Research Articles (Animal, Wildlife and Grassland Sciences)
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Item Open Access The effect of dietary non-protein nitrogen content on the meat quality of finishing lambs(SASAS, 2024) Einkamerer, O. B.; Ferreira, A. V.; Fair, M. D.; Hugo, A.The effect of increasing the non-protein nitrogen content of low-fibre finishing diets on the meat quality of South African Mutton Merino wether lambs was investigated. Four similar dietary treatments were formulated with different non-protein nitrogen contents (16.6 g/kg, 28.3 g/kg, 40 g/kg, and 51.7 g/kg) on a dry matter basis. The study was conducted over 71 days. Muscle lipid content was higher on the 40 g/kg compared to 16.6 g/kg and 28.3 g/kg non-protein nitrogen diets. Myristic acid and total saturated fatty acid content of lamb muscle tissue was higher, whereas the total unsaturated fatty acid content of the same tissue was lower following a high dietary non-protein nitrogen content. A high non-protein nitrogen diet (51.7 g/kg) reduced conjugated linoleic acid content of adipose tissue, compared to 28.3 and 40 g/kg non-protein nitrogen treatments. Malonaldehyde content of fresh lamb meat was higher on the 28.3 g/kg compared to the 16.6 g/kg non-protein nitrogen diet. The malonaldehyde content of the treatment containing 40 g/kg non-protein nitrogen was higher than the 51.7 g/kg when stored for 90 days. Therefore, the non-protein nitrogen content of low-fibre lamb finishing diets does not affect mutton fatty acid composition and quality parameters. Protein quality and its effect on ruminant meat quality requires more attention.Item Open Access Relationship between body morphometry in Bapedi rams and sperm characteristics measured using Computer-aided Sperm Analysis(SASAS, 2024) Maqhashu, A.; O’Neill, H. A.; Ngcobo, J. N.; Nephawe, K. A.; Ramukhithi, F. V.; Sebei, J. P.; Mapholi, N. O.; Bovula, N.; Mphaphathi , M. L.; Nedambale, T. L.Ram fertility is not defined by a single trait. Quantifiable physical parameters that are correlated to fertilization capacity of sperm are required to advise farmers on ram selection activities. The objective was to investigate the relationship between body measurements and sperm traits of Bapedi rams conserved in situ and ex situ. Before semen collection and body measurements, body temperature was taken. Semen was collected from 33 rams (two ejaculates/ram weekly, with 2 d resting period, age = 2–6 y). Body weight (BW, kg), body measurements [body length, head length, head width, rump height, rump width, rump length, tail length, heart girth, and scrotal circumference (SC)]; and semen volume (ml), sperm concentration (billion/ml), and sperm motility parameters were measured using Computer-aided Semen Analysis System (CASA®). The semen pH was measured using a microprocessor pH/mV/°C meter fitted with a glass probe. Body condition scores (BCS) of the rams were recorded on a scale of 1 to 5. Data were analysed using the PROC univariate procedure of SAS. BW of Bapedi rams was 38–57 kg in all groups. There was uniformity in all body measurements of Bapedi sheep regardless of method of conservation. Body temperature during semen collection; scrotal circumference; semen volume, pH, and concentration; sperm total motility; and kinematics in Bapedi rams using both methods of conservation were similar. Strong correlations between BW, BCS, and SC with semen volume were found. Rump length positively influenced sperm normality. BW, BCS, and SC can be included in the selection criteria for improving the reproductive performance of Bapedi breeding rams. Farmers can use SC and rump length to predict semen volume and sperm normality.Item Open Access Metagenomic assessment of nitrate-contaminated mine wastewaters and optimization of complete denitrification by indigenous enriched bacteria(Frontiers, 2023) Moloantoa, Karabelo M.; Khetsha, Zenzile P.; Kana, Gueguim E. B.; Maleke, Maleke M.; Van Heerden, Esta; Castillo, Julio C.; Cason, Errol D.Nitrate contamination in water remains to be on the rise globally due to continuous anthropogenic activities, such as mining and farming, which utilize high amounts of ammonium nitrate explosives and chemical-NPK-fertilizers, respectively. This study presents insights into the development of a bioremediation strategy to remove nitrates (NO3−) using consortia enriched from wastewater collected from a diamond mine in Lesotho and a platinum mine in South Africa. A biogeochemical analysis was conducted on the water samples which aided in comparing and elucidating their unique physicochemical parameters. The chemical analysis uncovered that both wastewater samples contained over 120 mg/L of NO3− and over 250 mg/L of sulfates (SO42-), which were both beyond the acceptable limit of the environmental surface water standards of South Africa. The samples were atypical of mine wastewaters as they had low concentrations of dissolved heavy metals and a pH of over 5. A metagenomic analysis applied to study microbial diversities revealed that both samples were dominated by the phyla Proteobacteria and Bacteroidetes, which accounted for over 40% and 15%, respectively. Three consortia were enriched to target denitrifying bacteria using selective media and then subjected to complete denitrification experiments. Denitrification dynamics and denitrifying capacities of the consortia were determined by monitoring dissolved and gaseous nitrogen species over time. Denitrification optimization was carried out by changing environmental conditions, including supplementing the cultures with metal enzyme co-factors (iron and copper) that were observed to promote different stages of denitrification. Copper supplemented at 50 mg/L was observed to be promoting complete denitrification of over 500 mg/L of NO3−, evidenced by the emission of nitrogen gas (N2) that was more than nitrous oxide gas (N2O) emitted as the terminal by-product. Modification and manipulation of growth conditions based on the microbial diversity enriched proved that it is possible to optimize a bioremediation system that can reduce high concentrations of NO3−, while emitting an environmentally-friendly N2 instead of N2O, that is, a greenhouse gas. Data collected and discussed in this research study can be used to model an upscale NO3− bioremediation system aimed to remove nitrogenous and other contaminants without secondary contamination.Item Open Access Effective field immobilisation and capture of giraffe (Giraffa camelopardalis)(MDPI, 2022) Deacon, Francois; Daffue, Willem; Nel, Pierre; Higgs, RuanOne of the highest occurrences of mortalities among giraffes (Giraffa camelopardalis) takes place during immobilisations, captures and translocations. Common mistakes, human error, unforeseen risks, the awkward anatomy and the sheer size of the animal are leading factors for giraffes’ mortalities during these operations. Many risks can be circumvented but some risks are unpreventable, often due to terrain characteristics (rivers, deep ditches, holes and rocky terrain). From 2011 to 2021, seventy-five giraffes were successfully immobilised and captured to collect biological and physiological data from eight different study areas across South Africa. A 0% mortality and injury rate was achieved and, therefore, the techniques described in this paper are testimony to the advances and improvements of capture techniques and drugs. Biological information and capture experiences were noted for 75 immobilised giraffes, of which, knockdown time data were recorded for 43 individuals. Effective and safe immobilisation requires a competent team, proper planning, skill and knowledge. In this manuscript, we address procedures, techniques, ethical compliance, welfare and safety of the study animals. General experiences and lessons learned are also shared and should benefit future captures and immobilisations by limiting the risks involved. The sharing of experiences and information could influence and improve critical assessments of different capture techniques and can likely contribute to the success rate of immobilisation and translocation success for giraffes in the future.Item Open Access Anthropogenic influences on distance traveled and vigilance behavior and stress-related endocrine correlates in free-roaming giraffes(MDPI, 2021) Scheijen, Ciska P. J.; Van der Merwe, Sean; Ganswindt, Andre; Deacon, FrancoisGiraffes are an important tourist attraction, and human presence to wildlife is increasing. This has an impact on an animal’s behavior and its endocrine correlates. Studies on other species show alterations in movement patterns, vigilance, and stress-related hormone levels in the presence of humans. Limited information is available on how anthropogenic activities alter giraffe’s behavior, social structure, and related endocrine parameters. The purpose of this study was to obtain insight into anthropogenic influences on giraffe’s behavior and adrenal activity. We used GPS devices mounted onto giraffes to compare the distance walked in the presence or absence of human observers. We also conducted behavioral observations to assess their vigilance and collected fecal samples to analyze their fecal glucocorticoid metabolite (fGCM) concentrations. Giraffes walked significantly further distances in the presence of humans, but the cumulative time that observers were present decreased the hourly distance walked with an observer present, suggesting that the giraffes were becoming habituated. The number of observers present significantly increased the percentage of time spent on observing an observer as well as the number of unhabituated individuals present in the herd. The percentage of time spent observing a human observer did not decrease with the increase of habituation. Last, fGCM concentrations increased with human presence but decreased when individuals became habituated to human presence. More research is needed to understand the effect of anthropogenic influences in different scenarios (e.g., tourism, vehicles, hunting, etc.).Item Open Access Mitochondrial sequences reveal a clear separation between Angolan and South African giraffe along a cryptic rift valley(BioMed Central, 2014) Bock, Friederike; Fennessy, Julian; Bidon, Tobias; Tutchings, Andy; Marais, Andri; Deacon, Francois; Janke, AxelBackground: The current taxonomy of the African giraffe (Giraffa camelopardalis) is primarily based on pelage pattern and geographic distribution, and nine subspecies are currently recognized. Although genetic studies have been conducted, their resolution is low, mainly due to limited sampling. Detailed knowledge about the genetic variation and phylogeography of the South African giraffe (G. c. giraffa) and the Angolan giraffe (G. c. angolensis) is lacking. We investigate genetic variation among giraffe matrilines by increased sampling, with a focus on giraffe key areas in southern Africa. Results: The 1,562 nucleotides long mitochondrial DNA dataset (cytochrome b and partial control region) comprises 138 parsimony informative sites among 161 giraffe individuals from eight populations. We additionally included two okapis as an outgroup. The analyses of the maternally inherited sequences reveal a deep divergence between northern and southern giraffe populations in Africa, and a general pattern of distinct matrilineal clades corresponding to their geographic distribution. Divergence time estimates among giraffe populations place the deepest splits at several hundred thousand years ago. Conclusions: Our increased sampling in southern Africa suggests that the distribution ranges of the Angolan and South African giraffe need to be redefined. Knowledge about the phylogeography and genetic variation of these two maternal lineages is crucial for the development of appropriate management strategies.