Symposium review: An abundance of replacement heifers: What is the economic impact of raising more than are needed?

Historically, most dairy producers raised every heifer born, to ensure a supply of future replacements. However, advancements in transition and reproductive management, coupled with widespread use of sex-sorted semen in dairy heifers and cows, have led to an oversupply of dairy replacement heifers in the United States. With current market values for prepartum heifers at $1,300 and estimated raising costs ranging from $1,700 to $2,400, dairies that continue to produce quantities of heifers in excess of anticipated needs with plans of selling the extras on the open market are likely to experience significant economic loss. Adult cow herd turnover is the key driver behind the number of heifers needed to calve; however, mortality, disease, fertility, and elective culling losses throughout the heifer-raising period determine the total number of heifers that must be retained and raised to meet anticipated needs. A convenience sample of 50 US dairy herds revealed an average heifer inventory of 102% of total milking and dry cows. In this data set, the mean annualized adult herd turnover was 39%. With a mean stillbirth risk of 5.7% in calving heifers, a culling risk of 10.2% by 13 mo of age, a reproductive failure risk of 6.8% in breeding heifers, and an additional culling risk of 6.4% in pregnant heifers, only 74% of calving events with a heifer birth yielded a heifer that entered the lactating herd. Much of this heifer removal was elective, and making the correct culling decisions at the appropriate time yields the best return for the herd. To demonstrate how a herd might approach the elective culling issue, a records-based exercise with 2 large Holstein herds was performed to estimate the cost versus benefit of 3 different elective culling approaches, using a combination of genetic potential and growth performance as the selective criteria. However, the culling of heifers results in economic losses, because the revenue received is less than the cost incurred during raising. Selective culling of heifers soon after weaning yielded the best results in both herds, but despite the predicted improvement in lactation performance of the retained group, the cost associated with removal was greater than the benefit predicted. Culling a group early and then culling a second group just before calving yielded the largest loss. Moving forward, herds should breed more carefully to produce better-quality heifers from more superior dams and sires and consider the use of beef semen in inferior animals. However, to reduce the risk of not producing an adequate supply of replacement heifers, dairies should add an additional buffer to their anticipated needs. Using the assumptions within this project, having 10% extra calving events with a heifer birth would allow the annualized adult herd turnover to rise from 39 to 43% in case economic conditions or health status of the herd should change. If these heifers are not needed, the selection criteria outline could be used to help identify more valuable animals to retain.

Perdas econômicas causadas por lesões nodulares características de reação vacinal contra febre aftosa em bovinos abatidos em Mato Grosso do Sul, Brasil / Econômic losses caused by carcterisitc nodular injuries of vaccine reaction against foot-and-mouth disease in cattle slaughtered in Mato Grosso do Sul, Brazil

Para avaliar a incidência e estimar as perdas econômicas decorrentes de lesões nodulares características de reação vacinal contra febre aftosa foi acompanhado o abate de 72.000 bovinos no Mato Grosso do Sul, de maio a junho de 2018. O estudo foi realizado com base na avaliação macroscópica das lesões, que resultaram em uma incidência/mês média de 99,0% no rebanho abatido. O peso médio de descarte devido ao abscesso foi de 1,56kg/carcaça e a perda estimada foi de 673.920kg/ano ou 44.928 arrobas/ano. O preço médio de venda da carne foi de R$ 11,65/kg, sendo estimada perda de R$ 7.851.168,00/ano (US$ 2.116.117,79/ano). A elevada incidência de lesões nodulares características de reação à vacina contra febre aftosa nos bovinos abatidos no Mato Grosso do Sul representa um problema sanitário e econômico relevante na cadeia da carne.

Prejuízo econômico por abscessos vacinais retirados de carcaças de bovinos em um frigorífico sob serviço de inspeção federal em Minas Gerais

Abscessos são formações purulentas que surgem principalmente na região do pescoço das meias carcaças de bovinos em decorrência de reações vacinais. Essas lesões e possíveis partes contaminadas com pus são removidas durante a inspeção post mortem, de acordo com o Regulamento de Inspeção Industrial e Sanitária de Produtos de Origem Animal (RIISPOA), durante o processo de abate e são condenadas. A remoção do abscesso causa perda de porção cárnea, levando a uma redução do peso final da carcaça e consequente prejuízo econômico. Cuidados com o manejo vacinal são importantes para evitar o surgimento desses abscessos. O objetivo do presente estudo foi quantificar as meias carcaças com abscessos vacinais e avaliar o prejuízo econômico proveniente da excisão das partes cárneas contendo as lesões. O presente estudo foi realizado durante um mês em um frigorífico sob Serviço de Inspeção Federal localizado em Minas Gerais. Foram coletados os abscessos retirados pelo agente de inspeção das 100 primeiras carcaças de bovinos abatidos no dia, o que totalizou uma amostra de 20% da média abatida no mês. As carcaças com abscessos foram quantificadas e as partes excisadas foram pesadas diariamente e, no final do período, foi verificado o valor do prejuízo em arrobas. De um total de 2.000 carcaças inspecionadas e avaliadas para fim do estudo, 865 (43,25%) apresentaram um ou mais abscessos vacinais, resultando em um prejuízo de 237,100 kg removidos das carcaças, correspondendo a 0,274 kg por animal lesionado. O valor da perda no final do período de coleta foi de R$ 2.181,37 reais, o que leva a um decréscimo de R$ 2,52 reais por animal. A constatação de significativo prejuízo econômico decorrente da presença de abscessos vacinais nas carcaças inspecionadas demonstra a necessidade de se refletir sobre o manejo vacinal dos animais provenientes da região bem como a qualidade da vacina, com objetivo de diminuir a frequência dessas lesões, evitando assim que o...

Abscesses are purulent formations that appear mostly in the neck of bovine half-carcasses due to vaccine reactions. Such lesions and possibly pus-infected parts are removed during the post-mortem inspection service, in compliance with the Regulations of Industrial and Sanitary Inspection of Products of Animal Origin (RIISPOA, acronym in Portuguese), during lhe slaughtering process, and the procedure is condemned. The removal of the abscesses causes loss of meat, leading to a reduction of the final weight of the carcass and consequent economical losses. Safe animal management practices are important to avoid the occurrence of lesions. The aim of this study was to quantify the carcasses with vaccine abscesses and to assess the economic losses from the excision of the parts containing lesions. The present study was carried out over the course of one month in a slaughterhouse in Minas Gerais, under federal inspection. Abscesses were collected by the inspection agents from the first hundred bovine carcasses slaughtered each day, which, at the end of the study, was equivalent to 20% of the monthly slaughter average. The carcasses with abscesses were quantified, the excised parts were weighed daily and, at the end of the period, the loss values were verified in arrobas (one arroba is equivalent to 15 kilos). Out of a total of 2,000 carcasses inspected and evaluated for the purpose of this study, 865 (43,25%) registered one or more vaccine abscesses, resulting in a loss of 237.1 kg removed from the carcasses, corresponding to 0.274 kg per damaged animal. The final value of the losses was R$ 2,181.37, representing a decrease of R$ 2.52 per animal. The verification of significant economical losses due to the presence of abscesses in the inspected carcasses demonstrates the need for consideration about vaccination handling, as well as the quality of the vaccine, with the goal of reducing the frequency of such lesions, avoiding thus, with the procedure...

Modelling the economic efficiency of using different strategies to control Porcine Reproductive & Respiratory Syndrome at herd level.

PRRS is among the diseases with the highest economic impact in pig production worldwide. Different strategies have been developed and applied to combat PRRS at farm level. The broad variety of available intervention strategies makes it difficult to decide on the most cost-efficient strategy for a given farm situation, as it depends on many farm-individual factors like disease severity, prices or farm structure. Aim of this study was to create a simulation tool to estimate the cost-efficiency of different control strategies at individual farm level. Baseline is a model that estimates the costs of PRRS, based on changes in health and productivity, in a specific farm setting (e.g. farm type, herd size, type of batch farrowing). The model evaluates different intervention scenarios: depopulation/repopulation (D/R), close & roll-over (C&R), mass vaccination of sows (MS), mass vaccination of sows and vaccination of piglets (MS + piglets), improvements in internal biosecurity (BSM), and combinations of vaccinations with BSM. Data on improvement in health and productivity parameters for each intervention were obtained through literature review and from expert opinions. The economic efficiency of the different strategies was assessed over 5 years through investment appraisals: the resulting expected value (EV) indicated the most cost-effective strategy. Calculations were performed for 5 example scenarios with varying farm type (farrow-to-finish - breeding herd), disease severity (slightly - moderately - severely affected) and PRRSV detection (yes - no). The assumed herd size was 1000 sows with farm and price structure as commonly found in Germany. In a moderately affected (moderate deviations in health and productivity parameters from what could be expected in an average negative herd), unstable farrow-to-finish herd, the most cost-efficient strategies according to their median EV were C&R (€1'126'807) and MS + piglets (€ 1'114'649). In a slightly affected farrow-to-finish herd, no virus detected, the highest median EV was for MS + piglets (€ 721'745) and MS (€ 664'111). Results indicate that the expected benefits of interventions and the most efficient strategy depend on the individual farm situation, e.g. disease severity. The model provides new insights regarding the cost-efficiency of various PRRSV intervention strategies at farm level. It is a valuable tool for farmers and veterinarians to estimate expected economic consequences of an intervention for a specific farm setting and thus enables a better informed decision.

Livestock Disease Management for Trading Across Different Regulatory Regimes.

The maintenance of livestock health depends on the combined actions of many different actors, both within and across different regulatory frameworks. Prior work recognised that private risk management choices have the ability to reduce the spread of infection to trading partners. We evaluate the efficiency of farmers' alternative biosecurity choices in terms of their own-benefits from unilateral strategies and quantify the impact they may have in filtering the disease externality of trade. We use bovine viral diarrhoea (BVD) in England and Scotland as a case study, since this provides an example of a situation where contrasting strategies for BVD management occur between selling and purchasing farms. We use an agent-based bioeconomic model to assess the payoff dependence of farmers connected by trade but using different BVD management strategies. We compare three disease management actions: test-cull, test-cull with vaccination and vaccination alone. For a two-farm trading situation, all actions carried out by the selling farm provide substantial benefits to the purchasing farm in terms of disease avoided, with the greatest benefit resulting from test-culling with vaccination on the selling farm. Likewise, unilateral disease strategies by purchasers can be effective in reducing disease risks created through trade. We conclude that regulation needs to balance the trade-off between private gains from those bearing the disease management costs and the positive spillover effects on others.

Assessment of China's H5N1 routine vaccination strategy.

In this study, a simulation model was used to assess the epidemiological and economic impacts of the routine vaccination strategy for H5N1 in China at the national level. The results of the simulation show that a routine vaccination strategy at the national level could have a substantial impact on decreasing H5N1 outbreaks; it could therefore markedly reduce the severity and duration of an H5N1 epidemic at the national level in China. Under a routine vaccination programme, when a flock is infected, the number of depopulated birds could be reduced by approximately 91%, the outbreak duration could be reduced by one-fourth, and the probability of an H5N1 outbreak could be reduced to 51.5%. Although the use of vaccination has obvious benefits, if indirect costs were not considered, the mean direct cost of simulated disease control without vaccination was only 1.36% of the cost of the routine vaccination strategy, and this former approach would have saved 57 billion yuan for all poultry in China from 2004 to 2012. Traditional H5N1 control strategies with culling programmes at the national level represented a better choice for China.

Quantifying the Value of Perfect Information in Emergency Vaccination Campaigns.

Foot-and-mouth disease outbreaks in non-endemic countries can lead to large economic costs and livestock losses but the use of vaccination has been contentious, partly due to uncertainty about emergency FMD vaccination. Value of information methods can be applied to disease outbreak problems such as FMD in order to investigate the performance improvement from resolving uncertainties. Here we calculate the expected value of resolving uncertainty about vaccine efficacy, time delay to immunity after vaccination and daily vaccination capacity for a hypothetical FMD outbreak in the UK. If it were possible to resolve all uncertainty prior to the introduction of control, we could expect savings of £55 million in outbreak cost, 221,900 livestock culled and 4.3 days of outbreak duration. All vaccination strategies were found to be preferable to a culling only strategy. However, the optimal vaccination radius was found to be highly dependent upon vaccination capacity for all management objectives. We calculate that by resolving the uncertainty surrounding vaccination capacity we would expect to return over 85% of the above savings, regardless of management objective. It may be possible to resolve uncertainty about daily vaccination capacity before an outbreak, and this would enable decision makers to select the optimal control action via careful contingency planning.