Browsing by Author "Osuga, Isaac M."

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    Aflatoxin Contamination Detected in Nutrient and Anti-Oxidant Rich Edible Stink Bug Stored in Recycled Grain Containers
    (Public Library of Science, 2016) Musundire, R.; Osuga, Isaac M.; Cheseto, Xavier; Irungu, Janet; Torto, Baldwyn
    Recently, there has been multi-agency promotion of entomophagy as an environmentallyfriendly source of food for the ever increasing human population especially in the developing countries. However, food quality and safety concerns must first be addressed in this context. We addressed these concerns in the present study using the edible stink bug Encosternum delegorguei, which is widely consumed in southern Africa. We analysed for mycotoxins, and health beneficials including antioxidants, amino acids and essential fatty acids using liquid chromatography coupled to quadrupole time of flight mass spectrometry (LC-Qtof-MS) and coupled gas chromatography (GC)-MS. We also performed proximate analysis to determine nutritional components. We identified the human carcinogen mycotoxin (aflatoxin B1) at low levels in edible stink bugs that were stored in traditonally woven wooden dung smeared baskets and gunny bags previously used to store cereals. However, it was absent in insects stored in clean zip lock bags. On the other hand, we identified 10 fatty acids, of which 7 are considered essential fatty acids for human nutrition and health; 4 flavonoids and 12 amino acids of which two are considered the most limiting amino acids in cereal based diets. The edible stink bug also contained high crude protein and fats but was a poor source of minerals, except for phosphorus which was found in relatively high levels. Our results show that the edible stink bug is a nutrient- and antioxidant-rich source of food and health benefits for human consumption. As such, use of better handling and storage methods can help eliminate contamination of the edible stink bug with the carcinogen aflatoxin and ensure its safety as human food.
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    Big Opportunities for Tiny Bugs: Rush to Boost Laying Hen Performance using Black Soldier Fly Larvae Meal
    (Journal of Economic Entomology, 2023-12) Munga, Leonard M.; Osuga, Isaac M.; Munguti, Jonathan M.; Subramanian, Sevgan; Kidoido, Michael K.; Ghemoh, Janice C.; Mwendia, Charles M.; TangaChrysantus M.
    Rising feed cost challenges due to expensive conventional protein sources continue to make headlines in Africa causing drops in profit margins. We assessed the impact of insect (Hermetia illucens Linnaeus larvae meal, HILM) protein as a substitute for soybean meal and sunflower seed cake on layer chicken performance and profitability. Our results showed that apart from the growers, chicks (12.37 g/bird) and layer hens (2.02 g/bird) fed diets with 75% HILM inclusion levels had significantly higher average daily weight gain. The average daily feed intake (ADFI) and feed conversion ratio (FCR) varied significantly when the chicks and layer hens were provided with the HILM-based diets. For the chicks and layer hens, the lowest ADFI and FCR were observed in birds subjected to diets with 75% and 100% HILM compared to the growers fed diets with 50% HILM. Significantly higher egg production was observed for layer hens fed diets containing 75% of HILM throughout the first (87.41%) and second (83.05%) phase production cycles. Layer hens fed HILM-based diets had a 3–10% increase in egg laying percentage. There was higher profit margins when birds were fed diets containing 75% of HILM (~1.83 and 5.98 US$ per bird), which mirrored the return on investment estimated at 63.95% and 33.36% for the pullets (growers) and laying hen, respectively. Our findings demonstrate that diets with 75% HILM provided optimum growth performance, reduced feeding costs, increased weight gain and egg production as well as improved economic returns for commercial on-farm poultry production systems.
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    Cellular Immune Response and Abomasum worm burden in Goats Vaccinated with HC58cDNA Vaccine against H. contortus Infection
    (www.iiste.org, 2013) Osuga, Isaac M.; Muleke, C. I.; Yan, Ruofeng; Sun, Yanming; Osuga, I.M.; Shivairo, R.S.; Li, Xiangrui
    Abstract Vaccination with DNA vaccines derived from adult H. contortus induces significant level of protection against homologous infection in goat. To date however, mechanism of protection is not well understood, especially in goat. In this study, HC58 DNA vaccinated goats were artificially infected with 5, 000 dose of infective H. contortus L 3 (third larval stage), and cellular immune responses and abomasum worm burden examined. The results showed that peripheral CD4+, CD8+ T and B lymphocytes for nematode challenged
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    Effect of Supplementing Rhodes Grass Hay (Chloris gayana) with Berchemia Discolor or Zizyphus Mucronata on the Performance of Growing Goats in Kenya.
    (Journal of Animal Physiology and Animal Nutrition, 2011-06) Osuga, Isaac M.; Abdulrazak, S. A.; Muleke, C. I.; Fujihara, T.
    Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.
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    In vitro Assessment of Ruminal Fermentation Characteristics of Tropical Browse Mixtures Supplemented with Yeast
    (Japanese Society of Grassland Science, 2012-03) Wambui, C. C.; Ando, S.; Abdulrazak, S. A.; Osuga, Isaac M.; Ichinohe, T.
    An in vitro ruminal gas production study was conducted to assess the effect of yeast supplementation on rumen fermentation of tanniniferous tropical browse mixtures prepared by mixing Berchemia discolor with Acacia brevispica, Acacia elatior, Acacia mellifera, Balanites aegyptiaca, Grewia bicolor or Zizyphus mucronata in a 1:1 dry weight ratio. The six browse mixtures were incubated with buffered rumen fluid alone or supplemented with dried Japanese Sake yeast (JSY) or polyethylene glycol (PEG). Ruminal gas production characteristics were evaluated using the Gompertz equation. The JSY addition increased gas production volume (P < 0.05) and numerically increased the maximum gas production rate constant. Time to reach the maximum gas production rate was shortened by PEG addition as compared to the JSY and control treatments. It is possible that JSY promoted the rumen microbial activity in addition to forming complexes with tannins thereby upgrading the in vitro ruminal digestion of tropical browse mixtures.
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    Lead and Copper Levels in the Soil, Water, Serum and Tissues of Livestock Feeding on Dumpsite Waste in Urban Slums of Industrial Towns in Western Kenya
    (2013) Osuga, Isaac M.; Maina, N J; Muleke, C I; Mutai, K J; Karubiu, O N; Bebe, B
    Knowledge of toxic metal levels in livestock feeding on dumpsite waste is important for assessing the effects of pollutants in animals and contaminant intakes by human. A study was conducted in western Kenya to determine the lead and copper levels in the soil, water, serum and tissues of livestock feeding on refuse dumpsite waste in Webuye and Mumias urban towns suspected to be polluted with these metals. Indigenous free ranging cattle, sheep, goats and chicken were investigated. The samples: soil (5), water (5), dumpsite wastes (7), serum (76) and 17 kidney/liver were analyzed. Lead and copper levels were determined by the conventional aqua regia digestion protocol and read using the atomic absorption spectrophotometer. The mean lead and copper levels in the soil and water of 1.16 – 2.86mg/kg and 0.001mg/L were below acceptable risk limits of 5 – 25mg/kg and 0.015mg/L, respectively. The mean lead levels in serum of cattle, sheep, goats and chicken were 0.86, 0.82, 0.54mg/L and 0.76, 0.46, 0.21mg/L in Bungoma and Mumias towns respectively, and they exceeded acceptable risk limit levels of 0.01mg/L. The lead levels in kidney/livers of cattle, shoats and chicken were 1.2; 1.5; 1.0mg/kg respectively, and exceeded the acceptable risk limits of 0.5 mg/kg. Based on this study, the lead and copper levels in the soil, water and dumpsite wastes in Bungoma and Mumias towns are below the acceptable risk limits. However due to bio-accumulation process observed in animal tissues, there is need to continuously monitor the status of these heavy metals and create public awareness on good animal feeding practices in the urban slums to avoid mineral toxicity in animals and man through the food chain.
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    Potential nutritive value of various parts of wild sunflower (Tithonia diversifolia) as source of feed for ruminants in Kenya
    (world-food.net, 2012) Osuga, Isaac M.; Abdulrazak, S. A.; Muleke, C. I.; Fujihara, T.
    Various parts of the wild sunflower (Tithonia) were analysed for their chemical composition and degradation characteristics. Pyrethrum marc (pymarc), a common agro-industrial by-product was also analysed to compare the potential nutritive value. Leaves and flowers both young and mature were harvested, dried and ground. The crude protein (CP) content ranged from 143.3 g/kg dry matter (DM) in pymarc to 235.6 g/kg DM in mature Tithonia leaves. The neutral detergent fibre (NDF) content was highest in pymarc (421 g/kg DM) and least in mature leaves (264.8 g/kg DM). Concentration of polyphenolic compounds was highest in young leaves and lowest in young flowers. However, the concentrations were far below levels (50.0 g/kg DM) known to have detrimental effects in ruminants. Flowers were more digestible than leaves but overall pymarc recorded the highest value of 60.5% organic matter digestibility (OMD). The same trend was recorded for metabolizable energy (ME). Addition of polyethylene glycol (PEG), a tannin-binding agent did not yield significant increase in gas production values except for mature flowers, which also recorded significant increases in both OMD and ME. Tithonia forages (leaf and flower) at both young and mature vegetative state have high nutritive value compared to pymarc. However, mature leaves and young flowers are slightly higher in CP and low in concentration of phenolic compounds than young and mature leaves and flowers, respectively. This depicts the high potential of Tithonia shrub in feeding of ruminants. Key words: Tithonia diversifolia, pymarc, gas production, rumen fermentation