One of the advantages of being at the sharp end of the global pig industry for five decades is the amount of farm records you accumulate – 12 drawers in three steel cabinets in my case. From time to time I need to have a clear-out and tend not to keep anything going back more than 25 years back.
The information I have squirreled away since 1990 on the problems of incorrect ventilation was fascinating, so I decided to collect details from some 60 farm visits, quite a few of them comprising before-and-after results; “after” being what happened when the ventilation was improved. I then tapped into information from the literature, conference papers and pig journals. What emerged is set out in Table 1 below.
The results are rather sobering to say the least. Not providing the degree of ventilation that modern sensors, controllers and building design can now get right for you, is insidious and expensive.
Insidious because, even today, once I get out my measuring kit, there are too many farms I visit that are sufficiently “out” on either LCT or ECT for it to have the effect suggested in the table and which the management hadn’t picked up.
Expensive because if you convert the table to an MTF (saleable lean meat per tonne of food fed) figure, it shows that incorrect ventilation alone can cost as much as 30kg MTF (7-105Kg). This is equivalent to a price hike of 20% on every tonne of growout food purchased.
This situation is silly because this degree of underachievement squanders much of the potential of the super genetics we have now.
The most recent three big units I witnessed that had uprated their growers’ ventilation to one of the sophisticated, fully sensored and computer controlled systems now available on the market got a return of 8:1 and a payback of under a year – just three to four batches put through.
On this basis, the new technology is not expensive, even if it may look that way in terms of capital cost when deciding to upgrade to a modern “all-in” system, that handles so many aspects of ventilation throughout a whole year of changes both inside and outside the building.                         Â
| Table 1: The likely cost of poor ventilation on pigs 7-105kg | |||||
| Performance depression from sub-optimal factors | |||||
| LCT or ECT | Appetite | Stress* | Health | Result | |
| Food conversion | 0.10 | 0.10 | 0.05 | 0.20 | 0.45 worse |
| Daily gain (g/day) | 30 | 20 | 10 | 50 | 110g/day slower |
* Difficult to measure, minimal estimate only.
