Seasonal effects on amino acid profile and their physiological implications for semen quality traits in Iraqi Awassi rams

Abstract:

Seasonal climatic changes in Iraq affected the physiological characteristics and several vital indicators of seminal fluid in Awassi rams (n = 10) during the autumn and spring seasons. Semen samples were collected over a period of nine weeks; in each season, samples were examined weekly, in addition to the quantification of selected amino acids. In the spring season, the results showed a statistically significant in sperm concentration and motility (mass and individual), as well as an increase in total antioxidant capacity, fertility percentage, and the concentrations of several amino acids, including threonine, isoleucine, leucine, aspartic acid, proline, cysteine, and total essential amino acids (1.79 ± 0.16, 3.43 ± 0.83, 82.00 ± 1.83, 25.36 ± 2.58, 90.00 ± 0.01, 84.6 ± 0.12, 11.12 ± 2.01, 26.99 ± 1.11, 20.30 ± 2.02, 7.90 ± 2.00, 2.92 ± 1.99, 207.32 ± 1.13), respectively. Conversely, in the autumn season, a statistically significant was observed in the percentages of dead sperm, total sperm abnormalities, plasma and acrosomal membrane abnormalities, total malondialdehyde concentration, and the concentrations of glutamine and glycine (16.33 ± 1.42, 13.00 ± 1.02, 11.60 ± 1.03, 16.22 ± 1.65, 29.55 ± 1.19, 130.20 ± 1.20, 13.90 ± 1.44), respectively. Overall, the amino acid composition of seminal plasma may play a significant role in improving fertility and semen quality during the spring season due to its antioxidant properties. In contrast, seasonal climatic variations may alter seminal components associated with sperm physiology, which are directly or indirectly linked to heat stress and its impact on ram fertility. Ultimately, ram fertility may be predicted by the amino acid profile of seminal plasma, which may serve as a biomarker of climatic influence, semen quality, Awassi ram fertility, and nutritional status.