Due to the increasing demand for alternative feed ingredients, the utilization of oilseed by-products in animal nutrition has been sought as a promising solution to ensure cheap and environmentally sustainable feedstuffs. Oilseed cakes and meals remain in huge amounts after the extraction of oil and represent a good alternative to protein sources in animal feeding. Cold-pressed cakes are the by-product of mechanical screw-pressing of oilseed, while oilseed meals remain after oil solvent-extraction method. Cold-pressing is a cheap, easy, and rapid process to obtain cakes even starting from small quantities of raw materials.
Currently, the demand for cold-pressed oilseed cakes is high because of the simple equipment needed, which can be used directly at the farm site and in rural areas. Instead, solvent extraction methods have some limits like cost, toxicity and the damage to the environment is quite excessive, even though they are used most common.
Furthermore, animal feed production from cold-press oilseed cakes can reduce the environmental pollution and have beneficial effect on animal performance and health. Therefore, the utilization of cold-pressed oilseed cakes in animal nutrition is recognized as a feasible and crucial point in promoting environmental sustainability and ecofriendly concept on one hand, as well as providing cheap and valuable feed ingredient that could diminish the dependence on non-sustainable traditional feedstuffs on the other hand.
Cold-pressed cakes from rapeseed, hempseed, linseed, sunflower seed, camelina seed and pumpkin seed can be used as alternatives to conventionally used protein feed ingredients. These cakes are distinguished by high nutritive values as they contain considerable amount of crude protein and essential amino acids, and high lipid content which make them suitable protein and energy source for ruminants and non-ruminants. Furthermore, cakes as a feed ingredient may be efficiently utilized as a source of essential fatty acids, particularly for the production of animal products with n-3 and n-6 PUFA which have demonstrated numerous beneficial health effects.
Reported effects on animal production performance are contradictory and vary depending on the type and nutritional profile of cake, supplementation level, animal category, experiment duration, etc. Special attention should be focused on anti-nutritional compounds that can limit feed intake and nutrient utilization. Thus, in order to avoid these harmful effects, the inclusion of cakes in animal nutrition, particularly in feed formulations for pigs and poultry should be restricted to a certain level.