Efficiency of using frying fats in feeding of broiler chickens

The purpose of the research is to assess the effect of additional additives (proteins, carbohydrates and fats) in the main diet of broiler chickens on changes in morphological and biochemical parameters of the blood. The research confirmed the possibility of replacing fresh oils with fried triglycerides obtained after frying meat semi-finished products in the finishing diets of broiler chickens. The highest production efficiency of EPEF (European Production Efficiency Factor) 422–435 was achieved with late input of frying fats (25–36 days of the experiment), which ensured a live weight of broiler chickens at the level of 2700 g, livability 94.4 % and feed conversion ratio 1.68 kg. Early use of frying triglycerides (in 1–2 phases of feeding) reduced productivity the EPEF index decreased by 15–25 % due to a drop in livestock livability (up to 87.5 %) and an increase in feed conversion ratio (up to 1.77). Blood biochemistry revealed oxidative stress with early input of frying fats. For example, an increase in MDA (+ 17.6 %), AST activity (+ 33.6 %) and a decrease in total antioxidant protection (–9.2 %) were observed. Later use of frying fats (finisher phase) minimized negative effects. A statistically significant decrease in uric acid by 11–13 % was observed with normal liver transaminase activity (AST, ALT). It has been shown that it is possible to input of frying fats (SolPro McD, KFS MC 12) only at the finisher stage (25–36 days) to maintain poultry productivity at the level of the control group, prevent oxidative stress and maintain meat quality characteristics.