Agriculture

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Annotation and comparative analysis of P450s, their redox partners and secondary metabolite gene clusters in the bacterial phylum Firmicutes
(University of Zululand, 2021-11) Padayachee, Tiara
Cytochrome P450 monooxygenases (CYPs/P450s), heme thiolate proteins, are well known for their role in organisms’ primary and secondary metabolism. P450s are also involved in the generation of secondary metabolites with biotechnological value. P450s require electrons to perform their function, and these electrons are provided by iron-sulfur (Fe-S) cluster proteins known as ferredoxins. However, to date, comparative analysis of P450s, redox proteins and P450s involved in secondary metabolite production is not reported in the bacterial phylum Firmicutes. This study aimed to address this research gap. Genome-wide analysis of P450s in 972 Firmicutes species belonging to 158 genera revealed that only 229 species belonging to 37 genera have P450s; 38% of Bacilli species, followed by 14% of Clostridia and 2.7% of other Firmicutes species, have P450s. The pathogenic or commensal lifestyle influences P450 content to such an extent that species belonging to the genera Streptococcus, Listeria, Staphylococcus, Lactobacillus, Lactococcus and Leuconostoc do not have P450s, except for a handful of Staphylococcus species that have a single P450. Only 18% of P450s are found to be involved in secondary metabolism and 89 P450s that function in the synthesis of specific secondary metabolites are predicted. A total of 281 ferredoxins were found amongst 227 Firmicutes species. Four types of ferredoxins were found in this phylum, namely, 2Fe-2S, 4Fe-4S, 7Fe-8S and 2[4Fe-4S]. The dominant type found amongst this phylum was 4Fe-4S with 140 ferredoxins followed by 2Fe-2S with 97 ferredoxins, 7Fe-8S with 32 ferredoxins and 2[4Fe-4S] with 12 ferredoxins. To date, evolutionary analysis of these proteins across the domains of life is confined to observing the abundance of Fe-S cluster types and the diversity of ferredoxins within a type is not reported. To address this research gap, here a subtype classification and nomenclature for ferredoxins based on the characteristic spacing between the cysteine amino acids of the Fe-S binding motif as a subtype signature was proposed. To test this hypothesis, comparative analysis of ferredoxins between Firmicutes and ferredoxins collected from species of different domains of life that are reported in the literature has been carried out. Various ferredoxin subtypes were found amongst Firmicutes species. Eleven different subtypes were found amongst 2Fe-2S ferredoxins with subtype 20 being the dominant subtype. 4Fe-4S had five subtypes with subtype 2 being dominant, and 2[4Fe-4S] had three subtypes with subtype 9 being dominant. It is interesting to note that 7Fe-8S only had one subtype showing a preference to that specific ferredoxin subtype. Three subtypes of 2Fe-2S and two subtypes of 2[4Fe-4S] were found to be common between the Archaea and Firmicutes species, indicating their shared common ancestral origin. Overall, the study results supported the hypothesis proposed by our laboratory that organisms’ lifestyles impact P450 repertoire in their genomes. This is clearly evident in the bacterial phylum Firmicutes where a pathogenic or commensal lifestyle resulted in complete or nearly loss of P450s in the species. This study also is the first to propose ferredoxin subtype classification and identification of ferredoxins that have common ancestor origin (between Archean and Bacteria) and those are subjected to lateral gene transfer from prokaryotes (Archean/Bacteria) to eukaryotes.
Assessment of minor ions and trace element chemistry in groundwater in Luvuvhu catchment, Limpopo province, South Africa.
(Univeristy of Zululand, 2022) Madondo, Takalani Patience
Agricultural activities are often associated with contamination of water, which resulted in high concentration of nutrients and trace metals in the shallow aquifer. Occurrence and distribution of nutrients and trace metals in the groundwater of intensively irrigated region of Luvuvhu catchment was carried out to determine the status of groundwater quality and its suitability for drinking. Groundwater samples were collected and analysed for physiochemical parameters. The results suggest that the concentration of nutrients and trace metals in the groundwater are below the permissible limit of drinking water standards recommended by the World Health Organization and South African standards except pH, K and Pb. Low pH (51%), potassium (31%) and lead (100%) restrict the groundwater usage for drinking. Relation between groundwater flow direction and EC, sulphate, nitrate, and ammonium contents indicate that it is mostly constant towards the centre of the study area, but sudden enrichment is noticed in the downstream. Silica and fluoride has increased along with the direction of groundwater flow. Trace metals (B, Pb and Zn) show decreasing trend in the flow direction. However, pH, K, Li, Cr, and phosphate concentrations do not show significant variation along the flow direction. Positive relation between nitrate, EC, sulphate, and ammonium implies that groundwater quality is affected by the surface contamination sources, and mostly from irrigation return flow, through the application of fertilizers and organic manures. However, groundwater with high silica and fluoride also has high nitrate, which justifies that wastewater infiltration from the surface has triggered the mineral dissolution in the vadose. Trace metals does not correlate with nitrate. High concentrations of trace metals are recorded with low nitrate, which implies that metals are derived from mineral weathering. However, boron concentrations in a few wells show positive relation with nitrate, which justified the impact of natural sources and irrigational activities.
Assessment of selenium supplementation on the attainment of puberty in Merino ram lambs
(2023) Makhado, Ngelekanyo Elaine
In small ruminants, the attainment of puberty is influenced by different factors, such as season of birth, photoperiod, nutrition, breed type, management, genetics, endocrine regulation, body weight and the development of the reproductive system. This study was conducted to evaluate the effect of selenium (Se) supplementation on the attainment of puberty in South African Merino ram lambs. Forty South African Merino ram lambs were divided into two groups, Se-supplemented (n = 20) and control (n = 20). The treatment group received a dosage of 0.34 mg Se per kg in the form of sodium selenite at two-week intervals for an experimental period of 130 days. The phenotypic parameters were evaluated weekly. Semen was collected each week using an electroejaculator and was analysed for volume, pH, appearance, motility, viability, morphology and concentration. Blood samples were collected bi-weekly to determine the concentration of glutathione peroxidase (GSH-Px), cortisol and reproductive hormones. Collected data were analysed using analysis of variance, and the means were separated through the Student’s t-test. At 6 months, motile spermatozoa were collected from 80% of the supplemented group compared to 60% of the control. The Se treated group showed significantly higher semen quality in the form of improved spermatozoa motility, concentration, increased percentage of live spermatozoa, decreased percentage of dead spermatozoa and fewer spermatozoa abnormalities compared to the control group. Supplementation with Se had no effect (P > 0.05) on body weight and scrotum circumference. Selenium supplementation significantly (P < 0.05) improved testicular measurements and decreased the age to attain puberty. Supplementation with Se also increased luteinising hormone and testosterone concentrations (P < 0.05). However, Se supplementation did not affect glutathione peroxidase and cortisol concentrations (P > 0.05). The control group attained puberty at 6.5 months based on ejaculated semen with viable spermatozoa. Therefore, it was concluded that Se supplementation hastened the attainment of South African Merino ram lambs’ puberty to 6 months. Treatment also improved testicular measurements, semen quality and reproductive hormones concentration of South African Merino ram lambs.
An assessment of the contribution of peri-urban agriculture on household food security in Tongaat, eThekwini Municipality
(University of Zululand, 2018) Khumalo, Nolwazi Zanele; Sibanda, M.
Despite South Africa’s economic growth having been accelerated considerably in the country, poverty levels have not decreased as one would have expected. Urban and peri-urban agriculture have been introduced as a livelihood strategy to alleviate poverty and ensure household food security. Food insecurity is conventionally theorized as a rural development problem and the current theoretical tools to comprehend the challenge and frame the responses are inadequate to address food insecurity in urban areas. The aim of this study was to assess the contribution of peri-urban agriculture on household food security in in Tongaat peri-urban area of eThekwini Municipality. A quantitative approach, employing a cross-sectional design was used to gather data. Stratified random sampling was employed, and a total of 208 households (109 farming and 99 non-farming households) were sampled. Data analysis was done through descriptive statistics and inferential statistics (econometric modelling using a probit regression model). On average, respondents were about 46 years old. There was a high rate of unemployment with the majority (51%) of the total sample indicated that they were not formally employed. The results revealed that labour for gardening activities was predominantly supplied by female household members. A greater proportion (about 46%) of the interviewed farming households in Tongaat were involved with field crops (which included cabbages, spinach, sweet potato and avocado) followed by livestock rearing which accounted for about 40 percent of the sample, poultry (about 35%), fruits (about 4%) and flowers (about 3%). The majority (50% and 62%) of crop and livestock farmers respectively reported that limited land availability and drought were the major farming challenges for each category of farming. The results from the HDDS tool, showed that a greater proportion (54%) of the farming households consumed >6 food groups (deemed to be food secure) as compared to their counterparts, the non-farming households (40%) percent that were consuming >6 food groups. On the other hand, a greater proportion (12 and 47.5%) of the non-farming households were consuming <3 and 4 to 5 food groups respectively (deemed to be food insecure and moderately food secure in that manner). The finding is further supplemented by the HFIAS measure which revealed that a greater proportion (about 72%) of the farming households indicated that they never or rarely worried about food shortages (deemed to be food secure) as compared to their counterparts – the non-farming households (about 61%) that never or rarely worried about food shortages. Again, a lesser proportion (about 4%) of the farming households indicated that they often had to cut down on meal size or on the number of meals (deemed to be severely food insecure) as compared to their counterparts – the non-farming households (about 10%) that indicated that they often had to cut down on their meal size or on the number of meals. Overall farming households were beffer off or more food secure than their non-farming counterparts. Overall the total sampled households showed mixed perceptions regarding the practice of peri-urban agriculture in Tongaat. Overall, there were mixed feelings vi (perceptions) ranging from neutral, positive and negative with respect to societal recognition; attitude; social value; economic; health and knowledge impacts. However, farming households showed an affirmative perception towards the practice of peri-urban agriculture than the non-farming households. Results from the probit regression model showed that the variables land size and land tenure were important predictors with regard to the practise of peri-urban agriculture. The study recommends that peri-urban agriculture should be promoted as a tool to achieve household food security and that land issues regarding to land sizes and land tenure be attended to if peri-urban agriculture is to contribute more positively in ensuring household food security within the peri-urban spheres.
Characterisation of Production Systems and Phenotypic Traits of Indigenous Chickens in Communal Areas of KwaZulu-Natal
(University of Zululand, 2018-03) Vilakazi, Bongiwe, Nontobeko
Indigenous chicken genetic resources play a major role in rural communities. There is therefore a need for their sustainable use and conservation. Conservation requires knowledge of production systems, phenotypic and genetic characteristics. The aim of this study was to understand the production systems and phenotypic variation among indigenous chickens in some areas of KwaZulu-Natal. A survey was conducted in six districts of KwaZulu-Natal to characterise indigenous chicken production systems;, predict body weight from linear body measurements of indigenous chickens using principal component analysis, and identify the morphological variation among indigenous chicken populations. Small flock sizes ranging from 2 to 80 indigenous chickens were observed in households. The majority of farmers started rearing a few indigenous chickens sourced from related stock through inheritance, gifts and buying. Indigenous chickens were reared as a source of meat, eggs and income. Most farmers (72%), were not aware of the importance of conserving indigenous chickens. The most common constraints raised by farmers were diseases, predators and theft. The most commonly practised production systems were extensive and semi-intensive. Poor management in terms of feeding, watering and health was reported in all surveyed areas. Principal component analysis of linear body measurements extracted two principal components with a total variance of 63.94%. Principal component one, related to body size, had the largest share of breast circumference, body length and shank circumference. Principal component two, related to body shape, had high loadings on toe length, shank length and back length. The use of principal components was more appropriate than the use of original correlated variables in predicting the weight of indigenous chickens. Variation in morphological traits was observed; 10 plumage colours were realised from different locations, and variation was also observed in skin colour, eye colour, shank colour and comb type. Variation in phenotypes may reflect variation in the genome of the indigenous chickens. Discriminant analysis identified body weight as the most discriminating variable in differentiating indigenous chickens. Two major clusters were formed: the first by Newcastle, Port Shepstone and Cedara; the second by Pietermaritzburg and Ladysmith. Empangeni and Jozini individually joined the two clusters. Although Jozini showed itself to be more distant to the others, 51.1% of indigenous chickens were correctly assigned to their population. It was concluded that with the existing variation improvement in size and aesthetic characteristics of the indigenous chickens can be achieved through selection according to the needs of the farmers. Farmers require assistance on husbandry and management of indigenous chickens.
The characterisation of semen from Zulu Rams raised under extensive management conditions in KwaZulu-Natal
(University of Zululand, 2015) Chella, Lisa Coelleen; Kunene, N.W.; Lehloenya, K.
The Zulu sheep is an Nguni breed indigenous to the KwaZulu-Natal (KZN) province in South Africa, and is reported to be under threat of extinction. Studies investigating the factors that may be the cause of the declining numbers are required for the strategic planning of conservation programmes. The study was designed to evaluate some of the factors viz. ram age, season and geographic location, that influence reproductive performance in Zulu sheep populations based on the viability of Zulu ram semen. Spermiogramic parameters used to assess quality were: scrotal circumference (cm); semen volume (ml); semen pH; sperm concentration (x109), progressive and mass motility (%), and percentages of live and abnormal spermatozoa. Semen samples were collected via electro-ejaculation and analysed using a microscope while the scrotal circumference was measured using a flexible measuring tape. All data was analysed using the statistical software SPSS version 22. The average semen volume (ml) per ejaculate was 0.66, 1.11, 1.19, 0.82 and the sperm concentration 1.69, 2.79, 3.12, 3.07 (x109) for summer, autumn, winter and spring, respectively. The effects of age on all parameters were significant except for pH. There was a positive correlation between age and semen volume, concentration and semen colour. The values of volume, concentration, motility and live sperm increased linearly up to 3 years of age. Scrotal circumference and live spermatozoa were comparatively higher for rams at 3 years of age than at 4 years of age, while the values were the same at 1 and 2 years of age. The percentage of abnormal spermatozoa decreased down to 3 years of age, thereafter increasing from 4 years of age. The semen quality improved at 3 years of age and thereafter decreased. The effects of season on semen quality positively correlated in some of the geographic locations. For conservation purposes it would therefore be more efficient to select breeding sires from among the 3 year old rams for the autumn and winter breeding programme.
Chemo-morphological characterisation and some biological activities of pelargonium sidoides DC.
(University of Zululand, 2013) Mthiyane, Pretty Gqamile; Mavengahama, S.; Kleynhans, R.; Opoku, A.
Pelargonium sidoides DC (Geraniaceae) is one of several medicinal plants indigenous to South Africa. Various concoctions prepared from the plant are used for the treatment of tuberculosis, diarrhea, gonorrhea and fevers. The aim of this study was to evaluate the variability in qualitative and quantitative traits in P. sidoides accessions, correlate different morphotypes with the phytochemical content, and to the antimicrobial activity of P. sidoides extracts. Morphological characterisation of accessions of P. sidoides was done using IPGRI/IITA/BAMBNET list for Bambara groundnut. Principal Component Analysis (PCA) and Cluster Analysis (CA) were used to evaluate the morphological variability and to reveal the groups of different morphotypes. The PCA revealed that the first three principal components exhibited Eigenvalues greater than 1 and explained 74.170% of the total variability, contributing the entire variable to the morphological variation of the accessions established at the University of Zululand. Cluster analysis was able to group the morphotypes into two major groups with each group having two sub-groups. Nine groups of the morphotypes were selected and screened for coumarins (umckalin, esculin and scopoletin) using Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Coumarins are known to exhibit moderate antibacterial and significant immunomodulatory capabilities. Variation was observed in the phytochemical content (umckalin) of morphotypes of P. sidoides. The content of umckalin varied between 13.90 mg/ml and 4.41 mg/ml in the roots of morphotypes of P. sidoides and 0.15mg/ml and 3.90 mg/ml in the leaves of morphotypes of P. sidoides. Methanolic extracts from leaves and roots of selected morphotypes were screened for antimicrobial activity against Escherichia coli ATCC 8739, Staphylococcus aureus ATTC 6538, Shigella flexineri and Salmonella ssp. The antimicrobial activity was determined by agar-well diffusion method. The minimum inhibitory concentration (MIC) of active extracts was determined using the micro-plate dilution assay. Significant variation was observed among all accessions for all the investigated traits. The high morphological variation that was observed among morphotypes did not affect the phytochemical content and antimicrobial activity of P. sidoides. Most of the extracts showed relatively high antimicrobial activity against the tested bacterial strains with the inhibition zones ranging between 8.0 and 12.0 mm for leaves and 15.0 and 20.5 mm for the roots. The MIC values for active extracts ranged between 1.5 to 5 mg/ml. In vivo antidiarrheal activity of P.sidoides methanolic root extracts in rats (Sprague-Dawley) was investigated. In the castor oil induced diarrhea experiment, the rats that did not receive the P. sidoides plant extracts showed typical diarrheal signs, stools were too wet. P. sidoides extracts inhibited castor oil induced diarrhea in Sprague-Dawley rats at doses of 100, 200 and 400 mg/kg. The extracts reduced the weight of feacal pellets with extracts treated groups showing lower diarrheal severity than control rats. The variants utilised in this study seem to have similar compounds and could be all utilized in future research on cultivation practices. It was concluded that leaves of the plants may be harvested instead of roots to minimise the complete removal of the plants. The results of this study suggest that P. sidoides extracts possess anti-microbial activities against some of the tested microorganisms which are significant pathogens in humans. P. sidoides roots have the potential for the treatment of diarrhea.
Consumer perceptions, preferences, and their purchase intentions for organically grown products in Shelly Beach shopping centre, Port Shepstone
(University of Zululand, 2019) Wekeza, Siphelele Vincent; Sibanda, M.
In the last few years, the market of organically grown products has continued to grow. This is due to the continued increase of consumers’ concerns regarding the environmental, food safety and health issues, especially for food products. These issues have led to an increase in demand which outstrips the supply, which threatens the organic industry. The study aimed to analyse consumer perceptions, preferences and factors influencing the purchase of organically grown products in the Shelly Beach Shopping centre in Port Shepstone under the Ray Nkonyeni Local Municipality of the KwaZulu-Natal Province. The study was quantitative and employed a descriptive cross-sectional design. A systematic random sampling method was employed. The study comprised of 150 organically grown product consumers. Data were collected using structured questionnaires. Data was analysed using the Statistical Package for Social Sciences (SPSS) version 25 and STATA 14 software. Descriptive analysis of data was applied in the study to describe consumers’ characteristics, perceptions and preferences. A multiple regression analysis was used to test for the factors influencing the purchase intentions of organically grown products. The study suggested that women (about 63%) purchased organically grown products more than men. The results revealed that all consumers had at least 12 schooling years (matric education). Most (about 53%) of the interviewed consumers were not married (single; divorced or widowed). A greater proportion (about 45%) of the interviewed consumers that purchased organically grown products had family size which was about less or equal to 5 members and mostly (about 73%) of respondents were full-time employed. With regard to consumer perceptions towards organically grown products, results revealed that consumers that were environmentally conscious, concerned about food safety and healthiness had a positive attitude towards the purchase of organically grown products. Results from the multiple regression model revealed that factors such as; ethnicity; household size; employment status; household income and perceptions that organically grown products have a better smell and fresh were found to have a positive and significant influence on the purchase intentions in the study area while age, education, consumer perceptions that organically grown products have a good taste and of high quality and difficulty to access in the market were found to have a negative and significant influence on the purchase intentions. Consumer awareness and education programmes must be targeted at youth to inform them about organically grown products. Government funding should assist farmers in solving the “difficulty to access” issue of organically grown products.
Developing container protocol for screening sugarcane (Sacchurum officinarum L) varieties for tolerance to water-deficit stress
(University of Zululand, 2021) Chandiphosa, Misheck
In Zimbabwe, sugarcane (Sacchurum officinarum L) is an important crop grown for sucrose, ethanol and other by-products such as molasses, bagasse and filter cake. Drought due to climate change is projected to negatively reduce the production of sugarcane. The effects of water-deficit stress due to climate change can be mitigated by growing water-deficit stress tolerant sugarcane varieties. There is limited information on drought tolerant genotypes among the 14 released sugarcane varieties in the Zimbabwe Sugarcane Industry. Screening of these varieties can be effectively done in containers as it is rapid and economic. It has been noted that plants grown in containers under natural environmental conditions show symptoms of stress. Consequently, it was prudent to first develop a protocol that minimises the stress inherently associated with growing plants in a container. Sources of stress for container-grown sugarcane plants include the rate and frequency of applying irrigation water, growth medium, fertiliser rates and size of the container used. After obtaining the protocol that minimised stresses associated with these sources, the varieties were screened on their tolerance to water-deficit stress. Five experiments were done at the Zimbabwe Sugar Association Experiment Station (ZSAES) located in Chiredzi. The first experiment tested seven rates of applying irrigation water for sugarcane plants grown in container (35 cm top diameter, 23 cm bottom diameter and 27.5 cm height). The water application rates tested were 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 litres per container per day. The growth media used in this experiment were pine bark (6-8mm) + vermiculite (1:1 v/v) and ZSAES soil medium comprised of a mixture of top soil: composted cattle manure: sand (5:2:2 v/v). The study showed that water application rates greater than 2.5 L per container per day increased stem height, number of tillers anddry matter of sugarcane plants in the ZSAES soil medium over pine bark + vermiculite. However, reduced germination of cane setts and root dry matter was observed in plants grown in the ZSAES soil medium. The second experiment assessed the suitability of four media for growing sugarcane plants in containers. The media tested were filter cake only, filter cake + pine bark, pig manure + pine bark, and the ZSAES soil medium. Growing plants in pig manure + pine bark produced more iv tillers, shoot and root dry mass, green leaf area and number of leaves and leaf nutrient adequacy than the other media tested although stem height was suppressed. The third experiment assessed the suitability of five blend fertiliser rates for growing sugarcane plants in containers. The rates tested were 312.5mg/l, 937.5mg/l, 1562.5mg/l, and 2187.5mg/l of Triple 16 blend fertilizer (16% N, 16% P2O5 and 16% K2O) and Hoagland nutrient solution per container (control). The study revealed that the application of 937.5mg/l Triple 16 blend fertiliser fortnightly until 56 days after planting (DAP) resulted in more tillering but, also reduced stem height in all the four media tested. This was deemed adequate nutrition for sugarcane plants. The fourth experiment tested the interactions of pot sizes and three growth media for suitability for growing sugarcane plants in containers. The three sizes of containers tested in the experiment were respectively small (25.5 cm deep x 31.3 cm diameter), medium (45 cm deep x 54 cm diameter) and large (90 cm deep x 54 cm diameter). The three media used were filter cake, filter cake+ pine bark and the ZSAES soil medium. Filter cake + pine bark in large containers produced sugarcane plants with thicker and taller stems and heavier total plant dry matter than the other treatments. The fifth experiment tested all 14 commercial sugarcane varieties in Zimbabwe for their tolerance to water-deficit stress by growing the varieties in two levels of irrigation viz well-watered (100%) and water stress (30% of daily water volume applications). The varieties tested were ZN1, ZN2, ZN3, ZN4, ZN5, ZN6, ZN7, ZN8, ZN9, ZN10, CP72-1312, NCo376, N14 and CP 72-2086. All things considered, sugarcane varieties that can be grown by cane famers when faced with drought instigated by climate change are NCo376, ZN1, ZN8, ZN10 and N14.
Development of an embryo-larval chronic toxicity test using the sea urchins Tripneustes gratilla and Echinometra mathaei
(University of Zululand, 2019) Pillay, Anthea Chloe
Toxicity tests use organisms to assess the effects of the bioavailable fraction of toxicants in effluents and environmental media, such as water and sediment. Test organisms must be highly sensitive and ecologically relevant. Gametes of the sea urchins Echinometra mathaei and Tripneustes gratilla are used for acute toxicity testing purposes in South Africa through the fertilisation test (e.g. for testing effluents and seawater samples). However, this test has raised questions on the longer-term, sub-lethal effects of toxicants in effluents and other environmental media tested. The aim of this study was thus to develop a chronic toxicity test using the larvae of these sea urchins, to allow for more comprehensive toxicity testing. To achieve this aim, the influence of temperature on larval development to the 4-arm pluteus stage was first evaluated, to determine the duration of the toxicity test. Embryos of the sea urchins were exposed to three temperatures, namely 20, 23 and 26 °C, and development was documented at 24 h intervals until the 4-arm pluteus larva was attained. The optimum temperature for normal larval development for both species was 23 °C, with the 4-arm pluteus stage attained at 72 h for E. mathaei and 96 h for Tripneustes gratilla. The sensitivity of the sea urchin larvae to potential reference toxicants copper and zinc was evaluated. Reference toxicants are critical for quality assurance in toxicity testing. The EC50s were used to construct control charts for each species. The control charts and coeffiecient of variation identifies the preferred reference toxicant, for E. mathaei as zinc and for T. gratilla as copper. The larval development test was then used to test the toxicity of seawater desalination brine, effluent from two wastewater treatment works and water collected in a marine environment that receives effluent from a pulp mill effluent concurrently with the fertilisation test. This was to compare the sensitivity of each test in detecting toxicity. The minimum acceptable toxicant dilution (MATD) was calculated from dose-response curves using the linear interpolation model and the index of difference was used a measure of sensitivity. The larval development test was generally less sensitive in detecting toxicity of seawater desalination brine and effluent compared to the fertilisation test, but the difference was negligible. In contrast, the larval development test was more sensitive in detecting toxicity of seawater samples collected from the receiving water of pulp mill effluent, but the results were highly variable. The fertilisation test would be the preferred choice for toxicity testing of seawater desalination brine, effluent and receiving water samples of pulp mill effluent as it is generally more sensitive, rapid and cost effective for sample analysis. However, this is not a definitive II decision because the larval development test may be more sensitive in other applications using different types of effluent or water samples from receiving environments.
Diet selection and foraging efficiency of Nguni goats in the Zululand Thornveld, Kwazulu-Natal
(2008) Mkhize, Ntuthuko R.; Scogings, P.F.; Nsahlai, I.V.
Foraging efficiency and diet selection are central processes in plant-herbivore interactions. An understanding of these important parameters of foraging behaviour underpins sustainable vegetation management and profitable animal production. As a step towards better understanding the browse-browser interactions in a sub-humid subtropical savanna, a Nguni goat breed was used as a model browser in cafeteria-style experiments. The primary objective of the study was to determine the seasonal and plant species patterns of foraging efficiency (indexed by short-term intake rates) and diet selection (indexed by intake). The secondary aim was to investigate how potential explanatory variables such as plant morphology (spinescence, long vs. short shoots and broad vs. fine leaves), phenology (evergreen vs. deciduous species) and plant chemistry (nitrogen, neutral detergent fibre, acid detergent fibre, acid detergent lignin, condensed tannin, cellulose and hemicellulose) are related with the observed patterns. Six browse species (Acacia natalitia, A. nilotica, Dichrostachys cinerea, Grewia occidentalis, Gymnosporia marangiiensis and Sciitia myrtind) were used in two experiments to estimate (1) short-term intake rates and (2) intake patterns at four times during the year (i.e. early, middle and late wet season and dry season). Intake rates varied significantly (P ~ 0.022) among plant species, with broad leaved species being consumed at higher rates than fine leaved ones. Intake rates were highest during the dry season (mean: 0.18 g s"1 ± SEM: 0.012 g s'1) and lowest in the late wet season (mean: 0.15 g s" ± SEM: 0.009 g s" ). Bite size was found to be the key variable influencing the intake rate of Nguni goats. No significant relationships were found between intake rate and either nitrogen, neutral detergent fibre, acid detergent fibre, acid detergent lignin, cellulose or hemicellulose concentrations. Condensed tannin concentration (% DM) was positively correlated with both intake rate (r = 0.65, P = 0.001, n = 24) and bite size (r = 0.53, P = 0.007, #i = 24). Diet selection was affected by the interactions between the seasons and browse species (P = 0.001). S. myrxina and G. occidentalis were consistently among the most preferred species through out all seasons, while the opposite was true for G. marangiiensis and A. nilotica. During the dry season, A. natalitia ranked third among the avoided species and inconsistently featured among the most preferred species later in wet seasons. The opposite was observed for D. cinerea. A positive relationship was also observed between intake (an index for diet selection) and condensed tannin (r = 0.27. P = 0.001, n = 144). Both foraging efficiency and diet selection were influenced more by the leaf and shoot morphology than spinescence. Plant chemistry did not clearly explain either foraging efficiency or diet selection patterns. These results have important implications for vegetation management and goat production in the Zululand Coastal Thornveld.
The effect of condensed tannins on goats’ body weight
(2010) Dludla, Sicelo Phumlani; Scogings, P.F.; Dziba, L.E.
Tannins are one of the most common plant secondary compounds. Amongst the tannins are condensed tannins (CT), which occur nearly in every plant species browsed by goats. Condensed tannins have a potential to bind proteins, reduce the feed intake and consequently reduce the body weight gain of goats. The study was conducted in order to determine the effects of different condensed tannin concentrations on the body weight gain of goats. The first experiment was conducted for three weeks in order to determine the effect of different condensed tannin concentrations in browse species. To eliminate the large chemical and physical variation in browse species and to have more control in feeding, the second experiment with artificial diets was conducted for four weeks. In each experiment, twenty-four goats were fed four different levels of condensed tannin-containing diets with six goats in each diet group. In the first experiment, a marginal negative relationship between condensed tannin concentrations and the body weight gain of goats was observed. There was no significant relationship between condensed tannin concentration and the browse intake, pellet intake and lucerne intake, protein intake, protein retention and protein loss by goats. In the second experiment, a significant negative effect of different CT concentrations on the body weight gain, pellet intake of goats as well as on the protein intake, faecal protein loss and protein retention of goats was observed. Protein retention and faecal protein loss were all affected by CT concentrations and yet did not affect growth. However, feed intake was affected by CT concentrations and affected growth. Studying the effects of condensed tannins using synthetic condensed tannins in the artificial diets is more informative than using condensed tannins in browse species. However, even condensed tannins in the artificial diets cannot explain the mechanisms which affect the body weight gain after consuming condensed tannin rich diets.
Effect of goat manure on growth, yield, and nutritional composition of Cucurbita argyrosperma
(University of Zululand, 2023) Zondo, Nomfanelo; van Jaarsveld, C.M. Ntuli, N.R. and Mavengahama, S.
Effect of microbial ecosystem from wild herbivores browsing tanniferous plants on goat rumen fibrolytic activity
(University of Zululand, 2016) Msimango, Nokwethemba Nqobile Philile; Fon, F.N.
Ruminant have developed advanced microbial ecosystem for digesting fibrous feedstuffs over the past years. The efficiency of harnessing energy from these forages is still a major problem as less than 60% of forages consumed are still passed out as faeces. Many factors have been associated with the poor breakdown of these forages including; complexity of fibre in forage types, inefficient microbes, microbial population, low rumen pH and presence of anti-nutritional compounds (lignin and alkaloids, saponnins and tannin). Therefore, understanding microbial ecosystems’ activities in ruminants is an essential step towards improving tanniferous browsers’ utilisation especially in goats which are often supplemented in winter during forage shortages. The study was conducted to identify potential rumen microbial ecosystems browsing tanniferous forages that might have evolved in their ability to degrade plant fibre in the presence of tannin that can potentially be used to improve domestic goat browse utilisation. Experiment 1 investigated the fibrolytic potential of microbial ecosystems giraffe, kudu, impala and consortia (A1 (giraffe + kudu, 1:1), A2 (giraffe + impala, 1:1), A3 (kudu + impala, 1:1), A4 (giraffe + kudu + impala, 1:1:1)). Crude protein enzyme extracts (CPZ) from fresh faecal samples were precipitated by 60% ammonium sulphate and assayed for exocellulase, endocellulase and hemicellulase by incubating with crystalline cellulose, carboxymethyl cellulose and xylan at 38℃ at pH of 5.5 for 1, 2, and 48 h, respectively. Enzyme specific activities were defined as μg of reducing sugar/mg CPZ. In vitro fermentation study was done by transferring 33 mL of fresh faecal inoculum into 67 mL of salivary buffer containing 1 g Acacia sieberiana and incubating for 72 h at 38℃. Apparent degradability (APD), true degradability (TD), neutral detergent fibre degradability (NDFdeg), acid detergent fibre degradability (ADFdeg), microbial yield (MY), metabolisable energy (ME) and total gas emitted (Gas) were measured. Cellulases, hemicellulase and in vitro degradability studies showed that microbial ecosystems from wild browsers (especially impala) and consortia possess a higher (P<0.05) potential to digest tanniferous forages with less enteric gas production than observed in goats, hence could be exploited as feed additives for improving digestibility and reducing enteric gas production in goats. In experiment 2, the effect of tannins on the fibrolytic potential of microbial ecosystems from goats, wild giraffe, kudu, impala and consortia (A1, A2, A3 and A4) were monitored. The method was the same as in experiment 1 except for the addition of 10% tannic acid. A microbial ecosystem treated with 10% tannin showed higher (P<0.05) fibrolytic enzyme activities and digestibility parameters compared to the control. The goat ecosystem showed some degree of adaptability to increased tannin but microbial ecosystems from wild browsers (impala and kudu) and consortia (A1, A2 and A3) showed a higher potential to digest tanniferous forages. The results demonstrated that wild herbivores especially impala and A1 consortia can tolerate minimal changes in tannin concentrations. Experiment 3 assessed the effect of in vitro inoculation of goat microbial ecosystems with inocula from wild herbivores (impala, kudu and giraffe) on in vitro fermentation, gas production and cellulase activity in goats. The method was similar to that of experiment 2 but for goat microbial consortia (N1 (goat + impala, 1:1), N2 (goat + kudu, 1:1), N3 (goat + giraffe+ kudu, 1:1:1) and N4 (goat + giraffe + kudu + impala, 1:1:1:1)). Manipulation of the goat ecosystem with microbes from the wild generally increased (P<0.05) cellulase and hemicellulase activities as presented by their high hemicellulase, endocellulase and exocellulase activities. The highest (P<0.05) NDFdeg, ADFdeg and TD were observed in N3 while HEMdeg and CELLdeg were high in the N1ecosystem. Therefore, wild ruminant browsers may be harbouring important potential fibrolytic microbial population with relatively high tannin tolerance which can be used to improve the browses digestibility of goats. The final experimental chapter monitored the effect of adding polyethylene glycol 4000 (PEG) to goat microbial consortia in vitro degradability of tanniferous feeds. The results showed that 5% PEG supplementation generally increased (P<0.05) hemicellulase, endocellulase and exocellulase activities in goats’ consortia when compared to the control. Digestibility of fibre was lower for diets not treated with PEG. Apart from N3, PEG increased (P<0.05) dry matter degradability of Acacia sieberiana but not microbial yield. The improvement of enzyme activities and dry matter digestibility upon addition of PEG in goat consortia highlights the inhibitory effects still possessed by tannins even when inoculated with potential fibrolytic microbes from wild browsers. Therefore, microbial ecosystems from wild browsers can contribute potential fibrolytic microbes with relatively high tannin tolerance that can improve forage digestibility and reduce enteric gas production in goats.
Effect of planting depth and cutting orientation on growth and yield of sweet potato (Ipomoea Batatas L.(LAM) cultivars for small scale production in Verulam
(University of Zululand, 2018) Pakkies, Ntombifuthi Zanele
Sweet potato (Ipomoea batatas L. (Lam) is an important root crop for small scale farmers in the KwaZulu-Natal province of South Africa. However, low storage root yields in small scale farming are attributed to a number of factors including poor selection of cultivars and possibly unsuitable cultivation practices. Therefore, two experiments were conducted over two growth seasons (2014/2015 and 2015/2016) to test the effect of sweet potato cultivar, orientation of cuttings at planting and planting depth of cuttings in the Verulam area of northern KwaZulu-Natal province. Both experiments were conducted in the field under rain fed conditions and both were laid out in a randomized complete block design (RCBD) with four replications per treatment. Experiment 1 tested four cultivars (Monate, Ndou, 199062.1 and Blesbok) in either horizontal or vertical orientation of cuttings at planting. In Experiment 2, cuttings of one cultivar (Bophelo) were planted at 5 different depths (5 cm, 10 cm, 15 cm, 20 cm and 25 cm) either horizontally or vertically. Vine lengths were measured at 3, 6, 9 and 12 weeks after planting on five randomly selected plants per plot. Aboveground biomass (ABM) yield, marketable yield (MY), non-marketable yield (NMY), storage root yield according to four size classes, total storage root yield and harvest index (HI) were determined at harvesting. Of the four cultivars tested in Experiment 1, cultivar 199062.1 scored the highest values for most parameters measured in season I, including MY, extra-large tubers (451 – 1000 g) and total storage root yield (significant, p<0.05). Cultivar Ndou scored the lowest values for all yield-related parameters measured in season I, but had the longest (significant p<0.05, at 12 weeks after planting) vines in season II. In season II, most differences among cultivars were not significant. For both experiments, there was generally a trend for plants grown from horizontally orientated cuttings to show higher values for most parameters measured than for plants grown from vertically orientated cuttings with significant (p<0.05) differences for total storage root yield and HI in season I. Planting cuttings to different depths did not have significant effect on any of the parameters measured, except for vine length at 12 weeks after planting for season II, where cuttings planted to a depth of 25 cm produced significantly (p<0.05) longer vines compared with other planting depths. However, it was observed that planting cuttings to a depth of 10 cm had a tendency to result in higher values for most parameters measured and 20 cm the lowest. The data collected in this study was preliminary and the experiments will have to be repeated before recommendations can be made to farmers with regards to the best cultivar, cutting orientation at planting and planting depth to use by small scale farmers at Verulam.
The effect of post-harvest ammonium sulphate application, planting time and sucker size on plant growth and yield of queen pineapple, ananas comosus
(University of Zululand, 2013) Mbatha, Bongumusa Wiseman; Zobolo, A.M.; Zharare, G.E.; Rabie, E.C.
Queen pineapple plant mortality as well as poor growth and development are some of the major problems facing the Hluhluwe pineapple producers. Approximately 20% of the plants do not produce fruit, due to mortality or poor growth. Queen pineapple plantings are currently established from suckers taken from harvested plants. The speed and development of suckers on the mother plant is not rapid enough to be used as planting material at fruit harvest. Therefore, suckers are left to grow on the mother plant for 6 to 8 months after harvesting the plant crop for the suckers to attain a suitable size for planting. The aim of the study was to determine, under field conditions, the effects and interactions of post-harvest ammonium sulphate fertilizer application and the duration of sucker growth on the production and quality of suckers as well as on the growth and development of subsequent plantings. Post-harvest (NH4)2SO4 application had a significant influence on the percentage increase in sucker fresh mass and length when interacting with the duration of sucker growth on the mother plant. Growing suckers on the mother plant for up to 8 months, after the application of post-harvest (NH4)2SO4, produced more plantable suckers than growing them for 6 or 10 months. Four sucker sizes were produced namely, size 2, 3, 4 and 5. Grading suckers by length produced more plantable material than grading by fresh mass. Plant gain in fresh mass and stem diameter, was positively correlated with sucker size and post-harvest (NH4)2SO4 application. At 2 months after planting, 6 symptoms that could lead to plant mortality were identified namely, wilted plants, plants toppling over, plants planted doo deep, plants growing slowly, plants with funnel rot and plant that dying back. The total percentage of these plant mortality symptoms was 19.6% in the March planting, 26% in the May planting and 33.1% in the August planting. Wilted plants and plants planted too deeply formed a greater proportion of the plants affected by the mortality symptoms in all the plantings. Some of the plants affected by the mortality symptoms recovered and grew into healthy plants, whereas some grew slowly and some died. Sucker size and post-harvest (NH4)2SO4 application had no significant effect on levels of mealybug, Dymicoccus brevipes and red mite, Dolichotetranychus floridanus infestation. Post-harvest (NH4)2SO4 application influenced the percentage of P and K in leaves in the May and August planting. Sucker size had an influence on N percentage in the March planting only. Plants established from smaller sucker sizes had a significantly higher N percentage than plants established from bigger sucker sizes. Sucker size had an influence on flowering failure. Plants established from a smaller sucker size had a higher percentage of flowering failure than the plants established from a bigger sucker size. The March planting had a higher percentage of plants that failed to produce flowers after flower induction than the May and August planting. The total percentage of plants that failed to flower in the March planting was 15.92% (7.39% due to plant mortality symptoms and 8.53% due to unknown causes), in the May planting it was 6.02% (4.69% due to plant mortality symptoms and 1.33% due to unknown causes) and in the August planting it was 7.56% (5.39% due to plant mortality symptoms and 2.17% due to unknown causes). Plant mortality symptoms were the main cause of flowering failure in the May and August plantings. Postharvest (NH4)2SO4 application had a significant effect on wilted plants in the March planting and on natural flowering in the August planting. Flowering failure resulted in fruit yield loss. Fruit yield was more influenced by the sucker size than by post-harvest (NH4)2SO4 application. There was a positive correlation between sucker size and fruit yield. Fruit size was used to determine the influence of post-harvest (NH4)2SO4 application and sucker size on the external and internal quality of the fruit. Post-harvest (NH4)2SO4 application had a significant influence on fruit length, inter-fruitlet cracks, winter speckle occurrence and total soluble solids. Sucker size was found to have an influence on the number of fruitlet spirals, fruit length, crown fresh mass, fruitlet cracks, winter speckle occurrence and total soluble solids. Black spot, nectary duct and internal browning infestation were influenced by the number of days the fruit were kept in storage after harvesting. Post-harvest (NH4)2SO4 application and sucker size had no significant influence on black spot, nectary duct and internal browning infestation. Eight months after fruit harvest in the March and May planting, evaluation was done to determine the effect of post-harvest (NH4)2SO4 application, sucker size and mortality symptoms on sucker yield. Plants established from bigger suckers produced longer and heavier suckers as well as a higher number of plantable suckers than plants established from smaller suckers. Healthy plants produced longer and heavier suckers as well as a higher number of plantable suckers than plants that were affected by the mortality symptoms. Plants treated with post-harvest (NH4)2SO4 produced quality planting material in terms of fresh mass and length. Leaving the suckers to grow for 8 months after fruit harvest produces more plantable material. Planting the planting material obtained from plants treated with post-harvest (NH4)2SO4 increased fruit yield and profit.
Effect of the Duration of Progesterone Treatment on Synchronising Oestrus outside the Natural Breeding Season in Merino Ewes
(University of Zululand, 2022) Zulu, Nhlakanipho Sam
This study aimed to evaluate the effect of the duration of progesterone treatment on the reproductive performance of South Africa Merino ewes during the spring breeding season. The study compared the effect of long and short-term progesterone treatment and its combination with or without equine chorionic gonadotropin on oestrous response and hormonal profiles. Seventy-six (76) Merino ewes aged between 2–5 years were allocated into two groups, 40 for long-term and 36 for short-term progesterone treatments. For the long and short-term progesterone treatment groups, controlled internal drug release devices were inserted for 14 and 11 days, respectively. At the withdrawal of the controlled internal drug release device, half of each group were injected intramuscularly with 300 IU of equine chorionic gonadotropin, resulting in four treatment groups. The oestrous response was monitored using teaser rams. Blood samples were collected to measure the serum progesterone and oestradiol concentrations. One-way ANOVA of the SPSS® software (IBM SPSS Statistics, Version 23.0, 2015, Armonk, NY., USA) was used for statistical analysis. The means were considered significant at P < 0.05. The overall oestrous response obtained was 96%. A greater proportion of the ewes showed oestrous signs at 48 and 60 hours post controlled internal drug release withdrawal. There was no significant difference (P > 0.05) in oestrous response and duration between the treatment groups. Overall, the mean interval to the onset of oestrus in this study was 46.8 ± 1.4 hours. Most ewes began exhibiting oestrus at 24 and 36 h post controlled internal drug release withdrawal. There was no significant difference (P = 0.07) in the mean interval to the onset of oestrus between the treatment groups. Progesterone hormone did not differ significantly (P > 0.05) between the treatment groups at controlled internal drug release insertion and removal and 48 hours post removal. However, oestradiol was significantly higher at controlled internal drug release removal and 48 hours post removal (P < 0.05) than at insertion in all treated groups. Therefore, it was concluded that using the progesterone synchronisation protocol, regardless of the duration or conjunction with eCG treatment, can effectively synchronise oestrus during the spring breeding season in South Africa Merino ewes. For seasonal breeders who use South Africa’s spring breeding season, the progesterone oestrous synchronisation protocol is recommended to improve the reproduction activity in Merino ewes.
Effect of the methanolic extract of Cassia abbreviata in the oxidative stress caused by overcrowding in indigenous chickens
(University of Zululand, 2017) Jobe, Martha Cebile; Kunene, N.W; Opoku, A.R
Indigenous chickens are the largest livestock species that are widely domesticated by rural farmers with poor management practices. Poor management affects the growth performance and health of chickens in various ways. Due to high demand and poor management of chickens, overcrowding has become one of the influencing factors that retard growth. Overcrowding results in metabolic disturbances, causing excessive free radicals production that leads to oxidative stress. The oxidative stress can be managed by introducing radical scavengers, the antioxidants. Interestingly, natural antioxidants from medicinal plants are being adopted for use mainly because the synthetic antioxidants have been observed to have side effects. The aim of this work was to assess the effect of the stocking density on the growth performance of indigenous chickens and to evaluate the effect of Cassia abbreviata extract on the oxidative stress in chickens caused by overcrowding. Phytochemical screening of Cassia abbreviata revealed the presence of alkaloids, flavonoids, terpenoids, tannins and saponins. Methanolic stem extract showed strong scavenging of 2,2’-azino-bis-(3-ethlybenzothiozoline-6-sulphonic acid), 2,2-diphenyl-1-picrylhydrozly, superoxide anion and hydroxyl radical; however poor scavenging of nitric oxide was observed. Reduction potential of the plant extract was dose dependent; the iron chelating activity was poor. The stocking density measures the number of chickens kept in a particular area and in this study, the number of chickens kept in a house had a great effect on the growth rate and body weight of chickens. In the 8th week the mean body weight at low stocking density was 2.743 ± 0.216 kg and for high stocking density it was 1.637 ± 0.004 kg. The serum levels of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were significantly higher (p<0.05) in chickens receiving the extract of Cassia abbreviata compared to the control group. The concentration for extract had an effect on the serum levels. The growth rate of the chickens was also higher in the Cassia abbreviata treated groups than that of the control chickens (p<0.05). Cassia abbreviata was able to inhibit lipid peroxidation as the malondiadehyde (MDA) content was significantly lower in the treated groups. Apparently, the plant’s extract stimulated growth in chickens. It is contingent that the plant extract exhibited antioxidant activity that inhibits the oxidative damages in overcrowded chickens. Histological results revealed that high dosages cause damages in the liver, thus concentration should be considered.
Effectof feed rations on livestock performance and impact of effective microorganisms on litter odour and other gases emissions.
(University of Zululand, 2022) Sithole, Victor Welcome
The increase in demand for animal protein has increased the demand for pork and beef by humans to supply this dietary protein. The short gestation period as well as the high number of piglets renders pig production relatively viable, hence increasing the number of farms. Feedlot farming has increased this production but not without high waste and odour emission which may be hazardous to animals, workers and the surrounding community members. Therefore, the aim of this study was to evaluate the effect of feed rations on livestock (cattle and swine) performance and the impact of effective microorganisms(EM) on litter type odour and other gaseous emissions. It was hypothesized that diet type and EM would not livestock litter odour and gaseous emissions. Experimental chapter one and two investigate the effect of feed type and effective microorganisms on performance and litter odour emission from feedlot cattle and swine, respectively. The EM was applied on litter at different treatment levels (10% EM, 20% EM, and 30% EM) to mitigate odour emissions. The results showed that different diets (starter, growerand finisher) fed to both cattle and swine improved (P<0.05) performance as the feed intake, weight gain and feed conversion ratio increased when animals changed from one diet to the other. However, it was also noted that the diet affected (P<0.05) odour emission from both beef cattle and swine manure. This was because the gaseous emission increased (P<0.05) as the beef animal’s diet changed from starter to grower while emissions from pig was also different (P<0.05) between starter and finisher. The gaseous compounds identified were classified into; Alcohols (4), aldehydes (6), volatile fatty acids (13), ketones (3), terpenoids (2), amides (3), phenolics (8), sulphur compounds(2) and nitrogen containing compounds (3) from beef litter. From pig litter, the gaseous compounds identified were classified into alcohols(5), aldehydes (5), volatile fatty acids(13), ketones (2), terpenoids (2), amides (1), phenolics (7), sulphur compounds (3) and nitrogen containing compounds (3). Among these gases, P-Cresol (4-methyl phenol) and phenol was assumed to have the highest potential hazardous effect in terms of air pollutants as listed by the US Environmental Protection Agency. Indole and skatole were also identified and have often been associated with acute bovine pulmonary edema and emphysema (ABPE) in cattle and boar taint in pigs. Effective microorganisms(EM) treatment showed no differences (P>0.05) among all litter treatment levels (10% EM, 20% EM, and 30% EM) but for the control. There were significant differences in the odour emitted between the different weeks (P<0.05) when compared to the control. P-Cresol, phenol, indole and skatole were reduced by EM to undetectable amounts in week 3 compared to the controls. However, dimethyl sulphide and dimethyltrisulphide were not mitigated by the use of EM hence further methods on how to mitigate these sulphurcompounds need to be explored. A 10% dose of EM for cattle litter treatment was preferred, sincethe effect of higher doses was minimal. However, for swine, a 30% EM dose treatment was recommended since most of the odorous compounds (Indole, skatole, phenol, and dimethylsulphide and dimethyl trisulphide) were reduced to undetectable amounts. It was also concluded that EM does not depend on concentrations to reduce odour from livestock manure, but time for the microbes to adapt, grow and multiply to mitigate odour. Keywords: Effective microorganisms, odour, volatile organic compounds, diet,P-Cresol, phenol, indole, skatole, dimethyl sulphide, dimethyl trisulphide, boar taint.
An ethnobotanical survey, antimicrobial activity and toxicity evaluation of plant species used for blood purification by rural communities in Northern Maputaland, South Africa
(University of Zululand, 2021-06) Zwane, Nontobeko Shokahle
A blood purifier is defined as a substance that removes toxins from the bloodstream via a process known as detoxification. Blood purification (cleansing) is highly crucial for the entire body functioning as the body depends on healthy blood.In South Africaherbal remedies, herbal teas, spices and traditional medicine are all used forthe purification of blood. The use of different supplements to purify or strengthen the blood are available in pharmaciesand informaltrading centreswithout any prescription from adoctor.Medicinal plant speciesused for blood purification are a large component of rural peoples’Materia Medica. This can bea concernasvery few of these products and plant specieshave beenscientifically tested for safety and efficacy. Therefore,ethnobotanical survey was conducted on bloodpurification plant speciesused inrural areasofnorthern Maputaland. Furthermore,an investigation intolaypeoples’concept of bloodpurificationand the respective plant speciesused were investigated. A total of 55 key informantswere chosen purposively and interviewedusing a structured questionnaire. The information gathered during the interviewswas documented along with the plant voucher specimens. Available plant samples were collected for extraction. The study found that the laypeople in northern Maputaland use blood purification as a dual strategy for health care reasons. This technique is used for the prevention and treatment of diseases caused by variouspathogens (skin infections, oral infections, urinary tract infections)andspiritual complications. The study documented 65plant species with Bridelia cathartica, Catunaregam obovata, Cymbopogon marginatus, Sclerocarya birrea, Senecioserratuloidesand Terminalia sericeabeing the most frequentlycited plant specieswithin these communities. Twenty-two plantspecies and 32setsof plant species combinations were recorded for the first time as blood purifiers. There were five new vernacular (IsiZulu) names mentioned by the participants (isikwakwane, upata, umhlakuva, umbungwa anduvemvane) that were not found in literaturepreviously. Most blood purification remedies were prepared as decoctions,and taken orally before breakfast.Aqueous and organic (1:1 dichloromethane methanol) extracts were prepared from 58plant samples that were available for collection in northern Maputaland. Antimicrobial viscreening using the minimum inhibitory concentration (MIC) assay was performed on selected bacterial pathogens involved in blood-related infections,i.e. Acinetobacter baumannii,Cutibacterium acnes,Listeria monocytogenes,Pseudomonas aeruginosa,Staphylococcus aureus, Streptococcus agalactiae and S. pyogenes. The most active aqueous extract came from Albertisia delagoensisroot with a noteworthy inhibition at0.13mg/ml MIC value against C. acnes.Whereasthe most active organic extract was Ozoroa engleriwith the MIC values of 0.004 mg/ml against C. acnes, 0.01mg/ml against S. agalactiaeand 0.02mg/ml against L. monocytogenes, S. aureusand S. pyogenesrespectively. Gymnosporia senegalensisand O. englerihad the broadest spectrum of antimicrobial activities with notableMIC values against four and five pathogens respectively. It was worth noting that the antimicrobial activity of A. delagoensis and Sapium integerrimum was evaluated for the first time and both have significant activities (MIC 0.16 mg/ml) against C. acnes. The antimicrobial activity of 308 plant combinations was evaluated using sum of the fractional inhibitory concentration index (ΣFIC). Once the ΣFIC of plant species combined in equal ratios was calculated, the combinations exhibited synergistic (61%), additive (16%), non-interactive (49%) and antagonistic (29%)effects. The broadest synergistic effect was displayed by Abrus precatorius + B. catharticaroot extracts, where the combination was synergistic against C. acnes, L. monocytogenes, S. aureus, A. baumannii and P. aeruginosa. The most synergistic effect was displayed by S. integerrimum + Strychnos spinosaroots having,the ΣFIC value of 0.33,against P.aeruginosa.The toxicity of the plant species was evaluated using the brine shrimp lethality assay (BSLA). When plant species were evaluated individually, the aqueous extracts had five plant speciesshowing potential toxicity (Dichapetalum cymosum, Ekebergia capensis, Gardenia volkensii, Trichilia emetica and Waltheria indica) and 12 organic extracts demonstrated toxicity. When dilutions of toxic extracts were made (1.00mg/ml, 0.50 mg/ml, 0.25 mg/ml, 0.13 mg/ml, 0.06 mg/ml and 0.03 mg/ml) it was observed that the toxicity of extracts decreased with lower concentrations. For the evaluation of the idifferent setsof combinationstested, two combinations(A. delagoensis + Pyrenacantha kaurabassana and D. cymosum+ Euclea natalensis)displayed consistent toxicity in both aqueous and organic extracts. Six combinations portrayed increased toxicity compared to when these plant species were tested individually. Overall, the results demonstrated that the use of medicinal plant species for infectious diseases related to blood purification is somewhat valid, since 35%of the plant extracts had noteworthy activity against some of the pathogens. The plant extracts displayed high antimicrobial activity against C. acnes, which for 80%of the time correlates with the traditional use reported by the participants. The results also demonstrated that the combination of plant species does not always guarantee increased efficacy, and that not all medicinal plant species are safe for use. This study served to provide an informative view to the concept of blood purification. It is clear that when looking into blood purification, ailments like acne and other skin disorders should not be disregarded. The role that blood purification play in lay peoples’ rituals emphasise thatholistic and spiritual healings of the laypeople should also be considered.

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