Development of extruded feed for animals based on oil and fat production waste

Abstract

Goal. To substantiate the expediency of developing extruded feed for animals based on oil and fat production waste. Methods. The process of extruding mixtures of oilseed meal and grain raw materials was studied on a PE-20 press-extruder. The mass fraction of moisture and volatile substances in samples of oil and fat production waste, starch-containing raw materials and extruded feed was determined by the gravimetric method, the mass fraction of protein by the Kieldal method, the mass fraction of lipids and fiber by the extraction method, the carbohydrate content by the polarimetric method, the ash content by the method of burning with subsequent cinefaction of the mineral residue, amino acid composition of the protein — by the method of ion exchange column chromatography, amino acid score of the samples — by the method of comparing the content of each essential amino acid in the protein of the raw material under investigation with the content of the same amino acid in the «ideal» reference protein. To determine the porosity of extruded material samples, they were covered with waterproof varnish, after drying they were placed in a measuring cylinder with water, taking into account the mass of water displaced from the cylinder, the volume of the extruded material sample with pores was determined. Mathematical methods were used to process the obtained results and Microsoft Office Excel 2003 and Statistica software packages were used. Results. The chemical (content of moisture, protein, lipids, carbohydrates, fiber, and ash) and amino acid (content of essential amino acids) composition of raw materials as the basis of extruded animal feed was determined. It was established that the waste of oil and fat production (sunflower and soybean meal), as well as starch-containing raw materials (oat groats) met the requirements defined in the relevant regulatory documentation. Using the data on the dependence of the porosity of the extruded mass on the ratio of its components, information on the protein content of the raw components, and their cost, a rational ratio of the components of the base of the extruded feed was established. The feed developed by the authors corresponded to the commercial analog in terms of porosity and cost but exceeded it in protein content by 3.2 times, and by 2.9 times in essential amino acid content. Conclusions. The obtained results indicate the possibility of using waste oil and fat production (sunflower and soybean meal) as raw materials for the production of extruded animal feed.