Epidemiology of gastrointestinal nematode parasitism in a commercial sheep flock and its implications for control programmes

SummaryPlant secondary metabolites (PSM) are widely known for their antinutritional properties; their excessive consumption can detrimentally affect herbivore health and, in some cases, survival. However, a growing body of evidence is suggesting that some classes of PSM may also have some positive effects on herbivores. Such positive effects include the antiparasitic properties of certain PSM and their beneficial consequences on the herbivore's fitness. One of the better-exploited classes of PSM that have been reported with anthelmintic properties is that of the condensed tannins. The consumption of moderate concentrations of condensed tannins has resulted in reduced level of parasitism in sheep and other ruminants. In this paper we discuss the conditions that should be met in order for the positive anthelmintic properties of PSM, and condensed tannins in particular, to be beneficial for parasitised sheep. We also examine whether PSM could have a role in controlling parasitism in ruminants and point out the future research needed to achieve an efficient use of PSM for parasite control.

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Effects of parasitism on the nutrient economy of sheep: an overview

Australian Journal of Experimental Agriculture ◽

10.1071/ea02228 ◽

2003 ◽

Vol 43 (12) ◽

pp. 1393 ◽

Cited By ~ 32

Author(s):

A. R. Sykes ◽

A. W. Greer

Keyword(s):

Nutritional Supplements ◽

Gastrointestinal Nematode ◽

Protein Supplementation ◽

Parasite Control ◽

Laboratory Studies ◽

Initial Acquisition ◽

Nematode Parasitism ◽

Per Se ◽

Peripartum Period ◽

Nutrient Economy

The experimental difficulties of qualifying the effects of gastrointestinal nematode parasitism on the nutrient economy of sheep from field and laboratory studies are discussed. The evidence available is reviewed and the conclusion drawn is that infection in the abomasum or small intestine induces protein deficiency while reducing supply through depression of appetite. It appears that the effects in susceptible animals — in lambs during the phase of initial acquisition of immunity and in ewes during the peripartum period — are largely reversible by protein supplementation. Quantified effects on mineral nutrition are few and are probably site-specific.The possibility that the host immune response per se may be implicated in the characteristic appetite depression is discussed. The need to understand the immune response's demand for specific amino acids is emphasised, particularly if nutritional supplements are to be used effectively in parasite control. A better understanding of the post-ruminal supply of amino acid in grazing animals will also be needed.

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Correlation of subclinical gastrointestinal nematode parasitism with growth and reproductive performance in ewe lambs in Ontario

Preventive Veterinary Medicine ◽

10.1016/j.prevetmed.2020.105175 ◽

2020 ◽

Vol 185 ◽

pp. 105175

Author(s):

Emma A. Borkowski ◽

Jacob Avula ◽

Elizabeth M. Redman ◽

William Sears ◽

Brandon N. Lillie ◽

...

Keyword(s):

Reproductive Performance ◽

Gastrointestinal Nematode ◽

Ewe Lambs ◽

Nematode Parasitism

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A cysteine protease from the latex of Ficus benjamina has in vitro anthelmintic activity against Haemonchus contortus

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-296120180070 ◽

2018 ◽

Vol 27 (4) ◽

pp. 473-480 ◽

Cited By ~ 2

Author(s):

Ledia Feitosa Wanderley ◽

Alexandra Martins dos Santos Soares ◽

Carolina Rocha e Silva ◽

Isaias Moreira de Figueiredo ◽

Andre Teixeira da Silva Ferreira ◽

...

Keyword(s):

Proteolytic Activity ◽

Cysteine Protease ◽

Haemonchus Contortus ◽

Anthelmintic Activity ◽

Gastrointestinal Nematode ◽

Bioactive Molecules ◽

Promising Alternative ◽

Ficus Benjamina ◽

Control Programmes

Abstract Haemonchus contortus is a gastrointestinal nematode that is responsible for high mortality rates in ruminant herds. The resistance of nematodes to synthetic anthelmintics is widespread and requires a continuous search for new bioactive molecules, such as proteins. The objective of this study was to evaluate the anthelmintic potential of a protease purified from the latex of Ficus benjamina against H. contortus . Fresh latex was collected from plants via small incisions in the green stems, the rubber was removed by centrifugation, and the latex protein extract (LPE) was obtained. After LPE fractionation with ammonium sulfate and chromatography of the fraction containing the highest proteolytic activity on CM-cellulose, a cysteine protease (FbP) was purified. FbP has a molecular mass of approximately 23.97 kDa, and its proteolytic activity was stable between pH 6.0 and pH 10 and over a broad temperature range, with optimum activity at 60 °C. FbP inhibited both the development and exsheathment of H. contortus larvae, with 50% effective concentrations of 0.26 and 0.79 mg/mL, respectively. We conclude that this cysteine protease from F. benjamina latex with anthelmintic activity against H. contortus could be a promising alternative for the development of products for use in parasite control programmes.

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Mineral nutrition and its effects on gastrointestinal immune function of sheep

Australian Journal of Experimental Agriculture ◽

10.1071/ea03002 ◽

2003 ◽

Vol 43 (12) ◽

pp. 1455 ◽

Cited By ~ 8

Author(s):

S. J. McClure

Keyword(s):

Mucosal Immunity ◽

Gastrointestinal Nematode ◽

Major And Trace Elements ◽

Future Research ◽

Internal Parasites ◽

Dietary Component ◽

Nematode Parasitism ◽

Dietary Components ◽

On Farm

Sustainable control of gastrointestinal nematode parasitism requires optimisation of protective mucosal immunity. This may involve controlling predisposing factors, of which nutrition is the easiest to manipulate, or immuno-enhancement, including that by dietary components. Minerals are 1 type of dietary component with the potential to alter regulation of mucosal immunity to parasites.In addition to more specific functions, both major and trace elements have wide-ranging roles in the activity of enzyme systems, with the potential to affect immunity via a number of pathways. While there is little reported work on the effects of minerals on mucosal immunity of ruminants, some important principles can be drawn from this work. These are discussed with work on immunity in general. Also indicated is the future research needed to explain the role of minerals in immunity to internal parasites and to permit the application of this understanding to on-farm situations.

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