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Objective

To estimate the marginal contribution of pasteurization of waste milk and colostrum to gross margin per calf at weaning and to estimate the minimum number of cattle on a dairy farm for pasteurization to be profitable.

Design

Randomized, controlled, clinical trial.

Animals

300 Holstein calves.

Procedure

The performance of calves fed pasteurized colostrum and waste milk was compared with the performance of calves fed nonpasteurized colostrum and waste milk. Costs, revenues, and gross margins for the 2 groups were compared.

Results

Calves fed pasteurized colostrum and waste milk were worth an extra $8.13 in gross margin/calf, compared with calves fed nonpasteurized colostrum and waste milk. The minimum number of cattle for which feeding pasteurized colostrum and waste milk was calculated to be economically feasible was 315 calves/d (1,260-cow dairy farm).

Clinical Implications

An economic benefit was associated with feeding pasteurized colostrum and waste milk. Additional benefits that may accrue include higher mean weight gain and lower mortality rate of calves as well as calves that have fewer days in which they are affected with diarrhea and pneumonia (J Am Vet Med Assoc 1996;209:751–756)

Free access
in Journal of the American Veterinary Medical Association

Summary

Computerized decision-tree analysis and simulation modeling were used to evaluate control and eradication strategies for pseudorabies virus (prv) in swine. Three alternative actions were considered for a hypothetical 100-sow, farrow-to-finish operation: (1) depopulation-repopulation, (2) test-and-removal of seropositives (t&r), and (3) vaccination (of the entire herd or of sows only). The expected monetary values for the vaccination and t&r alternatives were similar, which was consistent with the long-standing controversy over the best strategy for dealing with prv. When the prevalence rate of prv was ≤57%, t&r was found to be optimal; otherwise, vaccination of sows only was recommended.

Sensitivity analysis was performed to determine how modifications in some of the original assumptions affected the expected monetary values of each strategy. When higher gross margins for the producer were assumed, t&r was preferred at all prevalence rates. Vaccination was preferred when lower gross margins, lower vaccination costs, or better protective effect of prv vaccines on reproductive performance were assumed. The use of gene-deleted vaccines in conjunction with the t&r strategy was also evaluated. When this option was available, t&r was favored at any prevalence rate (t&r alone when the prevalence was ≤20%, or combined with gene-deleted vaccination at prevalences >20%). Depopulation-repopulation was not the best option under any circumstance. Once formulated, a decision-tree analysis can be adapted to the prevailing economic or epidemiologic conditions; hence, it is a useful tool in the prv decision-making process.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To estimate potential revenue impacts of an outbreak of foot-and-mouth disease (FMD) in the United States similar to the outbreak in the United Kingdom during 2001.

Design—Economic analysis successively incorporating quarantine and slaughter of animals, an export ban, and consumer fears about the disease were used to determine the combined impact.

Sample Population—Secondary data for cattle, swine, lambs, poultry, and products of these animals.

Procedure—Data for 1999 were used to calibrate a model for the US agricultural sector. Removal of animals, similar to that observed in the United Kingdom, was introduced, along with a ban on exportation of livestock, red meat, and dairy products and a reduction and shift in consumption of red meat in the United States.

Results—The largest impacts on farm income of an FMD outbreak were from the loss of export markets and reductions in domestic demand arising from consumer fears, not from removal of infected animals. These elements could cause an estimated decrease of $14 billion (9.5%) in US farm income. Losses in gross revenue for each sector were estimated to be the following: live swine, –34%; pork, –24%; live cattle –17%; beef, –20%; milk, –16%; live lambs and sheep, –14%; lamb and sheep meat, –10%; forage, –15%; and soybean meal, –7%.

Conclusions and Clinical Relevance—Procedures to contain an outbreak of FMD to specific regions and allow maintenance of FMD-free exports and efforts to educate consumers about health risks are critical to mitigating adverse economic impacts of an FMD outbreak. (J Am Vet Med Assoc 2002;220:988–992)

Full access
in Journal of the American Veterinary Medical Association

Objective

To determine financial impact of an outbreak of vesicular stomatitis in the San Luis Valley of southern Colorado.

Design

Survey and financial analysis.

Sample Population

16 ranchers whose beef herds were affected by the 1995 outbreak.

Procedure

Information concerning financial effects during the outbreak year was collected by personal interview of each rancher and examination of financial records.

Results

Affected herds ranged from 79 to 956 cows (mean, 345). Cow case-fatality rates ranged from 0 to 80%, with calf case-fatality rates ranging from 0 to 28% and overall case-fatality rates of 0 to 15%. Median financial loss was $7,818/ranch and mean financial loss was $15,565/ranch, excluding total financial losses associated with sale of calves. Primary financial losses for these beef herds were attributed to increased culling rates, death of pregnant cows, loss of income from calves, and costs for additional labor during the outbreak. Some costs were attributable to a decrease in market price for beef and a drought during the year after the outbreak.

Clinical Implications

Financial losses for an out-break of vesicular stomatitis can be attributed to effects of the disease and costs associated with imposed quarantines. (J Am Vet Med Assoc 1998; 212:820-823)

Free access
in Journal of the American Veterinary Medical Association

Objective

To identify the preferable testing and vaccination strategy for control of porcine parvovirus (PPV) during a 6-month period.

Design

Decision-tree analysis and computer simulations.

Sample Population

Computer modeling of 300-sow farrow-to-finish herd.

Procedure

Serologic testing of 30 females to estimate herd PPV prevalence versus not testing any females was the initial decision alternative. On the basis of serologic test results, herds were classified into 1 of 3 PPV-risk categories: low (≥ 80% seropositive females), moderate (40 to < 80% seropositive females), or high (< 40% seropositive females). Vaccinating all females, only gilts, or not vaccinating was the second decision alternative.

Results

For initial model assumptions (test sensitivity and specificity = 0.95; test cost = $5/female; vaccination cost = $0.30/dose; vaccination efficacy = 0.95; and foregone gross margin = $10.85/pig), vaccination of all females (with or without serologic testing) was preferable, but the financially preferable option was to omit serologic testing. Most profitable vaccination option varied with foregone gross margin, vaccination cost, and efficacy. For herds in which all sows were known to be immune, vaccinating only gilts was financially preferable, and serologic testing was not warranted. Variation in expected monetary losses was less in vaccination options than with nonvaccination.

Clinical Implications

For most herds in the United States, serologic screening for PPV prior to selection of a vaccination program is unlikely to be cost-effective, because vaccination is inexpensive ($0.30/dose) and effective (95%). At current profit margins ($10.85/pig), vaccination of all females has the least-risk and is the preferred option.

Free access
in Journal of the American Veterinary Medical Association

Objective—

To evaluate the decision to test for milk antimicrobial residues in milk from dairy cows treated with procaine penicillin G (PPG).

Design—

Economic-decision analysis after stochastic simulation.

Sample Population—

1,000 computer-simulated cows/model.

Procedure—

Meta-analysis of the Food Animal Residue Avoidance Databank was used to generate PPG disappearance curves for cows given single PPG treatments, IM, of 6,600 U/kg (3,000 U/Ib) of body weight or 26,400 U/kg (12,000 U/lb), and multiple treatments at 26,400 U/kg (12,000 U/lb), IM. These curves were entered into 1,000-replication stochastic pharmacokinetic models, generating population-level milk PPG profiles for each treatment group for each day after treatment, which were subjected to economic-decision analyses of feasibility of residue testing. The model was evaluated for changes in herd size, proportion of herd available for testing, milk production, test price, test sensitivity/specificity, and withdrawal periods.

Results—

For both single-treatment groups, a 2-day withdrawal period avoided violative residues. However, nearly two thirds of the cows risked false identification for violative residues. For the multiple-treated group, nearly 40% had violative residues after a 5-day withdrawal period, and an additional 10 to 15% risked false identification for violative residues. Economic analysis yielded a decision against testing; mean cost was $2 (ie, 5% more than the mean cost of not testing).

Clinical Implications—

Complex dynamics of current milk residue tests discourage practitioners from recommending procedures to clients. In general, increases in herd size, milk production, proportion of a herd available for testing, or milk price will increase the value of testing. Increasing test sensitivity decreases its desirability to producers. (J Am Vet Med Assoc 1997;211:419–427)

Free access
in Journal of the American Veterinary Medical Association

Summary:

A field trial was conducted to measure differences in performance between selenium-supplemented and nonsupplemented heifers on a 1,200-cow California dairy. One hundred seventeen 19- to 27-month-old Holstein heifers were randomly assigned to treatment (n = 59) and control (n = 58) groups. A federally approved, commercially available, sustained-release intraruminal selenium bolus was administered to each heifer in the treatment group. Blood samples were taken from treated and control animals to assess selenium values before and after bolus administration and again after introduction to the milking ration. Production data were obtained from an on-farm computerized record system for each heifer during her first lactation.

Mean blood selenium concentrations in treated heifers were higher than those in control heifers from posttreatment day 30 until after calving. Data analyzed in midlactation and late lactation indicated no significant differences between treated and control groups in somatic cell count, days not pregnant, total milk produced, or times bred.

Free access
in Journal of the American Veterinary Medical Association

Summary

Twenty-nine California dairy herds were studied over a 12-month period from 1988 to 1989 as part of the National Animal Health Monitoring System. Monthly interviews administered to dairy producers were used to measure the costs of all health-related expenditures and disease incidence in these herds. Of the total $1,523,558 reported, $1,355,467 (89%) was attributed to cost of disease events and $168,091 (11%) to cost of disease prevention. Most (78%) of the cost of disease events was attributable to death and culling losses. Veterinary services accounted for only $54,099 (4%) of total costs, 64% of which was used for disease prevention, compared with 36% for disease treatment. Udder disease was the most costly category of diseases reported at an average of $49.85/head at risk annually, followed by reproductive problems at $38.05. Through the use of sampling strategies less biased than those used in other surveys, the National Animal Health Monitoring System is designed to provide statistically-valid estimates of disease incidence and costs across broad geographic areas, potentially benefiting all those interested in the economics of livestock diseases in the United States.

Free access
in Journal of the American Veterinary Medical Association

Summary

Data on costs associated with episodes of disease and disease prevention, including expenditures for veterinary services, were collected from 57 California beef cow-calf herds during 1988-1989 as part of the National Animal Health Monitoring System. Mean cost associated with episodes of disease was $33.90/cow-year, with $0.78 and $1.37/cow-year being spent for veterinary services and drugs, respectively. The highest costs for veterinary services related to episodes of disease were for dystocia, lameness, and ocular carcinoma. For disease prevention, mean expenditures for veterinary services were $1.67/cow-year, nearly all of which was spent on prevention of reproductive tract conditions. Preventive expenditures for veterinary services related to female infertility (pregnancy examination), vaccination against brucellosis and male infertility (breeding soundness examination) were $0.72, $0.39, and $0.22/cow-year, respectively. Many costs associated with episodes of disease and disease prevention were similar to those reported from Colorado National Animal Health Monitoring System beef herds.

Free access
in Journal of the American Veterinary Medical Association

Summary

Sixty cow-half herds of more than 50 cows each were randomly selected for a prevalence survey of bovine trichomoniasis in California. Herd size, as judged by the number of bulls, ranged from 1 to 210 bulls (median = 8; mean = 59 ± 15.8). Preputial smegma was collected from 729 bulls (median = 6 bulls/herd) and cultured for Tritrichomonas foetus. Of 57 herds from which samples were collected, 9 (15.8%) had at least one infected bull. Of the 729 bulls from which samples were cultured, 30 (4.1%) were infected. Correcting for sensitivity of the diagnostic test yielded a prevalence of 5.0%. Infection rates for bulls >3 years old and ≤3 years old were 6.7% and 2.0%, respectively (P > 0.025). Median herd sizes were 14 bulls (range, 6 to 114) for infected herds and 7 (range, 1 to 210) for uninfected herds. These findings suggest that trichomoniasis is common in California beef herds. Because several bulls <4 years old were infected, we suggest that control measures stressing replacement of older bulls with younger ones should be combined with diagnostic procedures in those younger replacements, to ensure that they are not already infected.

Free access
in Journal of the American Veterinary Medical Association