By-products of human food production

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Conference: Forum 8: Nutrition: Contributions: Posted Contributions: By-products of human food production

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  By Petra Wolf on Thursday, December 30, 1999:

P. Wolf, J. Kamphues and M. Coenen (1998): Unconventional feedstuffs in pig nutrition
Proc. 2nd Annual Conference of the European Society of Veterinary and Comparative Nutrition (1998), 86

Efforts at saving resources, to avoid environmental pollution as well as to reduce costs of waste disposal led to a frequent use of unconventional feedstuffs in pig feeding. Omnivorous species like pigs are predisposed to utilize byproducts with various fiber, fat and starch contents. Such products originate from production, transport, processing or consumption of food and their usage is stimulated by low costs of energy or protein. Furthermore unconventional feedstuffs show a high variability of chemical composition between different products as well as within several batches of the same product.
Due to high variations in nutrient contents efficient utilization of unconventional feedstuffs demands higher efforts of analyzes in general to reach a necessary safety of use and a continuity of nutrient supply. Furthermore typical composition of these products (for example fatty acids of leftovers or hazelnut skins lead to soft bacon fat?) or sodium content of food (insufficient water supply leads to risk of intoxication?) have to be considered. In dependence on nutrient contents or deficits specific supplements are necessary at concept a ration (special mineral supplements with low sodium content due to high amounts of leftovers rich in sodium; supplementation of crude fiber to products low in fiber like bakers� products as well as an addition of crude protein or individual amino acids to products of high energy density such as potato chips).
In such byproducts the hygienic quality has to be considered due to a short shelf live and risks for spoilage (very moist products: bacterial spoilage; semimoist or nearly dry products: moulds or yeasts!). Further problems are potential contaminants like packaging materials or pathogens. It is only allowed (in Germany) to feed leftovers with ingredients of animal origin after an appropriate processing (3 ways: 90 �C about 60 minutes or 121 �C about 20 minutes under 3 bar or conditions of meat meal production) and official licence and control. In general special chances exist for farms with liquid feeding systems to use liquid or nearly dried byproducts even if some problems can occur due to the characteristics of those products (viscous materials that get sticky; possibility to clean the feeding system?).