Mohamed Nasr Alrez^1*

¹ Faculty of Veterinary Medicine, University of Hama, Syria.

(*Corresponding author: Mohamed Nasr Alrez, Email: m.alriz@hama-univ.edu.sy). 

Received: 29/ 9/ 2025                   Accepted: 4/ 1/ 2026

Abstract: 

The aim of the research was to study the effect of nano-selenium Nano-Se on reproductive efficiency in Awassi sheep. Forty ewes of similar ages and weights were used in the experiment, and they were fed a uniform concentrated feed. The ewes were distributed into four groups: Group T1 was considered a control and was given a daily dose of distilled water. Group T2 was given a dose of 0.25 mg/kg per day of Nano-Se, while Group T3 was given a dose of 0.5 mg/kg per day of Nano-Se. Group T4 was given a dose of 1 mg/kg per day of Nano-Se. The treatment lasted from July 1st to 30th, for a month before the start of the breeding season. The results indicated a significant increase (P≤0.05) in the rate of onset of estrus and the length of the estrus period, as well as a decrease in the onset of estrus period after the end of treatment with Nano-Se. A significant increase in the pregnancy rate was observed in the treatment groups compared to the control group (T1). Meanwhile, the T3 group, treated with a dose of 0.5 mg/kg, achieved a higher rate of twin births and birth rate compared to the control group and the other treatment groups. The results also showed a significant improvement (P≤0.05) in the weights and growth of lambs born in the treatment groups compared to the control group (T1). The study concludes that administering Nano-Se to Awassi ewes before the start of the breeding season led to improved reproductive parameters, increased pregnancy rates, twin births, and higher birth weights.

Keywords: Oral administration, Nano selenium, Reproductive efficiency, Awassi sheep.

 Full paper in Arabic: PDF