The economic impact of BVD on zootechnical and production ... · Outline of the presentation ....

UMR1300 Biology, epidemiology and risk analysis

in animal health

Oniris – INRA, Nantes, France

Christine Fourichon

The economic impact of BVD

on zootechnical and production results

in dairy and beef operations

BVD expert panel

Leuvenum, May 18, 2016

Variable consequences of BVDV infection

Quantification of production effects in dairy herds

Estimation of direct costs in dairy herds

Estimation of direct costs in beef herds

Effect of vaccination in beef herds

Further questions

Outline of the presentation

Virus introduction in a naïve herd

• All animals are susceptible

• Spread of the virus depends on:

Herd characteristics

Type of virus introduction

Control measures

Chance!

=> From undetected to acute case

Long-lasting infection

• Duration of persistence of the virus in a herd

• Risk of re-introduction of the virus

Variable consequences of BVDV infection in a herd

Possible issues after virus introduction in a herd

Decrease in herd

performance

Clinical signs : BVD +

other diseases

Virus spread in the herd

Virus introduction

Treatments

Economic consequences at

the farm level

From undetected

infection to severe case

Depends on farm

characteristics

=> High variability

Variable consequences of BVDV infection in a herd

Quantification of production effects in a dairy herd

Case studies

• Clinical case (farm with diseased animals detected)

• Example of one farm in Brittany

40 dairy cows, 290,000 litres milk quota, beef cows

Before 2000: high health status, no history of BVD

In 2000: suddenly high incidence of diseases and

impaired performance

Abortions

Retained placenta

Poor reproduction (delayed heat, AI return)

Mastitis

Low milk yield

Poor growth in heifers


Field survey: results in Brittany

• Performance data: milk recording & AI

• BVD data

6000 to 7000 herds

systematic antibody testing

in bulk-tank milk

every 6 months

=> herd status

BVD Herd status: repeated ELISA on bulk-milk

An

tib

od

ies a

nti

-BV

DV

4 results with high antibodies

time

Increase of

antibodies

4 results with low antibodies

Steady very high

=> persistent virus

circulation

Steady high =>

past important

virus circulation

Seroconversion =>

recent infection

Steady low => free

of infection



Average effect on reproduction

Herd BVD Status

(antibodies in bulk

tank milk)

AI returns at 3

weeks

Late AI returns

Seroconversion No effect + 12%

Steady very high Ab No effect + 11%

Steady high Ab No effect + 3%

Late AI return => embryo or foetal loss

AI return at 3 weeks => failure to conceive

Interval between 2 consecutive AI (in days)

Dis

trib

uti

on

of

AI re

turn

s (

%)

19 25 26

1 2 3 4 5 6 7 8

0


Average effect on milk yield

Herd BVD Status

(antibodies in bulk

tank milk)

In the current

year

In the following

year

Seroconversion No effect - 0.3 kg / d

Steady very high Ab - 0.6 kg / d - 0.6 kg / d

Steady high Ab - 0.4 kg / d - 0.4 kg / d


Average effect on milk somatic cell counts

Herd BVD Status

(antibodies in bulk

tank milk)

In the current

year

In the following

year

Seroconversion + 6 000 + 12 000

Steady very high Ab + 27 000 + 25 000

Steady high Ab + 12 000 + 14 000


Average effect on incidence of clinical cases (literature)

• Calf diseases: x 2 to x 4

• Calf mortality (after 2 days): +35%

• Stillbirths and abortions: x 2 to x 3

• Retained placenta: +6% (+38% in dams with a PI calf)

• Clinical mastitis: +4% to +11%

Estimation of direct costs in a dairy herd

Description of the dairy herd for cost calculations

• Reference herd 40 cows, heifers, calves 7200 kg milk / cow-year 290,000 litres quota

• Severity of infection and production effects of BVDV

Population approach in herds with recent virus spread evidenced by bulk-milk antibody testing: “Average effect” herd => average estimates of effects “High effect” herd => 95% CI limit or high estimates

of effects

Case approach: “acute case herd“ with virus isolated => performance after / before

Disease and production effects (40-cow herd)

Reproduction

Abortion (case)

AI return (%)

Delayed 1st AI (%)

Other cow diseases

Clinical mastitis (case)

Subclinical mast: SCC (M/ml)

Retained placenta (case)

Milk yield (total litres)

Calf and heifer diseases

Death (case)

Treatments (case)

Infected - Infected - Acute

average effect high effect case

+ 6

+ 14

+ 19

+ 22

+ 100

-

-25 000

+ 8 (PI)

-

+ 2

+ 4

-

+ 5

+ 42

+ 4

-16 000

+ 8

+ 12

+ 1

+ 2.2

-

+ 3

+ 27

+ 1

-8 500

+ 5

+ 8


Partial budgeting

• Summing up all production effects:

Direct effect on gross margin

Indirect relationship with gross margin

• Consequences on:

revenues

production costs

• Differences between:

reference herd

BVDV positive herd

• Time-period: one year


Decreased revenues

Increased costs

Increased revenues

Decreased costs

Unfavourable differences Favourable differences


Partial budgeting

• Differences case / reference

Dead calves

Calves

-

Clinical mastitis

Decreased

milk yield Total herd milk yield

Calves

+ -

-

Clinical mastitis

Decreased

milk yield

Discarded

milk

Total herd milk yield

Calves

+

+

-

-

-

Clinical mastitis

Decreased

milk yield

Discarded

milk


Calves

Milk replacer

+

+

-

-

-

-

Increased SCC

Decreased

milk yield

Discarded

milk


Calves

Milk replacer

+

+

-

-

-

-

Increased SCC

Penalties

Decreased

milk yield

Discarded

milk

Milk price


Calves

Milk replacer

+

+

+

-

-

-

-

-

Increased SCC

Penalties

Decreased

milk yield

Discarded

milk

Culling

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

-

-

-

-

-

+

-

-/+

Cull cows sales

+

Increased SCC

Penalties

Decreased

milk yield

Discarded

milk

Culling

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

-

-

-

-

-

+

-

-/+

Cull cows sales

+

Replacement

Increased SCC

Penalties

Decreased

milk yield

Discarded

milk

Culling

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

-

-

-

-

-

-

+ +

-

-/+

Cull cows sales

+

Replacement

AI return

(embryonic or

fetal death)

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

+ +

-

-/+

Cull cows sales

+

Replacement

AI return

(embryonic or

fetal death)

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

-/+

Cull cows sales

+

Replacement

Abortion

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

-/+

Cull cows sales

+

Replacement

Retained

placenta

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

-/+

Cull cows sales

+

Replacement

Overall effects

of BVDV infection

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

-/+

Cull cows sales

+

Replacement

REVENUES

Overall effects

of BVDV infection

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

Variable costs +

Concentrates

-

-/+

Cull cows sales

+

Replacement

COSTS

Opportunity

costs

• Milk price

• Milk sales (lower herd milk yield)

• Calves sold (death, calving int.)

• Carcass value

• Opportunity cost: Margin / ha land for extra

replacement heifers

Unfavourable differences Favorable differences

• Treatments of calves and cows

• Milk replacer

• Inseminations

• Variable costs for extra replacement

heifers (identification, concentrates,

forage, insemination, basic veterinary

costs, ...)

• Calves sold (replacement)

• Culled cows (SCC, reproductive failure,…)

• Milk replacer (discarded milk)

• Reduced feeding costs for calves

• Reduced feeding costs for cows (less milk)

R-

C+ C-

R+


Overall effects

of BVDV infection

Penalties

Decreased

milk yield

Discarded

milk

Culling

Calving to

conception int.

Carcass

weight and price

Milk price


Calves

Milk replacer

+

+

+

+

+

-

-

-

-

-

-

-

+ +

-

-

Variable costs +

-/+

Cull cows sales

+

Replacement

Opportunity

costs

Number of cows

+

+

Heifers

+ +

QUOTA

• Milk price

• Milk sales (lower herd milk yield)

• Calves sold (death, calving int.)

• Carcass value


replacement heifers


heifers and cows to produce the quota

Unfavourable differences Favorable differences

• Treatments of calves and cows

• Milk replacer

• Inseminations

• Variable costs for extra replacement

heifers (identification, concentrates,

forage, insemination, basic veterinary

costs, ...)

• Variable costs for extra heifers and cows

to produce the quota

• Calves sold (replacement)

• Culled cows (SCC, reproductive failure,…)

• Culled cows and calves sold due to

increased herd size to produce the quota

• Milk replacer (discarded milk)

• Reduced feeding costs for calves

• Reduced feeding costs for cows (less milk)

R-

C+ C-

R+


Economic consequences: reduced gross margin

Average High Acute case effect herd effect herd herd

Total costs Production below quota in €/1000 litres of milk 11 19 39 for the farm 3,100 5,300 11,500


• Production equal to quota

in €/1000 litres of milk 8 14 -

for the farm 2,200 4,000 -

Economic consequences: reduced gross margin

Average High Acute case effect herd effect herd herd

In EUR/1000 litres of milk Production below quota Total costs 11 19 39



Total costs 8 14 -

Compared to other diseases in a sample of 205 farms

In EUR/1000 litres of milk


Total costs of production diseases 32

Total costs of mastitis 11

Reduced farm income -15% -25% -50%


Partial budgeting

• Underlying assumptions of the method used

“stable” situations (at least one-year effect)

some effects underestimated (e.g. heifer death)

no major impairment of farm management

Description of variability of possible consequences

• Simulation approach

distribution of production effects

different virus spread

farm characteristics

consider quota (30% variation)

Estimation of direct costs in a beef herd

Beef cattle farms

Production effects

– Known effects • Abortion

• Mortality of PI calves

• Respiratory diseases

– Scarce data to quantify these effects

Consequences on income

– Production effects directly reduce the income

– Seasonal calving => spread and impact can vary widely

– Flexibility of the farming system varies a lot


Beef cattle farms

Simulation approach

– Farming system • Herd size, breed, specialized

• Age at which males and females are sold

• Calving season

– Epidemiological situation • Herd naïve or not

• Introduction of the virus (type and number of animals)

– Control strategy


Beef cattle farms

Simulation approach

– Example • 90 cows, Charolais, specialized

• Naïve herd

• 1 pregnant dam with a PI calf is bought

• No control strategy


Beef cattle farms

Persistence of the virus in the herd


Beef cattle farms

Prevalence of PIs and dams with PIs

Dam with PI fetus

PI


Beef cattle farms

Production losses

PI mortality

abortions


Beef cattle farms

Direct costs


Beef cattle farms

Persistence of the virus in the herd with vaccination

Further questions

Beef and dairy cattle farms

Other scenarios (farming systems, reintroduction, date of introduction, …)

Vaccinated herds

Reduction of production effects other than mortality and abortion in infected animals

Herd immunity

Compliance

Indirect costs

Possible trade restrictions

Price of live animals

Conclusion

Direct economic consequences of BVD in dairy farms

• around 10 to 20 EUR/1000 litres on gross margin in

infected herds (most often undetected)

• Up to 4 times higher in acute case herds

• Comparable to average costs of mastitis

• High / other sources of variation of gross margin

Direct economic consequences of BVD in beef farms

• 4000 € in 5 years in a newly infected naïve herd

• Up to 20 000 € in 5 years in worse case scenarios

Leuvenum, May 18, 2016

Thanks

for your attention! …

Questions?

[email protected]

The economic impact of BVD on zootechnical and production ... · Outline of the presentation ....

Documents

Transcript of The economic impact of BVD on zootechnical and production ... · Outline of the presentation ....