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Masters Degrees (Animal and Poultry Science)

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Browsing Masters Degrees (Animal and Poultry Science) by Subject "Anthelmintics."

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    Gastrointestinal (nematode) infections in small ruminants : epidemiology, anthelmintic efficacy and the effect of wattle tannins.
    (2010) Ahmed, Mawahib Alhag Ali.; Nsahlai, Ignatius Verla.
    Nematode parasites have become the biggest problem for small ruminant production in South Africa due to their resistance to the commercial anthelmintics. Notable, wattle tannin has been used as an alternative strategy for control. However, the concentration and the frequencies can likely influence its effect on the parasites control. The objective of this study was to determine the degree of pasture infestation and nematode infection in sheep and goats, as well as investigate nematode resistance to the anthelmintics, and the potential of wattle tannin in nematode control. The first study dealt with the epidemiology of internal parasites. Eight Merino ewes and eight Nguni does averaged 7-18 months of age were observed for 1 year during the months of February 2008 to January 2009 at the University of KwaZulu-Natal Research Farm (Ukulinga). Egg count per gram (EPG) and coccidian oocysts per gram (OPG) were counted according to Mc Master Technique (Hansen & Perry, 1994) by magnifying parasitic eggs from monthly rectal faecal samples dissolved in saturated sodium chloride. Faecal samples also were cultured for 15 days to identify infective nematode larvae (L3) using Baermann technique. Herbage samples were collected monthly from four paddocks as well to count L3 on the pasture. Sheep live weight was also recorded monthly. Seasonal effects was significant (P<0.05) on the EPG, OPG, faecal culture L3 and pasture L3. A higher level of infection was observed in summer (wet) than in winter (dry season). Trichostrongylus spp larvae were the most prevalent larvae (26.5%) while Strongyloides, Haemonchus contortus, Nematodirus and Cooperia spp occurred in the faecal culture by percentage of 20.9%, 16%, 16% and 14.5%, respectively. For parasite resistance, Ivermectin 1% (IVM), Closantel 5% (CST) and a combination of Abamectin 0.08% and Praziquantel 1.5% (CPA) were evaluated. Twenty four sheep (12 females and 12 males) aged between 7-18 months were used for 21 days. Animals were naturally infested by gastro-intestinal parasites. EPG and faecal culture L3 were counted on day 0, 7, 14 and 21. Closantel was the most effective. Haemonchus spp. were least affected whilst Trichostrongylus spp. were the most affected by all drugs. In the third study, wattle tannins were evaluated as an alternative nematode control drug. Three experiments (Exp.) were conducted to determine the effect of tannin concentration (Exp.1 and 2) and frequency (Exp.3) on nematode parasites. In Exp.1, 0, 0.8, 1.6 and 2.4 g tannin/kg BW were drenched for three consecutive days per sheep (16 females and 8 males, aged 8-9 months) for 21 day. In Exp.2, 30 sheep (14 males and 16 females, aged 9-18 months) were randomly allocated into three tannin treatments (0, 0.8 and 1.6 g tannin/kg BW) and drenched for a day. In Exp.3, 26 sheep (11 males and 15 females aged 9-18 months) were divided into three groups of 9, 9, and 8 sheep each. These groups were drenched with 1.6 g tannins/kg BW/day; once, twice or thrice for the 3 groups respectively. For the three experiments, EPG and L3 larvae were counted in individual feacal samples. For all tannin treatments, EPG decreased (P<0.05) over time. Though the differences among tannin levels and frequencies varied (P<0.05) over time, EPG consistently decreased with increasing tannin level and frequency. Thus 1.6 and 2.4 g tannin /kg BW for 3 consecutive days had nearly similar effects on the EPG. The results of this study are rather inconclusive that weather conditions such as rainfall had a direct effect on internal parasites development. Nematode parasites at Ukulinga Research Farm were resistant to the commercial anthelmintics used. Drenching with 1.6g wattle tannin/kg BW over three successive days is enough to reduce EPG and reduce the degree of pasture contamination.
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    In vitro assessment of selected ethno-medicinal plants as potential alternatives for the control of gastrointestinal nematodes in sheep and goats.
    (2018) Mhlongo, Lindokuhle Christopher.; Nsahlai, Ignatius Verla.
    Commercial anthelmintics are becoming ineffective against gastrointestinal nematodes (GIN) of ruminants due to development of resistant parasites. Research is exploiting anthelmintic ethno-medicinal plants for an alternative remedy. This study assessed the in vitro: (1) dose activity at different concentrations, (2) combined synergistic activity of ethanolic crude plant extracts on mixed GIN of sheep and goats; and (3) cytotoxic activity of these extracts on kidney vero cells. During assessment of in vitro dose activity, faecal samples of sheep and goats that were grazing on contaminated pasture were collected, cultured (12 days) to L3 larvae stage, and treated with 40, 20, 10, 5, 2.5, 1.25 and 0.25% v/v of Allium cepa, Ananas comosus, Bidens pilosa, Carica papaya, Crinium macowanii, Gunnera perpensa, Nicotiana tabacum, Ricinus communis, Sarcosterma viminale, Trema orientalis, Urtica dioica, Vernonia amygdalina, Zanthozylum capense, Zingiber officinale, Zizyphus mucronata and Aloe vanbalenii extracts. Larvae were subjected to Baermann technique for isolation and later observed under a microscope (10x objective). During the assessment of synergism at 1.25% v/v concentration (1:1), 28 crude plant extract combinations from eight (8) mostly edible plants namely: Allium cepa, Ananas comosus, Bidens pilosa, Carica papaya, Vernonia amygdalina, Zingiber officinale, Aloe vanbalenii and Nicotiana tabacum (inedible) were tested for their synergistic activity. The simple and Webb’s fractional product method were used to compute interactions of crude plant extract combinations. During assessment of cytotoxic activity MTT assay was used to assess effect of 16 individual plant extracts mentioned above on vero kidney cells. Results revealed that goats had a significantly higher efficacy than sheep at 40% (P=0.0253) and 20% (P=0.038) concentration (v/v); but goats had significantly lower efficacy at concentration (v/v) 1.25% (P= 0.0305) and 0.625% (P= 0.0158) relative to sheep. On the other hand, both goats and sheep had insignificant (P>0.05) efficacy for CPEs concentration (v/v) 10%, 5% and 2.5%. Plant species had no effect on efficacy at concentration (v/v) 40%, 20%, 10%, 5%, 2.5%, but had significant effect at lowest concentration (v/v) of 1.25 % (P=0.0085%) and 0.625 (P=0.0234%) which was not dose-dependent. Few plants had high activities at the lowest tested concentration (0.625% v/v). In goats it was Gunnera perpensa (89.47%±12.40), while in sheep Gunnera perpensa (100%±12.40), Urtica dioica (95.24%±12.40), Zizyphus mucronata (90.47%±12.40), Allium cepa (90.47%±12.40), Aloe vanbalenii (85.71%±12.40) and Bidens pilosa (80.95%±12.40). Interactions following Webb’s fractional product method were antagonistic and synergistic, whereas those following simple method yielded synergistic interactions only. In goats, V. amygdalina + Z. officinale (100%) was the most efficacious, while in sheep, A. cepa + C. papaya (100%), V. amygdalina + Z. officinale (100%), V. amygdalina + Z. officinale (100%) and A. comosus + N. tabacum (100%) were most efficacious. Animal species had a significant effect (P<0.001) on efficacy of combinations, efficacy was lower in goats (89.16%±0.95) relative to sheep (95.45%±0.095). Plant species did not affect (P>0.05) the efficacy of crude plant extract combinations. Vernonia amygdalina (IC50 = 0.01 mg/ml) followed by Zingiber officinale (IC50 =0.02 mg/ml) were the most cytotoxic crude extracts, while Allium cepa (IC50 = 0.27) and Aloe vanbalenii (IC50 = 0.22 mg/ml) were the least cytotoxic crude extracts. Cytotoxicity increased in a dose dependent manner. The concentration-cell viability relationship was negative linear in most crude plant extracts. While it was negative quadratic for Gunnera perpensa, Zingiber officinale and Vernonia amygdalina. Anthelmintic crude plant extracts are efficacious against GIN of sheep and goats. Although they are mostly harmless minimum effective concentration should be used. Crude plant extracts that were efficacious at the lowest concentration and observed synergistic crude plant extract combinations should be tested in vivo. Keywords: Anthelmintics, Animal species, Activity, Cytotoxic, Crude plant extract(s), Concentration, Ethno-medicinal, Gastrointestinal nematodes, Goats, In vitro, Plant species, Resistant, Sheep.
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    Use of indigenous methods to control gastro-intestinal nematodes in chickens.
    (2018) Majola, Nkanyiso Goodman.; Chimonyo, Michael.
    Millions of resource-limited farmers depend on indigenous knowledge (IK) to sustain chicken health. The level of understanding on these IK systems is low. The objectives of the study were to: (1) explore IK used to control gastro-intestinal nematodes in chickens; (2) assess the extent of use of IK to control gastrointestinal nematodes (GIN) in chicken and to (3) evaluate the efficacy of selected medicinal plants used by farmers to control GIN in chickens. The study was conducted in the Jozini local community. Indigenous knowledge is sourced from parents, forefathers, knowledgeable community members through oral communication. Medicinal plants are prepared using different methods such as boiling and soaking in water. Chickens are dewormed after displaying clinical symptoms of GIN infestation. Birds take a maximum of three days to recover after treatment. Male farmers were 3.968 times likely to be using IK than females. Male farmers were more cultural and depended on IK more than females. Farmers owning larger flock sizes were 8.196 times more likely to use IK than farmers with small flock sizes. Resource-limited farmers were 1.701 times likely to use IK than less-poor farmers. Famers owning cattle were 1.998 times likely to use IK than farmers not owning cattle. The extent of use of IK was influenced by demographics and the availability of medicinal plants. The medicinal plants tested in Trial 3 were Gomphocarpus physocarpus, Cissus quadrangularis and Aloe maculata. These were the popular plants used in Jozini. Birds on the control had higher mean faecal egg count (FEC) (321.3) of than Gomphocarpus physocarpus (270), Cissus quadrangularis (185) and Aloe maculata (155). These results showed that the selected medicinal plants have anthelmintic potential and needs to be promoted. Keywords: medicinal plants, gastro-intestinal nematodes, anthelmintics, faecal egg counts.