Herd size and bovine tuberculosis persistence in cattle farms in Great Britain

2009 ◽  
Vol 92 (4) ◽  
pp. 360-365 ◽  
Author(s):  
Ellen Brooks-Pollock ◽  
Matt Keeling
Keyword(s):  
Great Britain ◽  
Bovine Tuberculosis ◽  
Herd Size ◽  
Cattle Farms

scholarly journals Effects of trading networks on the risk of bovine tuberculosis incidents on cattle farms in Great Britain

2020 ◽  
Vol 7 (4) ◽  
pp. 191806
Author(s):  
Helen R. Fielding ◽  
Trevelyan J. McKinley ◽  
Richard J. Delahay ◽  
Matthew J. Silk ◽  
Robbie A. McDonald
Keyword(s):  
Great Britain ◽  
Bovine Tuberculosis ◽  
Disease Risk ◽  
Herd Size ◽  
Risk Area ◽  
High Risk Area ◽  
Trading Patterns ◽  
Additional Approach ◽  
Trading Networks ◽  
Cattle Farms

Trading animals between farms and via markets can provide a conduit for spread of infections. By studying trading networks, we might better understand the dynamics of livestock diseases. We constructed ingoing contact chains of cattle farms in Great Britain that were linked by trading, to elucidate potential pathways for the transmission of infection and to evaluate their effect on the risk of a farm experiencing a bovine tuberculosis (bTB) incident. Our findings are consistent with variation in bTB risk associated with region, herd size, disease risk area and history of previous bTB incidents on the root farm and nearby farms. However, we also identified effects of both direct and indirect trading patterns, such that connections to more farms in the England High-Risk Area up to three movements away from the root farm increased the odds of a bTB incident, while connections with more farms in the England Low-Risk Area up to eight movements away decreased the odds. Relative to other risk factors for bTB, trading behaviours are arguably more amenable to change, and consideration of risks associated with indirect trading, as well direct trading, might therefore offer an additional approach to bTB control in Great Britain.

scholarly journals Contact chains of cattle farms in Great Britain

2019 ◽  
Vol 6 (2) ◽  
pp. 180719 ◽  
Author(s):  
Helen R. Fielding ◽  
Trevelyan J. McKinley ◽  
Matthew J. Silk ◽  
Richard J. Delahay ◽  
Robbie A. McDonald
Keyword(s):  
Great Britain ◽  
Bovine Tuberculosis ◽  
Bimodal Distribution ◽  
Disease Spread ◽  
Scale Free ◽  
Network Analyses ◽  
Directed Paths ◽  
System Data ◽  
Epidemiological Characteristics ◽  
Cattle Farms

Network analyses can assist in predicting the course of epidemics. Time-directed paths or ‘contact chains' provide a measure of host-connectedness across specified timeframes, and so represent potential pathways for spread of infections with different epidemiological characteristics. We analysed networks and contact chains of cattle farms in Great Britain using Cattle Tracing System data from 2001 to 2015. We focused on the potential for between-farm transmission of bovine tuberculosis, a chronic infection with potential for hidden spread through the network. Networks were characterized by scale-free type properties, where individual farms were found to be influential ‘hubs' in the network. We found a markedly bimodal distribution of farms with either small or very large ingoing and outgoing contact chains (ICCs and OCCs). As a result of their cattle purchases within 12-month periods, 47% of British farms were connected by ICCs to more than 1000 other farms and 16% were connected to more than 10 000 other farms. As a result of their cattle sales within 12-month periods, 66% of farms had OCCs that reached more than 1000 other farms and 15% reached more than 10 000 other farms. Over 19 000 farms had both ICCs and OCCs reaching more than 10 000 farms for two or more years. While farms with more contacts in their ICCs or OCCs might play an important role in disease spread, farms with extensive ICCs and OCCs might be particularly important by being at higher risk of both acquiring and disseminating infections.

scholarly journals Evaluating the Bovine Tuberculosis Eradication Mechanism and Its Risk Factors in England’s Cattle Farms

2021 ◽  
Vol 18 (7) ◽  
pp. 3451
Author(s):  
Tabassom Sedighi ◽  
Liz Varga
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Animal Health ◽  
Dynamic Bayesian Network ◽  
Policy Makers ◽  
Domain Experts ◽  
Actual Experience ◽  
Complex Evaluation ◽  
Risk Areas ◽  
Cattle Farms

Controlling bovine tuberculosis (bTB) disease in cattle farms in England is seen as a challenge for farmers, animal health, environment and policy-makers. The difficulty in diagnosis and controlling bTB comes from a variety of factors: the lack of an accurate diagnostic test which is higher in specificity than the currently available skin test; isolation periods for purchased cattle; and the density of active badgers, especially in high-risk areas. In this paper, to enable the complex evaluation of bTB disease, a dynamic Bayesian network (DBN) is designed with the help of domain experts and available historical data. A significant advantage of this approach is that it represents bTB as a dynamic process that evolves periodically, capturing the actual experience of testing and infection over time. Moreover, the model demonstrates the influence of particular risk factors upon the risk of bTB breakdown in cattle farms.

scholarly journals Future Risk of Bovine Tuberculosis (Mycobacterium bovis) Breakdown in Cattle Herds 2013–2018: A Dominance Analysis Approach

2021 ◽  
Vol 9 (5) ◽  
pp. 1004
Author(s):  
Andrew W. Byrne ◽  
Damien Barrett ◽  
Philip Breslin ◽  
Jamie M. Madden ◽  
James O’Keeffe ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Policy Development ◽  
Strong Predictor ◽  
Herd Size ◽  
Analysis Approach ◽  
Dominance Analysis ◽  
Control Programmes ◽  
Significant Spatial Variation ◽  
Future Risk ◽  
Cattle Herds

Bovine tuberculosis (bTB) remains a significant endemic pathogen of cattle herds, despite multi-decadal control programmes being in place in several countries. Understanding the risks of future bTB breakdown (BD) and the associated characteristics of herds and index breakdowns could help inform risk categorisation. Such risk categories could then contribute to tailored management and policies. Here, we estimated the future risk of herd BD for the cohort of herds that were derestricted during 2013 in Ireland using multivariable logit regression models, with a dominance analysis approach. One third of herds that were derestricted in 2013 experienced a breakdown during the follow-up five year period (1469/4459; 33%). BD length was a significant predictor of future risk, primarily driven by long BDs > 230 days relative to short BDs < 130 days (OR 95%CI: 1.157–1.851), as was having had a previous BD (OR 95%CI: 1.012–1.366). Herd-size was the dominant predictor of future risk (accounted for 46% of predicted variance), suggesting significant increase in risk of future breakdown with increasing (log) herd-size (OR 95%CI: 1.378–1.609). There was significant spatial variation in future risk across counties, and it was the second most dominant predictor of future risk (25% of predicted variance). The size of index breakdowns was not a strong predictor of future risk over a 5-year period. These findings can inform a risk-based policy development.

scholarly journals Bovine Tuberculosis (Mycobacterium bovis) Outbreak Duration in Cattle Herds in Ireland: A Retrospective Observational Study

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 815
Author(s):  
Andrew W. Byrne ◽  
Damien Barrett ◽  
Philip Breslin ◽  
Jamie M. Madden ◽  
James O'Keeffe ◽  
...  
Keyword(s):  
Risk Factors ◽  
Observational Study ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Animal Health ◽  
Herd Size ◽  
Policy Formation ◽  
Nitrogen Loading ◽  
Management Policy ◽  
Retrospective Observational Study

Bovine tuberculosis (bTB) outbreaks, caused by Mycobacterium bovis infection, are a costly animal health challenge. Understanding factors associated with the duration of outbreaks, known as breakdowns, could lead to better disease management policy development. We undertook a retrospective observational study (2012–2018) and employed Finite Mixture Models (FMM) to model the outcome parameter, and to investigate how factors were associated with duration for differing subpopulations identified. In addition to traditional risk factors (e.g., herd size, bTB history), we also explored farm geographic area, parcels/farm fragmentation, metrics of intensity via nitrogen loading, and whether herds were designated controlled beef finishing units (CBFU) as potential risk factors for increased duration. The final model fitted log-normal distributions, with two latent classes (k) which partitioned the population into a subpopulation around the central tendency of the distribution, and a second around the tails of the distribution. The latter subpopulation included longer breakdowns of policy interest. Increasing duration was positively associated with recent (<3 years) TB history and the number of reactors disclosed, (log) herd size, beef herd-type relative to other herd types, number of land parcels, area, being designated a CBFU (“feedlot”) and having high annual inward cattle movements within the “tails” subpopulation. Breakdown length was negatively associated with the year of commencement of breakdown (i.e., a decreasing trend) and non-significantly with the organic nitrogen produced on the farm (N kg/hectare), a measure of stocking density. The latter finding may be due to confounding effects with herd size and area. Most variables contributed only moderately to explaining variation in breakdown duration, that is, they had moderate size effects on duration. Herd-size and CBFU had greater effect sizes on the outcome. The findings contribute to evidence-based policy formation in Ireland.

scholarly journals Commercial practice of out-wintering dairy heifers in Great Britain

2020 ◽  
Vol 82 ◽  
pp. 161-169
Author(s):  
Norton E. Atkins ◽  
Keith E. Walley ◽  
Liam A. Sinclair
Keyword(s):  
Great Britain ◽  
High Performance ◽  
Animal Health ◽  
Live Weight ◽  
Herd Size ◽  
Dairy Farmers ◽  
Commercial Practice ◽  
Dairy Heifers ◽  
Supplementary Feed ◽  
Strip Grazing

The majority of dairy cattle in Great Britain (GB) are housed during winter but replacement heifers are out-wintered on some farms, a practice that may reduce the need for high capital-cost housing and facilitate herd expansion. Dairy farmers that were out-wintering replacement heifers in GB in 2012 were surveyed to determine current practice and attitudes. A typical system involved heifers strip grazing pasture or a crop, with baled grass silage as supplementary feed; strongly resembling outdoor wintering systems in New Zealand. Many used more than one grazed forage; predominantly, pasture on 68%, kale on 53% and fodder beet on 33% of farms. Supplementary feed was 44% of the diet in younger, and 35% in older heifers. Although farms were approximately three times larger than the national average and 60% were expanding, expanding herd size was not the primary reason for out-wintering, with the main reasons being to reduce cost and improve animal health and welfare. Farmers that out-wintered heifers typically reported good animal average dairy gain of 0.6 kg/d and high body condition, however, this contrasts with some measured performance in GB. Farmers may benefit from accurate feed allocation and monitoring heifer live weight during winter to ensure high performance.  

scholarly journals Production and Health Management from Grazing to Confinement Systems of Largest Dairy Bovine Farms in Azores: A Farmers’ Perspective

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3394
Author(s):  
Ivo Medeiros ◽  
Aitor Fernandez-Novo ◽  
Susana Astiz ◽  
João Simões
Keyword(s):  
Production Systems ◽  
Health Management ◽  
Bovine Milk ◽  
Herd Size ◽  
Farm Size ◽  
Economic Viability ◽  
Health Prevention ◽  
Dual Purpose ◽  
Control Programs ◽  
Cattle Farms

The intensification of bovine milk production in the Azores has led farmers to increase farm size and specialization in grasslands, implementing confined and semi-confined production systems. Fixed milking parlours (FMP) have progressively gained more popularity, at the expense of conventional mobile milking systems (MMS). The present study aimed to evaluate the associations between production and health management in dairy cattle farms, with FMP or MMS, in grasslands (São Miguel, Azores), according to the farmers’ perspective. A total of 102 questions about production and health management were surveyed in 105 farms with >30 dairy cows each. Farms with FMP were associated (p ≤ 0.05) with larger herd size, better facilities, and specialized management, however, the adoption of preventive and biosecurity measures should be improved by these farmers. MMS farms implemented a lower level of disease prevention or control programs, less frequent transhumance, and showed a wider vocation to dual-purpose (milk and cross beef) than FMP farms. In conclusion, MMS and FMP farms tried to optimize yield and economic viability in different ways using grasslands. Several biosecurity and health prevention constraints were identified for improvement.

A new genetic evaluation system for pedigree beef cattle in great britain

1992 ◽  
Vol 1992 ◽  
pp. 200-200
Author(s):  
J.G.E. Bryan ◽  
N.R. Wray ◽  
R. Crump ◽  
D.G. Nicholson ◽  
R. Thompson
Keyword(s):  
Great Britain ◽  
Beef Cattle ◽  
Evaluation System ◽  
Genetic Improvement ◽  
Herd Size ◽  
Genetic Progress ◽  
Selection Decisions ◽  
Speed Up ◽  
Beef Herd ◽  
Analysis Of Performance

The need to speed up the rate of genetic progress in beef cattle, particularly in economically significant traits such as growth and carcase merit has always been recognised by the Meat and Livestock Commission. This is achieved through the Beefbreeder Pedigree Recording Service which records over 1,000 pedigree herds in Great Britain. Traditionally, analysis of performance records from pedigree herds has been carried out using within herd contemporary comparisons.Average pedigree beef herd size in Great Britain is typically less than 20 cows which limits accuracy and scope for genetic improvement when making within herd selection decisions.

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