Agronomic performance of indoor-sprouted fodder systems and their potential as a protein– energy source in rabbit nutrition

Abstract:

Shrinking grazing lands and unpredictable rainfall paterns across East Africa have intensified the need for year-round livestock feed alternatives that are independent of field cultivation. This research assessed the agronomic performance of four indoor-sprouted fodder species— maize (Zea mays), barley (Hordeum vulgare), sorghum (Sorghum bicolor), and cowpea (Vigna unguiculata)—and evaluated their potential as a protein–energy source for growing rabbits at the National Institute of Livestock Research, Nairobi, Kenya, between February and July 2022. Seeds were sprouted on perforated trays (3.2 kg m⁻²) inside a naturally ventilated greenhouse (24 ± 3 °C, 65 % RH) and harvested on days 6, 8, and 10 to identify the optimal growth window. Proximate analysis, mineral profiling, and DM-recovery calculations were performed at each harvest. A parallel 56-day feeding trial used 48 weaned New Zealand White rabbits (35 d, 631±19 g) allocated to four dietary treatments (n = 12): basal pellet supplemented with 25 % DM from maize, barley, sorghum, or cowpea sprouts (all harvested on day 8). Maize produced the highest fresh biomass per tray (6.12 kg), while cowpea yielded the highest crude protein (23.8 % DM) and calcium (1.82 % DM). DM recovery declined from day 8 to day 10 across all species, confirming day 8 as the optimal harvest point. Rabbits receiving cowpea sprouts recorded the highest daily gain (24.1gd⁻¹) and best FCR (3.31), whereas sorghum-fed animals performed least favourably (19.2gd⁻¹ , FCR 3.84). These findings confirm that cowpea sprouts harvested on day 8 represent the most efective protein–energy supplement for rabbit production in tropica East African conditions.