Search Results

Abstract

OBJECTIVE To estimate costs associated with prevention and treatment of bovine respiratory disease (BRD) in preweaned calves on US beef cow–calf operations.

DESIGN Cross-sectional survey.

SAMPLE 43 beef cow–calf producers whose operations had a history of BRD in preweaned calves.

PROCEDURES Mail and electronic surveys were developed and administered to producers in Nebraska, North Dakota, and South Dakota to obtain information regarding costs of BRD prevention and treatment. Descriptive statistics were generated. Mixed linear regression models were used to assess factors associated with the costs of vaccines, medicine, and labor and percentage time spent on prevention and treatment of BRD in cows, replacement heifers, and preweaned calves.

RESULTS 7 mail and 36 electronic surveys were completed. Median annual costs for BRD vaccines were $2.25, $4.00, and $6.25/animal, and median annual labor costs for vaccination were $4.58, $3.00, and $5.00/animal for cows, heifers, and preweaned calves, respectively. Median annual costs for medicine and labor to treat preweaned calves for BRD were $11.00 and $15.00/ affected calf, respectively. Adjusted mean annual BRD vaccine cost for preweaned calves ($7.67/animal) was significantly greater than that for cows ($3.18/animal) and heifers ($4.48/animal).

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that labor costs associated with BRD vaccination and treatment were similar to or exceeded the cost of vaccines and medicine, and most of those labor costs were associated with gathering and sorting cattle. Therefore, costs associated with labor as well as medicine and vaccines should be considered during the development of BRD prevention and treatment plans.

Abstract

Objective—To evaluate and update the previously quantified effects of management, marketing, and certified health programs on the sale price of beef calves sold through a livestock video auction service.

Design—Longitudinal study.

Sample—41,657 lots representing 5,042,272 beef calves sold from 1995 through 2009.

Procedures—Data describing each lot of beef calves marketed from 1995 through 2009 by a livestock video auction service were obtained from sale catalogues. For each year of the study, multiple regression analysis was used to quantify the effect of management, marketing, and certified health programs on sale price.

Results—Sale date, base sale weight, quadratic effect of base weight, sex of calf, region of origin, breed description, inclusion in a certified health program, and number of calves in the lot significantly affected sale price for every year of the study. Variation in body weight, flesh score, and number of days between sale and delivery date had significant effects on price in most of the years; frame score and calves with horns affected price in 7 of 15 years; age and source verification influenced sale price in every year since source verification was introduced in 2005; and the auction service's progressive genetics program increased price during the 1 year that program was available.

Conclusions and Clinical Relevance—Some management, marketing, and certified health initiatives have consistently increased the sale price of beef calves, and producers can increase the price of their calves by implementing these practices.

Abstract

Objective—To evaluate the effects of a voluntary regional bovine viral diarrhea virus (BVDV) control project implemented in the Upper Peninsula of Michigan.

Design—Longitudinal study.

Sample—294 cattle producers and 11,917 cattle from the Upper Peninsula.

Procedures—Producer participation was assessed to determine the effectiveness of the project's promotional and educational campaigns. Participating herds were screened for cattle persistently infected (PI) with BVDV by real-time reverse transcriptase PCR assay on ear notch specimens from all newborn calves and cattle that did not calve (bulls and young stock) during the year of enrollment. Responses to a survey administered to producers 4 years after project initiation were evaluated to assess the project's effect on BVDV management practices implemented by producers.

Results—294 of 495 (59%) known cattle producers in the Upper Peninsula participated in the project, and 11,917 cattle from 232 herds were tested for BVDV, of which 22 (0.18%) cattle from 9 (3.9%) herds were identified as PI with BVDV and euthanized or slaughtered. Of 140 survey respondents, 85 (61%) indicated they would test all new herd additions for BVDV, 83 (59%) would quarantine new herd additions for 30 days before introducing them to the main herd, and 81 (58%) would use the fact that their herd was free of cattle PI with BVDV for marketing purposes.

Conclusions and Clinical Relevance—Results indicated that the project enhanced producer knowledge about BVDV and led to changes in producer behavior regarding BVDV management. Stakeholder engagement was as critical to project success as was increased BVDV knowledge.

Abstract

Objective—To collect and partially characterize strains of bovine viral diarrhea viruses(BVDVs) isolated from persistently infected (PI) calves born to vaccinated dams, determine genetic diversity of the isolated viruses, and identify regional distribution of genetically similar virus subpopulations.

Sample Population—17 noncytopathic (NCP) BVDVs from PI calves from 11 herds of beef or dairy cattle.

Procedures—Viral RNA was extracted from infected cell cultures, and BVDV-specific PCR primers were used to amplify > 1,000 bases of the viral genome. Derived sequences were used for molecular phylogenetic analyses to determine the viral genotype and viral genogroup and to assess genetic similarity among BVDVs.

Results—Analysis of the 17 NCP strains of BVDV failed to detect a viral genotype or viral genogroup not already reported to exist in the United States. One virus was classified as genotype 1, genogroup 1b, and 16 viruses were classified as genotype 2, genogroup 2a. Genotype 2 strains were genetically diverse, and genetic similarities were not obvious among viruses from geographic regions larger than a small locale.

Conclusions and Clinical Relevance—Viruses isolated from herds where a genotype 1, genogroup 1a BVDV vaccine was administered prior to breeding were primarily genetically diverse genotype 2, genogroup 2a BVDVs. Vaccination with multiple BVDV genotypes may be needed to improve protection. Methods used in this study to obtain and analyze field strains are applicable to assessing efficacy of current BVDV vaccines. Candidates for future vaccines are viruses that appear able to elude the immune response of cattle vaccinated against BVDV with existing vaccines.

Abstract

Objective—To determine the effects of constant exposure to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) on health and performance of feedlot cattle.

Design—3 controlled trials.

Animals—Crossbred feedlot cattle (trial 1, n = 184; trial 2, 138; trial 3, 138).

Procedures—Weaned calves were or were not vaccinated against BVDV at feedlot arrival (trial 1) or 2 (trial 2) or 3 (trial 3) weeks before feedlot arrival. During trial 1, half of the calves were commingled with PI cattle throughout the feeding period. During trial 2, 63 calves were exposed to PI cattle before weaning and all calves were exposed to PI cattle throughout the feeding period. During trial 3, all study calves were exposed to PI cattle throughout the feeding period. Morbidity and mortality rates and average daily gain (ADG) data were analyzed.

Results—During trial 1, calves maintained with PI cattle had a higher morbidity rate regardless of BVDV vaccination than did calves not exposed to PI cattle; however, for calves maintained with PI cattle, the morbidity rate for those vaccinated against BVDV was less than that for those not vaccinated against BVDV. During trial 2, calves exposed to PI cattle before weaning or vaccinated against BVDV had lower morbidity and mortality rates and increased ADG, compared with those for calves not exposed to PI cattle before weaning or vaccinated against BVDV. During trial 3, health and performance did not vary between calves that were and were not vaccinated against BVDV.

Conclusions and Clinical Relevance—Exposure of cattle to BVDV naturally or through vaccination before or at feedlot arrival mitigated the negative effects of constant exposure to PI cattle.

Abstract

Objective—To quantify effects of certified health programs on the sale price of beef calves sold through a livestock videotape auction service.

Design—Longitudinal study.

Sample Population—26,502 lots representing 3,205,192 beef calves sold through a livestock videotape auction service between 1995 and 2005.

Procedures—Data describing each lot of beef calves that were marketed from 1995 through 2005 by a livestock videotape auction service were obtained from sale catalogues. For each year of the study, multiple regression analysis was used to quantify the effect of certified health programs on sale price.

Results—For each year of the study, beef calves that qualified for the 2 most intensive certified health programs sold for significantly higher prices, compared with prices for similar calves that were not in a certified health program, had not been vaccinated against respiratory tract viruses, and were not weaned before delivery. Price premiums for calves in the most intensive certified health program ranged from $2.47/100 lb (hundredweight [cwt]; 1 cwt equals 45.45 kg) in 1995 to $7.91/cwt in 2004. Price premiums paid for calves qualifying for the next most intensive certified health program ranged from $0.99/cwt in 1996 to $3.47/cwt in 2004. The percentage of the total number of lots in the 2 most intensive certified health programs increased over time.

Conclusions and Clinical Relevance—Findings from this study indicated that implementation of the 2 most intensive certified health programs consistently increased the price of beef calves, and these price premiums increased over time.

Abstract

Objective—To evaluate associations between neonatal serum IgG1 concentration and pre- and postweaning morbidity and mortality rates and average daily gains (ADGs) in beef calves and define a cutoff point for serum IgG1 concentration necessary for optimal health and performance of beef calves.

Design—Nonconcurrent cohort study.

Animals—1,568 crossbred beef calves.

Procedure—Single radial immunodiffusion was used to quantitate IgG1 concentration in sera collected from calves between 24 and 72 hours after birth. Logistic regression, ANCOVA, and likelihood ratios were used to analyze data.

Results—In the preweaning period, lower perinatal IgG1 concentrations were significantly associated with higher morbidity rates, higher mortality rates, and lower ADGs. Calves with serum IgG1 concentration < 2,400 mg/dL were 1.6 times as likely to become ill before weaning and 2.7 times as likely to die before weaning as calves with higher serum IgG1 concentrations. Calves with serum IgG1 concentration of at least 2,700 mg/dL weighed an estimated 3.35 kg (7.38 lb) more at 205 days of age than calves with lower serum IgG1 concentration. No significant association of serum IgG1 concentration with feedlot morbidity, death, or ADG was identified.

Conclusions and Clinical Relevance—By use of likelihood ratios, the threshold of serum IgG1 concentration for optimal health and performance of calves was higher than values reported previously. Implementation and maintenance of management and intervention strategies designed for early detection and treatment of calves at risk for failure of passive transfer will likely result in increases in preweaning health and performance parameters.