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- Author or Editor: Paul Bartlett x
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Summary:
A stratified random sample of 50 Ohio dairy herds, monitored for 1 year between March 1988 and May 1989, was used to estimate the component costs of clinical mastitis per cow-year overall and by organism, the component costs of an episode of clinical mastitis overall and by organism, and the incidence of clinical mastitis by organism. Each herd was visited monthly by a veterinarian who conducted on-farm interviews and completed standardized data-collection forms designed to elicit economic information about the on-farm costs of clinical mastitis and mastitis prevention. Producers collected milk samples prior to treatment of clinical mastitis cases. Culturing methods allowed identification of 18 specific mastitis pathogen classifications. Annual costs estimated were on a per cow-year and clinical episode basis. The monthly mean population of cows monitored was 4,068. Mastitis prevention cost $14.50/cow-year, whereas the cost incurred by producers because of clinical cases of mastitis was $37.91. Organisms prevalent in the cows’ environment caused the most costly types of mastitis. Disregarding contaminated samples and episodes for which no milk samples were taken, mastitis for which 2 organisms were isolated accounted for 35.5% of costs of clinical mastitis, followed by cases for which Escherichia coli (21.3%) was isolated, cases for which culturing yielded no growth (8.6%), and cases for which esculin-positive Streptococcus spp (6.4%), Klebsiella spp (5.7%), esculin-negative CAMP-negative Streptococcus spp (5.1%), Enterobacter spp (4.8%), coagulase-negative Staphylococcus spp (4.1%), coagulase-positive Staphylococcus spp (3.0%), S agalactiae (2.5%), and Bacillus spp (1.2%) were isolated. Other categories of classification each accounted for < 0.5% of costs. Mean cost per clinical episode was $107.11. Mean incidence of clinical mastitis was 38.74 cases/100 cowyears. Mixed infections had the highest incidence (mean, 4.80 cases/100 cow-years), followed by cases with no growth (2.96), E coli (2.10), esculin-positive Streptococcus spp (1.94), coagulase-negative Staphylococcus spp (1.60), esculin-negative CAMP-negative Streptococcus spp (1.25), coagulase-positive Staphylococcus spp (1.04), Enterobacter spp (0.36), and Klebsiella spp (0.27).
Objective
To determine whether certain characteristics of dogs offered for adoption are associated with successful adoption.
Design
Retrospective cohort study.
Animals
1,468 relinquished dogs offered for adoption at a local humane society.
Procedure
Data regarding dogs offered for adoption were obtained from surveys completed by previous owners. Data were analyzed by use of bivariate statistics and multivariable logistic regression.
Results
Of dogs offered for adoption, 1,073 were successfully adopted, 239 were not adopted, and 157 were returned to the shelter after adoption. Terrier, hound, toy, and nonsporting breeds were found to be significantly associated with successful adoption (P< 0.05, χ2 analysis). Certain coat colors (gold, gray, and white), small size, and history of an indoor environment were also significant predictors of successful adoption. The correlation coefficient (0.048) indicated that only a small percentage of variance in adoption success could be explained by the multiple logistic regression model.
Clinical Implications
Animal shelter managers with limited kennel capacity may wish to periodically use surveys to determine whether the type of dog being offered to the public reflects the type of dog the public will adopt. (J Am Vet Med Assoc 1998;213:478-482)
Summary
Seventy-two lactating dairy cows with left displacement of the abomasum were blindly assigned to treatment by use of the roll-and-toggle procedure or right paralumbar fossa pyloro-omentopexy. All cows were from the same large dairy herd, and survival in the herd and daily milk production were measured for 120 days after treatment. The mean cost was $256.50 for roll-and-toggle cases ($50 for the procedure, $95.70 in milk loss and $110.80 in livestock losses). The mean cost was $406.40 for the pyloro-omentopexy cases ($150 for the procedure, $87.80 in milk loss, and $168.60 in livestock losses). A possible interaction with metritis was discovered, in that pyloro-omentopexy cases cost about $100 more than roll-and-toggle cases when metritis was absent (31 cases) or moderate (32 cases), and cost several times more when metritis was severe (9 cases). Results of the study were in agreement with those of other studies that indicated that the closed repositioning and stabilization techniques are generally less expensive and have comparable results with open repositioning and stabilization techniques. Veterinarians may wish to consider use of this nonsurgical technique for the routine correction of left displacement of the abomasum in dairy cattle.
Summary
For efficient disease management in dairy production, the influence of disease prevention strategies on farm profitability must be known. A survey of mastitis control practices, milking machine function and maintenance, and cow environmental conditions was conducted with 406 dairy producers on the Michigan Dairy Herd Improvement-somatic cell counting program responding. These survey data, in conjunction with Dairy Herd Improvement production data, were used to develop a model estimating the marginal value products of mastitis control practices. Lost milk production associated with increased somatic cell count was calculated for each herd. Mastitis control practices, milking machine function and maintenance, and cow environmental conditions were used as independent variables in an analysis of covariance model with lost milk production as the dependent variable. Variables significant in explaining changes in production from increased somatic cell count were the use of teat dip, use of sanitizer in the wash water, milking cow bedding, summer nonlactating cow housing, summer calving locations, type of regulator, alternating pulsation, and rolling herd average milk production. The marginal value product (change in revenues received) from the use of iodine, chlorhexidine, and quaternary ammonium-type teat dips were $13.79, $16.09, and $22.17/cow/year, respectively, and these changes were statistically significant. However, sanitizer in the wash water was associated with a decrease in production. Management practices that have previously been shown to be economical and did not appear in the final model included nonlactating cow therapy and single-use paper towels.
Abstract
Objective—To determine the effect of hyperimmunization with an Escherichia coli J5 bacterin on serum IgG2 concentration, incidence of clinical mastitis, and rate of survival to the end of the lactation period (ie, day 305) in adult lactating dairy cattle.
Design—Randomized controlled trial.
Animals—1,012 Holstein cows in their second lactation and greater.
Procedures—All cows were given 3 doses of the J5 bacterin; cows in the hyperimmunization group were given an additional 3 doses during the first 3 months of lactation. Blood was collected from a small sample of cows to determine anti-J5 IgG2 concentrations.
Results—Cows in the hyperimmunization group had higher mean serum anti-J5 IgG2 concentrations than did control cows 28 days after administration of the fourth, fifth, and sixth doses of the J5 bacterin. However, mean serum anti-J5 concentrations during the subsequent lactation were not significantly different between groups. The proportions of cows that developed clinical mastitis were not significantly different between groups. However, control cows were more likely to have severe clinical mastitis than were cows in the hyperimmunization group. The percentage of control cows that remained in the herd to day 305 was significantly lower than the percentage of cows in the hyperimmunization group that did.
Conclusions and Clinical Relevance—Results suggested that hyperimmunization of mature lactating dairy cattle was associated with increased serum anti-J5 IgG2 concentrations and decreased incidence of severe clinical mastitis, but did not alter survival rate of cows that developed severe clinical mastitis.
Summary
Forty-eight herds participating in the 1988/1989 Ohio National Animal Health Monitoring System dairy project were monitored for 1 year to determine the effects of environment and management on mortality in preweaned calves. Environmental factors were evaluated by veterinarians during monthly visits to the herds. Management procedures were measured through the use of a questionnaire administered near the end of the project. Mortality in preweaned calves was calculated for each herd by using data from project records on calf mortality and animal inventory, which were collected monthly by veterinarians. Relationships between the management/environment variables and calf mortality were examined by use of analysis of covariance. Herd size, days on a nipple feeder, navel disinfection, type of housing, and whether each calf observed with diarrhea was treated with antibiotics were the variables that had an impact on herd mortality. These variables explained approximately 39% of the variation in mortality among herds.
Objective—
To determine the effect of administration of vitamin E (D-α-tocopherol) on the incidence of retained placenta, metritis, and clinical mastitis during early lactation and on tocopherol concentrations.
Design—
Prospective randomized controlled study.
Animals—
420 Holstein cows
Procedure—
Vitamin E (3,000 mg, IM, once) was administered to 204 cows 8 to 14 days before expected parturition, and 216 control cows were not treated. The number of cows that had retained placenta, metritis, clinical mastitis, displaced abomasum, and clinically apparent acetonemia or hypocalcemia were recorded. Serum concentrations of tocopherol, the tocopherol:cholesterol ratio, and glutathione-peroxidase activity were determined from samples obtained before administration of vitamin E, 7 and 14 days after administration, and at 30 days after parturition from 36 treated and 36 control cows.
Results—
Administration of vitamin E significantly decreased the incidence of retained placenta and metritis (13/204 [6.4%] and 8/204 [3.9%], respectively, for the vitamin E-treated group; 27/216 [12.5%] and 19/216 [8.8%], respectively, for the untreated group) but did not affect the incidence of clinical mastitis. Serum vitamin E concentration was significantly higher in treated than in control cattle at 7 and 14 days after administration, but serum tocopherohcholesterol ratio was significantly higher only at 7 days after administration.
Clinical Implications—
Parenteral administration of a single injection of vitamin E before parturition may decrease the incidence of retained placenta and metritis in dairy cows but will increase serum concentrations for 7 to 14 days after administration. (J Am Vet Med Assoc 1997;211:466–469)
Summary
Supplementation of selenium and vitamin E to enhance disease resistance in dairy cattle has become common, particularly to prevent periparturient reproductive disorders and mastitis. To establish reference values for serum vitamin E and selenium concentrations in postparturient dairy cattle and to determine whether serum concentrations of these micronutrients varied with season and stage of lactation, cows from a stratified random sample of 50 herds were studied for 1 year. Blood samples were collected from each of the 50 study herds twice, from the 10 most recently parturient cows or from 10% of the herd, whichever was greatest. Mean concentration of vitamin E and selenium was 2.55 μg/ml and 78.12 ng/ml, respectively. Vitamin E concentrations were significantly (P < 0.05) higher during the summer and fall than during the winter and spring. Selenium concentrations were significantly (P < 0.05) lower during the summer and fall than during the winter and spring. Herd, season of blood sample collection, and time since parturition were significant (P < 0.02) in explaining variation in vitamin E and selenium concentrations.
Abstract
Objective—To determine factors that influenced culling or death of cows with left displaced abomasum (LDA) subsequent to correction by a roll-and-toggle (R&T) procedure or via laparotomy.
Design—Cohort study.
Animals—810 Holstein dairy cows with LDA.
Procedures—Data regarding method of repair and risk factors for survival after correction of LDA were collected during a 1-year period. Outcomes were compared at days 14 and 60 after LDA correction for 3 groups of cattle (veterinarians performed R&T [V-R&T], herd personnel performed R&T [H-R&T], and veterinarians performed surgical repair via laparotomy [V-Surg]).
Results—Survival rates 14 days after LDA correction for the V-R&T, H-R&T, and V-Surg groups were 87% (286/329), 81% (327/403), and 85% (66/78), respectively. At 60 days after LDA correction, survival rates for the V-R&T, H-R&T, and V-Surg groups were 79% (260/329), 71% (286/403), and 73% (57/78), respectively. Multivariable analysis indicated that factors positively associated with failure to remain in the herd at 60 days after LDA correction included current mastitis status, history of a previous LDA, high preoperative risk, and correction of LDA by herd personnel rather than by a veterinarian.
Conclusions and Clinical Relevance—Correction of LDA by veterinarians via an R&T procedure yielded results that were generally comparable to those for correction by veterinarians via laparotomy. Although survival rates at days 14 and 60 after surgery differed significantly between the V-R&T and H-R&T groups, herd personnel in this study used the R&T procedure to correct LDA and achieved survival rates within the range for those of practicing veterinarians.
Abstract
Objective—To determine the effect of bovine leukemia virus (BLV) infection on absolute neutrophil and lymphocyte concentrations in healthy lactating Holstein dairy cattle.
Design—Observational cross-sectional survey.
Animals—311 healthy lactating Holstein dairy cattle from herds in Michigan (n = 2), Wisconsin (1), Iowa (1), and Pennsylvania (1).
Procedures—Whole and anticoagulated (EDTA) blood samples were collected. Serum samples were tested for antibody against BLV by use of an ELISA. Absolute neutrophil and lymphocyte concentrations were measured in EDTA blood samples with an automated hematology analyzer and manual differential cell counts.
Results—208 cows tested positive and 103 cows tested negative for anti-BLV antibodies. Neutrophil concentration was not significantly different between BLV-positive versus BLV-negative cattle. The distribution of lymphocyte concentration was positively skewed for the entire cow population (n = 311) and the BLV-positive subset (208). In contrast, lymphocyte concentration distribution was approximately normal for BLV-negative cows (n = 103). Consequently, the presence or absence of BLV infection strongly influenced the calculated neutrophil-to-lymphocyte concentration ratio.
Conclusions and Clinical Relevance—Results indicated that absolute lymphocyte concentration is significantly affected by BLV infection in dairy cattle. Accordingly, hematologic reference intervals should be derived from healthy animals that are not infected with BLV and patient BLV status must be considered for meaningful interpretation of lymphocyte concentration. We recommend that the calculated neutrophil-to-lymphocyte ratio be abandoned because it does not provide more information than direct comparison of patient absolute leukocyte concentration with updated reference intervals from healthy BLV-negative cattle.