Uganda Journal of Agricultural Science (UJAS)
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Effect of supplementing lactating goats fed on aflatoxin contaminated feed with calcium bentonite and activated charcoal on aflatoxin M1 concentration, excretion and carryover in milk
Get PDFAflatoxin is a collective term for a group of toxic and carcinogenic secondary metabolites produced by some strains of Aspergillus flavus and Aspergillus parasiticus during growth, on feeds and foods. The fungal spores are found worldwide, in air and soil, and infest both living and dead plants and animals. An experiment was conducted to investigate the concentration, total excretion and carry-over of Aflatoxin B1 (AFB1 ) into milk as Aflatoxin M1 . Nine crossbred lactating goats were divided into three groups of three each, based on the level of milk production. Commercial Aflatoxin B1 (AFB1 ) was administered to all groups at a rate of 100 ppb in the diet. Group I served as control (T1 ). In group II (T2 ), calcium bentonite (CaB) and in group III (T3 ), activated charcoal (AC), were added at the rate of 1% of Dry Matter Intake (DMI). Dry matter intake was not significantly different (P>0.05) among T1 (1.22), T2 (1.14) and T3 (1.13). Daily milk yield was also not significantly different (P>0.05) among treatments T1 (0.91), T2 (0.86) and T3 (1.03) during the experimental period of 14 days. The AFM1 concentration, excretion and carry-over of AFB1 in T1 continued to increase with time, whereas, the same was seen to decline in the adsorbent fed groups T2 and T3 . The results suggest that supplementation of CaB or AC at 1% of DMI for lactating goats result in a reduction in AFM1 content in milk and carryover of aflatoxin from feed to milk without causing any change in composition of milk
Amelioration of sandy soils in drought stricken areas through use of Ca-bentonite
Get PDFSoil moisture shortage is a major limiting factor to agricultural production in eastern Africa, inview of increased drought incidences and seasonal rainfall variability. This study evaluated thepotential for Ca-bentonite (a 2:1 clay mineral) as a possible amendment for increased moistureretention by sandy soils in drought stricken/prone areas in Uganda. The study was conducted bothin the greenhouse at NARL-Kawanda and in the field, Nakasongola district. In the greenhouse(27-30oC), Ca-bentonite was mixed with a sandy soil in proportions of 0, 5, 10, 15 and 20% byweight, replicated three times. The mixtures were watered to field capacity (30% water) thenmaize (Longe V) planted and left to grow for 5 weeks without any additional water application.Under field conditions, Ca-bentonite was applied on sandy soils in the drought-prone Lwabiyatasub county, Nakasongola district in central Uganda. Treatments included: Ca-bentonite appliedat 0, 1.25 and 2.5 t ha-1; DAP at 0, 62.5 and 125 kg ha-1; urea at 0 and 60 kg ha-1; and farmyardmanure (FYM) at 0, 1.25 and 2.5 t ha-1, arranged in a randomised block design with three replicates.Under greenhouse conditions, Ca-bentonite application significantly (P<0.05) increased the soilmoisture retention, pH, N, P, Ca and Mg content, and subsequently, maize dry matter yield.Averaged over 2 seasons, field application of 2.5 t Ca-bentonite ha-1 increased maize grain yield by37.6%. Yields were significantly (P<0.05) higher (79.8 to 82.0% above the control) where bentonite(2.5 t ha-1) was combined with DAP (62.5 kgha-1 or FYM (2.5 tha-1). The results suggest that Cabentonite has potential as a soil amendment for moisture conservation, neutralising acidity, andimproving N, P, Ca and Mg content in sandy soils, and consequently support crop growth andyield. Thus calcium bentonite presents a possible amelioration for sandy soils of low fertility indrought stressed environments. It is thus a promising technology for climate change adaptationin drought prone areas
Factors affecting conception rates in cattle following embryo transfer
Get PDFEmbryo Transfer Technology (ETT) plays an important role in improving productivity of dairycattle (Bos indicus). Embryo Transfer Technology allows top quality female livestock to improvea herd or flock in much the same way that artificial insemination has allowed greater use ofsuperior sires. The technology hastens genetic enhancement by virtue of its capacity to reducegeneration interval and is also useful in progeny testing programmes. A retrospective studyanalysed conception rates data collected over a period of six years, from 2007 to 2012. A total of 115embryos had been transferred during that period. The factors affecting conception rates (CR)included embryo developmental stage, deposit site and stage of recipient in days after estrus. Thedeposit site had a significant effect on CR (χ2=0.27395; p<0.05). The quality and stage of theembryo development influenced the CR. Generally, CR reduced as the growth of the embryo.Days after estrus also significantly affected the CR, whereby transfer on day 8 resulted in moreconceptions in recipient animals. Even though ETT has several benefits and requires consistentpromotion, challenges such as lack of trained personnel and equipment for ovulation and packagingof embryos at the farm site need to be addressed
Detection and identification of etiological agents (Liberibacter spp.) associated with citrus greening disease in Uganda
Get PDFCitrus Huanglongbing (HLB), commonly referred to as citrus greening, is one of the majordisease challenges of citrus. In Uganda, there was limited information on Liberibacter spp., thecausal organisms of HLB disease, and its psyllid vectors despite the presence of HLB symptoms oncitrus. The objective of this study was to identify the Liberibacter spp. and psylla vector speciesresponsible for HLB in Uganda. Other native plant species that could be hosts to pathogens andthe psyllid vectors, but are not in the citrus genus, were also investigated. A survey was conductedin 15 citrus growing districts, and symptomatic citrus leaf samples collected, as well as citruspsyllid nymphs and adults for isothermal detection of pathogens in the laboratory. Two types ofbacterial pathogens responsible for HLB were detected, namely Candidatus Liberibacter africanus(CLaf), known as the African type; and Candidatus Liberibacter asiaticus (CLas), known as theAsian type. CLaf was found in Mukono and Wakiso districts in Central Uganda and in Mbarara inWestern Uganda; while CLas was found in Budaka and Tororo districts in Eastern Uganda. Citruspsyllids, which are the major known disease vectors were present in seven out of the fifteendistricts. Psyllid vector identification by morphological means indicated Trioza erytreae, the Africanpsyllid to be the insect vector. Psyllids were common on tangerines (66.7%), Sour Orange (13.3%)and Rough Lemon (13.3%); and least on Washington Navel (6.7%). Three non-citrus plants,Stephania abyssinica (Dill. & A. Rich) walp var. tomentella (Oliv.) Deils (Menispermaceae),Diospyros mespiliformis (Ebenaceae) and Ficus spp (Moraceae) were found to be alternative hostplants for the psyllid
Comparison of in vitro digestibility using slaughtered and fistulated cattle as sources of inoculum
Get PDFIn vitro methods of feed evaluation utilise rumen liquour from fistulated cattle. Fistulated cattle are associated with high acquisition and maintenance costs in addition to its implications on animal welfare. An experiment was conducted to compare in-vitro dry matter (INVDMD) and organic matter (INVOMD) digestibility of four diets using two sources of inocula namely; (i) slaughtered cattle and (ii) fistulated steers. Four fistulated crossbred (Friesian × Ankole) steers were assembled and fed on four diets in a Latin Square change-over arrangement. The two-stage Tilley and Terry (1963) method of nutrient digestibility was used. The overall INVDMD significantly increased with dietary crude protein levels (P <0.05). There was no difference in INVDMD obtained from slaughtered cattle or fistulated steers as inocula sources. Rumen liquour from slaughtered cattle can successfully replace use of fistulated cattle as the source of inoculum
Germination of Afrocarpus usambarensis and Podocarpus milanjianus seeds in Sango Bay, Uganda
Get PDFSango Bay is a unique forest ecosystem, comprising swamp forests which are of great conservation value. It has been degraded for a long time by overharvesting of Afrocarpus usambarensis and Podocarpus milanjianus. Although these species produce seeds, regeneration in the forests has been poor, thus causing concern about the sustainability of the species. The objective of this study was to evaluate germination of seeds of these two species in the nursery for on-farm planting. Seed germination of A. usambarensis and P. milanjianus was evaluated between March 1999 and December 2003. Fourty eight nursery beds were constructed and each sown with 100 seeds. Seeds were subjected to eight pre-treatments and six watering levels. Afrocarpus usambarensis seeds had a mean germination of 45% and P. milanjianus seeds had 23%, under the same conditions. Seeds of A. usambarensis took 35-55 days to germinate, compared to 30-48 days for P. milanjianus. A combination of watering with 10 litres twice a day and soa
Determination of hormonal combination for increased multiplication of tissue culture potato plantlets
Get PDFUse of plant growth hormones either singly or in combination is vital for rapid multiplication of virus-free in-vitro potato (Solanum tuberosum L. ) plantlets for the production of clean seed potato. This study was carried out at Kachwekano Zonal Agricultural Research and Development Institute, Kabale district in south-western Uganda to identify a suitable hormonal combination and optimum concentrations for production of a high number of In-vitro plantlets for three farmer-preferred varieties Kachpot-1, Kinigi, and Victoria. Eight hormonal combinations were formulated and tested using a completely randomized design with three replicates in the tissue culture laboratory. Ten shoot tips from in-vitro raised plantlets were excised and transferred to each of these hormonal combinations. The effect of hormonal combinations was variety dependant. N3 produced the highest mean number of nodes (6.42), buds (4.32) and tallest plantlets (7.38) for Kinigi. N2 produced the highest number of buds in Kachpot 1. N4 produced the tallest plantlets (7.19), highest mean number of buds (5.88) and nodes (7.66) for Victoria. Therefore, N3, N2 and N4 should be used for rapid In-vitro propagation of Kinigi, Kachpot 1 and Victoria respectively
Tephrosia vogelii for control of fleas in free-range poultry
Get PDFChicken production is the leading type of poultry farming in eastern Africa. However, diseasesand parasites are limiting factors in production. Ectoparasites in particular lead to reduced eggproduction, and reduced hatchability, since the hens usually abandon eggs following ectoparasiticinfestation. Ethno-veterinary medicine may be the only readily accessible and affordablealternative for controlling diseases in rural areas, where access to modern medicines and extensionservice delivery is lacking. This study was conducted in Luuka district in eastern Ugandatovalidate the efficacy of Tephrosia vogelii (a shrub) in controlling fleas (Echinophaga spp.) on freerange poultry. Ectoparasites ranked second, after predators, in causing losses in poultry. Themajority of the respondents had substantial knowledge of ethno-veterinary remedies, their sideeffects, and the required precautions of handling the drugs. In a majority of households, poultrywas owned and managed by women. About 82% of the respondents had heard of Tephrosia vogeliias remedy for agricultural pests; while 68% admitted having used it on their poultry. Mostrespondents preferred using herbal medicine compared to conventional medicine, saying that theformer was accessible, affordable, effective and environmentally friendly. Experiments werecarried out and replicated in a completely randomised design. During experimental trials, it wasfound out that Tephrosia vogelii extracts of concentrations of 25, 33.3 and of 50% w/v had a longterm protective effect. The effect lasted up to 5 days. These concentrations killed up to100% ofthe fleas. The difference in re-infestation between the treated and control chickens on Days 6, 7and 8 was significant (p < 0.001). Permethrin at the recommended rates, killed 100% of the fleas.The rate of re-infestation by fleas varied with concentration, being higher at low concentrationsfor both Tephrosia vogelii and permethrin. There was no significant difference in efficacy betweendry leaves extracts compared to fresh leaves extracts at similar concentrations. The LD 50 for thedried and fresh leaves extracts were 50 ml of the standard extract in 1200 and 800 ml at roomtemperature, respectively
Effectiveness of a biological control agent Palexorista gilvoides in controlling Gonometa podorcarpi in conifer plantations of Uganda
Get PDFWidespread defoliation of plantation forests by insect pests causes economic losses worldwide.Successful pest outbreak management requires knowledge of effective pest management options.Currently, such knowledge is inadequate for Gonometa podocarpi an indigenous pest that hasdevastated conifer plantations in Uganda since the 1960s. The pest is a serious defoliator ofconifers in East Africa and was first described from Mt. Elgon Kenya, where its larvae weredefoliating indigenous conifer; Podocarpus spp. The pest has since adapted to feeding on exoticconifers. There have been several serious resurgences of this pest in Uganda, the latest being2011 and 2012. Studies carried out during the peak of these outbreaks in Muko, Kiriima andMafuga Central Forest reserves in South Western Uganda established G.podocarpi infestations inKiriima and Mafuga but none in Muko. The studies also identified a tachnid fly, Palexoristagilvoides as a potential biological control agent for G. podocarpi. Field and laboratory studiesfurther established that P. gilvoides is a larval parasitoid of G.podocarpi, with parasitism levels of43.0 and 62.0% in the field and laboratory respectively. These levels of parasitism are consideredhigh enough to control the pest. However, causes of this pest resurgence need further investigations
Uptake of resistant varieties and integrated management packages for bean root rot disease in western Uganda
Get PDFThe common dry bean (Phaseolus vulgaris L.) is the most widely grown food legume in Uganda,however, its production in western Uganda has been threatened by the bean root rot diseases.Resistant varieties and integrated soil and crop management package for the bean root rot disease,developed by the National Beans Research Programme, were promoted from 2003 to 2007 inBushenyi and Kisoro Districts that were most susceptible to this disease. This study was conductedto assess the level of uptake of technologies and practices promoted in the target area, and factorsinfluencing the decision to adopt. Data were collected using a semi-structured questionnairethat was administered to 160 purposively selected bean farmers. The Poisson regression modelwas used to determine the factors influencing the number of technologies and practices used. Thestudy revealed that majority (95.0%) of the bean farmers had adopted at least one of the improvedbean varieties promoted. The results further show that NABE 12C, NABE 13 and NABE 14 werethe most preferred improved varieties. Preference was mainly attributed to high yield, palatabilityand short cooking time. Use of improved and resistant varieties (95.0%), sowing of one seed perhole (72.5%) and Farm Yard Manure (71.3%) were the most commonly used in management ofthe bean root rot disease. Analysis of the sequential combination of technologies adopted revealthat most farmers in Kisoro district used improved varieties + Farm Yard Manure + Row planting+ One seed per hole; while the farmers in Bushenyi mainly used a combination of improvedvarieties + Farm Yard Manure +Crop Rotation + One seed per hole. Poisson results indicated thatadoption was significantly and positively influenced by access to bean information, number oftimes a farmer was trained, participation in farmer to farmer seed loan scheme, record managementand the price of improved varieties. Age of household head had a negative influence andsignificantly reduced the expected number of technologies and practices used in the managementof BRR disease by 20%. To sustain the use of bean root rot management technologies and practices,there is need to support establishment of community-based seed production systems which havealready shown evidence of success in other areas and crops to ensure availability of sufficient quantities of seed and access to resistant varieties; support rural enterprises which provideinputs; and ensure farmers’ continued access to information though use of different channelsand media