Semen Characteristics and Blood Metabolites of Hi-Plus Buck Rabbits Fed on Microalgae Nannochloropsis oculata Meal during the Summer Season

Abstract

Feeding tiny amounts of micro-algae meal to animals enhances animal physiology by improving immune response, disease resistance, and gut function, as well as enhancing anti-inflammatory and antibacterial protection, reproductive performance, feed conversion ratio, and weight gain. The purpose of this study was to identify the impact of dietary microalgae meal (Nannochloropsis oculata) on physical semen quality, serum biochemical parameters, and oxidative status of Hi-Plus buck rabbits for 12 weeks during the summer. A total of 45, Hi-Plus buck rabbits aged 20-24 weeks were divided into three equally comparable experimental groups. Bucks in the first, second, and third groups were daily supplemented in their diets with 0% (control), 0.50% (T1), and 1.0% (T2) microalgae meal, respectively. Semen and blood samples were collected to evaluate semen quality traits and some serum biochemical constituents, and oxidative status, as well as serum triiodothyronine (T3) and testosterone (Ts) hormones concentrations. The obtained data revealed that dietary supplementation of Nannochloropsis oculata meal significantly improved most physical semen characteristics, including ejaculate volume, progressive sperm motility, semen pH value, sperm cell concentration, total sperm output, live sperm, and semen quality factor. Blood serum glucose, total proteins, and their fractions increased significantly in T1 and T2, compared with the control group, while total serum cholesterol and hepatic enzymes concentrations recorded a significant decrease in bucks supplemented with T1 and T2, compared with the control group. The total antioxidant capacity of serum significantly increased in both two levels of microalgae, compared with the control group. Serum T3 concentration significantly increased in both levels of dietary microalgae compared with the control group. In conclusion, dietary supplementation with Nannochloropsis oculata meal (1.0%) was advised to improve semen quality, serum constituents, and antioxidative status without any adverse effects on the liver and kidney functions of rabbits.