BRD's Impact On Costs
Just how hard does BRD hit producers' pocketbooks in treatment costs and animal performance? To find out, Iowa State University veterinarians and animal scientists compiled data from 2,146 feedlot cattle in 17 feedlot tests from 1988 to 1997.
The study aimed to determine the impact of BRD on veterinary treatment costs, average daily gain (ADG), carcass traits, mortality and net profit. A second study then identified factors that accurately predict the incidence of BRD.
The Iowa researchers found morbidity caused by BRD was 20.6%. On average, each treatment for BRD cost $12.39; 81% was for drug costs and 19% was for veterinary and feedlot services.
Mortality rate of calves diagnosed and treated for BRD was 5.9% vs. 0.35% for those not diagnosed with BRD. ADG was reduced for treated steers vs. non-treated steers during the first 28 days on feed but did not differ from 28 days to harvest, probably due to compensatory gain.
Net profit was $57.48 lower for treated steers. Of this difference, 82% was due to a combination of mortality and treatment costs. Of the net profit difference, 18% was due to improved performance and carcass value of the non-treated steers. See Figure 1.
The Iowa researchers also determined factors that can help predict the incidence of BRD. Using data from 496 steers and heifers in nine feedlot tests, the effects of age, weaning and use of modified live virus (MLV) or killed vaccines were examined to predict BRD.
Younger calves, non-weaned calves and calves vaccinated with killed vaccines had higher BRD morbidity than those that were older, weaned or MLV-vaccinated, respectively. Moreover, treatment regimes that precluded relapse resulting in re-treatment prevented reduced performance and loss of carcass value.
The researchers concluded that using MLV and weaning calves 30 days prior to shipment can significantly reduce the incidence of BRD.
Disposition scores were also monitored among the animals, but researchers pointed out that the number of animals was limited for this part of the study. Disposition scores did not account for differences in the occurrence of BRD; however, ADG and net profit appeared to be lower for wilder steers than for docile steers.
For more information contact Iowa State's Nolan Hartwig at 515/294-8791 or e-mail [email protected]
Pre-shipping Vs. Arrival
When it comes to health and performance of beef calves received in the feedlot, pre-shipping medication programs are no more effective than arrival medication programs using tilmicosin phosphate. So say researchers at New Mexico State University's Clayton Livestock Research Center.
When the percentage of cattle treated for BRD is low, arrival time is the optimum time to administer medications en masse, researchers say.
In the first of two experiments, researchers treated 96 steers with tilmicosin phosphate (TP) either before shipping, upon arrival or not at all. The percentage of steers treated for BRD decreased for animals treated with TP (control - 71.9%, preshipping - 45.2%, and arrival - 46.9%). The week that calves were treated for BRD differed as well.
In the second experiment, 240 steer and bull calves were treated with or without chlortetracycline, in addition to being treated with TP either before shipping, upon arrival or not at all.
In that experiment, the number of calves treated for BRD decreased for steers treated with TP and for those treated upon arrival (control - 40%, preshipping - 18.7%, and arrival - 7.5%). Averaged across days, serum concentrations of immunoglobulin decreased for steers treated with TP.
Neither of the experiments noted any differences among the treatments in ADG, daily dry matter intake, or gain:feed ratio for the overall receiving period.
For more information contact Glenn Duff at 505/374-2566 or e-mail [email protected]
Vitamin E Advantageous
Supplementing receiving diets with high levels of vitamin E can reduce anti-microbial treatment costs, according to researchers at Oklahoma State University. But, the vitamin E supplements do little to improve ADG and feed conversion, researchers add. (See "Feeder Research" page 6-BF, May 2000 BEEF.)
Researchers fed 694 shipping-stressed calves a common receiving diet of soybean hulls, corn, wheat middlings, cottonseed hulls and a protein supplement containing lasalocid. Feed intake was not restricted and the diet was supplemented with 2000 I.U. of vitamin E for 0, 7, 14 or 28 days.
When animals met specific criteria for morbidity, a regimen of antibiotic drugs was used. Most symptoms occurred within the first seven to 14 days. The percent of calves identified as sick and thus requiring treatment with anti-microbial drugs was 67.8%, 68.3%, 61.8% and 60.3% for 0, 7, 14 and 28 days, respectively.
Medical costs decreased 9.4% and 17.2% for seven and 14 days, respectively. For cattle fed 2000 I.U. of vitamin E for 28 days, anti-microbial treatment costs were reduced by 22.4%. The medical costs (minus the cost of providing 2000 I.U. of vitamin E for 28 days) provided a 38 cents/head savings.
Regardless of dietary treatment, ADG and feed conversion were not improved.
Improved carcass value, which further improves profits, also may be a benefit of vitamin E supplementation, researchers say.
For more information contact Jeff Carter at 405/744-8877 or e-mail [email protected]
BRD And Carcass Quality
The negative effects of BRD extend all the way to carcass quality, according to Oklahoma State University researchers. They found the long-term effects of BRD can cost producers up to $40/head of carcass value 200 days post-backgrounding.
A total of 406 crossbred, sale barn heifers were backgrounded and followed through finishing and harvest. Heifers were categorized by severity of the BRD complex: 0 treatments: "healthy;" one treatment: "mild case;" greater than one treatment: "severe case."
Heifers that had a more severe case of BRD during the backgrounding period had lower ADG - 2.32 lbs., 2.17 lbs. and 1.83 lbs. for healthy, mild and severe cases, respectively.
However, once heifers entered the finishing period, animals with mild or severe cases of BRD during backgrounding actually showed some compensatory gain (2.83 lbs., 2.85 lbs. and 2.90 lbs., respectively, for healthy, mild and severe cases).
While BRD during the background period might not have long-term effects on feeding performance, there were significant differences in carcass traits and overall carcass value, researchers say.
Final live weights and hot carcass weights of heifers tended to be slightly lower due to increased BRD severity.
The biggest long-term effect from BRD during backgrounding was impact on marbling score. This sizeable decrease in marbling score caused a 25% reduction in percent Choice carcasses (66%, 59% and 41%, respectively, for healthy, mild and severe cases of BRD).
This reduction can cost producers money when marketing cattle on a grid. Comparing healthy calves to calves that had a severe BRD case during the backgrounding period on a basic grid, only about a $3/cwt. difference of carcass value was shown.
However, calculating in lower hot carcass weights and medical costs, the margins show a larger spread. When comparing healthy heifers to calves that had a mild case of BRD or to heifers that had a severe case of BRD, net return carcass values were $11.48/head and $37.34/head lower. This is an impact that occurred approximately 200 days post-backgrounding.
The OSU researchers suggest the only real solution to BRD is prevention, such as value-added cattle that have been preconditioned.
For more information contact Don Gill at 405/744-6060 or e-mail [email protected]
Intranasal Is Best
When given only at processing, an intranasal IB R-P13 vaccine may benefit ADG and feed conversion in newly arrived feeder calves, according to researchers at New Mexico State University. But delaying vaccination with a modified live viral vaccine until seven days after arrival offers no advantage, and the modified live vaccine does not negatively affect performance during the first seven days.
In one experiment, calves were given either an intranasal (IN) vaccine, an intramuscular (IM) vaccine or no vaccine (control) at processing. Compared to those given an IM vaccine, calves given the IN vaccine had significantly greater ADG and improved feed conversion.
In another experiment, calves were given either no vaccine at processing and an IM vaccine on day 7, an IN vaccine at processing and an IM vaccine on day 7, an IM vaccine at processing and on day 7, or no vaccines at all (control). For the overall 28-day period, vaccinated calves had improved feed conversion compared to controls. From days 15 to 28, feed conversion improved for calves vaccinated at processing vs. delayed vaccination.
The percent morbidity did not differ among treatments in either experiment.
For more information contact Glenn Duff at 505/374-2566 or e-mail [email protected]
Ear Vs. Neck
Ear injection of a clostridial bacterium toxoid vaccine (Alpha-7) does not appear to influence ADG or rate of growth promotant implant payout, say Kansas State University researchers.
In a 129-day study, 200 previously non-implanted heifers were given one of four treatments: vaccine in left neck and implant in left ear, vaccine in left neck and implant in right ear, vaccine in right ear and implant in left ear, vaccine in right ear and implant in right ear.
Vaccinating in the base of the ear vs. vaccinating in the neck significantly increased ear temperature, but 28-day gains were similar. Weight gains for opposite and same ear placement of vaccine and implant were similar. Regardless of vaccination site, testosterone concentrations in the blood were similar for heifers implanted in the right ear.
For more information, contact Dale Blasi at 785/532-5427 or e-mail [email protected]