Volume 214, Issues 1–2, 30 November 2015, Pages 80–88
- Open Access funded by Biotechnology and Biological Sciences Research Council
- Under a Creative Commons license
Open Access
Highlights
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- 47 farmers in Botswana were trained to use targeted selective treatment for worms of small ruminants.
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- Goats from treated herds showed greater improvements in health than those from untreated herds.
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- The system was adopted successfully by farmers with a range of levels of literacy and education.
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- Mixed methods were used for evaluation and interpretation of the system within a cultural context.
Abstract
Due
to the threat of anthelmintic resistance, livestock farmers worldwide
are encouraged to selectively apply treatments against gastrointestinal
nematodes (GINs). Targeted selective treatment (TST) of individual
animals would be especially useful for smallholder farmers in low-income
economies, where cost-effective and sustainable intervention strategies
will improve livestock productivity and food security. Supporting
research has focused mainly on refining technical indicators for
treatment, and much less on factors influencing uptake and
effectiveness. We used a mixed method approach, whereby qualitative and
quantitative approaches are combined, to develop, implement and validate
a TST system for GINs in small ruminants, most commonly goats, among
smallholder farmers in the Makgadikgadi Pans region of Botswana, and to
seek better understanding of system performance within a cultural
context. After the first six months of the study, 42 out of 47 enrolled
farmers were followed up; 52% had monitored their animals using the
taught inspection criteria and 26% applied TST during this phase. Uptake
level showed little correlation with farmer characteristics, such as
literacy and size of farm. Herd health significantly improved in those
herds where anthelmintic treatment was applied: anaemia, as assessed
using the five-point FAMACHA© scale, was 0.44–0.69 points
better (95% confidence interval) and body condition score was 0.18–0.36
points better (95% C.I., five-point scale) in treated compared with
untreated herds. Only targeting individuals in greatest need led to
similar health improvements compared to treating the entire herd,
leading to dose savings ranging from 36% to 97%. This study demonstrates
that TST against nematodes can be implemented effectively by
resource-poor farmers using a community-led approach. The use of mixed
methods provides a promising system to integrate technical and social
aspects of TST programmes for maximum uptake and effect.
Graphical abstract
Keywords
- FAMACHA©;
- Participatory epidemiology;
- Livestock management;
- Goats;
- Targeted selective treatment;
- Nematodes
1. Introduction
Gastrointestinal
nematodes (GINs) affect health and production in livestock worldwide by
reducing the productive value of animals through declines in milk
production, growth rate, fertility, and increased susceptibility to
other diseases (Cobon and O’Sullivan, 1992, Perry and Randolph, 1999 and Thumbi et al., 2013).
In South-East Asia and sub-Saharan Africa, helminth infection is ranked
as the animal health constraint with the highest impact on
resource-poor livestock keepers (Perry et al., 2002).
Globally,
the acute threat of anthelmintic resistance makes whole-group
treatments unsustainable and has led to adoption of targeted treatment
strategies in intensive livestock production systems (Van Wyk, 2001, Kenyon et al., 2009 and Charlier et al., 2014).
Targeted selective treatment (TST) is based on the premise that most
animals are able to cope unaided even in the face of severe parasite
challenge (Malan et al., 2001),
so it is possible to avoid losses to the whole flock or herd by only
treating the subset that are clinically affected by heavy parasite
infection (Van Wyk, 2008, Molento et al., 2009 and Leask et al., 2013). At the same time, parasites that are not exposed to the drug (i.e. in refugia)
will maintain non-resistant alleles in the population, diluting the
genetic contribution of any anthelmintic resistant worms which survive
in the treated animals ( Van Wyk, 2001).
However, uptake of the selective treatment approach is limited by the
reluctance of farmers to risk sacrificing short term productivity in the
interests of long term sustainability (Charlier et al., 2014).
In
resource-poor regions, GINs affect the livelihoods of individual
subsistence farmers rather than the profit margin of large production
systems. Despite small average herd sizes, subsistence farmers are
unlikely to have the resources for regular whole-group treatments and
face high costs of anthelmintic drugs relative to animal value. In
addition, those grazing on communal pastures, as is the norm in
Botswana, are not able to practise other recommended strategies to
control GINs such as pasture management and rotation, and selective
breeding (Krecek and Waller, 2006, Van Wyk et al., 2006 and Riley and Van Wyk, 2009).
TST would enable rapid gains in animal health and production for
relatively small investments in chemotherapy, and an inherently
sustainable approach from the outset. However, limited access to
education for farmers and sparse animal health support systems could
challenge the implementation of TST.
The blood-sucking nematode Haemonchus contortus is the number one helminth infection impacting resource-poor livestock keepers ( Perry et al., 2002). TST for H. contortus infection can be implemented using simple indicators, and primarily the FAMACHA© system, which uses ocular mucous membrane colour as an indication of anaemia caused by haemonchosis (Malan et al., 2001). This system has been implemented and validated around the world as a method for TST in both sheep and goats ( Bath et al., 2001, Vatta et al., 2002, Vatta et al., 2001, Kaplan et al., 2004, Mahieu et al., 2007, Di Loria et al., 2009, Scheuerle et al., 2010, Sotomaior et al., 2012, Maia et al., 2014, Maia et al., 2015 and Nabukenya et al., 2014). Both the FAMACHA© system and the Five Point Check© system, which includes FAMACHA©
and additional checks for clinical signs caused by non-haematophagic
internal parasites, are designed for easy use by farmers without
veterinary skills ( Bath and Van Wyk, 2009 and Maia et al., 2014).
However, the use of these systems has been primarily studied in
commercial flocks, with few studies on its application in resource-poor
settings, and no investigations of the constraints or opportunities
associated with the social context in which it is implemented ( Nabukenya et al., 2014 and Maia et al., 2015).
In
this study we used a novel mixed method approach to determine the
feasibility of introducing TST for sustainable and cost-effective
management of GINs in small ruminants by smallholder subsistence
farmers, the majority of whom had not previously used anthelmintics.
Mixed methods research, where qualitative and quantitative approaches
are combined to address the same aim, provides the potential to better
understand how TST can be implemented within existing technical, social,
and educational contexts in a way that is valuable to resource-poor
farmers and sustainable (Ozawa and Pongpirul, 2014).
Previous research has neglected this area, focusing instead on
technical improvements in TST and validating its effectiveness for
anthelmintic resistance and economics. We aimed to empower the farmers
to assess and manage the health of their own livestock, thereby
increasing resilience and food security. At the same time, we were able
to assess the performance and benefits of TST in this setting, and
understand the social context of implementation, such that we are better
placed to embed TST into livestock management programmes elsewhere.
