OPTIMISING FEED CONVERSION RATIO
In a country constantly under pressure from cheap imports and high feed prices, it’s no surprise that feed conversion (FCR) always stays a focus point. FCR can be calculated with different equations. We need to be aware of the differences between the equations, as well as the real meaning of the different constituents used in the equations.
FCR = Feed consumed ÷ growth = kg feed/kg growth.
Feed consumed is the actual feed intake of the birds over a specific period and growth the actual growth (gain in live weight) measured over the same period.
FCR = Feed used ÷ live weight = kg feed/kg live weight.
Feed used is the difference between feed delivered and feed in stock at the end of the growing cycle and live weight is mostly the average weight of the birds (empty crop) delivered at the abattoir.
It’s important to realise that feed used includes feed consumed, feed wastage and even perhaps theft, while growth is mostly measured as the increase in live weight, weighing birds with full crops compared to the empty crop live weight as received at the abattoir.
It’s always good to use breed standard as a benchmark although many producers don’t want to refer to the breed standards. Keep in mind that the breed standard FCR is calculated as a combination of the scientific and commercial equation, with feed intake (not feed used) and live weight being used. The live weight used is full crop and this calculation also does not take into account any mortality. The live weight used as a divider is close to genetic potential of the bird and all of the above result in a fairly low FCR compared to commercial figures. The important aspect is however the trend as can be seen in Figure 1 that clearly shows FCR is getting worse as the birds get older.
Optimum FCR will have a different meaning for different people. For some it might be the lowest FCR possible and for others it might be the FCR where feed