University of Zambia Journal of Agricultural and Biomedical Sciences

A Qualitative and Biochemical Analysis of Biofloc from an Indoor Biofloc Technology System Culturing Oreochromis Karongae.

Mon, 27 Nov 2023 13:58:13 +0000

The structure of microbial communities in a Biofloc Technology (BFT) system has great influence on the optimal functioning of the system. This makes understanding the microbial composition in BFT of paramount importance. A study was conducted to characterize the microorganisms in an indoor biofloc technology system. The microorganisms were qualitatively and biochemically analyzed. Qualitative analysis of microorganisms in BFT was carried out using microscopy and plate culture of bacteria and fungi. Isolated bacterial were identified by colony morphology, gram staining and microscopic observation. Catalase test as biochemical test was also used in identifying bacteria. Biochemical analysis of the biofloc was achieved through proximate analysis of nutrients following AOAC (2002) methods. The biofloc sample used in the present study was obtained from culture water of three 1000l circular fiberglass tanks with a working volume of 580l of biofloc water per tank. Oreochromis karongae fingerlings where stocked in the three tanks at a stocking density of 6kg/m3 per tank and cultured for 12weeks. The fish were fed 30% CP on-farm formulated feed (2mm pelleted) with a feeding rate of 1.5% of total estimated fish biomass. Maize flour was added in tanks to maintain an optimum C/N ratio (above 10) for heterotrophic bacteria production. Microscopy of the biofloc water revealed various types of microorganisms which included Protozoa (e.g. ciliates), Zooplanktons (e.g. Rotifers and copepods) and nematodes, heterotrophic bacteria and fungi. It was noted that the bacteria were all heterotrophic bacteria which confirmed their utilisation of organic carbon in the BFT system to produce microbial protein. The biochemical composition of biofloc showed that the nutritional quality of biofloc was appropriate for tilapia with the exception of lipid content which was found to be (3.25%). This value is considered low for aquaculture feed as a range of 5- 10% lipid content in feed is recommended. BFT is a promising field which will enable aquaculture to grow towards an environmentally friendly approach because of the ability of microorganisms to recycle nutrients in the system.

Effects of Different Levels of a Locally Made Probiotic (BiolatemTM ) Administered via Drinking Water on Growth Performance of Broiler Chickens

Mon, 27 Nov 2023 15:22:03 +0000

This study aimed at determining the growth performance of broiler chickens offered varying amounts of a locally made probiotic (Biolatem™) in drinking water. One hundred and ninety-two (192) day-old chicks were bought from a local hatchery, and divided into four groups (n = 48). The groups were randomly allocated to four levels of Biolatem™ via drinking water (i.e., 0, 5, 8 and 10mL of Biolatem™ per 5L of drinking water). Both the water and feed were offered to the birds in all treatment groups ad libitum from 0 – to 42 days of age. Feed and water intake was monitored daily, and body weights were assessed at 0, 7, 14, 21, 28, 35 and 42 days of age. Weight gains and feed conversion ratios were calculated weekly. Generally, birds that received Biolatem™ in water showed higher (p < 0.05) total weight gains, daily weight gains and final body weights at 42 days of age than those that consumed water without Biolatem™. Among birds that received Biolatem™, those that were offered 8mL of Biolatem™ per 5L of drinking water had better performance (p < 0.05) in the variables assessed. It was concluded that Biolatem™ positively influenced the growth performance of the broiler chickens, and the best performance was exhibited by birds that were consuming water with 8mL of Biolatem™ per 5L in it.

Towards the Development of a Finger Millet (Elesine Coracana L. Gaertn) Breeding Programme in Zambia

Racheal Msikita — Tue, 05 Dec 2023 14:48:00 +0000

Finger millet [Eleusine coracana (L.) Gaertn] is one of the potential cereals that can be used to mitigate climate resilience among the smallholder farmers who are the major growers. It has the capacity to adapt to extreme environmental conditions as well as growing under a wide range of wider agro ecology an advantage to other cereals, which can be capitalized in breeding. However, the breeding of finger millet in Zambia is constrained by the lack of knowledge on the genetic information, compared to other small grains cereal crops. Therefore, a study was conducted to assess the diversity of mutant lines in the six generation. A pure line selection from a landrace finger millet variety Mutubila was sourced from the Sorghum and Millet Breeding Program of the Zambia Agriculture Research Institute (ZARI) in 2013. Seed was divided into four lots of 1 kg and subjected to gamma ray mutagenic treatment at 0 (control), 100, and 150 and 200 at the National Institute for Scientific and Industrial Research (NISIR) in Lusaka in 2014. An equal amount of Irradiated seed (First mutation generation) from each dose was planted in Mpulungu during the off season of 2013 in plots of 50m x 50m spacing 30cm intra row and 30cm intre rows. The second generation showed 99% plant survival with 0, 70% plant survival with 100, 10% plant survival with 150 and 0% plant survival with 200. Therefore, the subsequent segregating generations from 100 were used for selection. The mutant lines were selected from generations that were exposed to different culling rates as generations increased, after repeated selection 40 mutant lines were selected planted with six checks using an Alpha Lattice design with two replications and eight blocks, 48 genotypes were evaluated for agronomic performance. Results revealed that the mutant lines were diverse in number of productive tillers per plant, main ear length that ranged from: 3 to 15 and 4.4cenmetre to 14.5cenmtre respectively, while for number of fingers per earhead and grain yield ranged from: 3 to 17 and 0.58 to 2.5kilogram per hectare respectively. Productive number tillers, Finger length, straw weight, and number of fingers were strongly and positively correlated to grain yield (R2 > 0.67). There were X clusters, highest number of sub clusters was (11) in cluster I. Maximum inter-cluster distance was observed between clusters V and IV, V and VII, V and IX and VII and XI, indicating wider divergence among these clusters. Minimum inter-cluster distance was between II and III, VIII and X, I and VIII. Distant clusters indicated that genotype present in one cluster differed completely from the one in the other clusters, thus could be used for generating superior genotypes. The study showed that selecting for yield components as the mutants are advanced results in divergent lines which can be recombined to breeding high yielding and disease tolerant finger millet. We conclude therefore, that mutation breeding for Finger Millet can be used to generate diversity and divergent lines can be recombined to develop improved genotypes for commercialisation.

In Vitro Susceptibilities of Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa and Escherichia coli to the inner Gel of Aloe nuttii Baker and Aloe chabaudii Schonland found in Zambia.

Ellah Zingani, Hanzooma Hatwiko, Nosia M'hango — Tue, 05 Dec 2023 00:00:00 +0000

The genus Aloe has a long history of medicinal usage in the world and is believed to treat various ailments. It contains bioactive compounds that work synergistically against various microbes. A comparative study of the two Zambian Aloe species Aloe nuttii Baker and Aloe chabauddii was done with the objectives to determine the antimicrobial activity, the minimum inhibition concentration and the susceptibility of microbes namely Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa and Escherichia coli. The study was a quantitative, comparative laboratory based study. A Liquid-Liquid extraction method modified from Marjory Cowan, 1999 was used. The extracts were tested on microbes using the Agar Disk Diffusion Method modified from Kirby Bauer 1966 and assessed by the growth inhibition zones. The two fold dilution method modified from Doughari, 2007 was used to find the Minimum Inhibitory Concentration. Only the water extracts of Aloe nuttii Baker inhibited the growth of all the five microbes tested as indicated by the growth inhibition zones as follows: S. aureus 12±2mm, S.spp.10.3±0.7mm, P. aeruginosa 9.3±1.7mm, E. coli 10.7±1.3mm and Candida albicans 14±0.6mm. In contrast, Aloe chabaudii extracts displayed no antimicrobial activity. The MIC of Aloe nuttii Baker was found to be 1500mg/ml for Candida albican, P. aeruginosa and E. coli and 3000mg/ml for S. aureus. In contrast Aloe chabauddi did not inhibit any microbial growth. Invitro, Staphylococcus aureus, Candida albicans, Pseudomonas aeriginosa and Escherichia coli were susceptible to the inner gel of aloe nutty baker but in contrast showed no susceptibility to the inner gel of aloe chabaudii schonaland found in Zambia.

Investigating Practices Among Fish Farmers That Predispose Them To Malaria Infection: An Analytical Cross Section Survey In Mongu And Limulunga Districts Of Western Province, Zambia

Ellah Zingani, Lungowe Nakweba — Wed, 06 Dec 2023 16:11:44 +0000

Malaria is a parasitic disease that is transmitted between humans through the bite of the infected female Anopheles mosquito. Zambia has recently experienced a growing demand for fish, which is largely triggered by the growing population and an emergent urban middle class within Zambia and neighbouring countries. Various fish farming practices are carried out on small-scale, smallholder and commercial levels. Western Province is among the provinces in Zambia where fish farming is done. In 2014, Zambia became the sixth largest producer of farmed fish (mainly breams – a local name for tilapia) in Africa and the largest in the Southern African Development Community (SADC) and between 2012 and 2015, the malaria prevalence started to climb from 12.6 to 15.6 per cent in Western Province of Zambia. This study set out to investigate the practices of fish farmers that predispose them to malaria infection in Mongu (45) and Limulunga (30) districts of the western province of Zambia. The data collection tool was an interviewer-administered questionnaire (demographic characteristics, malaria knowledge, and fish farming practices). The data were analysed using the Statistical Package for Social Sciences (SPSS) version 22. Out of a total of 75 fish farmers, 83% of the participants had good knowledge of malaria while 17% had poor knowledge, and an association was found between the two highest levels of education (Tertiary and Secondary) and knowledge on malaria according to the chi-squared test (p<0.005) and also showed that 73% (n=55) had their ponds near their houses and 3% (n=20) had their ponds far from their houses. Practices such as not draining ponds, working around the ponds at night without protective clothing, and having ponds near households predispose fish farmers to malaria infection in Mongu and Limulunga districts in Western Province, Zambia. Collectively, 21% of fish farmers practice unsafe fish farming, which could potentially increase malaria transmission levels in Western Province, Zambia.