DETERMINATION OF THE FEEDING VALUE OF FOOD INDUSTRY BY-PRODUCTS

Tatiana Dumitra Panaite, Rodica Diana Criste, Mariana Ropota, V. Criste, Gabriela Vasile, Margareta Olteanu, Monica Mitoi, Raluca Socoliuc, Al. Vlaicu

Abstract
    The use of plant by-products from the food industry in animal feeding is a way of reusing resources with a high feeding potential. With the view of their potential use in poultry diets, 5 by-products (rapeseeds meal, grape seeds meal, flax meal, buckthorn meal and pumpkin meal) were characterized chemically and physically to determine their feeding value. The chemical determinations revealed a variable content of protein, ranging between 11.91% (grape seeds meal) and 34.88% (pumpkin meal). The rape seeds meal has 33.15% protein, with high concentrations of limiting amino acids (1.85% lysine, 0.71% cystine and 0.71% methionine), compared to the grape seeds meal (0.42% lysine) or the buckthorn meal (0.16% cystine; 0,17% methionine). The flax meal has a high concentration of α linolenic acid (42.93 g/100 g total fatty acids), and the grape seeds meal has a high antioxidant capacity (493.074 mMTrolox/g). The grape seeds meal has a high concentration of Fe (362 mg/kg), while the rapeseed meal has a high concentration of manganese (82.9 mg/kg), selenium (1.2 mg/kg) and zinc (95 mg/kg). The pumpkin meal has high concentrations (mg/kg) of Co (0.78), Cu (19.2), Ni (447) and Mo (116). The gross energy level (MJ/kg) was 16.94 (rapeseeds meal); 18.07 (grape seeds meal); 18.94 (buckthorn meal); 19.31 (flax meal); 20.10 (pumpkin meal). These results show that the analysed by-products meet the feeding requirements to be used as feed ingredients in layer diets.

Key words: meals, rapeseed, grape seeds, flax, pumpkin, buckthorn, chemical composition