Biological functions as affected by summer season-related multiple environmental stressors (heat, nutritional and walking stress) in Malpura rams under semi-arid tropical environment

• Published in: Biological rhythm research Vol. 48; no. 4; pp. 593 - 606
• Main Authors: Kumar, Davendra, Sejian, Veerasamy, Gaughan, John B., Naqvi, S. M. K.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 04.07.2017; Taylor & Francis Ltd
• Subjects: Body weight; Heat stress; Malpura ram; Motility; multiple stress; Nutrient deficiency; nutritional stress; reproduction; Seasonal variations; Semen; sheep; Testosterone; Tropical environment; walking stress
• ISSN: 0929-1016; 1744-4179
• DOI: 10.1080/09291016.2017.1299364

The study was conducted with the primary objective to establish the impact of simultaneously imposed multiple stressors (thermal, nutritional and walking) on various biological functions in Malpura rams. The study was conducted for a period of 45 days. Twenty adult Malpura rams (average BW 44.9 Kg) were used in the present study. The rams were divided into two groups, CON (n = 10; Control) and MS (n = 10; multiple stressors). Both body weight (p < 0.05) and body condition scoring (p < 0.01) were lower in MS compared with CON rams. All the scrotal measurements reduced significantly (p < 0.01) in MS rams. All the testicular measurements also reduced significantly (p < 0.01) in MS as compared to CON rams. The seminal attributes, individual motility (p < 0.05), rapid motility (p < 0.05) and curvilinear velocity (p < 0.05) were significantly reduced in CON rams. However, slowness (p < 0.05), linearity (p < 0.05) and straightness (p < 0.05) parameters significantly increased in MS as compared to CON rams. In addition, plasma testosterone concentration was lower (p < 0.05) in MS rams. The study established the impact of multiple stressors on growth and reproductive performance of Malpura rams. Further, the results revealed that the only semen quality was affected by multiple stressors, but the semen production remained intact between the groups, indicating the extreme adaptive capability of Malpura rams to hot semi-arid tropical environment.