Ecological production and use of feed additives

Life cycle assessment of the essential amino acids Methionine, Lysine and Threonine in animal autrition.

In the public mind there is an ongoing debate about the environmental impacts of farming and intensive livestock production. Also there is a beneficial and open minded discussion about the environmental benefits and costs of chemical production for the food chain. Providing these intensive discussions with detailed information contributes to a sustainable comprehension of the advantages of the production of supplemental essential amino acids covering both; the significant improvement of feed and food quality and the sustainable reduction of environmental pollution. Therefore the question as to the potential of the chemical industry to contribute to environmental protection seems to be a viable worthwhile goal. A better understanding of the ecological synergy between sustainable production in chemistry, environmental protection and welfare of animals and final consumers is needed.

The life cycle assessments methodology represents an international scientific standard for the evaluation of all impacts resulting from technical production processes. The impact of agriculture on the environment is an interesting topic due to ecological health and natural resources. In general, the impacts of agricultural are well known and a set of agri-environmental indicators have been designed for an effective monitoring of renewable raw materials.

Amino acids are building blocks of proteins and thus all life. They are important elements of the nutritional value of feed ingredients. Methionine is the first limiting amino acid in poultry nutrition and is produced by synthesis from petro-chemical raw materials, whilst for Lysine, first-limiting in pig, production based on biotechnological production with renewable raw materials. Threonine the next important essential amino acid in animal nutrition is also sourced by modern biotechnology.

Today life cycle assessments, based on poultry diets with identical nutritional value as the functional units, can compare the use of supplemental amino acids in animal nutrition versus equivalent amounts of these essential building blocks from natural protein sources such as soybean meal and rapeseed meal. The overall principle applied in life cycle assessments is the comparison of substantially equal feed sources. That means, two options are always drawn to provide the same nutritional recommendations of the animals. One option covers the nutritional demand of essential amino acids through sources such as soybean meal or rape seed meal. The other provides the same amount of nutritionally recommended amino acids by supplemental sources. Additional quantities of domestically, or locally, produced wheat is added to balance the energy content of the different diets. Thus, 118 kg wheat supplemented with 1.0 kg of an amino acid premix consisting of methionine, lysine and threonine can substitute 119 kg of a feed based on soy meal and soy oil, or alternatively 126 kg wheat supplemented with 1.0 kg of an amino acid premix will substitute 127 kg of a feed based on rape seed meal, rape seed oil and soybean meal (Figure 1).

Figure 1. The functional equivalence of different options for the life cycle assessment of amino acids in animal nutrition.

An independent lice cycle assessment on greenhouse gas emissions of the use of supplemental methionine was recently conducted by the International Council of Chemical Associations (ICCA) in collaboration with McKinsey. The common procedure of the ICCA-approach was to identify a specific ratio between emissions caused by chemical production and the overall savings of emissions during the application of the specific chemical substances during its product life. This demonstrated that globally for each 1 metric ton of CO2 emitted during the synthesis of methionine, in total 23 metric tons of CO2 emissions can be saved over the product's life cycle. The basis of the calculation is the world wide use of about 750,000 mt methionine which is the actually assumed market volume for DL-Methionine. The area of eutrophication is another important environmental impact category, the use of supplemental Methionine in broiler nutrition shows further impressive results; world wide ammonia emissions can be reduced by 26 metric tons per ton NH3 emitted in production as well as 7 metric tons of nitrate per ton NO3 – caused by production (see Figure 2).

Figure 2. Worldwide emissions abatement by supplementing animal feed with supplemental methionine on basis of the overall world market demand of 750,000 metric tons (year 2009).

Not only environmental protection or animal welfare benefit from the sustainable use of feed additives in animal nutrition, but also the efficient use of farmland. The earlier cited ICCA-study clearly demonstrates that the effective supplementation with amino acids, for example methionine, to animal feed significantly impacts the reduction in the area of farmland land in use. Improved feed conversion ratio improves the efficiency of production and reduces the demand of feed raw materials; a worldwide use of 750,000 metric tons of methionine can save some 15 million hectare of crop land.

Against this background, and according to international studies, more than 10 million hectare of arable land are destroyed each year through erosion caused by climatic impact and this annual figure is increasing: These figures show clear potential to balance the growing need for other feed or food production as well as to cover the nutritional demand of the continuously growing number of people on the earth.