Effects of Bovine Viral Diarrhea Virus (BVDV) Persistently Infected (PI) Calves in the Feedyard and Management of PI Calves after Initial Identification
BVD Control; The Future is Now January 31, 2006 Denver, Colo.

Bill Hessman DVM

Field Trials
Trial 1 Feedyard close-out performance comparing PI pens and Non-PI pens ( Oct. 2003) Trial 2 Starter yard close-out performance comparing differing PI exposure levels. (July 2004)

Trial 1

Oct. 2003 June 2004 Prevalence, Morbidity, Mortality and Performance Southeastern, sale barn origin 5 Buyers

1 pen removed from study

PI and Non-PI groups 2284 head in 24 pens IHC tested at arrival

Results

Prevalence Rate

.31% (7 PI animals)

Pen Prevalence Rate
19 Non-PI pens, 5 PI pens 21% (5 of 24 pens placed had at least 1 PI)

2 pens had 2 PI animals

5 of 7 PIs survived to slaughter (71 %) 3 of 7 PIs required antibiotic therapy (43 %)

Results (cont.)

# Head Pens Wt In Wt Out Deads In Wt Gain DOF ADG Consump Dry F/G Deads In COG Deads In

NPI PI

1731 553

571 574

976 931

405 357.04

180 177.58

2.25 2.00.07

14.02 13.75.53

6.26 6.94.02

.691.767.05

P -value

% Morb. NPI PI

p-VALUE

1st Relapse Rate 46.0 43.7
2nd Relapse Rate 55.4 54.8

# of Tx 1.72 1.68

Med. Cost Per Head 25.40 23.10

% Mort. 6.96 10.37

% Railers 6.34 6.39

49.52 42.31

Mortality by DOF

< 31 DOF

% % DIFF

< 61 DOF

< 91 DOF

< 121 DOF

< 151 DOF

Close Out

9.23 5.03

9.91 5.88

10.0 6.43

10.1 6.68

10.3 6.90

NPI 2.03

Effect of PI on BRD mortality versus No PI: Days on Feed
553 cattle with PI exposure 1731 cattle with no PI exposure
31 DOF : 61 DOF : 91 DOF : 121 DOF : 151 DOF : Closeout : P<0.0001 P=0.0007 P=0.0008 P=0.0022 P=0.0027 P=0.0019

Trial 2

Evaluate the Effects of Persistent Infection with BVDV on Morbidity, Mortality and Performance in High Risk Feedlot Cattle.

Investigators

Bill Hessman DVM Dave Sjeklocha DVM Tim Murphy PhD Robert Fulton DVM, PhD Julia Ridpath PhD Mark Payton PhD

Cattle Empire Trial

Starter Phase (60 days)
July 1, 2004 New Starter yard (10,000 head) 5 cwt Southeastern sale barn origin Limit fed Not implanted

Testing and Confirmation

Tested 21,743 head in 240 pens BVD PI test by Antigen Capture Elisa by ear notch on arrival by Haskell County Animal Hospital, Sublette, Ks.
Positive tests confirmed by Dr. Fulton at OSU
Ag Capture IHC PCR VI Viruses subtyped by sequencing of 5 UTR at USDA

(Ridpath)

Processing

On arrival

5-way viral (MLV BHV 1, PI3, BRSV, killed BVD 1a

and BVD 2a)

Mannheimia and Pasteurella
Dewormer Clostridial Metaphylactic Injection Individual Identification and weighed

Re-vaccination (day 10)

5-way viral (MLV BHV 1, PI3, BRSV, BVD 1a and 2a)
Treatment Group Classification
PI animal at arrival and left in pen
PI animal at arrival and removed to quarantine pen
No PI animal at arrival, placed next to a PI pen

NPIER

No PI animal at arrival, placed next to a PIR pen
No PI animal at arrival and remained totally unexposed
Trial 2: Evaluate the Effects of Persistent Infection with BVDV on Morbidity, Mortality and Performance in High Risk Feedlot Cattle: Performance Weight Gain Feed Gain Dry M Average Daily Gain Cost of Gain Morbidity % # 1st Pulls # 2nd Pulls Relapse rate 1st # 3rd Pulls Relapse rate 2nd # 4th Pulls Relapse rate 3rd Railer % Mortality % Treatment cost # treatments

Cattle Empire BVD Trial

ALLEY 1-LEAVE PIS IN ALLEY 2-REMOVE PIS ALLEY 3-REMOVE PIS
PI PENS NPIE PENS PIR PENS NPIER PENS NPIU PENS QUARANTINE PENS

PI Animal Removal

Ag Capture test ran daily Positive animals pulled from pen within 48 hrs of processing for re-sampling. Positives in alley 1 (PI) returned to pen. Positives in alleys 2 & 3 (PIR) removed to quarantine.
Follow-up samples for Dr. Fulton
Notch in PBS Notch in formalin Serum samples Nasal swabs
Animals in quarantine were not re-vaccinated or treated for health issues.

Quarantine Pens

Analysis
21,743 animals tested in 240 pens/lots Analysis based on: Pens with majority of DOF at highest risk 214 pens with 19,336 head eligible for analysis Outliers removed (COG deads in outcome) 207 pens with 18,765 head eligible for analysis Pens with no status change throughout starter phase 167 pens with 15,348 head eligible for analysis Outliers removed (COG deads in outcome) 163 pens with 15,058 head eligible for analysis

Statistical analysis

Analysis of variance procedures conducted on all response variables using PROC MIXED in PC SAS Versions 9. Pairwise t-tests(LSMEANS) statement with DIFF option to determine differences in status. Significance level of 0.05 was used for all comparisons

Ineligibility

Pens removed from analysis
One lot of cattle placed in 2 pens with different status
Feedyard close-out data based on lot
Missing sample at processing
Dead on truck and not tested
2 loads for 1 lot arriving at different date with PI in last load.

PI Prevalence Rate

88 Antigen Capture positives at HCAH
2 animals subsequently found to be acutely infected 86 true PIs of 21,743

Prevalence rate of.40%

74 pens PI positive 67 pens PI positive

(240 pens tested)

Positive pen rate of 31%
(pens with no status change and outliers removed)

Positive pen rate of 41%

PI Survival Rate
22/86 (25.6%) Died during starter phase

Cause of death

14/22 (64%) 6/22 (27%) 1/22 (4.5%) 1/22 (4.5%) Mucosal Disease Respiratory Other Bloat
4/37 (10.8%) Railed from PI pens-starter phase 43/86 (50%) Survival Rate - Sold to slaughter or railed light

PI Virus Subtypes

BVDV 1b BVDV 1a BVDV 2 77.9% 11.6% 10.5%
Results Performance Summary
PENS WITH NO STATUS CHANGE

OUTLIERS REMOVED

STATUS PI PIR NPIE NPIER NPIU

PENS 63

WT GAIN D IN 78 c 87 bc 93 bc 105 ab 111 a
F/G DRY D IN 11.02 a 8.27 ab 7.27 b 6.57 b 6.44 b
ADG D IN 1.25 c 1.36 bc 1.49 ab 1.61 a 1.65 a
COG D IN 1.63 a 1.22 ab 1.02 b 0.91 b 0.89 b

Results Health Summary

MORB % 34.0 ab 36.0 a 29.2 bc 24.8 c 28.5 bc

RELAPSE RATE

RAIL % 4.5 a 4.7 a 3.6 ab 2.7 b 2.7 b
MORT % 3.5 a 2.9 a 2.4 ab 1.3 b 1.6 b
TX $ / HD 16.80 a 15.84 a 16.45 a 14.30 a 15.46 a
AVG # OF TXS 1.79 a 1.73 a 1.72 a 1.58 a 1.65 a
46% a 43% ab 45% ab 35% c 39% bc
PI vs PIR and NPIE vs NPIER
Performance Outcomes Pens with no status change and outliers removed
WT. OUT PENS D IN PI PIR P-value 0.96 WT. OUT PENS D IN NPIE NPIER P-value 0.39
WT. GAIN/HD D IN 0.18 WT. GAIN/HD D IN 0.27
F/G D IN 11.02 8.27 0.06 F/G D IN 7.27 6.57 0.74
ADG D IN 1.25 1.36 0.2 ADG D IN 1.49 1.61 0.3
COG D IN 1.63 1.22 0.07 COG D IN 1.02 0.91 0.73
Health Outcomes Pens with no status change and outliers removed
MORB % PI PIR Pvalue 33.6 36.1 0.4 1ST RELAPSE 0.6 2ND RELAPSE 0.06 3RD RELAPSE 0.06 RAIL % 4.52 4.74 0.8 MORT % 3.52 2.92 0.29 TX COST 16.80 15.84 0.39 AVG # OF TXS 1.79 1.73 0.32
MORB % NPIE NPIER P-value 29.2 24.8 0.32
1ST RELAPSE 45.3 35.1 0.03

2ND RELAPSE 0.66

3RD RELAPSE 30.4 23.6 0.48

RAIL % 3.58 2.68 0.45

MORT % 2.38 1.27 0.18

TX COST 16.45 14.30 0.19

AVG # OF TXS 1.72 1.58 0.13

Biologic Groups

Performance Outcomes
Pens with no status change and outliers removed
WT GAIN D IN 83 93.09 F/G D IN 9.72 7.74.17 ADG D IN 1.33 1.44.11 COG D IN 1.42 1.12.18
TREATMENT GROUP PI & NPIE PIR & NPIER P-VALUE

PENS 49 51

Health Outcomes
1ST RELAPSE % 46 41.03 TX COST /HD PLACED 16.68 15.36.11
TREATMENT GROUP PI & NPIE PIR & NPIER P - VALUE

MORB % 32 33.73

RAIL % 4.2 4.1.63

MORT % 3.1 2.4.09

# OF TXS 1.77 1.68.07
In-contact Pen Exposure Effect
(fence vs. water tank exposure)
Fence vs Water Tank Exposure
TREANMENT GROUP FENCE WATER TANK P - VALUE

PENS 5 7

WT GAIN D IN 99 89.53

F/G D IN 7.18 7.55.73

ADG D IN 1.49 1.42.66

COG D IN 0.951 1.097.38

TREATMENT GROUP MORB % BRD MORB % 1ST RELAPSE % RAIL % MORT % BRD MORT % TX COST /HD PLACED AVG # OF TXS
FENCE WATER TANK P - VALUE

24.91 32.45.41

23.37 32.45.32

41.5 48.3.41

2.37 3.64.51

2.90 2.39.68

1.73 2.26.62

14.72 17.40.34

1.68 1.74.70

Economic Analysis

Based on purchase costs, production costs and mortality differences.

Trial 1

Cost/head in PI pens

$47.43

Trial 2
Cost/head in exposed population

$67.49

Cost/head in total population

$41.17

ADDED VALUE?