Boosting energy metabolism in poultry (and pig) diets

28 September 2020, at 1:27pm

The challenge for everyone involved in poultry production is to feed birds with a balanced diet, at the lowest cost, yet still produce eggs and meat that meet the customers’ requirements and attract premium prices to maximize profit, all while meeting environmental and animal welfare requirements.

Commercial feed manufacturers and farmers have faced this challenge for many years as they seek to reduce the cost of feed without compromising the birds’ productivity. This is an important consideration as feed constitutes the highest variable cost in poultry production, accounting for at least 70% of total production cost.

Energy is already the most expensive nutrient when formulating poultry diets and that is unlikely to change given the stiff competition for available energy sources for human food. This means energy feed ingredients are becoming scarce and expensive for use in poultry production.

The continuous increase in cost of feed ingredients (like maize and wheat) has forced feed manufacturers and farmers to use more by-products of grain milling in their rations. These by-products are highly variable in their nutrient composition and are low in energy density compared to whole grains. This often results in poor feed intake, weight gain, feed conversion ratio (FCR), and general low productivity of the bird.

Thanks to genetic improvements, modern chickens consume less feed per unit of body weight gain and reach their target weight in fewer days than their predecessors. As a result, the level of nutrients needs to be adjusted. The high cost of supplemental energy necessitates the optimization of metabolizable energy (ME) in the diets, especially during finisher period, when feed consumption is at its highest.

Feed intake and feed efficiency in poultry is regulated, at least in part, by ME levels. Fast-growing animals, such as broilers, pigs, and layers, require substantial amounts of energy to grow muscle tissue. All animals get the energy in their cells from adenosine triphosphate (ATP). The amount of ATP in cells is strictly regulated, and it is only available for a short period of time; characterized by a high need in energy.

Creatine plays a key role in energy balance in muscle cells. The system “creatine phosphate/creatine” acts as a buffer, guaranteeing the permanent availability of ATP molecules. Creatine phosphate is a dynamic storage of energy-rich phosphate and ensures a stable supply of ATP/ADP in the cell.

Human athletes take creatine monohydrate as a dietary supplement to support their energy metabolism, particularly of muscle cells. High performing animals need creatine to support their muscle growth. Evonik Industries has developed a feed additive called GuanAMINO® which contains guanidinoacetic acid (GAA), an amino acid derivate and natural precursor of creatine.

Formed mainly in the kidney from the amino acids glycine and arginine, GAA is transported to the liver, where most of it is transformed into creatine. The body can replace creatine losses to a certain extent through de-novo synthesis, nevertheless, the remainder must be supplied by the diet. In high yielding animals such as meat type broilers and laying birds the inevitable creatine loss may be a performance limiting factor, especially in the absence of raw materials, such as fish meal, which contain creatine.

The addition of GuanAMINO® to poultry diets has proven effective in improving energy utilization and FCR. It is also beneficial in diets low in arginine. Arginine is required in high concentration by poultry because they are unable to synthesize this amino acid in vivo. In low protein diets, which have become more common with rising prices for oilseed meals, arginine is the rate-limiting factor for GAA (and creatine) biosynthesis. Because GAA is the direct precursor of creatine, GAA should also be capable of sparing arginine.

GuanAMINO® is added to the feed over the entire growth period at 600 to 1,200 g/ton of feed. The recommended dosage per species is as follows:

Table 1. Recommended Dosage Levels










Post weaned Piglets

Growing finishing Pigs

g/ton of Feed








With its energy and arginine sparing effect, GuanAMINO® provides a good return on investment when included in the feed. Using least cost formulation software, nutritionists are advised to add GAA as an ingredient using the matrix shown in the table below. They should then include GuanAMINO® at its market price and put a limit on the ingredient maximum side as per the dosage given on the table above.

The software will pick GuanAMINO®. This way, the nutritionist is able to optimize the formulation without exceeding the recommended dosage. This approach will always be cheaper than one formulated by just adding GuanAMINO® on top and will perform better than one formulated without supplementing GAA.

Table 2. GuanAMINO® Matrix


Matrix Values

Guanidinoacetic acid (GAA)




Crude Protein




Arginine Digestibility


AMEn Poultry


Proven benefits of using GuanAMINO® supplementation include:

  • Reduced cost of feed resulting from energy and arginine sparing mainly in layer and broiler feed
  • Reduce FCR up to 9.3 units
  • Improved final body weight by up to 125g and average daily gain by 3.4g
  • Improve hatchability and fertility of eggs in breeder birds and enhance performance of their progenies
  • Optimized breeder reproductive traits as well as feed conversion of their progenies resulting into increased number of marketable day-old chicks
  • Higher number of piglets/sows per year
  • Reduced number of stillborn piglets
  • Improved livability and preweaning mortality
  • Higher weaning weights
  • Increased post weaning performance
  • Increased carcass yield (lean meat)

GuanAMINO® can be put in compounded feeds and in premixes and is stable in most processing and environmental conditions.