross frequency. Semen characteristics were significantly ( < 0.01) improved in winter after 72 h of cold storage compared with those in summer. The summer season had a significant effect ( < 0.01) on seminal plasma antioxidant biomarkers (TAC, MDA, CAT, and GPx). Furthermore, the farrowing rate was significantly ( < 0.05) higher in the winter season. In conclusion, our results showed that the low MMP of boar sperm and the downregulation of seminal plasma antioxidant biomarkers in summer lead to poor semen quality and poor fertility in Hampshire-Ghungroo crossbred boars in a subtropical climate. To alleviate the heat-stress-induced poor sperm fertility in boars and to optimize the fertility of boars during summer in subtropics, there is a need for scientific interventions in terms of genetics [less exotic inheritance (below 50%)], nutrition, and management.
在温带地区，由于亚热带气候，公猪会经历环境热应激，导致其精液质量和繁殖力与本地品种相比严重受损。考虑到上述影响，本研究旨在评估季节对亚热带气候下具有50%外来血统和本地血统的杂交公猪精液质量、精浆抗氧化状态和繁殖力的影响。本研究共使用了14头汉普夏-贡格鲁杂交公猪，研究在夏季和冬季进行。评估了精子特征，即活力、存活率、异常率、顶体完整性、低渗肿胀试验（HOST）结果以及线粒体膜电位（MMP）。使用计算机辅助精液分析（CASA）评估精子运动学参数。对公猪精浆中的抗氧化生物标志物（谷胱甘肽过氧化物酶，GPx；过氧化氢酶，CAT；以及总抗氧化能力，TAC）和脂质过氧化（丙二醛，MDA）进行了分析。夏季对反应时间和假爬跨有显著（<0.01）负面影响，而精液体积和精子浓度在冬季显著（<0.01）更高。同样，冬季精子异常率显著（<0.01）更低。在冬季，精子质量参数，即总活力、前向运动活力、存活率、顶体完整性和HOST反应性显著（<0.01）改善。然而，在夏季，新鲜样本和储存72小时后的精子MMP显著（<0.01）更低。季节对以下精子运动学参数有显著（<0.05）影响：平均路径速度、直线速度、曲线线性速度、头部侧向位移幅度和鞭打交叉频率。与夏季相比，冬季冷藏72小时后精液特征显著（<0.01）改善。夏季对精浆抗氧化生物标志物（TAC、MDA、CAT和GPx）有显著（<0.01）影响。此外，冬季产仔率显著（<0.05）更高。总之，我们的结果表明，夏季公猪精子的低MMP和精浆抗氧化生物标志物的下调导致亚热带气候下汉普夏-贡格鲁杂交公猪精液质量差和繁殖力低。为了缓解热应激对公猪精子繁殖力的不良影响，并优化亚热带地区夏季公猪的繁殖力，需要在遗传学[减少外来血统（低于50%）]、营养和管理方面进行科学干预。
