Isaac Osuga

Dr. Isaac Osuga


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
20 September 2019 in Animals
Verified
Journal Article
Open access
PDF file
SCShaphan Yong Chia
Shaphan Yong Chia
CTChrysantus Tanga
Chrysantus Tanga
IOIsaac Osuga
Isaac Osuga
AAAlphonce O. Alaru
Alphonce O. Alaru
DMDavid M. Mwangi
David M. Mwangi
MDMarcel Dicke
Marcel Dicke
Pig production is one of the fastest growing livestock sectors. Development of this sector is hampered by rapidly increasing costs of fishmeal (FM), which is a common protein source in animal feeds. Here, we explored the potential of substituting FM with black soldier fly larval meal (BSFLM) on growth and blood parameters of pigs as well as economic aspects. At weaning, 40 hybrid pigs, i.e., crossbreeds of purebred Large White and Landrace were randomly assigned to five iso-nitrogenous and iso-energetic dietary treatments: Control (0% BSFLM and 100% FM (T0)), and FM replaced at 25% (T25), 50% (T50), 75% (T75) and 100% (T100) with BSFLM. Average daily feed intake (ADFI), average daily gain (ADG), body weight gain (BWG) and feed conversion ratio (FCR) were calculated for the whole trial. Hematological and serum biochemical parameters, the cost–benefit ratio (CBR) and return on investment (RoI) were evaluated. No significant effect of diet type was observed on feed intake and daily weight gain. Red or white blood cell indices did not differ among diets. Pigs fed T25, T75 and T100, had lower platelet counts compared to T0 and T50. Dietary inclusion of BSFLM did not affect blood total cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein. CBR and RoI were similar for the various diets. In conclusion, BSFLM is a suitable and cost-effective alternative to fishmeal in feed for growing pigs.

4 September 2021 in Animals
Verified
Journal Article
Open access
PDF file
MWMoses Wachira
Moses Wachira
IOIsaac Osuga
Isaac Osuga
JMJonathan Mbonge Munguti
Jonathan Mbonge Munguti
MAMary Ambula
Mary Ambula
SSSevgan Subramanian
Sevgan Subramanian
CTChrysantus Tanga
Chrysantus Tanga
In Sub-Saharan Africa, Nile tilapia (Oreochromis niloticus L.) make up over 80% of aquaculture production. However, the local aquaculture farmers are restricted by the unavailability and expensive cost of formulated rations. To reduce reliance on the scarce and expensive fishmeal used in fish feeds, alternative insect protein has been successfully utilized in many aquafeeds. However, data on the influence of insect-based feed on the growth and economic benefit of feeding tilapia with the emerging insect-based diet are scanty. This study investigated the effect of partially and completely substituting fishmeal with black soldier fly larval meal (BM) on growth and economic parameters of tilapia. The O. niloticus was fed a standard commercial diet as a control (100% FM; 0% BM), BM33 (67% FM; 33% BM), BM67 (33% FM; 67% BM) and BM100 (0% FM; 100% BM) for 20 weeks in randomly assigned cages mounted in an 800 m2 earthen pond. Results from this study showed that diet type significantly (p < 0.05) affected the feed intake of the fish as well as weight gain. The feed conversion ratio and survival rate of O. niloticus did not vary across the different diets. Fish fed Diet1 had a 15% increase in weight when compared to fish fed the control diet. Return on investment and the cost–benefit ratio was similar across the diets, suggesting that BM is a suitable and cost-equivalent dietary supplement of FM up to 100% in aquafeed for growing tilapia fish in earthen ponds for the market.

28 May 2021 in Sustainability
Verified
Journal Article
Open access
PDF file
ESEsther Khayanga Sumbule
Esther Khayanga Sumbule
MAMary Ambula
Mary Ambula
IOIsaac Osuga
Isaac Osuga
JCJanice Ghemoh Changeh
Janice Ghemoh Changeh
DMDavid Miano Mwangi
David Miano Mwangi
CTChrysantus Tanga
Chrysantus Tanga
The acceptance of eco-friendly black soldier fly larvae meal (BSFLM) as sustainable alternative protein ingredient in poultry feeds continues to gain momentum worldwide. This study evaluates the impact of BSFLM in layer chick and grower diets on the growth, carcass quality and economic returns. Mean weekly weight gain and total live weight per chick and grower varied significantly. The highest final weight gain was achieved when birds were provided diet with 25.6% BSFLM. Average daily feed intake (ADFI), average daily weight gain (ADG) and overall weight gain of the chick varied significantly, except for the feed conversion ratio (FCR). For grower birds, ADFI, ADG, FCR and overall weight gain did not vary significantly across the various feeding regimes. The weight of the wings and drumsticks had a quadratic response with a maximum weight obtained at 33% inclusion of BSFLM. The weight of the internal organs were not significantly affected by dietary types. Positive cost–benefit ratio and return on investment was recorded for diet types with higher BSFLM inclusion levels (>75%). Diets with 25% and 100% BSFLM inclusion were the most suitable and cost-effective, respectively. Thus, BSFLM represents a promising alternative source of protein that could be sustainably used in the poultry industries.

3 May 2024 in Scientific African
Verified
Journal Article
Open access
MKMercy W. Kariuki
Mercy W. Kariuki
DBDidier K. Barwani
Didier K. Barwani
VMVincent Mwashi
Vincent Mwashi
JKJim Katu
Jim Katu
JMJonathan M. Munguti
Jonathan M. Munguti
IOIsaac Osuga
Isaac Osuga

3 June 2023 in International Journal of Agricultural Sustainability
Verified
Journal Article
Open access
DBDidier Kichochi Barwani
Didier Kichochi Barwani
CMCatherine Nyambune Maindi
Catherine Nyambune Maindi
SBSamy Bashizi Bacigale
Samy Bashizi Bacigale
DKDieudonné Musale Katunga
Dieudonné Musale Katunga
MGMathew Gitau Gicheha
Mathew Gitau Gicheha
IOIsaac Osuga
Isaac Osuga

30 April 2025
Verified
Book Chapter
Open access
PDF file
IOIsaac Osuga
Isaac Osuga
CMCatherine Maindi
Catherine Maindi
VMVincent Mwashi
Vincent Mwashi
CTChrysantus Tanga
Chrysantus Tanga
In the face of climate change and variability and the need to enhance aquaculture production sustainability, production and utilization of novel feed resources for aquaculture while maintaining or contributing to environmental sustainability is critical. Insects have been shown to produce critical biomass suitable for animal feed with minimal environmental footprints. The insect biomass has been shown to be of high nutritional quality and therefore can be used as feed for fish. Fish feed formulations have been successfully done and incorporated diets for various fish species with very positive results. The incorporation of the insect meals in aquafeeds has also been shown to reduce the cost of fish feeds and improve the overall profitability of fish farming enterprises. In this chapter, the utilization of insect meals in the formulation of aquafeeds and the effect on the performance of fish is presented. This includes the replacement of fishmeal as the main animal protein source in fish feeds and the nutritional quality of insect meals as important sources of proteins for green, profitable, and sustainable aquaculture. It is certain that in the near future, large-scale insect farming and processing to produce insect meals as an ingredient of fish feeds will have positive impact on the sustainability and profitability of aquaculture.