Agriculture

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Browsing Agriculture by Author "Fon, F.N."

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    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.
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    In vitro evaluation of nutritional content and anthelmintic values of Kigelia africana fruit to domesticated ruminants
    (University of Zululand, 2019) Ndwandwe, K.C.; Fon, F.N.
    Food security is at risk due to the ever growing world population. More effort should be put on improving agricultural production since farming provides the primary source of food for humans. Livestock farming; be it commercial or small scale, plays a major role in supplementing the protein component of human food especially with the expensive nature of plant proteins. In northern KwaZulu-Natal, both large (cow) and small (goat and sheep) ruminant farming plays a vital role in the rural communities as they do not only provide proteins, but are used for traditional ceremonies, bride price, prestige and clothing. These ruminants require adequate and constant nutrient availability to meet their best production standards but forage availability and quality declines, especially in winter, which results in poor animal performance. Besides forage limitation, water scarcity is also a major problem in this area with the recent drought that hit in 2015. Therefore, alternative indigenous forages with feed potential and high moisture should be investigated, as water from feed can assist in improving animal production in this area. Kigelia africana plant has been reported to produce fruits (sausage fruit) that are suspected to have high moisture, be rich in secondary compounds and persist throughout the dry season but are not used by animals as feed. Rather, it has been used by humans as flavour, to ferment traditional beers, treat worms and even as an aphrodisiac. Hence, the aim of the study was to explore Kigelia africana fruit (sausage fruit) as a potential feed supplement and its anthelmintic value in domesticated ruminants. Five feed portions were made from the sausage fruits; 1. Exocarp (Ex), 2. Endocarp (En), 3. Endocarp plus seeds (En+SS), 4. Seeds (SS) and 5. Whole fruit (Wf). The nutritional value of feed portions was determined by measuring their chemical composition and the force required to break-open the fruit (shear force). For chemical composition, dry matter (DM), moisture content (MC), crude protein (CP), condensed tannins (CT), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), cellulose and hemi-cellulose were measured. Fibre components were analysed using the ANKOM filter bag method while proteins were analysed using the Kjeldhal method. Acid butanol Assay and the Warner-Blatzer shear device were used to analyse condensed tannins. Shear force was measured using the Warner Blatzer shearing device where maximum force required the feed (F Max), distance covered vi by the blade at breakage (dL at break), and force during break (F at break) were measured. For in vitro digestibility the Daisy incubator from ANKOM Technology was used with inocula from rumen fluid and 1 g sample, incubated at 38ºC in an anaerobic chamber for 72h. Apparent (APD) and True degradability (TD) and microbial yields (MY) were measured. For anthelmintic activity, the Helminth motility test was conducted with extracts of phenolic compounds from Ex, En, En+SS and SS at five levels (control 0g, 5g, 10g, 15g and 20g) using Baerman’s technique and L3 larva survival was counted at 10x magnification. The results revealed that En+SS (21%) had the lowest (p<0.05) DM, followed by En, Wf, Ex and SS (49.65%). This implies that En+SS (79%) showed the highest (p<0.05) MC, followed by En, Wf, Ex and SS (50.3%). In terms of fibre composition, SS and Ex had the highest cellulose content (32% and 42% respectively). Ex had the highest (P˂0.05) NDF, ADF and ADL (70.67%, 59.18% and 17.69% respectively) compared to other feed portions. The highest protein content was observed in SS (12.55%), followed by Wf (3.9%) and En+SS (3.8%) while the lowest was seen in Ex (2.9%). There were higher contents of lignin and cellulose on the Ex than on the En, which was associated with plant mechanisms to protect themselves against herbivory. Ex required the highest FMax (1060.1N) to break the feed while En had the lowest shear force of 540N, which were all lower than the maximum force that can be generated by most ruminant’s jaws. For digestibility studies, En and En+S had the highest (p<0.05) TD of 554.46 g/kg and 539.32 g/kg respectively while Wf, Ex and En were not statistically different but Wf was relatively higher than both. For its anthelmintic potential, it was found that Kigelia africana fruit treatments had an overall of 96% larva mortality percentage when compared to the control. There were no significant differences between L3 larva survival and mortality at different treatment levels of all Kigelia africana extracts but for the control. The result from the chemical composition of the different feed portions and whole fruit, shows that Kigelia africana has feed potential as its constituents are comparable to most types of hay especially with a crude protein of above 8%. Its high moisture content could be of potential benefit especially in winter where water sources are scarce. The force required to break the Ex was a major limitation to gain access to En and SS that were relatively easier to break. Hence the removal of the hard exocarp can reduce Kigelia africana fruit’s shearing force and make it accessible for chewing. Both APD and TD showed vii digestible values higher than most hays, hence, it has feed potential for ruminants. Strong anthelmintic properties were also demonstrated in all extracts with high mortality of larva. Further in vivo experimentation is required to establish the anthelminthic activity prior to rural farmer’s application.
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    Performance of Nguni goats supplemented with sweet potato vines
    (University of Zululand, 2018) Luthuli, Cynthia Fikile; Fon, F.N.
    Goats are small ruminants that play a major role in food security, especially as their meat and milk serve as vital sources of protein in most rural houses in developing countries. Goats in developing countries mostly depend on veld as feed that often does not provide the nutrient requirements necessary for optimum production. Supplementary feeds available are often expensive especially for emerging farmers but crop residues like banana leaves, cassava, sweet potato vines and other indigenous crop residues not exploited may be used as a cheaper source of feed supplement. More rural emerging farmers in Northern KZN communities seem to be farming sweet potatoes which implies that the vines could be available cheaper for supplementary feeding if found with feed potential. Thus, the aims of this study were to survey the knowledge and perception of indigenous forage supplementation especially sweet potato vines, the effect of vine cutting frequency on the chemical composition and in vitro digestibility as well as sweet potato yields of different sweet potato cultivars and the final aim looked at the effect of vine supplementation on goat’s intake and performance as well as its anthelminthic potential, if any. The survey was conducted in 7 wards of KwaMthethwa community area under Umfolozi local Municipality, where 15 farmers were interviewed per ward using a questionnaire. The effect of vine cutting frequency (after 60, 75 and 125 days) on the vine chemical composition (crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent ADL, condensed tannin (CT)) and in vitro digestibility (apparent digestibility (APD), true digestibility (TD), microbial yield (MY)) as well as sweet potato yields of the different cultivars (Beauregard (BRGT), 1990, A40 and A45) were done at Owen Sithole College of Agriculture (OSCA) farm and University of Zululand Agriculture laboratory. Goats (32) of similar average weight, were categorised into four groups of eight and placed in individual pens. They were given hay ad libitum and supplemented with four different rations (0kg, 1.5kg, 2kg and 3kg) of sweet potato vines (SPV) from 1990 as best cultivar. The effect of 1990 supplementation on goats’ hay intake (total feed intake (TFI) and in vitro digestibility (DMD) and performance (weight gain (WG), average daily weight gain (AVD) and feed conversion ratio (FCR)) were measured. Anaemic condition of goats was monitored as well as egg counts for haemonchus contortus infestation. The survey results showed that farmers seem to have an idea of supplementing, however majority fed maize in the afternoons, for goats to be able to come back for kraaling without a header. Most farmers agreed that goats were losing condition due to diseases and malnutrition, but rural farmers rejected the use of sweet vi potato vines as feed supplement even when it was available because they believed it causes fatal diarrhoea. It was found that nutrient status of vines was reduced (P<0.05) as the plant matures, and fibre (NDF and ADF) increased as vine matured. The CP concentration was decreased (p<0.05) and CT increased (p<0.05) as the plant matured, with an exception of A45 cultivar that had lower tannin concentration even at 120 day after planting (DAP). Furthermore, harvesting vines at 75 DAP improved (P<0.05) the yields of sweet potato tubers and vines. The Cultivar 1990 was considered the best because it produced the highest yields of forage materials as well as tubers hence not compromising its original purpose of production for human consumption. It was observed that goats given 3kg SPV (T4) had the highest (p<0.05) final weight (FW), total weight gain (TWG) and average daily gain of 26.05kg, 4.18kg and 74.56g/day, respectively. Moreover, the feed intake increased (P<0.05) with increasing feed levels of sweet potato vines. Most interestingly, the egg per gram (EPG) was reduced in all groups of goats fed sweet potato vines but not for the control group. The results from these studies showed that sweet potato vines have a feed potential as well as anthelminthic potential and rural farmers can be advised to apply it at T4 levels after 75 days of harvest and no diarrhoea signs were observed.