Serologic response to Mannheimia haemolytica in calves concurrently inoculated with inactivated or modified-live preparations of M. haemolytica and viral combination vaccines containing modified-live bovine herpesvirus type 1.

OBJECTIVE: To assess the serologic response of calves to inactivated and modified-live (ML) Mannheimia haemolytica (MH) preparations given alone and concurrently with combination viral vaccines containing ML bovine herpesvirus type 1 (BHV-1). ANIMALS: 642 calves seronegative for BHV-1. PROCEDURES: In experiment 1, 192 calves received 1 of 3 MH preparations alone or concurrently received 1 of 3 MH preparations and 1 of 4 combination viral vaccines. In experiment 2, 450 calves received 1 of 4 MH preparations alone or concurrently received 1 of 4 MH preparations and 1 of 5 combination viral vaccines. Pretreatment and posttreatment blood samples were processed to obtain serum, which was analyzed to detect concentrations of antibodies against MH leukotoxin and BHV-1. RESULTS: In experiment 1, antibody titers against MH leukotoxin in calves receiving MH and ML virus vaccine appeared decreased, albeit nonsignificantly, compared with titers for calves receiving MH preparations alone. In experiment 2, all groups (except for 1) concurrently receiving an MH preparation and viral vaccine had a significant decrease in antibodies against MH leukotoxin. In both experiments, there was a significant decrease in the number of calves responding to MH leukotoxin when ML viral vaccine was coadministered. CONCLUSIONS AND CLINICAL RELEVANCE: Coadministration of ML BHV-1 and MH preparations interfered with the serologic response to MH leukotoxin in calves seronegative for BHV-1. Serologic response to MH leukotoxin may be substantially improved in seronegative calves when MH vaccination is delayed until after calves have received a dose of ML BHV-1 vaccine.

Effect of management, marketing, and certified health programs on the sale price of beef calves sold through a livestock video auction service from 1995 through 2009.

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.

Effect of certified health programs on the sale price of beef calves marketed through a livestock videotape auction service from 1995 through 2005.

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.