Neonatal vitamin A supplementation improves sheep fertility potential

Yating Li; Pengkang Song; Jiamin Zhao; Weipeng Zhang; Xiangdong Liu; Xiaoyang Lv; Junxing Zhao

doi:10.3389/fvets.2024.1370576

Neonatal vitamin A supplementation improves sheep fertility potential

Front Vet Sci. 2024 May 2:11:1370576. doi: 10.3389/fvets.2024.1370576. eCollection 2024.

Authors

Yating Li¹, Pengkang Song¹, Jiamin Zhao¹, Weipeng Zhang¹, Xiangdong Liu², Xiaoyang Lv³, Junxing Zhao¹

Affiliations

¹ College of Animal Science, Shanxi Agricultural University, Jinzhong, Shanxi, China.
² Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, United States.
³ International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement, Yangzhou, Jiangsu, China.

Abstract

This study aimed to explore the effects of neonatal vitamin A (VA) supplementation on testis development and spermatogenesis. A total of 32 newborn lambs were intramuscularly injected with corn oil (control group) or corn oil + 2500 IU/kg BW VA (VA group). They were slaughtered and sampled at 3 weeks and 8 months of age to analyze spermatogenesis, cell proliferation, hormone secretion, antioxidant status of the testis, and adult sheep sperm parameters. Compared with the control group, the expression of spermatogonial differentiation-related genes in VA group was up-regulated (P < 0.05). Testis weight, seminiferous tubule diameter, number of spermatogonium and spermatocyte, and sperm density increased significantly in VA group at 8 months of age (P < 0.05). Neonatal VA injection upregulated the expression of the cell proliferation marker PCNA and cell cycle-related genes in the testis (P < 0.05). VA increased the concentrations of testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in the serum and upregulated steroidogenesis-related genes in the testis (P < 0.05). The antioxidant levels in the VA group were maintained at high levels. The total antioxidant capacity (T-AOC), antioxidant enzyme content and antioxidant-related genes were increased in the testis (P < 0.05). Furthermore, neonatal VA injection activated retinoic acid (RA) signaling to maintain the blood-testosterone barrier (BTB) in the testis of 3-week-old sheep. AMP-activated protein kinase (AMPK) and protein kinase B (AKT) signaling were also modulated in the sheep testis (P < 0.05). Taken together, VA supplementation in newborn rams promotes testis development and spermatogenesis to improve fertility.

Keywords: antioxidant; hormone; sheep; sperm; testis; vitamin A.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the National Natural Science Foundation of China (31972559), Distinguished and Excellent Young Scholar Cultivation Project of Shanxi Agricultural University (2022JQPYGC01), and Open Project Program of International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement (IJRLD-KF202206).