1
|
Chylinski C, Athanasiadou S, Thüer S, Grovermann C, Moakes S, Hoste H, Petkevicius S, Verwer C, Verkaik J, Werne S. Reducing anthelmintic inputs in organic farming: Are small ruminant farmers integrating alternative strategies to control gastrointestinal nematodes? Vet Parasitol 2023; 315:109864. [PMID: 36638764 DOI: 10.1016/j.vetpar.2022.109864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 12/15/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
To counter the global spread of anthelmintic resistance (AR), considerable efforts have been invested in the development and dissemination of sustainable alternatives to control gastrointestinal nematode (GIN) infections in small ruminants. The degree to which these have been accepted and integrated by farmers, particularly in organic systems, where the drive to reduce chemical inputs is arguably even more pressing, has been little studied. To identify whether more comprehensive actions are needed to support the uptake of alternative GIN controls amongst organic farmers, this study conducted a survey in five European countries on organic dairy goat and meat sheep farmers to gain insight into current GIN control strategies and farmer attitudes towards AR and alternative measures in these countries. The structured survey was disseminated in the five European countries Switzerland, France, Netherlands, Lithuania and United Kingdom, receiving a total of 425 responses, 106 from organic dairy goat farmers and 319 from organic meat sheep farmers. Regression analyses were carried out to identify factors impacting anthelmintic drenching on meat sheep production systems, whereas all data were analysed descriptively. Four key findings emerged: i) The frequency of anthelmintic treatments averaged less than two per animal a year in all production systems; ii) Overall, organic farmers seemed well informed on the availability of alternative GIN control methods, but fewer stated to put them into practice; iii) Targeted selective treatment (TST) strategies of anthelmintics appears to be not commonly incorporated by organic farmers; iv) Despite operating under national and EU organic regulations, each of the organic dairy goat (Switzerland, France and Netherlands) and meat sheep (Switzerland, Lithuania and United Kingdom) production systems developed distinct approaches for GIN control. To increase uptake of alternatives to GIN control and optimise anthelmintic use, initiatives that promote research dissemination, farmer participatory and knowledge transfer activities at national level would be desirable.
Collapse
|
2
|
Bates AJ, Greer A, McAnulty R, Jackson A. Targeted selective treatment with anthelmintic for New Zealand dairy heifers. Vet Parasitol 2022; 309:109757. [DOI: 10.1016/j.vetpar.2022.109757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 06/12/2022] [Accepted: 06/18/2022] [Indexed: 11/16/2022]
|
3
|
Dos Santos IB, Anholeto LA, de Sousa GA, da Silva Nucci A, Gainza YA, Figueiredo A, Dos Santos LAL, Minho AP, Barioni-Junior W, Esteves SN, Niciura SCM, de Souza Chagas AC. Investigating the benefits of targeted selective treatment according to average daily weight gain against gastrointestinal nematodes in Morada Nova lambs. Parasitol Res 2022. [PMID: 35624382 DOI: 10.1007/s00436-022-07549-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/12/2022] [Indexed: 10/18/2022]
Abstract
The objective of this study was to evaluate a method of targeted selective treatment (TST) of Morada Nova lambs, based on the average daily weight gain (DWG). For this, 114 lambs in the rainy and 102 in the dry season were randomized into three treatments: control (CT), routine (RT, treated every 42 days), and targeted selective (TST, treated according to DWG). Packed cell volume (PCV) and eggs per gram of feces (EPG) tests were performed. The anthelmintic resistance of parasites was assessed by the EPG count reduction test (FECRT), RESISTA-Test©, and molecular test. For CT, RT, and TST groups, the following results were obtained: mean EPG values were 4665.1, 3063.5, and 3462.1 in the rainy season and 4475.1, 1341.7, and 2863.4 in the dry season, respectively; mean PCV values were 32.1, 33.4, and 32.3% in the rainy season and 33.9, 36.0, and 35.1% in the dry season; mean DWG readings were 0.087, 0.101, and 0.094 kg in the rainy season and 0.102, 0.113, and 0.112 kg in the dry season; efficacies of levamisole in FECRT were 66.4, 24.1, and 76.4% in the rainy and 90.7, 12.4, and 64.8% in the dry season, respectively; in the RESISTA-Test©, the LC50 values were 0.482, 1.926, and 0.117 µg.mL-1 in the rainy and 0.437, 0.851, and 0.045 µg.mL-1 in the dry season, respectively; the frequencies of the homozygous-resistant genotype were 57.1, 71.4, and 40.0% in the rainy and 47.8, 55.9, and 41.9% in the dry season. In conclusion, TST reduced the development of resistance through refugia maintenance, without productive losses, contributing to the sustainability of sheep breeding.
Collapse
|
4
|
Melville LA, Hayward A, Morgan ER, Shaw DJ, McBean D, Andrews L, Morrison A, Kenyon F. Precision worm control in grazing lambs by targeting group treatment based on performance of sentinels. Animal 2021; 15:100176. [PMID: 33637437 DOI: 10.1016/j.animal.2021.100176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 12/21/2020] [Accepted: 01/04/2021] [Indexed: 10/22/2022] Open
Abstract
Given the economic impact of gastrointestinal nematode infection on livestock farming worldwide, and increasing anthelmintic resistance, it is imperative to develop practical, efficient and sustainable control strategies. Targeted selective treatment (TST), whereby anthelmintic treatments are administered to animals individually, based on selection criteria such as weight gain, has been shown to successfully maintain animal productivity whilst reducing the selection pressure for anthelmintic resistance and the economic cost of treatment in experimental and commercial settings. Despite the benefits of the TST approach, the equipment and time required to monitor animals individually make this strategy unsuitable for some farming enterprises. The sentinel group approach aims to maintain the benefits observed using TST whilst reducing these requirements. The study involved two experiments, each following a group of 80 lambs through their first grazing season. Anthelmintic treatment of the whole group was determined by monitoring the weight gain of identified sentinel lambs within it every 2 weeks: when 40% of the sentinel lambs failed to reach their weight gain targets, the whole group was treated. The sentinel lambs consisted of 45% of the group (n = 36) in experiment one and 20% (n = 16) in experiment two. A control group of 20 lambs was co-grazed with the main group during both experiments; in experiment one, the sentinel approach was compared with a TST approach, in which control lambs were treated on an individual basis in response to weight gain. In experiment two, the sentinel approach was compared with conventional prophylaxis, where all lambs in the control group were treated at strategic time points throughout the season (= strategic prophylactic treatment). The sentinel lambs were found to be representative of overall group performance regardless of the proportion of sentinels within the group: they recorded similar growth rates and reached weight gain targets simultaneously at each time point and overall. Live-weight gain was also similar between sentinel and control animals in both experiments. The findings of the current study suggest that monitoring sentinel lambs comprising 20% of a group of grazing lambs is sufficient to determine the need for anthelmintic treatment within the whole group, and that this approach maintains production in line with conventional or TST treatment regimes.
Collapse
Affiliation(s)
- L A Melville
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK.
| | - A Hayward
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK
| | - E R Morgan
- Queens University Belfast, School of Biological Sciences, 19, Chlorine Gardens, Belfast BT9 5DL, UK
| | - D J Shaw
- Royal (Dick) School of Veterinary Studies & Roslin Institute, The University of Edinburgh, Easter Bush Campus, Roslin EH25 9RG, UK
| | - D McBean
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK
| | - L Andrews
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK
| | - A Morrison
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK
| | - F Kenyon
- Department of disease control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 0PZ, UK
| |
Collapse
|
5
|
McBean DW, Greer AW, Kenyon F. The Happy Factor treatment threshold, used to determine Targeted Selective Treatment decisions for lambs, is transferable between farms. Animal 2021; 15:100178. [PMID: 33589351 DOI: 10.1016/j.animal.2021.100178] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 10/22/2022] Open
Abstract
Weight gain-based treatment decision-making has been shown to successfully reduce the number of anthelmintic treatments without compromising production as part of a Targeted Selective Treatment (TST)-based worm control strategy in sheep. The effects of using an efficiency threshold (Standard Threshold (ST)) developed on one farm were examined to establish whether there was a need to tailor the threshold for individual farm conditions. The Standard Threshold had been used on a number of farms, and data from these trials were used here. The ideal threshold (Estimated Treatment Threshold) for each farm was calculated using the same method as the original threshold, and the effect on the number of treatments given and subsequent productivity was estimated. Estimated treatment thresholds were calculated to be higher on all farms including the original, resulting in increased numbers of treatments due. The effect of the increased number of treatments was calculated to have no effect on productivity however, and it was concluded that the ST was sufficient, at least initially, for successful implementation of TST and that further refinement could be made using locally derived data if required.
Collapse
Affiliation(s)
- D W McBean
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, Scotland, United Kingdom.
| | - A W Greer
- Faculty of Agriculture and Life Sciences, P.O. Box 85084, Lincoln University, Lincoln 7647, New Zealand
| | - F Kenyon
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, Scotland, United Kingdom
| |
Collapse
|
6
|
Weber SH, Dos Santos SK, Heinzen BC, Viana NP, Sotomaior CS. Comparison of nonlinear mathematical models for lamb growth analysis. Trop Anim Health Prod 2021; 53:151. [PMID: 33538904 DOI: 10.1007/s11250-021-02597-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/27/2021] [Indexed: 10/22/2022]
Abstract
With the objective to determine the best mathematical model that could demonstrate the relationship between body weight and age in crossbred sheep, and to evaluate its applicability in different farms, 9985 live weight records of 837 crossbred lambs of Texel, Ile de France, Suffolk, and Hampshire Down breeds were used. Brody, von Bertalanffy, Richards, Logistic, and Gompertz models were fitted to the weight data, which were compared based on adjusted R2, Syx%, chi-square, and Kolmogorov-Smirnov tests, as well as residual analysis. After selecting the model, lambs whose weights at different ages fell within, below, or above ±20% of the values predicted by the model were classified as medium, low, or high performance, respectively. To validate the model, we used a validation dataset comprising 2898 weights of lambs from 6 different farms. Based on statistical analysis and biological characteristics (sigmoid trend of weight over time, weight at birth, and standard deviation), the model that best represented the growth of the lambs was the Richards model. The percentage of lambs classified as below, within, and above the predicted values based on the model was highly similar for the original and validation data, which indicates that this model could be used in different farms. It was concluded that the Richards model best described the live weight growth of crossbred lambs and aided in classifying the lambs as high, medium, or low performance, thereby providing a complementary tool in management decision-making.
Collapse
|
7
|
Sargison ND, Mazeri S, Gamble L, Lohr F, Chikungwa P, Chulu J, Hunsberger KT, Jourdan N, Shah A, Burdon Bailey JL. Conjunctival mucous membrane colour as an indicator for the targeted selective treatment of haemonchosis and of the general health status of peri-urban smallholder goats in southern Malawi. Prev Vet Med 2020; 186:105225. [PMID: 33348303 DOI: 10.1016/j.prevetmed.2020.105225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The world's growing population is becoming increasingly centred around large cities, affording opportunities for peri-urban food production. Goats are well-suited to conversion of resources that are available in peri-urban settings into meat and occasionally milk. Haemonchus contortus has been described as "the nemesis of small ruminant production systems in tropical and subtropical regions"; hence control of haemonchosis through planned animal health management affords a pragmatic first step in improving the production efficiency of peri-urban goats. This study of peri-urban goat production investigated the potential value of targeted selective treatment of haemonchosis. 452 peri-urban goat keepers in southern Malawi were visited during three seasonal periods with relevance to the epidemiology of haemonchosis. 622, 599 and 455 individually identified goats were clinically examined during the dry season, the rainy season, and shortly after the end of the rainy season, respectively. Data were recorded for sex, age, weight, conjunctival mucous membrane colour score (FAMACHA©), body condition score (BCS) and faecal worm egg count (FEC); and where possible for pregnancy and lactation status. Animals with pale ocular mucous membranes were treated with 10 mg/kg albendazole, then re-examined 14 days later. Animals with pink mucous membranes, but FECs ≥250 eggs per gram were also re-examined and treated 14 days later. The results show high variability in growth rates deduced from the ages and bodyweights of each of 999 goats at the time of their enrolment. FAMACHA© scores alone were a poor index for the targeted selective treatment of haemonchosis, because they failed to identify too many animals that would have required treatment at different times of year and using different FAMACHA© and FEC cut-offs. Combining the indices of FAMACHA© scores ≥4, body condition scores ≥2, and age >18 months was more reliable in identifying those animals requiring treatment when different epidemiologically-relevant FEC thresholds for different seasons were taken into account. Inclusion of late pregnancy or early lactation status would have resulted in very few animals requiring treatment being missed. The use of conjunctival mucous membrane colour scoring in this way provided a valuable insight of the general health status of the peri-urban goats, to create opportunities for planned animal health management to improve productivity. The efficacy of albendazole treatment was poor, putatively due to drug resistance, or poor drug bioavailability in goats. In summary, our study shows opportunities for better production efficiency in peri-urban goats, and demonstrates the value of simple clinical diagnostic indices as decision support tools in planned animal health management.
Collapse
Affiliation(s)
- N D Sargison
- University of Edinburgh, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian, EH25 9RG, UK.
| | - S Mazeri
- University of Edinburgh, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian, EH25 9RG, UK
| | - L Gamble
- Mission Rabies, Worldwide Veterinary Service, 4 Castle Street, Cranborne, Dorset, BH21 5PZ, UK
| | - F Lohr
- Mission Rabies, Worldwide Veterinary Service, 4 Castle Street, Cranborne, Dorset, BH21 5PZ, UK
| | - P Chikungwa
- Department of Animal Health and Livestock Development, PO Box 2096, Lilongwe, Malawi
| | - J Chulu
- Department of Animal Health and Livestock Development, PO Box 2096, Lilongwe, Malawi
| | - K T Hunsberger
- MSD Fellowship for Global Health, Merck & Co., Inc., Kenilworth, NJ, USA
| | - N Jourdan
- MSD Fellowship for Global Health, Merck & Co., Inc., Kenilworth, NJ, USA
| | - A Shah
- MSD Fellowship for Global Health, Merck & Co., Inc., Kenilworth, NJ, USA
| | - J L Burdon Bailey
- Mission Rabies, Worldwide Veterinary Service, 4 Castle Street, Cranborne, Dorset, BH21 5PZ, UK
| |
Collapse
|
8
|
Abstract
Refugia-based strategies are intended to help slow the development of anthelmintic resistance by providing a population of parasites that are not exposed to the treatment. Evidence from field studies is lacking. There is no single way to incorporate refugia into a parasite control program. There are many options available varying greatly in complexity and practicality, and none are suitable for all situations. Incorporating refugia into production systems typically requires a change in farmer mindset and greater input of time, labor, and/or technology, but is necessary to help preserve anthelmintic efficacy and promote sustainable animal production systems.
Collapse
Affiliation(s)
- Andrew W Greer
- Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 85084, Christchurch, Canterbury 7647, New Zealand.
| | - Jan A Van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, P/Bag X04, Onderstepoort 0110, South Africa
| | - Joseph C Hamie
- Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 85084, Christchurch, Canterbury 7647, New Zealand; Department of Agricultural Research Services, Lunyangwa Agricultural Research Station, PO Box 59, Choma Road, Mzuzu, Malawi
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, P/Bag X04, Onderstepoort 0110, South Africa
| | - Fiona Kenyon
- Disease Control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, Scotland
| |
Collapse
|
9
|
Rizzon Cintra MC, Ollhoff RD, Weber SH, Santos Sotomaior C. Is the Famacha © system always the best criterion for targeted selective treatment for the control of haemonchosis in growing lambs? Vet Parasitol 2019; 266:67-72. [PMID: 30736949 DOI: 10.1016/j.vetpar.2018.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 12/12/2018] [Accepted: 12/12/2018] [Indexed: 10/27/2022]
Abstract
Targeted selective treatment (TST) aims to aid in the control of gastrointestinal nematodes in small ruminants, identifying animals that require treatment with the purpose of preserving the Refugia population and delaying the buildup of anthelmintic (AH) resistance. The objective of this study was to evaluate the effectiveness of both productive and clinical indicators in the selective treatment of gastrointestinal parasites in growing lambs. Two experiments were carried out between 2015 and 2016. Experiment 1: lambs (n = 70) exclusively raised on pasture were evaluated from the ages of 60 days to 180 days old. Experiment 2: lambs (n = 48) raised on pasture and fed concentrated commercial supplementation were evaluated from the ages of 60 days to 150 days old. Parasitological (eggs per gram of feces - EPG), productive (average daily weight gain - DWG), and clinical (hematocrit - Ht and FAMACHA© system - F) parameters were measured every 14 days. The lambs were divided into 4 experimental groups with different criteria for AH treatment: the control group (CG), was treated with AH every 30 days; the FAMACHA© group (FG), in which lambs classified as F3, F4, and F5 were treated with AH; Daily weight gain group (DWGG), in which lambs with average DWG ≤ the average DWG of the CG minus one standard deviation were treated with AH; FAMACHA© + daily weight gain group (FDWGG), in which lambs classified as F3, F4 and F5 and/or lambs with average DWG ≤ the average DWG of the CG minus one standard deviation were treated with AH. In experiment 1, no significant differences in the general means of DWG and Ht (p > 0.05) were observed between experimental groups, although the lowest mean EPG was observed in the CG (p < 0.05). In experiment 2, the lowest mean EPG (p < 0.05) was also observed in the CG (1044.5 EPG), and the highest mean (p < 0.05) in the FG (4845.5 EPG). There were differences in the mean DWG of the CG (198.4 g) and FDWGG (200.0 g), which were both higher (p < 0.05) than that of the FG (90.5 g), and similar (p > 0.05) to the DWGG (151.8 g). In both experiments, considering the total mean number of AH treatments, FG had the lowest number of lambs treated with AH (p < 0.05), with the DWG and FDWGG being similar to each other (p > 0.05). Even when Haemonchus is the major parasite, it is not recommended to use the FAMACHA© system as an exclusive criterion for TST in growing lambs. The DWG productive criterion can be used effectively in the TST of growing lambs.
Collapse
Affiliation(s)
- Maria Christine Rizzon Cintra
- Graduate Program in Animal Science, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil
| | - Rüdiger Daniel Ollhoff
- Graduate Program in Animal Science, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil
| | - Saulo Henrique Weber
- Graduate Program in Animal Science, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil
| | - Cristina Santos Sotomaior
- Graduate Program in Animal Science, School of Life Sciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, 80215-901, Brazil.
| |
Collapse
|
10
|
|
11
|
Soto-barrientos N, Chan-pérez J, España-españa E, Novelo-chi L, Palma-ávila I, Ceballos-mendoza A, Sarabia-hernández J, Santos-ricalde R, Cámara-sarmiento R, Torres-acosta J. Comparing body condition score and FAMACHA© to identify hair-sheep ewes with high faecal egg counts of gastrointestinal nematodes in farms under hot tropical conditions. Small Rumin Res 2018; 167:92-9. [DOI: 10.1016/j.smallrumres.2018.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
12
|
Keegan JD, Good B, Hanrahan JP, Lynch C, de Waal T, Keane OM. Live weight as a basis for targeted selective treatment of lambs post-weaning. Vet Parasitol 2018; 258:8-13. [DOI: 10.1016/j.vetpar.2018.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 06/01/2018] [Accepted: 06/02/2018] [Indexed: 11/27/2022]
|
13
|
Morgan-Davies C, Lambe N, Wishart H, Waterhouse T, Kenyon F, McBean D, McCracken D. Impacts of using a precision livestock system targeted approach in mountain sheep flocks. Livest Sci 2018. [DOI: 10.1016/j.livsci.2017.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
14
|
Abstract
Parasitic roundworm infections are ubiquitous in grazing livestock. Chemical control through the frequent 'blanket' administration of anthelmintics (wormers) has been, and remains, the cornerstone in controlling these infections, but this practice is unsustainable. Alternative strategies are available but, even with the plethora of best practice advice available, have yet to be integrated into routine farming practice. This is probably due to a range of factors, including contradictory advice from different sources, changes to advice following increased scientific understanding, and top-down knowledge exchange patterns. In this article, we discuss the worm control options available, the translation of new best practice advice from science bench to field, and ideas for future work and directions.
Collapse
|
15
|
Sargison ND. Keys to solving health problems in small ruminants: Anthelmintic resistance as a threat to sustainable nematode control. Small Rumin Res 2016; 142:11-5. [DOI: 10.1016/j.smallrumres.2016.02.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
16
|
Vijayasarathi MK, Sreekumar C, Venkataramanan R, Raman M. Influence of sustained deworming pressure on the anthelmintic resistance status in strongyles of sheep under field conditions. Trop Anim Health Prod 2016; 48:1455-62. [DOI: 10.1007/s11250-016-1117-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
|
17
|
Laurenson YC, Kahn LP, Bishop SC, Kyriazakis I. Which is the best phenotypic trait for use in a targeted selective treatment strategy for growing lambs in temperate climates? Vet Parasitol 2016; 226:174-88. [PMID: 27514904 DOI: 10.1016/j.vetpar.2016.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 07/02/2016] [Accepted: 07/08/2016] [Indexed: 11/22/2022]
Abstract
Targeted selective treatment (TST) requires the ability to identify the animals for which anthelmintic treatment will result in the greatest benefit to the entire flock. Various phenotypic traits have previously been suggested as determinant criteria for TST; however, the weight gain benefit and impact on anthelmintic efficacy for each determinant criterion is expected to be dependent upon the level of nematode challenge and the timing of anthelmintic treatment. A mathematical model was used to simulate a population of 10,000 parasitologically naïve Scottish Blackface lambs (with heritable variation in host-parasite interactions) grazing on medium-quality pasture (grazing density=30 lambs/ha, crude protein=140g/kg DM, metabolisable energy=10MJ/kg DM) with an initial larval contamination of 1000, 3000 or 5000 Teladorsagia circumcincta L3/kg DM. Anthelmintic drenches were administered to 0, 50 or 100% of the population on a single occasion. The day of anthelmintic treatment was independently modelled for every day within the 121day simulation. Where TST scenarios were simulated (50% treated), lambs were either chosen by random selection or according to highest faecal egg count (FEC, eggs/g DM faeces), lowest live weight (LW, kg) or lowest growth rate (kg/day). Average lamb empty body weight (kg) and the resistance (R) allele frequency amongst the parasite population on pasture were recorded at slaughter (day 121) for each scenario. Average weight gain benefit and increase in R allele frequency for each determinant criterion, level of initial larval contamination and day of anthelmintic treatment were calculated by comparison to a non-treated population. Determinant criteria were evaluated according to average weight gain benefit divided by increase in R allele frequency to determine the benefit per R. Whilst positive phenotypic correlations were predicted between worm burden and FEC; using LW as the determinant criterion provided the greatest benefit per R for all levels of initial larval contamination and day of anthelmintic treatment. Hence, LW was identified as the best determinant criterion for use in a TST regime. This study supports the use of TST strategies as benefit per R predictions for all determinant criteria were greater than those predicted for the 100% treatment group, representing an increased long-term productive benefit resulting from the maintenance of anthelmintic efficacy. Whilst not included in this study, the model could be extended to consider other parasite species and host breed parameters, variation in climatic influences on larval availability and grass growth, repeated anthelmintic treatments and variable proportional flock treatments.
Collapse
|
18
|
McBean D, Nath M, Lambe N, Morgan-Davies C, Kenyon F. Viability of the Happy Factor™ targeted selective treatment approach on several sheep farms in Scotland. Vet Parasitol 2016; 218:22-30. [DOI: 10.1016/j.vetpar.2016.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/05/2016] [Accepted: 01/07/2016] [Indexed: 01/05/2023]
|
19
|
|
20
|
Cornelius M, Jacobson C, Besier R. Factors likely to influence the adoption of targeted selective treatment strategies by sheep farmers in Western Australia. Prev Vet Med 2015; 121:325-31. [DOI: 10.1016/j.prevetmed.2015.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 11/18/2022]
|
21
|
Valcárcel F, Aguilar A, Sánchez M. Field evaluation of targeted selective treatments to control subclinical gastrointestinal nematode infections on small ruminant farms. Vet Parasitol 2015; 211:71-9. [DOI: 10.1016/j.vetpar.2015.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 04/10/2015] [Accepted: 04/20/2015] [Indexed: 11/24/2022]
|
22
|
Charlier J, Morgan ER, Rinaldi L, van Dijk J, Demeler J, Höglund J, Hertzberg H, Van Ranst B, Hendrickx G, Vercruysse J, Kenyon F. Practices to optimise gastrointestinal nematode control on sheep, goat and cattle farms in Europe using targeted (selective) treatments. Vet Rec 2015; 175:250-5. [PMID: 25217603 DOI: 10.1136/vr.102512] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Due to the development of anthelmintic resistance, there have been calls for more sustainable nematode control practices. Two important concepts were introduced to study and promote the sustainable use of anthelmintics: targeted treatments (TT), where the whole flock/herd is treated based on knowledge of the risk, or parameters that quantify the severity of infection; and targeted selective treatments (TST), where only individual animals within the grazing group are treated. The aim of the TT and TST approaches is to effectively control nematode-induced production impacts while preserving anthelmintic efficacy by maintaining a pool of untreated parasites in refugia. Here, we provide an overview of recent studies that assess the use of TT/TST against gastrointestinal nematodes in ruminants and investigate the economic consequences, feasibility and knowledge gaps associated with TST. We conclude that TT/TST approaches are ready to be used and provide practical benefits today. However, a major shift in mentality will be required to make these approaches common practice in parasite control.
Collapse
Affiliation(s)
- J Charlier
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - E R Morgan
- School of Veterinary Science, University of Bristol, Langford House, Langford, North Somerset BS40 5DU, UK
| | - L Rinaldi
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Naples, Italy
| | - J van Dijk
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst, Neston, Cheshire CH64 7TE, UK
| | - J Demeler
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag Strasse 7-13, 14163 Berlin, Germany
| | - J Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, PO Box 7063, Uppsala, Sweden
| | - H Hertzberg
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
| | - B Van Ranst
- Dairy DataWarehouse, Uniform-Agri BV, Oostersingel 23, Assen, The Netherlands
| | - G Hendrickx
- Avia-GIS, Agro-Veterinary Information and Analysis, Risschotlei 33, 2980 Zoersel, Belgium
| | - J Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - F Kenyon
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK
| |
Collapse
|
23
|
O'Shaughnessy J, Earley B, Mee J, Doherty M, Crosson P, Barrett D, de Waal T. Controlling nematodes in dairy calves using targeted selective treatments. Vet Parasitol 2015; 209:221-8. [DOI: 10.1016/j.vetpar.2015.02.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 02/20/2015] [Accepted: 02/22/2015] [Indexed: 10/23/2022]
|
24
|
Verschave SH, Vercruysse J, Forbes A, Opsomer G, Hostens M, Duchateau L, Charlier J. Non-invasive indicators associated with the milk yield response after anthelmintic treatment at calving in dairy cows. BMC Vet Res 2014; 10:264. [PMID: 25394846 PMCID: PMC4234833 DOI: 10.1186/s12917-014-0264-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/29/2014] [Indexed: 11/26/2022] Open
Abstract
Background Gastrointestinal nematodes are an important cause of reduced performance in cattle. Previous studies in Europe showed that after anthelmintic treatment an average gain in milk production of around 1 kg per day/cow can be expected. However, (1) these studies have mainly evaluated group-based anthelmintic treatments during the grazing season or at housing and (2) little is known about parameters affecting variations in the treatment response amongst cows. A better knowledge of such parameters could help to select animals that benefit most from treatment and thus lead to a more rational use of anthelmintics. Therefore, a randomized, non-blinded, controlled clinical trial was performed on 11 commercial dairy farms (477 animals) in Belgium, aiming (1) to study the effect of eprinomectin treatment at calving on milk production and (2) to investigate whether the milk yield response was related to non-invasive animal parameters such that these could be used to inform targeted selective treatment decisions. Results Analyses show that eprinomectin treatment around calving resulted in an average (± standard error) increase of 0.97 (±0.41) kg in daily milk yield that was followed up over 274 days on average. Milk yield responses were higher in multiparous compared to primiparous cows and in cows with a high (4th quartile) anti-O. ostertagi antibody level in a milk sample from the previous lactation. Nonetheless, high responses were also seen in animals with a low (1st quartile) anti-O. ostertagi antibody level. In addition, positive treatment responses were associated with higher faecal egg counts and a moderate body condition score at calving (2nd quartile). Conclusions In conclusion, this study provides novel insights into the production response after anthelmintic treatment at calving and factors which influence this. The data could be used to support the development of evidence-based targeted selective anthelmintic treatment strategies in dairy cattle.
Collapse
Affiliation(s)
- Sien H Verschave
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Andrew Forbes
- Merial SAS, 29 Avenue Tony Garnier, Lyon, 69007, France.
| | - Geert Opsomer
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Miel Hostens
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Luc Duchateau
- Department of Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Johannes Charlier
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| |
Collapse
|