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Health and productivity - 'Disease control is king'

'Disease control is king' and 'Pigs are precious' were two of the remarks made by John Dean, professor at Minnesota State University at a recent conference in Rovereto, N. Italy. Analysis of the major components of production profitability variation were the CDL group (culls, deads and lightweights) which accounted for 55%, followed by feed conversion efficiency (FCE) at 28% and finally average daily (ADG) gain, 17%.

'Disease control is king' and 'Pigs are precious' were two of the remarks made by John Dean, Professor at Minnesota State University at a recent conference in Rovereto, North Italy. Analysis of the major components of production profitability variation were the CDL group (culls, deads and lightweights) which accounted for 55%, followed by feed conversion efficiency (FCE) at 28% and finally average daily (ADG) gain 17%.

Even in the face of high feed prices, the amount of kilogrammes of good quality meat that goes out of the finishing shed is the most critical component production-wise. One could say 'Kilos are King'.

The most damaging effect on productivity and profitability is disease. I have seen producers increase the pig size from 100 to 120 kg to try to compensate for a nearly 20% mortality, cull and lightweight scenario, following chronic porcine circovirus type 2 (PCV2) infection.

It also follows on from my previous weblog, where some countries have a 30-35% mortality/ cull problem from a combination of diseases.

Difficult
Attributing the effect of a particular disease to an individual herd and its performance is difficult. It depends on a number of factors such as housing, management, hygiene and immune status of the herd, which consequently affects the challenge of the infection and the severity of the expression of the disease. Multiple infections are even harder.

In a very recent report from Denmark (Nielsen and others, 2008), they surveyed 74 case farms with recent clinical PCV2 infections or typical post-weaning multisystemic wasting disease (PMWS) and 74 which did not, as controls (see Table 1).

Table 1. Case control study of PMWS on 148 farms in Denmark

 

Case herds (+PMWS)

Control herds

Difference

Weaner mortality (%)

11.2

3.1

8.1

Weaner ADG (g)

392

428

-36

Finisher mortality (%)

5.2

3.2

2.0

Finisher ADG (g)

777

829

-52


The higher weaner mortality in the early stages is expected, especially in the early stages of breakdown, as well as in the finishers, but the level of reduced growth rate of 52 g in the finishers was probably higher than expected but actually has been previously reported as a 5-7 kg/pig drop in liveweight in finishing sheds. This may account for the comments we have had back from the field, 'that we did not know how badly PCV2 was affecting performance until we started vaccinating against it'.

Pig finishing house
So if we take a 1,000 pig finishing house, taking pigs from 25-100 kg in 100 days and the price is €1/kg liveweight, for simplicity. It does not include any variations for poor grading or effects on FCE. Let's look at the impact of some diseases on productivity (see Table 2) as an approximate guide.

Table 2. Effects of various diseases on production efficiency in a finishing house

 

Disease

Mortality/Cull (%)

Growth rate reduction (g)

Batch production value (€)

Efficiency (%)

1

No disease

0

0

100,000

100

2

Non-disease losses

2

0

98,000

98.0

3

PMWS/PCV2*

2

-52

91,008

91.0

4

Enzootic pneumonia

1

-37

93,411

93.4

5

PRRSV

1.2

-37

93,218

93.2

6

PRDC

4.2

-126

81,981

82.0

7

Ileitis

1

-35

93,605

93.6

8

Colitis

0

-30

95,060

95.1

9

Swine dysentery

2

-70

89,280

89.3

10

Mixed enteric infection

3

-135

82,175

82.2


Key: * from Table 1

PRRSV - Porcine reproductive and respiratory syndrome virus
PRDC - Porcine respiratory disease complex - sum of line 3, 4 & 5
Mixed enteric infection - sum of 7, 8 & 9

As the number of diseases or co-infections builds up on a farm, one can see what a dramatic effect those lost kilos can have on production efficiency and profitability.

3 comments

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    Torben Svendsen

    I believe in your data, whereever they come from. They show the importance of receiving good quality 25 kg pigs to your finishing herds - this is the main goal. SPF if possible. Why buy all infections?

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    blonde

    If the herd can build up an immunity then surely a vaccine can be produced to be given to all pigs in all herds to minimise this disease?

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    David Burch

    Hi blonde - there are vaccines for all the above diseases except colitis and swine dysentery caused by Brachyspira bacteria. Vaccines have been produced in the past for B. hyodysenteriae but have never been commercialised due to poor efficacy. Work is on-going in Australia looking to develop more vaccines, but it is difficult to stimulate a local immunity in the gut by just using an injection, which developes a systemic immunity. You need to stimulate an immune response in the gut, like with the ileitis vaccine, using a live attenuated strain. This has not been easy to do with Brachyspira hyodysenteriae yet.

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