Effects of dried Azolla pinnata supplementation on growth, biochemistry, and reproduction in female rabbits

This study evaluated the impact of incorporating varying levels of dried Azolla pinnata as a partial or full substitute for soybean meal protein on growth performance, productivity, and selected biochemical, immunological, hormonal, and antioxidant parameters in New Zealand White (NZW) female rabbits. The study conducted at the South Sinai Research Station of the Desert Research Center, Egypt, from May to November 2023. The trial involved 45 eight-week-old NZW female rabbits. These were randomly assigned to three dietary groups: a control group fed a standard concentrate diet, a group where 50% of soybean protein was replaced with Azolla (GΙ), and a group where soybean protein was completely replaced with Azolla (GΠ). Findings revealed that the GΙ group (50% Azolla replacement) achieved superior growth performance throughout the study period. Conversely, the GΠ group (100% Azolla replacement) experienced a significant reduction in body weight during later growth stages. Regarding productivity, no marked differences among the groups were observed in birth numbers. However, birth mortality rates were notably lower in the GΠ group, despite a significant reduction in kit weights during the first four weeks postpartum. Biochemical analyses showed that Azolla inclusion affected blood parameters based on supplementation level and duration. In the first month, the GΠ group exhibited elevated total protein and globulin concentrations alongside a reduced albumin-to-globulin ratio, while the trend reversed in the second month. During pregnancy, total protein and globulin levels increased in both supplemented groups. Additionally, Azolla influenced kidney and liver function markers, lipid profiles, immunoglobulin concentrations, thyroid hormones, and reproductive hormones, with variations noted across groups and stages of the experiment. Therefore, partial replacement of soybean meal protein with 50% dried A. pinnata improved growth performance without adverse effects on reproductive outcomes or biochemical balance in NZW female rabbits. However, complete replacement (100%) negatively impacted growth and certain productivity parameters, indicating that while Azolla has beneficial properties, its optimal use lies in partial substitution rather than total replacement to maintain rabbit health and performance.