In a study of potential biological control agents, two strains of Bacillus thuringiensis (Bt) and one of Clonostachys rosea f. Integration of the best plant extracts with the best biological control agents to control sheep nematodes in vivo (Chapter 6).
Helminths of small ruminants
In the weevil, gastrointestinal nematodes are important members of the order Strongylida, which contains Trichostrongyloidea, Strongyloidea, Metastrongyloidea and Ancylostomatoidea, and most of them belong to the superfamily Trichostrongyloidea.
Gastrointestinal nematode
The effects of nematode parasites on the host are manifested as loss of condition, rough coat, diarrhea, jaw, anemia and death (Hale, 2006). Diagnosis of nematode infection in the host can be made by examining the host's feces for parasite eggs and larvae (Sloss and Kemp, 1978).
Chemical control of nematodes
- Benzimidazoles
- Imidazothiazoles and Tetrahydropyrimidine
- Macrocyclic lactones
- Other anthelmintics
Deficiency of microtubules inhibits many cellular functions such as transport, cell division, neuronal transmission and cell differentiation, ultimately leading to cell death in the worm (Prichard, 2005). There are other active ingredients represented by other common anthelmintics on the market, such as salicylanilides (closantel).
Anthelminthic resistance
The use of the above chemicals either independently or in combinations has led to a reduction in the ability of the chemicals to reduce the parasite burden in livestock. For example, Kohler (2001) reported that benzimidazoles alter the structure of B-tubulin isotypes in the parasites, and nicotinic agonists alter.
Other problems of anthelmintics use
Alternatives to anthelminthic
- Copper wire particles
- Grazing management
- Breeding for host resistance
- Vaccination strategy
- Nutrition
- Botanical extracts
- Mechanisms of botanical extracts
- Biological control
- Earthworms
- Viruses
- The soil amoeba, Theratromyxa weberi Zwillenberg
- Protozoa
- Micro-arthropods
- The fungus Duddingtonia flagrans Cooke
- The fungus Clonostachys rosea f. rosea Schroers
- The bacterium Bacillus thuringiensis Berliner
This fungus belongs to a heterogeneous group of fungi in the family Deuteromycetes (Waller et al., 2006). Bacillus thuringiensis produces crystals of protein insecticidal δ-endotoxins (crystal proteins or Cry proteins) (Ito et al., 2006).
Conclusions
Delta-endotoxins bind to the cells lining the midgut membrane and create pores in the membrane. These studies confirmed that Cry proteins cause intestinal damage in both nematodes and insects.
Prevalence of worm resistance in gastrointestinal nematodes of dairy goats under extensive management conditions in the South West. The prevalence of worm resistance in nematode parasites of sheep in southern Latin America: Brazil. The prevalence of worm resistance in nematode parasites of sheep in Southern Latin America: Argentina.
Prevalence of anthelmintic resistance in nematode parasites of sheep in southern Latin America: Paraguay. Evidence of multiple anthelmintic resistance in sheep and goats reared under the same control in coastal Kenya. Possibilities of biological control of free-living stages of nematode parasites in livestock.
- Introduction
- Materials and methods
- Collection of plants and preparation of extracts
- In vitro screening of plant extracts
- Statistical
- Results
- Experiment 1: Screening of ethanol extracts for anthelmintic activity
- Experiment 2: Screening of different extracts of five plant species for anthelmintic
- Discussion
- Conclusions
- References
Plant extracts with anthelmintic properties are considered one of the most promising alternatives for the control of GIN (Waller et al., 2001; Gillian et al., 2004). In addition, fig trees may have unidentified but active compounds, such as the enzyme ficin (Stepek et al., 2004), which may be responsible for different levels of larval mortality. Warburgia salutaris is a traditional medicinal plant used as an anthelmintic in South African traditional medicine (Fennell et al., 2004; Mohanlall and Odhav, 2009).
Water is the main solvent used in traditional medicine for the preparation of plants (Sparg et al., 2002). These findings support those of Le Dang et al. 2010) who tested various organic solvent extracts of Chenopodium ficifolium Smith for insecticidal activity against melon and cotton aphid, Aphis gossypii Glover, on cucumber plants. Methanol and ethanol extracts were active (causing more than 80% mortality), while other extracts such as acetone, ethyl acetate and dichloromethane had a lower range between 16-69% (Le Dang et al., 2010).
- Introduction
- Material and methods
- Study area
- Experimental design and sheep management
- Sample collection and parasitological analysis
- Statistical analysis
- Results
- Larval infestation from the pasture
- Live-weight gain
- Nematode egg counts
- Efficacy of treatments
- Numbers of larvae recovered from faecal cultures
- Conclusions
- References
The history of herbal medicine is almost as old as human civilization (Iqbal et al., 2001). A wide range of plants and plant extracts have been traditionally used as anthelmintic treatments in humans (Waller et al., 2001). The arrow indicates the time when plant extracts were dosed for three consecutive days and the square indicates the time of CAP repetition.
There was no difference (P>0.05) between plant extracts although the effect of time was significant (P<0.05). This is consistent with our findings of increased efficacy due to repeated dosing with plant extracts for three consecutive days. Dosing sheep with plant extracts for three consecutive days reduced EPG and larval load from faecal culture.
Introduction
Materials and methods
- Formulation of biocontrol agents
- Animals used in Experiment 1
- Feed preparation
- Experimental design and sample collection
- Animals and experimental design for Experiment 2
- Sample collection
- Statistical analysis
Clonostachys rosea and Bacillus thuringiensis (Bt) products were each added to the standard diet at a dose of 1g kg-1 BW. Diatomaceous earth product was added to the standard diet at a dose of 2% for each sheep. Sheep were fed the standard diet daily between 0700-0900 and then given field hay and water ad libitum.
During a 7-day pretreatment period, sheep were randomly assigned to individual sheep feed stalls to acclimate to handling facilities. During the experiment, sheep were assigned to one of four treatments: Standard feed without treatment, 2% DE, Bt at1g kg-1 BW per day and C. Efficiency of each treatment was estimated using the following formula, according to Peña et al.
Results
- Effect of treatments on nematode eggs per gram (EPG)
- Effect of treatments on nematode larvae per gram (LPG)
- Effect of treatments on nematode larvae development (LD)
- Efficacy of treatments
- Effect of C. rosea on nematode egg counts
- Effect of C. rosea on count of nematode larvae
- Effect of C. rosea on nematode larvae development
- Efficacy of C. rosea dosages
On Day 7, the Control had the highest LD of 3.9%, there were significantly fewer larvae developing after treatments with DE at 3.8% and Bt at 2.5%, and C. LSD=least significant difference; CV% = coefficient of variance Numbers with the same letters are not significantly different at P=0.05. LSD=least significant difference; CV% = coefficient of variance Numbers with the same letters are not significantly different at P=0.05.
Discussion
In the present study, the fungus caused the majority of larval mortality and the number of infective larvae decreased on the second day after initiation of fungal feeding. This indicates that to reduce larval infestation, there must be sufficient amounts of fungal elements in faeces (Larsen et al., 1998). Therefore, the second experiment was designed to assess the frequency of dosing required to produce a significant and long-lasting reduction in the number of infective larvae when fungal chlamydospores were delivered at a fixed rate for an extended period.
As with this study, Stear et al. 2007) reported that fungi can control nematodes, but their effect is greatest if dosed or applied daily. This reduction in infective L3 stages on herbage will subsequently prevent the build-up of nematode burdens in their hosts, which typically cause subclinical and/or clinical infections, particularly in small ungulates (Larsen et al., 1998; Peart, 2002). For these reasons, it is important that a biocontrol agent passes through the digestive tract of an animal and is emptied together with the nematode eggs in the faeces, where it germinates, captures and destroys free-living stages of nematodes (Larsen et al., 1998) Thamsborg et al., 1999).
Conclusions
It has shown great promise against free-living stages of trichostrongylide nematodes in cattle (Larsen et al., 1995). Clonostachys rosea (Schroers) has been proposed as a nematophagous fungus with potential to control livestock nematodes (Zhang et al., 2008). It has been shown that the number of nematode larvae on a pasture depends on the stocking rate of livestock (Thamsborg et al., 1996).
The preventive effect of the fungus Duddingtonia flagrans on trichostrongyle infections in pastured lambs. Several fungal species such as Duddingtonia flagrans (Cooke) trap and kill developing larval stages of parasitic nematodes in the faecal environment (Larsen et al., 1995). The number of larvae recovered from faecal cultures increased with time for control but consistently decreased for the rest of the treatments (Table 6.4), with the effect of treatment reaching significance (P<0.001) from day 14 to the end.
- Introduction
- Materials and methods
- Formulation of a C. rosea product
- Animals, diets and experiment design
- Sample collection
- Weather data
- Statistical analysis
- Result
- Body-weight gain
- Effect of treatments on nematode eggs per gram (EPG)
- Effect of treatments on nematode larvae per gram
- Effect of treatments on nematode larvae development (LD)
- Third-stage larvae (L 3 ) on pasture grass
- Efficacy of treatment
- Discussion
- Conclusions
- References
The fungus effectively captures nematode larvae present in feces, reducing the larval population on pasture (Faedo et al., 1998). Furthermore, several field studies in small ruminants have reported positive effects of fungal treatment in adult sheep and goats grazing on naturally degraded pastures (Faedo et al., 1998; Waghorn et al., 2003; Paraud et al., 2006). Although the results of most studies are encouraging, it appears that successful treatments in cattle have not been consistently effective in small ruminants (Faessler et al., 2007).
Clonostachys rosea produces cell wall degrading enzymes, including chitin, glucan and cellulose degrading enzymes (Lübeck et al., 2002). This may account for the difference in results between this study and the above studies of Epe et al. 2007), as the number of animals per paddock was higher in both their experiments. Efficacy of the nematode-trapping fungus Duddingtonia flagrans against three species of gastrointestinal nematodes in laboratory fecal cultures of sheep and goats.
- Introduction
- Materials and methods
- Pastures, animals, treatments and design
- Experimental procedures and sample collection
- Sample collection
- Statistical analysis
- Results
- Third-stage larvae on pasture
- Effect of treatments on nematode eggs per gram (EPG)
- Effect of treatments on nematode larvae per gram (LPG) of faeces
- Effect of treatments on nematode larvae development (LD)
- Efficacy in reducing nematode egg in faeces
- Nematicidal efficacy in reducing larvae in faecal cultures
- Body-weight gain
- Discussion
- Conclusions
- References
In fact, daily feeding of fungal chlamydospores has been successfully used to control parasitic nematodes in small ruminants (Terrill et al., 2001; Baloyi et al., 2012). In line with Baloyi et al. 2012) CR administration did not affect sheep nematode eggs. In addition, Terrill et al. 2004) observed a nematicidal effect with 94% efficiency in goats infected with a mixed culture of GIN and fed D.
Similarly, in goats, extracts of AC can significantly inhibit nematode egg production (Sujon et al., 2008). Plant extracts with anthelmintic properties inhibit egg hatching and larval development of nematodes (Molan et al., 2000). The effectiveness in reducing nematode egg production using plant extracts has been demonstrated in vitro and in vivo (Githiori et al., 2006).
- Conclusions
- Recommendations
- Further research
- References
In vivo studies were conducted using ethanol extracts of the five selected plants, comparing their performance with a positive control, a commercial drug combination of Abamectin and Praziquantel, using sheep as experimental animals. Both the biological control agents and DE did not affect EPG, but reduced the number of L3 GIN larvae. Other researchers have found similar results. rosea isolate was pathogenic on sheep GIN larvae. 2005) reported a toxic effect of Bt isolates on nematode larvae. 2009) also found that DE reduced the number of goat GIN larvae.
The World Health Organization estimates that more than 2.9 billion of the poorest and most vulnerable people on earth, and especially children, are infected with nematodes, seriously harming their health (Martin et al., 2011). Roles of organic soil amendments and soil organisms in the biological control of plant-parasitic nematodes: a review. Add salt to saturation, indicated by the presence of salt at the bottom of the container after stirring for 15 minutes.
