Feasibility and implications of breeding sheep for resilience to nematode challenge

Bisset, S.A.; Morris, C. A.

doi:10.1016/s0020-7519(96)80056-7

Cited by 142 publications

(84 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although Clunies Ross did not use the term, later studies described the latter phenomenon as disease resilience (Albers et al 1987;Bisset and Morris 1996;Bishop 2012;Doeschl-Wilson and Lough 2014), which is typically defined in terms such as a capacity to maintain high productivity in the face of ongoing infection (Bisset and Morris 1996;Bishop 2012). More recently, interest in the impact of non-infectious stressors on animal performance has used the term resilience to describe these broader aspects of an animal's response to environmental challenges (Hermesch and Dominik 2014).…”

Section: Historical Concepts Of Resiliencementioning

confidence: 99%

Resilience in farm animals: biology, management, breeding and implications for animal welfare

2016

View full text Add to dashboard Cite

Abstract.A capacity for the animal to recover quickly from the impact of physical and social stressors and disease challenges is likely to improve evolutionary fitness of wild species and welfare and performance of farm animals. Salience and valence of stimuli sensed through neurosensors, chemosensors and immunosensors are perceived and integrated centrally to generate emotions and engage physiological, behavioural, immune, cognitive and morphological responses that defend against noxious challenges. These responses can be refined through experience to provide anticipatory and learned reactions at lower cost than innate less-specific reactions. Influences of behaviour type, coping style, and affective state and the relationships between immune responsiveness, disease resistance and resilience are reviewed. We define resilience as the capacity of animals to cope with short-term perturbations in their environment and return rapidly to their pre-challenge status. It is manifested in response to episodic, sporadic or situation-specific attributes of the environment and can be optimised via facultative learning by the individual. It is a comparative measure of differences between individuals in the outcomes that follow exposure to potentially adverse situations. In contrast, robustness is the capacity to maintain productivity in a wide range of environments without compromising reproduction, health and wellbeing. Robustness is manifested in response to persistent or cyclical attributes of the environment and is effected via activity of innate regulatory pathways. We suggest that for farm animals, husbandry practices that incorporate physical and social stressors and interactions with humans such as weaning, change of housing, and introduction to the milking parlour can be used to characterise resilience phenotypes. In these settings, resilience is likely to be more readily identified through the rate of return of variables to pre-challenge or normal status rather than through measuring the activity of diverse stress response and adaptation mechanisms. Our strategy for phenotyping resilience of sheep and cattle during weaning is described. Opportunities are examined to increase resilience through genetic selection and through improved management practices that provide emotional and cognitive enrichment and stress inoculation.Additional keywords: affective state, allostasis, animal behaviour, animal temperament, animal welfare, disease resistance, genetic selection, homeostasis, resilience, robustness, stress inoculation.

show abstract

Section: Historical Concepts Of Resiliencementioning

confidence: 99%

Resilience in farm animals: biology, management, breeding and implications for animal welfare

2016

View full text Add to dashboard Cite

show abstract

“…Resilience has been assessed in terms of productivity under nematode challenge compared with productivity in non-infected animals (Albers et al, 1987) and the number of anthelmintic treatments required over a given period of pasture challenge (Bisset and Morris, 1996). Burke and Miller (2004) reported that Katahdin lambs required more anthelmintic treatments than Dorper lambs, indicating the susceptibility of Katahdin lambs than Dorper lambs.…”

Section: Tissue Eosinophilsmentioning

confidence: 99%

Markers/parameters for the evaluation of natural resistance status of small ruminants against gastrointestinal nematodes

Saddiqi¹,

Sarwar

Iqbal

et al. 2012

Animal

View full text Add to dashboard Cite

The high prevalence of anthelmintic-resistant gastrointestinal nematodes (GINs) throughout the world has led to the need for alternative worm control strategies. One of the possible substitutes to reduce the problems of drug resistance and residue is the evaluation/breeding of small ruminants for greater resistance to the GINs (organically produced), which in turn would be a helpful tool to predict the performance of an animal. At present, the existing diversity in the genetic potential to resist/tolerate GINs infection both within and between breeds has been validated. Successful selection of animals to define the genotype and identified resistance is related to the employed markers. A number of phenotypic traits such as faecal egg count (FEC), worm burden, serum antibodies, peripheral eosinophilia, packed cell volume, live weight, serum protein and albumin concentrations have been used for this purpose both in natural and artificial infections. Relatively resistant/tolerant animals have also been found to have mastocytosis, globule leucocytes, high levels of histamine and immunoglobulin (Ig) A and IgE concentrations. Of these traits, the principal and most practical measurement used to assess resistance status in animals undergoing similar parasite challenges is FEC. FEC has a positive/negative correlation with other biochemical, cellular and immunological parameters; however, the reliability of individual trial is often questioned and valuable information regarding the genetic makeup can be obtained from pooled data of a large number of trials and parameters. This paper covers all the aspects reported in the literature on various parameters considered to evaluate the resistance status of a range of small ruminant breeds.

show abstract

“…Tolerance is defined as the ability of the host to limit the impact of a given pathogen burden on host health, performance and ultimately on fitness (Painter, 1958 ;Simms & Triplett, 1994). In farm animal science, tolerance is sometimes termed resilience (Clunies-Ross, 1932;Albers et al, 1987 ;Bisset & Morris, 1996). Resistance and tolerance together define a host's defensive capacity, yet they have very different influences on hostxpathogen interactions.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, measuring tolerance follows the methodology of the analysis of reaction norms (Via & Lande, 1985). Analysing tolerance as a change in host performance from before to after pathogen attack, an approach sometimes applied for ' resilience' analysis (Bisset & Morris, 1996), is unjustified because it includes both natural temporal variation in host performance (e.g. in growth curves) and impact of pathogen burden on host performance.…”

Section: Introductionmentioning

confidence: 99%

Genetic analysis of tolerance to infections using random regressions: a simulation study

Kause

2011

Genet. Res.

View full text Add to dashboard Cite

SummaryTolerance to infections is the ability of a host to limit the impact of a given pathogen burden on host performance. This simulation study demonstrated the merit of using random regressions to estimate unbiased genetic variances for tolerance slope and its genetic correlations with other traits, which could not be obtained using the previously implemented statistical methods. Genetic variance in tolerance was estimated as genetic variance in regression slopes of host performance along an increasing pathogen burden level. Random regressions combined with covariance functions allowed genetic variance for host performance to be estimated at any point along the pathogen burden trajectory, providing a novel means to analyse infection-induced changes in genetic variation of host performance. Yet, the results implied that decreasing family size as well as a non-zero environmental or genetic correlation between initial host performance before infection and pathogen burden led to biased estimates for tolerance genetic variance. In both cases, genetic correlation between tolerance slope and host performance in a pathogen-free environment became artificially negative, implying a genetic trade-off when it did not exist. Moreover, recording a normally distributed pathogen burden as a threshold trait is not a realistic way of obtaining unbiased estimates for tolerance genetic variance. The results show that random regressions are suitable for the genetic analysis of tolerance, given suitable data structure collected either under field or experimental conditions.

show abstract

Feasibility and implications of breeding sheep for resilience to nematode challenge

Cited by 142 publications

References 17 publications

Resilience in farm animals: biology, management, breeding and implications for animal welfare

Resilience in farm animals: biology, management, breeding and implications for animal welfare

Markers/parameters for the evaluation of natural resistance status of small ruminants against gastrointestinal nematodes

Genetic analysis of tolerance to infections using random regressions: a simulation study

Contact Info

Product

Resources

About