By Andrew Fothergill, National Poultry Advisor at ForFarmers

“First, let’s consider what we measure as Feed Conversion Ratio (FCR) – in most commercial situations, it’s the tonnes of feed delivered into the growing houses, divided by the live weight of broilers weighed off the farm or into the processing factory.

But this isn’t always a reflection of the efficiency of the conversion of feed into saleable meat.

Other factors can impact this assessment, such as feed wastage from feeder design and management or issues with product quality, or a combination of both.

Health challenges can also impact FCR – either the efficient utilisation of feed or mortality, in the worst case, as feed consumed and converted into live weight is not realised as saleable product.

FCR is also vulnerable to the clearance of birds from farms.

Practices such as planned thinnings should be borne in mind, considering the need to raise house furniture, overall disturbance of the catching process, and worse still, multiple catching from flocks when market conditions are volatile.

Each catching activity can erode the potential FCR outcome.

Where to start with a strategy to optimise FCR?

Let’s begin by considering the value of FCR in a scenario where there are no outside influences, a feeding strategy to optimise returns.

Broiler chickens are generally predictable in their response to nutrient density, albeit this is a learned activity and improves with age.

If we consider the grow-out period as a whole, without getting lost in the finer detail of age-related individual nutrient responses, feed consumption generally falls as balanced diet density increases.

Birds reduce their total consumption in response to increasing diet density, where their perceived requirement of calories, protein and other nutrients can be satisfied at lower daily intake.

Thus reducing daily intake at a constant daily gain and improving FCR.

Over a range of diet densities that allow “normal” growth and development, using conventional feed ingredients, this response is initially virtually linear but will plateau at the highest achievable density.

The cost increments of formulations increasing in density are exponential.

As each progressive increment is made, usually on the basis of dietary energy with other nutrients maintained at a fixed ratio, the stepwise increases become increasingly costly.

The outcome in terms of financial cost efficiency is demonstrated below.

Initially, the improvement in FCR is financially rewarding in terms of feed cost per kg of live weight gain, until such a point whereby the incremental feed cost outweighs the benefit of reduced consumption per unit gain.

Based on this, our approach with the ForFarmers Apollo diets is to formulate to a density that delivers the lowest cost per kg live weight return.

Considering the real world in which we operate, and if we accept that scoring a “bullseye” every time is unlikely, we have a choice of aiming left or right of the bullseye.

To aim left is to reduce input costs but risk any drift in performance for whatever reason to erode returns, whereas to aim right will give some assurance of always playing in the most rewarding area of the economic returns field.

What about when feed costs rise due to rising raw material costs?

Indeed, producers should resist the temptation to reduce diet density to reduce input costs.

As feed costs rise, the value of low FCR becomes even more rewarding, with the differential between good and poor FCR returning even greater rewards.

FCR must be a focus to maintain as low as possible when feed raw material markets rise.

What is the relationship between FCR and growth rate?

Much of the improvement in FCR in modern broiler production is captured by exploiting daily live weight gain potential.

On any given day, a broiler chicken has maintenance “overheads” to carry, and the more growth we can achieve per day by taking advantage of these existing nutrient costs, the more efficient will be the outcome.

As long as a balanced diet has been provided, live weight and FCR outcomes are generally hand-in-hand of one another.

Given the value of broiler liveweight over feed cost, it is imperative that maximum growth potential is supported at the lowest cost per kg of gain by using a diet formulated to deliver both outcomes.

Consider the kilogrammes of live weight revenue produced from one tonne of feed at differing FCR outcomes – a relatively small difference can deliver a significant financial impact.

It is apparent that the economics of broiler production require growth potential to be maximised and feed nutrient density optimised to the lowest unit cost per kg of gain.