Economics of respiratory disease in dairy replacement heifers.

Bovine respiratory disease (BRD) is a frequent disease concern in dairy cattle and is most commonly diagnosed in young dairy heifers. The impact of BRD is highly variable, depending on the accuracy and completeness of detection, effectiveness of treatment, and on-farm culling practices. Consequences include decreased rate of weight gain, a higher culling risk either as heifers or as cows, delayed age at first service, delayed age at first calving, and in some cases, lower future milk production. In this data set of 104,100 dairy replacement heifers from across the USA, 36.6% had one or more cases diagnosed within the first 120 days of age with the highest risk of new cases occurring prior to weaning. Comparison of the raising cost for heifers with BRD and those without a recorded history of BRD resulted in an estimated cost per incident case occurring in the first 120 days of age of $252 or $282, depending upon whether anticipated future milk production differences were considered or not. Current market conditions contributed to a cost estimate that is significantly higher than previously published estimates, driven in part by the losses associated with selective culling of a subset of heifers that experienced BRD.

The cost of a case of subclinical ketosis in Canadian dairy herds.

The objective of this study was to develop a model to estimate the cost of a case of subclinical ketosis (SCK) in Canadian dairy herds. Costs were derived from the default inputs, and included increased clinical disease incidence attributable to SCK, $76; longer time to pregnancy, $57; culling and death in early lactation attributable to SCK, $26; milk production loss, $44. Given these figures, the cost of 1 case of SCK was estimated to be $203. Sensitivity analysis showed that the estimated cost of a case of SCK was most sensitive to the herd-level incidence of SCK and the cost of 1 day open. In conclusion, SCK negatively impacts dairy herds and losses are dependent on the herd-level incidence and factors included in the calculation.

Coût d'un cas d'acétonémie subclinique dans les troupeaux laitiers canadiens. L'objectif de cette étude consistait à développer un modèle pour estimer le coût d'un cas d'acétonémie subclinique (ASC) dans les troupeaux laitiers canadiens. Les coûts ont été dérivés des valeurs par défaut et comprenaient l'incidence accrue de maladie clinique attribuable à l'ASC, 76 $; un délai plus long avant la gestation, 57 $; la réforme et la mort au début de la lactation attribuable à l'ASC, 26 $; la perte de production laitière, 44 $. Compte tenu de ces chiffres, le coût de 1 cas d'ASC a été estimé à 203 $. Une analyse de sensibilité a montré que le coût estimé d'un cas d'ASC était le plus sensible à l'incidence de l'ASC au niveau du troupeau et au coût d'une journée ouvrable. En conclusion, l'ASC a un impact négatif sur les troupeaux laitiers et les pertes dépendent de l'incidence au niveau du troupeau et des facteurs inclus dans le calcul.(Traduit par Isabelle Vallières).

Economic value of ionophores and propylene glycol to prevent disease and treat ketosis in Canada.

A partial budget model was developed to evaluate the economic value of Rumensin Controlled Release Capsule (CRC) boluses when administered before calving to reduce disease and increase milk production. After accounting for disease incidences in a herd and the percentage by which Rumensin CRC can reduce them, and the increase in milk production attributable to administration of Rumensin CRC, the return on investment (ROI) per lactation was 4:1. Another partial budget model was developed to estimate the economic value of propylene glycol (PG) to treat ketosis when diagnosed by 3 different cow-side tests or when administered to all cows without using any cow-side testing. After accounting for the sensitivity and specificity of each test, ROI per lactation ranged from 2:1 to 4:1. The ROI was 2:1 when no cow-side testing was used. In conclusion, prevention of diseases that occur in the postpartum period and treatment of ketosis after calving yielded a positive ROI that varies based on disease incidence and method of diagnosis.

Valeur économique des ionophores et du propylèneglycol pour prévenir la maladie et traiter l'acétonémie au Canada. Un modèle de budget partiel a été développé pour évaluer la valeur économique des bolus de capsules à libération contrôlée (CLC) de Rumensin lors de l'administration avant le vêlage afin de réduire les maladies et d'accroître la production de lait. Après avoir tenu compte de l'incidence des maladies dans un troupeau et du pourcentage par lequel la CLC de Rumensin peut les réduire et de l'augmentation de la production de lait attribuable à l'administration de la CLC de Rumensin, le rendement du capital investi (RCI) par lactation était de 4:1. Un autre modèle de budget partiel a été développé pour estimer la valeur économique du propylèneglycol (PG) afin de traiter l'acétonémie lors du diagnostic par 3 tests différents pour les vaches ou lors de l'administration à toutes les vaches sans le recours à des tests auprès des vaches. Après avoir tenu compte de la sensibilité et de la spécificité de chaque test, le RCI par lactation s'échelonnait de 2:1 à 4:1. Le RCI était de 2:1 lorsqu'aucun test auprès des vaches n'était utilisé. En conclusion, la prévention des maladies qui se produit dans la période postpartum et le traitement de l'acétonémie après le vêlage a donné un RCI positif qui varie selon l'incidence de maladies et la méthode de diagnostic.(Traduit par Isabelle Vallières).

Expression of inflammation-associated genes in circulating leukocytes and activity of indoleamine-2,3-dioxygenase in dairy cattle with acute puerperal metritis and bacteremia.

OBJECTIVE: To investigate whether expression of genes associated with inflammation and activity of indoleamine-2,3-dioxygenase (IDO) correlated with disease status and prevalence of bacteremia in post-partum dairy cattle with and without acute puerperal metritis (APM). PROCEDURES: Blood was collected from cattle with APM and control cattle matched by parity and days in milk. Leukocytes were isolated and expression of 6 genes was quantified. Activity of IDO was measured in serum with higher performance liquid chromatography (HPLC). RESULTS: The relative expression of IL-1ß in cattle with APM was significantly lower than that in controls. IDO activity was not significantly different between bacteremic and non-bacteremic cattle CONCLUSIONS AND CLINICAL RELEVANCE: The expression of IL-1ß was lower in cattle with APM. The lower levels of IL-1ß expression in PBMCs of cattle with APM suggest impaired inflammatory responses and may contribute to the development of the disease in this population of animals.

Comparison of fluorescent antibody and microscopic agglutination testing for Leptospira in pregnant and nonpregnant cows.

Serum and urine samples from 30 cows (15 pregnant and 15 nonpregnant) from each of 10 Georgia dairy herds (total cows = 300) were examined by microscopic agglutination testing (MAT) and direct fluorescent antibody testing (FAT), respectively. Seven of the 10 herds had at least 1 cow with a positive FAT, and all of the herds had at least 1 cow with a reciprocal MAT titer > or =100 for 1 or more serovars. Serological testing was not helpful in identifying the infecting serovar for cows with a positive FAT result. The MAT titers for all 7 of the serovars evaluated were significantly correlated with one another, with 17 (81%) of the 21 Spearman rank correlation coefficients > or =0.4 in magnitude. Twenty (56%) of 36 FAT-positive cows did not have a titer that was highest for any particular serovar. Four of the 7 herds that reported using a Leptospira borgpetersenii serovar Hardjo-bovis vaccine had one or more FAT-positive cows compared with 3 out of 3 herds that reported they were not using this type of vaccine, although this difference was not statistically significant.

Evaluation of factors that affect embryonic loss in dairy cattle.

OBJECTIVE: To identify potential risk factors for embryonic loss before 35 to 42 days of gestation in dairy cattle. DESIGN: Prospective observational study. ANIMALS: 381 cows. PROCEDURE: Body condition score was determined at the time of artificial insemination (AI; day 0) and on days 20, 23, and 27 and between days 35 and 41; serum progesterone concentration was measured on days 0; 20 or 21; and 23, 24, or 25. Cows were excluded from analyses if day 0 serum progesterone concentration was > or = 1.0 ng/mL and classified as pregnant on day 23 if serum progesterone was > 1.5 ng/mL on day 20 or 21 and day 23, 24, or 25. Cows were examined via transrectal ultrasonography on day 27 or 28 and rectally palpated for pregnancy on days 35 to 41. RESULTS: 39% of cows that were pregnant on day 23 lost their embryo by day 27, and 18% of cows that were pregnant on day 27 or 28 were not pregnant on days 35 to 41. Breeding a pregnant cow posed the greatest risk for embryonic loss at both time periods. Mean serum progesterone concentrations on day 21 or 22 and day 23, 24, or 25 were lowest for cows that lost an embryo between days 24 and 28. Cows with a linear somatic cell count score > 4.5 before AI were twice as likely to lose the embryo by 35 to 41 days, compared with cows with a score < 4.5. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that embryonic loss could be reduced by more accurate estrus detection, reducing mastitis, and strategies to improve progesterone concentration after breeding.

Levels of continuing veterinary medical education program evaluation: assessing a course on dairy reproductive management.

There are four different levels of continuing education program evaluation: participant perceptions of the program or course; participant competence with new skills, knowledge, and abilities; participant performance or change in behavior; and health care or client outcomes, such as resultant changes in patient care or herd/flock production performance. The purpose of this article is to describe different levels of evaluation and demonstrate some methods used in evaluating a continuing veterinary medical education (CVME) course in dairy reproductive management. Participants' learning needs were assessed using learning stage theory and a pre-test of knowledge. Post-program assessments included a test of knowledge, a satisfaction survey, a commitment to change, and self-reported behavior change. The results of the evaluation indicate that self-reports of learning needs do not necessarily reflect actual needs and that satisfaction with a course does not necessarily indicate behavior change. Providers of CVME must recognize the value of program evaluation, as well as the advantages and disadvantages of different evaluation methods.

Evaluation of effect of estradiol cypionate administered prophylactically to postparturient dairy cows at high risk for metritis.

OBJECTIVE: To determine whether 4 mg of estradiol cypionate (ECP) administered prophylactically to high-risk postparturient dairy cows decreases incidence of postpartum metritis. DESIGN: Randomized, placebo-controlled, triple-masked clinical trial. ANIMALS: 250 postparturient dairy cows in a herd with postparturient hypocalcemia, retained fetal membranes, dystocia, stillbirth, or twins. PROCEDURE: Cows were given 4 mg of ECP (treatment) or 2 mL of vegetable oil (control) by i.m. injection within 24 to 36 hours of calving. Monitoring rectal temperatures and evaluation for metritis was performed once daily for 10 days. Cows with fever > or = 39.7 degrees C (103.5 degrees F) were treated with 1.5 g of ceftiofur hydrochloride. RESULTS: When assessed by ordinal logistic regression, there were no differences between groups in incidence of mild or severe metritis. Cows that calved during the second or third quarter of the year were at increased risk of metritis, compared with those that calved during the fourth quarter. Following stratification by lactation (first and > or = 2), it was observed that multiparous cows that did not receive antimicrobials during the first 3 days of the postparturient period were 5 times as likely to have metritis, compared with cows treated with antimicrobials on the basis of fever or other concurrent disease. CONCLUSIONS AND CLINICAL RELEVANCE: Prophylactic administration of ECP to dairy cows at high risk for metritis did not reduce risk for metritis. Treating multiparous cows with antimicrobials on the basis of fever during the early postpartum period was associated with decreased incidence of metritis.