Socio-economic impacts of brucellosis on livestock production and reproduction performance in Koibatek and Marigat regions, Baringo County, Kenya.

BACKGROUND: Brucellosis in Africa is caused by Brucella species transmitted through contaminated or contacts with infected animals or their carcasses. The disease reduces livestock production and reproduction performance evident by frequent episodes of abortion, still births, swollen testes, weak calves/lambs and swollen joints. However, the socio-economic impacts of these brucellosis-associated symptoms on milk, fat, meat and blood production, infertility, sale value, dowry and costs of treatment has not been evaluated extensively in developing countries. In Baringo County, Kenya, there is a continuous movement of cattle as a result of trade and grazing, which predisposes many herds to brucellosis infection. The objective of this study was to investigate the socio-economic impacts of Brucella infection on production systems for sheep, goats, cattle and camels and explore the impact of brucellosis on livestock production and reproduction performance among livestock keeping communities in Baringo County, Kenya. The study adopted a cross-sectional survey using quantitative data collection methods. RESULTS: Results demonstrated an impact on milk production in suspected brucellosis cases resulting from abortions (OR = 0.151, P < 0.0001) and swollen joints (OR = 2.881, P < 0.0001). In terms of infertility, abortion as a symptom of brucellosis (OR = 0.440, P = 0.002), still birth (OR = 0.628, P = 0.042), and weak calf or lamb (OR = 0.525, P = 0.005) had an impact on infertility. In terms of sale value, abortion (OR = 0.385, P = 0.008), weak calf/lamb (OR = 2.963, P = 0.013) had an impact on sale value. Other analyses demonstrated that for dowry, swollen testes (OR = 5.351, P = 0.032), weak calf and lambs (OR = 0.364, P = 0.019) had a likelihood of reduction of dowry value. Finally, in terms of cost of treatment, abortion (OR = 0.449, P = 0.001), still births (OR = 0.208, P = 0.015), swollen testes (OR = 0.78, P = 0.014), weak calf/lambs (OR = 0.178, P = 0.007) and swollen joints (OR = 0.217, P = 0.003) significantly increased the costs of treatments. There was no impact on fat and meat and blood production. CONCLUSION: Even though there was a huge socio-economic impact on milk production, infertility, sale value, and dowry, it was the costs of treatment that was significantly impacted on all symptoms associated with brucellosis on this community. A 'One Health' approach in tackling the brucellosis menace as a holistic approach is recommended for both humans and their livestock.

Epidemiologic and economic analyses of pregnancy loss attributable to mastitis in primiparous Holstein cows.

The main objective of the study reported here was to examine the association between pregnancy loss (PL) and previous exposure to clinical or subclinical mastitis before breeding or during gestation in primiparous Holstein cows. A secondary objective was to estimate the cost of clinical mastitis during gestation, including that of PL attributable to mastitis in study cows. A total of 687 primiparous Holstein cows from 1 dairy farm were included in a matched case-control study. Study cows were declared pregnant via ultrasound on d 33 after timed artificial insemination (TAI). Case cows (n = 78) were those diagnosed as nonpregnant by rectal palpation on d 47 or 75 after TAI. Control cows were those confirmed as pregnant by rectal palpation on d 47 and 75 after TAI. Case cows were matched with eligible controls according to year of calving and calving-to-conception interval ±3 d. Cows were assigned to 1 of 3 groups: (1) cows not affected with clinical or subclinical mastitis; (2) cows affected with subclinical mastitis (Dairy Herd Improvement Association somatic cell score >4.5); and (3) cows affected with clinical mastitis during 2 exposure periods, 1 to 42 d before breeding or during gestation (1 to PL diagnosis day for case cows, and 1 to 75 d for control cows). Conditional logistic regression was used to model the odds of PL as a function of previous exposure to mastitis in study cows. Mastitis before breeding was not associated with PL. The odds of PL were 2.21 times greater in cows affected with clinical mastitis during gestation (95% confidence interval = 1.01, 4.83), compared with cows without mastitis, after controlling for breeding type and lameness. The cost of clinical mastitis during gestation was $149, which includes the cost ($27) of PL attributable to mastitis. In conclusion, this study provides evidence that clinical mastitis during gestation can cause PL in primiparous dairy cows leading to economic losses.

Preliminary survey on the impact of Schmallenberg virus on sheep flocks in South of Belgium.

Between late February and May 2012, a preliminary anonym survey was conducted among sheep farmers in south of Belgium in order to contribute to future estimations of the economic losses caused by Schmallenberg virus (SBV). Based on clinical signs consistent with SBV infection, this survey involved 13 meat sheep flocks considered as positive flocks with subsequent SBV detection by RT-qPCR [SBV-positive flocks (PF); total of 961 animals], and 13 meat sheep flocks considered as negative flocks (NF; total of 331 animals). These preliminary results indicated several significant characteristics that were more present in PF than in NF. These include an increased rate of abortions (6.7% in PF versus 3.2% in NF), of lambs born at term but presenting malformations (10.1% in PF versus 2.0% in NF) and of dystocia (10.1% in PF versus 3.4% in NF). Lamb mortality during the first week of life was reported more frequently in PF (8 of 13 PF, 61.5%) than in NF (1 of 13 NF, 7.7%). In PF, the observed prolificacy rate was 2-fold lower (93%) than expected (186%). The implementation of a survey at larger scale, including a high number of breeders, is necessary to allow a more detailed analysis of the SBV impact in the sheep sector.

Economic comparison of reproductive programs for dairy herds using estrus detection, timed artificial insemination, or a combination.

The objective of this study was to compare the economic outcome of reproductive programs using estrus detection (ED), timed artificial insemination (TAI), or a combination of both (TAI-ED) using a stochastic dynamic Monte-Carlo simulation model. Programs evaluated were (1) ED only; (2) TAI: Presynch-Ovsynch for first AI, and Ovsynch for resynchronization of open cows at 32 d after AI; (3) TAI-ED: Presynch-Ovsynch for first AI, but cows underwent ED and AI after first AI, and cows diagnosed open 32 d after AI were resynchronized using Ovsynch. Evaluated were the effect of ED rate (40 vs. 60%; ED40 or ED60), accuracy of estrus detection (85 vs. 95%), compliance with the timed AI protocol (85 vs. 95%), and milk price ($0.33 vs. 0.44/kg). Conception rate to first service was set at 33.9% and then decreased by 2.6% for every subsequent service. Abortion was set at 11.3%. Cows were not AI after 366 d in milk, and open cows were culled after 450 d in milk. Culled cows were immediately replaced. Herd size was maintained at 1,000 cows, and the model accounted for all incomes and costs. Simulation was performed until steady state was reached (3,000 d), and then average daily values for the subsequent 2,000 d were used to calculate profit/cow per year. Net daily value was calculated by subtracting the costs (replacement, feeding, breeding, and other costs) from the daily income (milk sales, cow sales, and calf sales). The ED40 models resulted in greater profits than the TAI-85 model but lower profits than the TAI-95 model. Both ED60 models resulted in greater profits than the TAI-95 model. Combining TAI and ED increased profits within each level of accuracy or compliance. Adding TAI to ED would increase overall profit/cow per year by $46.8 to $74.7 with 40% ED, and by $8.9 to $30.5 with 60% ED. Adding ED to TAI would increase profit/cow per year by $64.2 to $99.4 with 85% compliance and by $31.8 to $59.7 with 95% compliance. Although combining TAI and ED increased profits within each level of accuracy or compliance, when evaluated separately, ED60 with 95% accuracy or TAI with 95% compliance were as profitable as or more profitable than TAI-ED with low ED, accuracy, or compliance. Therefore, producers can improve their profits by combining TAI and ED as reproductive management; however, if a herd can achieve high ED with high accuracy or have high compliance with injections, using only ED or TAI might be more profitable than trying to do both.

Neospora caninum causes severe economic losses in cattle in the humid pampa region of Argentina.

This work estimates the economic losses due to Neospora abortions in the humid pampa region of Argentina.The total dairy and beef cattle population at risk of abortion is 1,771,326 and 9,726,684 head, respectively. In dairy cattle, there was an 8 % risk of experiencing abortion due to a variety of causes, but 16.5 % of them were due to Neospora caninum. The economic losses were estimated at US$1,415 (1,400-1,431) per abortion, which equates to a total loss of US$33,097,221 (15,622,600-119,349,693) for the dairy industry at the humid pampa region of Argentina. In beef cattle, the overall risk of abortion was estimated to be 4.5 % for all pregnancies,whereas 6.7 % are specifically due to N. caninum, with an economic loss of US$440 (range, 150-730) per abortion.This amounts to an annual loss to the beef industry of US$12,903,440 (range, 1,130,700-42,070,630) in the same area. The results of this study show that Neospora infections and thus abortions cause severe economic impacts in the dairy and beef industries in the humid pampa region of Argentina, which is one the most important areas of cattle production in the world [corrected].

Economic effect of bovine abortion syndrome in commercial dairy herds in Southern Chile.

Bovine abortion is a limiting factor for dairy business, as it decreases milk production and the potential, number of herd replacements, increases feeding and medical treatment costs, increases the number of artificial inseminations to obtain a calf as well as culling rates of cows. An estimation of the economic impact of abortion in dairy farms in Chile is not available yet. The aim of this study was to estimate the economic consequences of bovine abortion syndrome (BAS) in dairy cows from Chile. A stochastic model was proposed to evaluate the cost of an abortion on a yearly basis to include variability in cost and income by dairy and by year. The marginal total net revenue (ΔTNR) for a typical, lactation was obtained by the calculating the difference between total revenues (retail milk and calf sales) and total expenses (production cost (cows, feeding, labor, health) plus administrative and, general costs) for lactation with and without abortion. Production data were obtained from a retrospective study of 127 dairy herds located in southern Chile between 2000 and 2006. Milk production from cows with and without abortion was estimated by a mixed model using milk test day data. Production cost and prices paid to farmers were obtained from service company records (TODOAGRO S.A.). Cost and income value was corrected for inflation and expressed in the values from 2006. In addition, a separate analysis for different parities (1, 2, 3 or more) was performed. Distributions for the stochastic variables were obtained by fitting distributions from our database using @Risk. The stochastic variables included in the analysis were all related to income, feeding, depreciation, health, Artificial Insemination and general costs like fuel, salaries, taxes, etc. There was a high probability (89.20%) of a negative ΔTNR in lactations with abortion for overall, parities, with a mean loss of $ -143.32. Stratifying by parity, the predicted mean of the distribution for ΔTNR in each parity (1, 2, 3 or more) was also negative and the probability of a negative ΔTNR was 89.40%, 95.30% and 97.00%, respectively, but differs between them (p<0.05). For parity 1, mean ΔTNR was $ -120.92, parity 2 $ -116.35 and for parities ≥3 it was $ -132.26 and the mean was statistically different from the others (p<0.05). The age of culled cows was the input variable most correlated with TNR and dairy production was the second. However, the sale price of milk resulted in a low correlation with abortion cost.

Neospora caninum--how close are we to development of an efficacious vaccine that prevents abortion in cattle?

Neospora caninum is a protozoan parasite that causes abortion in cattle around the world. Although the clinical signs of disease in both dogs and cattle have now been recognised for over 20years, treatment and control options are still limited, despite the availability of a commercial vaccine in some countries of the world. The case for an efficacious vaccine has not been convincingly waged by farmers, veterinarians and other members of the agricultural and rural communities. In recent times, however, economic modelling has been used to estimate the industry losses due to Neospora-associated abortion, providing, in turn, the business case for forms of control for this parasite, including the development of vaccines. In this review, we document progress in all areas of the vaccine development pipeline, including live, killed and recombinant forms and the animal models available for vaccine evaluation. In addition, we summarise the main outcomes on the economics of Neospora control and suggest that the current boom in the global dairy industry increases the specific need for a vaccine against N. caninum-associated abortion.

[Epidemiological and financial considerations for the control of Neospora caninum on Swiss dairy farms]. / Epidemiologische und finanzielle Entscheidungsgrundlagen zur Kontrolle von Neospora caninum auf Schweizer Milchviehbetrieben.

Neospora caninum is widely recognized as one of the most important abortifacients in cattle and causes substantial financial losses to bovine livestock production. This study aimed to calculate the losses caused by N. caninum on Swiss dairy farms and to evaluate the efficacy and profitability of the control strategies culling, not breeding replacements and chemotherapy of calves on farm level. Three different farm sizes with high, medium and low herd prevalences were defined. Epidemiological and financial models were used to simulate the effect of control strategies on the prevalence over time and to perform a cost-benefit analysis. The median annual losses on farm level ranged between CHF 3094.- (= Euro 1875; 60 dairy cattle, high prevalence) and CHF 134.- (= Euro 81; 15 dairy cattle, low prevalence). Culling of animals that had any abortion or a N. caninum abortion, or not breeding replacements from such animals, respectively, were neither effective nor profitable. Only the strategy "not breeding replacements from N. caninum seropositive cows" on farms with a high prevalence was financially attractive. The strategy "chemotherapy of calves" should be re-evaluated as soon as new data regarding the efficacy of treatment and a corresponding protocol have been scientifically validated.

Anomalias congênitas em fetos bovinos abortados no Sul do Brasil / Congenital anomalies in aborted bovine fetuses in Southern Brazil

Abortos e mortes neonatais são causas importantes de perdas reprodutivas na bovinocultura. Abortos causados por anomalias congênitas são esporádicos, mas podem ocorrer de forma epidêmica. Um levantamento retrospectivo realizado no setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul incluiu 307 casos de aborto bovino submetidos de setembro de 2001 a março de 2007. Em dez casos (3,5 por cento), foram observadas anomalias congênitas, das quais, artrogripose, Amorphus globosus e fenda palatina (palatosquise) foram as mais freqüentes. Causas infecciosas foram investigadas, mas somente infecção por BVDV foi detectada por imunoistoquímica em um aborto com porencefalia.

Abortion, stillbirth and neonatal death are important causes of production losses to the livestock industry. Abortions caused by congenital anomalies may occur sporadically, or appear in epidemics. This retrospective study was conducted at Laboratory of Veterinary Pathology of Federal University of Rio Grande do Sul, and included 307 cases of bovine abortion submitted for diagnosis from September 2001 to March 2007. Most of them were from southern Brazil. Ten cases (3.25 percent) of congenital anomalies were seen. The most frequent congenital anomalies were artrogryposis, Amorphous globosus, and cleft palate (palatoschisis). Infectious causes were investigated, but only BVDV infection was detected by immunohistochemistry in one case, which was affected with porencephalia.

Pregnancy loss in dairy cows: the contributing factors, the effects on reproductive performance and the economic impact.

This study investigated the effects of the herd, cow parity, the insemination protocol and season on the incidence of pregnancy loss (PL) in dairy herds. Furthermore, we determined the downstream effects of PL on reproductive performance and its economic impact. The overall incidence rate of PL was 6.9% in 1,001 pregnant cows and its incidence peaked (p < 0.01) during the second trimester of gestation. GLIMMIX analysis revealed that cow parity was the important risk factor for the PL. The odds ratio showed that the likelihood of PL in cows with parities of 1 or 2 was decreased by 0.6 or 0.5 fold compared to the cows with a parity of 3 or higher. Following PL, the mean rate of endometritis was 23.2% and endometritis was more common (p < 0.05) when PL occurred during the third trimester than during the first and second trimesters. The mean culling rate was 46.4% and this did not differ with the period of PL. The overall mean intervals from PL to the first service and conception were 63.4 and 101.8 days, respectively. The mean interval from PL to first service was longer (p < 0.01) for cows with PL during the third trimester than for the cows with PL during the first and second trimesters. The economic loss resulting from each PL was estimated at approximately $2,333, and this was largely due to an extended calving interval and increased culling. These results suggest that cow parity affects the incidence of PL, which extends calving interval and causes severe economic loss of dairy herds.

An analysis of an early-warning system to reduce abortions in dairy cattle in Denmark incorporating both financial and epidemiologic aspects.

Emergency preparedness relies on the ability to detect patterns in rare incidents in an early stage of an outbreak in order to implement relevant actions. Early warning of an abortion storm as a result of infection with a notifiable disease, e.g. brucellosis, bovine viral diarrhea (BVD) or infectious bovine rhinotracheitis (IBR), is a significant surveillance tool. This study used data from 507 large Danish dairy herds. A modified two-stage method for detecting an unusual increase in the abortion incidence was applied to the data. An alarm was considered true if an abortion were detected in the month following the alarm month, otherwise false. The total number of abortions that could potentially be avoided if effective action were taken ranged from 769 (22.9%) to 10 (0.3%), as the number of abortions required to set the alarm increased from 1 to 6. The vast majority of abortions could, however, not be predicted, much less prevented, given this early-warning system. The false to true alarm ratio was reduced when the number of abortions that set the alarm increased. The financial scenarios evaluated demonstrated that the value of an abortion, the cost of responding to an alarm and the efficiency of the actions are important for decision making when reporting an alarm. The presented model can readily be extended to other disease problems and multiple-time periods.

Pregnancy loss in dairy cows: the contributing factors, the effects on reproductive performance and the economic impact

This study investigated the effects of the herd, cowparity, the insemination protocol and season on the incidenceof pregnancy loss (PL) in dairy herds. Furthermore, wedetermined the downstream effects of PL on reproductiveperformance and its economic impact. The overallincidence rate of PL was 6.9% in 1,001 pregnant cows andits incidence peaked (p<0.01) during the second trimesterof gestation. GLIMMIX analysis revealed that cow paritywas the important risk factor for the PL. The odds ratioshowed that the likelihood of PL in cows with parities of 1or 2 was decreased by 0.6 or 0.5 fold compared to the cowswith a parity of 3 or higher. Following PL, the mean rateof endometritis was 23.2% and endometritis was morecommon (p<0.05) when PL occurred during the thirdtrimester than during the first and second trimesters. Themean culling rate was 46.4% and this did not differ withthe period of PL. The overall mean intervals from PL tothe first service and conception were 63.4 and 101.8 days,respectively. The mean interval from PL to first servicewas longer (p<0.01) for cows with PL during the thirdtrimester than for the cows with PL during the first andsecond trimesters. The economic loss resulting from eachPL was estimated at approximately $2,333, and this waslargely due to an extended calving interval and increasedculling. These results suggest that cow parity affects theincidence of PL, which extends calving interval and causessevere economic loss of dairy herds.

Economic value of pregnancy in dairy cattle.

The objective of this study was to estimate the value of pregnancy for dairy cows. Effects of the stage of gestation, stage of lactation, lactation number, milk yield, milk price, replacement heifer cost, probability of pregnancy, probability of involuntary culling, and breeding decisions were studied. A bioeconomic model was used, and breeding and replacement decisions were optimized. A general Holstein herd in the United States was modeled. The average value of a new pregnancy was $278. The value of a new pregnancy increased with days in milk early in lactation but typically decreased later in lactation. Relatively high-producing cows and first-lactation cows reached greater values, and their values peaked later in lactation. The average cost of a pregnancy loss (abortion) was $555. The cost of a pregnancy loss typically increased with gestation length. Sensitivity analyses showed that an increased probability of pregnancy, an increased persistency of milk yield, and a smaller replacement heifer cost greatly reduced the average value of a pregnancy. The value of a new pregnancy was negative for relatively high-producing first-lactation cows when persistency of lactation and the probability of pregnancy were increased. Breeding was delayed when the value of pregnancy was negative. Changes in milk price, absolute milk yield, and probability of involuntary culling had less effect on the value of pregnancy. The value of pregnancy and optimal breeding decisions for individual cows were greatly dependent on the predicted daily milk yield for the remaining period of lactation. An improved understanding of the value of pregnancy may support decision making in reproductive management when resources are limited.

If control of Neospora caninum infection is technically feasible does it make economic sense?

Recent work on Neospora caninum, a protozoan parasite that causes abortions in dairy cattle has focused on a number of different control options. Modelling has suggested the most effective options for control but the present paper argues that the most effective option might not necessarily be optimal from an economic point of view. Decision trees, using published quantitative data, were constructed to choose between four different control strategies. The costs of these interventions, such as 'test and cull', therapeutic treatment with a pharmaceutical, vaccination or "doing nothing" were compared, and modelled, in the first instance, on the New Zealand and Australian dairy situation. It is argued however, that the relative costs in other countries might be similar and that only the availability of a registered vaccine will change the decision tree outcomes, as does the within-herd prevalence of N. caninum infection. To "do nothing" emerged as the optimal economic choice for N. caninum infections/abortions up to a within-herd prevalence of 18%, when viewed over a 1-year horizon, or 21% when costs were calculated over a 5 years horizon. For a higher (>or=21%) within-herd prevalence of N. caninum infection vaccination provided the best (i.e. most economic) strategy. Despite being the most efficacious solutions, 'test and cull' or therapeutic treatment never provided a viable economic alternative to vaccination or "doing nothing". Decision tree analysis thus provided clear outcomes in terms of economically optimal strategies. The same approach is likely to be applicable to other countries and the beef industry, with only minor changes expected in the relationships of decisions versus within-herd prevalence of N. caninum infection.

Economic considerations for diagnostic and control options for Neospora caninum-induced abortions in endemically infected herds of beef cattle.

OBJECTIVE: To compare economic outcome for herds not exposed to Neospora caninum with that for herds with various seroprevalences of N caninum infection and evaluate 3 control strategies. DESIGN: Economic simulation model. SAMPLE POPULATION: Beef herds with various seroprevalences of N caninum infection. PROCEDURE: A 5-year simulation model was used. Control strategies that were evaluated included culling females that fail to calve, selling seropositive females and purchasing seronegative replacements, and excluding the daughters of seropositive dams as potential replacements. RESULTS: For a 5-year period with low prices for feeder calves, endemic N caninum infection decreased mean return to fixed assets by 22.2% when true seroprevalence was 10% and by 29.9% when true seroprevalence was 70%. Percentage decrease in return to fixed assets was less dramatic when a 5-year period with high prices for feeder calves was evaluated. Analysis indicated that 2 control strategies (culling females that fail to give birth to a calf and selling seropositive female cattle and purchasing seronegative replacement female cattle) were not likely to be economically beneficial. The third control strategy (testing the entire herd for N caninum infection and excluding the female offspring of seropositive dams as replacements) appeared to be a reasonable control strategy. CONCLUSIONS AND CLINICAL RELEVANCE: For the assumptions in the model, endemic N caninum infection decreases return to fixed assets for cow-calf herds. Of the potential control strategies evaluated, testing the entire herd for N caninum infection and excluding the daughters of seropositive dams as potential replacements provided the best economic return.)

A mixture model for bovine abortion and foetal survival.

The effect of spontaneous abortion on the dairy industry is substantial, costing the industry on the order of US dollars 200 million per year in California alone. We analyse data from a cohort study of nine dairy herds in Central California. A key feature of the analysis is the observation that only a relatively small proportion of cows will abort (around 10;15 per cent), so that it is inappropriate to analyse the time-to-abortion (TTA) data as if it were standard censored survival data, with cows that fail to abort by the end of the study treated as censored observations. We thus broaden the scope to consider the analysis of foetal lifetime distribution (FLD) data for the cows, with the dual goals of characterizing the effects of various risk factors on (i). the likelihood of abortion and, conditional on abortion status, on (ii). the risk of early versus late abortion. A single model is developed to accomplish both goals with two sets of specific herd effects modelled as random effects. Because multimodal foetal hazard functions are expected for the TTA data, both a parametric mixture model and a non-parametric model are developed. Furthermore, the two sets of analyses are linked because of anticipated dependence between the random herd effects. All modelling and inferences are accomplished using modern Bayesian methods.

Simulated epidemiological and economic effects of measures to reduce piglet supply during a classical swine fever epidemic in The Netherlands.

The effects of additional measures adopted during a classical swine fever (CSF) epidemic to reduce piglet supply, namely, an insemination ban, abortion of sows and killing of young piglets, are studied using a stochastic, spatial, dynamic epidemiological simulation model of the pig sector in The Netherlands. The piglet supply derived from the epidemiological model is used as input for a sector-level market and trade model that simulates the pig market in The Netherlands. Changes in the economic welfare of different stakeholders are measured, as is the net welfare effect for the economy in The Netherlands. Sensitivity analysis is performed on parameters such as destruction capacity constraints and the duration of the high-risk period. Additional measures to reduce piglet supply are found to have no epidemiological impact, but they do involve larger economic welfare changes for stakeholders and a larger net welfare loss for the economy in The Netherlands. These findings do not support the use of the additional measures. Moreover, sensitivity analysis shows that such measures do not solve the problem of a shortage in rendering capacities.

Towards evaluating the economic impact of bovine neosporosis.

In spite of the global importance of neosporosis as a cause of bovine abortion, there is very little information about its economic consequences. The economic costs are a product of estimations of the quantity of the effects attributable to Neospora infection, and the particular unit costs of those effects. In this brief review, which arose from a workshop on the economics of coccidiosis held at the COST 820 meeting, Toledo 1998, we discuss the possible effects of neosporosis which are of economic significance and summarise the available estimates of their magnitude to provide a basis for further economic analysis. Neospora infection has been associated with abortion, increased culling and reduced milk yield. In addition, it has been diagnosed in cases of stillbirth and neonatal mortality, it is likely to contribute to early foetal death and resorption and it is responsible for a reduction in the value of female breeding cattle. In quantifying the role of Neospora, it is important that epidemiologically based, case-controlled studies are conducted because, given the extreme efficiency with which bovine Neospora infection is vertically transmitted, demonstration of prevalence of infection in affected animals (including foetuses) is not a true indicator of the significance of this disease. Relatively few epidemiological studies have been conducted, but in investigations in the USA, Holland and Britain, infected cows have been shown to be about three times more likely to abort than non-infected cattle. In the UK this approach has been used to estimate the proportion of abortions in the national dairy population which may be attributable to Neospora caninum.

The incidence and economic significance of ovine toxoplasmosis in Uruguay.

Antibodies to Toxoplasma gondii were measured before and after pregnancy in a 1:64 dilution of sera with the direct agglutination test in 1613 ewes from 18 farms in eight different counties of Uruguay from 1992 to 1994. The overall seroprevalence increased from 28.7% before mating to 38.5% after lambing in 2.5 years and thus the incidence was 9.8%. Losses due to toxoplasmosis during pregnancy were estimated to be 1.4-3.9% of the total number of ewes investigated, amounting to approximately US$1.4-4.7 million for the whole country.