Corn steep liquor, an alternative protein source

Feed is by far the highest cost factor in poultry growing. Keeping these expenses within limits is crucial, particularly in the developing world. A relatively unknown, but useful alternative protein source, is corn steep liquor.

By Zafar Ullah and Prof. Dr. Javed Iqbal Sultan, University of Agriculture, Faisalabad, Pakistan

The poultry industry is actively playing a key role in the provision of protein to the rapidly growing population in Pakistan. At present, poultry meat is the most economical animal protein source available for third world countries. In general, the majority of the population is protein deficient.

The share of poultry meat in Pakistan is 24.8% with 767,000 tonnes of the total meat production. To produce cost-effective broiler meat, it is necessary to provide balanced and economical feed. As feed accounts for nearly 70% of the total production cost, feeding an economical diet to birds will be helpful in minimising the gap between nutrient requirements and availability.

Easily available
The use of non-conventional feed ingredients and their by-products in poultry feed will be supportive in the formulation and manufacturing cost-effective broiler diets. The important point in selecting these ingredients is that they must be cheap and easily available. Corn steep liquor (CSL) is such a non-conventional protein source which is low-cost (just over 0.1 USD per kg) and easily available in the local market.

It is a by-product of the corn wet-milling industry. CSL is a viscous, slurry liquid feed ingredient with a dark brown colour. It is a mixture of soluble proteins, reducing sugars (dextrose) and natural organic acids (lactic acid) having ensiled ordure with acidic pH. Nutrient composition (Table 1) shows that high protein content makes it excellent protein source for use in poultry diets. Fat and Fibre portions are absent. Almost all the essential amino acids (Table 2) like lysine and methionine are present in a good proportion.

Minerals (Table 3) considered important in formulating the poultry diet for bone development and egg production (calcium and phosphorus) and electrolyte balance (sodium, potassium and chloride) are also a part of CSL. CSL is a good source of vitamin B-Complex (Table 4). The properties mentioned above could conclude that it could be used on an ‘as such basis’. A preliminary study confirmed that it could be used up to 15% in an as such basis in the diet of broilers with no any adverse effects.