![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
ABSTRACT
This study investigated sunflower seed meal (SSM) as dietary protein replacement of fish meal (FM) for Nile tilapia (Oreochromis niloticus) juveniles (initial mean weight of 19.8 ± 6.3 g) reared in earthen ponds for 210 days. SSM replaced 25%, 50%, 75%, and 100% (i.e., D25, D50, D75, and D100, respectively) of FM in an isonitrogenous and isocaloric diet. The optimum FM replacement level of D25 as predicted by the equation y = 177.5 + 26.5x – 7.9x2 yielded an optimum weight of about 184 g within 100 days. Thus D25 was the most effective SSM level for Nile tilapia growth in earthen ponds. Fish growth declined as SSM exceeded D25. The length-weight relationship (r ≥ 90%) depicted an isometric fish growth. Nutrient utilization parameters were similar in all the diets except for D100. The protein content of fish carcass was highest in the control and D25, while fiber level was highest in D100. Amino acids imbalance and high fiber content could have reduced the fish growth at D50, D75, and D100.
Acknowledgments
The authors wish to extend their gratitude to the Kenya Marine and Fisheries Research Institute (KMFRI) and Kenya Agricultural Research Institute (KARI) for provision of space and equipment, respectively, for this study. We also thank the following laboratory technicians for all the assistance during the experiment: Mr. Ezekiel Nyarumba, Mr. Meshack Mikume, Mrs. Alice Osinde, Mr. Ezekiel Ongubo, and Mr. Kennedy Nyachongi. Special thanks to the anonymous reviewers for improving the quality of this article.
Funding
This study was funded by the Kenya Agricultural Productivity and Agribusiness Project (KAPAP) grant number KAPAP — CGS/FP/2011/06.