Abstract
The use of nano-selenium (Nano-Se) in the rabbit industry has gained attention as an optimal selenium source due to its potential benefits. This study evaluated the effects of varying levels of Nano-Se in drinking water on growth, carcass traits, blood profiles, microbial counts, and economic efficiency in growing rabbits. Seventy-two male V-line rabbits (five weeks old) were divided into four groups: a control group (T1, 0 ppm Nano-Se) and three treatment groups receiving Nano-Se at 0.1 ppm (T2), 0.2 ppm (T3), and 0.3 ppm (T4) for eight weeks. Results showed significant improvements (p < 0.01) in growth performance, including final body weight, weight gain, feed intake, and feed conversion ratio, particularly at 0.1 ppm. Carcass yield and haemato-biochemical markers also improved significantly, with higher Nano-Se levels (0.2 and 0.3 ppm) enhancing kidney and liver functions and antioxidant activity, as reflected by reduced urea, AST, and MAD levels. Additionally, Nano-Se supplementation reduced pathogenic bacterial counts in the cecum, particularly Escherichia coli and Clostridium spp., and improved the total bacterial count at higher doses. Economically, Nano-Se supplementation decreased production costs and significantly increased net profit and efficiency, especially at the 0.1 ppm dose. In conclusion, Nano-Se, particularly at 0.1 ppm in drinking water, improved growth, health, and economic outcomes, positioning it as a valuable supplement for sustainable rabbit farming.