What protein level will maximise your profits

by 5m Editor
24 June 2005, at 12:00am

By Marcus Kenny, Carolyne Kemp and Colin Fisher, Aviagen - This article by Aviagen explains the need for varying dietary protein in order to maximise profits in a broiler operation.

What protein level will maximise your profits - By Marcus Kenny, Carolyne Kemp and Colin Fisher, Aviagen - This article by Aviagen International explains the need for varying dietary protein in order to maximise profits in a broiler operation. Aviagen

Aviagen publish nutrient density recommendations for diets fed to broilers in the starter, grower & finisher period (Table 1), with the comment that the nutrient levels need to be adjusted to maximise profitability under local conditions.

It is now widely accepted that the choice of dietary protein level is an economic decision to be made for each company or enterprise. This idea replaces the concept that birds have characteristic ‘requirements’ which should be met under all conditions.

The effect of dietary protein level on biological performance

Results from a recent Aviagen trial demonstrated the effect of increasing protein levels in the diet on Ross 308 male growth and FCR to 41 days of age and were consistent with previous trials and field experience. The control treatment was formulated to meet the current Ross 308 recommendations while the protein level in the trial treatment was formulated to achieve 85% of the control diet level.

In this article, protein refers to available amino acids and all trial diets were designed to provide different levels of balanced protein using the ideal amino acid profile as per the recommendations published in the Ross Broiler Manual (2002). It can be clearly seen from Figure 1 that bodyweight and FCR improve significantly as protein levels are increased. A lower dietary protein also affects white (breast) and dark (leg) meat yield. This effect is shown in Figure 2.

However, a lower protein level in the diet will be a cheaper formulation, so the effect on the overall financial performance of the flock needs to be assessed. Table 2 shows the margin per bird after feed cost for each diet. Although feed price has been reduced on the lower (85%) protein diet the margin is significantly reduced. Even in a situation where feed prices increase by 10%, the reduced protein treatment results in a lower margin than the control diet.

The balanced protein calculator

The example above demonstrates the impact of two very different levels of protein but does not indicate what level of protein optimises margin. To identify this, Aviagen have developed the Balanced Protein Calculator. This calculator is a tool which combines feed and revenue prices with broiler biological response data to establish the dietary amino acid level that maximises profit for different objectives e.g. farm versus eviscerated carcase margin. The biological response data is derived from a compilation of Aviagen amino acid response trials.

The calculation of an optimum balanced protein level involves several inputs (Figure 3) Feed cost at different protein levels is determined by conventional leastcost feed formulation based on relevant raw material costs. Costs of broiler rearing and processing are also used. Broiler performance at each protein level is then determined from response curves established from trial data and the revenue from different types of end product and costs are identified. These elements are then combined to calculate the profit for each level of balanced protein.

Biological response data

The most important part of the Balanced Protein Calculator is the set of biological response data. The data has been obtained by evaluating the amino acid response of the Ross 308 broiler in an ongoing series of trials between 2002 and 2004. In total 72 responses have been identified.

Calculating bird response

To combine the data from different trials all data were expressed relative to this treatment for the definition of bird response to protein. Slaughter weights of 1.7kg, 2.0kg. 2.5kg and 3.0kg for males and females separately were considered in the analysis.

Calculating costs, revenue and optimum amino acid level for an enterprise

Feed costs were calculated for protein levels of 70% to 130% of the Ross manual recommendation. Other costs such as chick cost and processing costs were also taken into consideration. The calculation of profit requires data for the various sources of income accruing to the enterprise; the value of live birds (per kg), of eviscerated carcass (per kg) and of portions.

Calculating the optimum amino acid level

The output from the calculation is a plot of profit against relative protein level and an example of farm growing margin is shown in Figure 4. In the example, feed cost data were based on ingredient prices in Asia for the range of dietary protein levels. Revenues were estimated at 0.75 USD per kg live weight, 1.25 USD per kg eviscerated carcass, 1.80 USD per kg breast meat and 2.05 USD per kg for leg meat. Estimated costs for chicks, broiler grower overheads and processing were constant for all protein levels.

The optimum amino acid level for maximum profit can also be calculated for eviscerated carcass and processed portions. Table 3 summarises this data for males, females and as hatched birds grown to 3kg. The optimal amino acid density for as hatched farm margin is 96% of the current Ross manual recommendations but for as hatched, portioned birds optimum margin is achieved at 106% amino acid density. As you would expect, the level of dietary protein most profitable, increases as additional sources of revenue are brought into consideration.

The responsiveness of the Ross broiler to increased amino acids explains why the optimal amino acid density for portions products is higher than that for farm margin. An additional factor influencing this economic response is the high liveability of the Ross broiler. The Aviagen pedigree selection process has minimised the incidence of metabolic related diseases even at high growth rates, hence feeding higher levels of nutrients to the Ross bird will not compromise liveability. Figure 5 below shows the liveability of Ross as hatched birds to increasing levels of protein and demonstrates that feeding the Ross bird for optimal performance does not compromise the welfare of the bird.

The cost of optimal amino acid density on financial performance

Using the Balanced Protein Calculator, can therefore provide information on the level of dietary amino acids most appropriate to meet the production objectives of the organisation As can be seen from Table 4, the difference in margin can be significant especially for an operation portioning product. For an operation producing 1 million broilers per week, profitability can be considerably enhanced by increasing dietary protein levels to 106% of those recommended in the Ross manual as seen in table 5.


  • The optimal amino acid density depends on the objectives of the organisation.

  • Aviagen have collated a unique set of biological response data showing how the Ross broiler responds to inputs of balanced amino acids.

  • The Balanced Protein Calculator combines biological response data with feed and revenue prices to identify the optimal dietary amino acid level to maximise farm, eviscerated and portions margin.

  • Maximum farm margin will be achieved at current Ross recommendations.

  • Maximum margins in companies deboning a large proportion of product will be achieved when higher levels of dietary amino acids are fed.

  • The excellent liveability of the Ross broiler allows profitability to be maximised without compromising welfare.

Source: Aviagen - June 2005