Uticaj primene konjugovane linolne kiseline na proizvodne rezultate i kvalitet mesa brojlera

Abstract

Osnovni cilj istraživanja u okviru ove doktorske disertacije je bio da se ispita uticaj konjugovane linolne kiseline (conjugated linoleic acid-CLA) na proizvodne rezultate (potrošnja hrane, prirast, konverzija), parametre mesnatosti (pocenat mesa u trupu) i kvalitet mesa brojlera (hemijski sastav, senzorne osobine, masnokiselinski sastav, uključujući sadržaj CLA, sadržaj malondialdehida). Za ogled su korišćeni brojleri Cobb 500 provenijencije podeljeni u četiri grupe po 30 životinja i hranjeni standardnim smešama po preporuci proizvođača, s tim što su se grupe razlikovale jedino u tome što su ogledne grupe imale u obroku dodat komercijalni preparat konjugovane kiseline, u preporučenoj količini od 2% u smeši u različitim fazama tova (O-I grupa 2% CLA od početka tova, O-II grupa 2% CLA od 11. dana tova, O-III grupa 2% CLA od 22. dana tova) i kontrolna grupa (K grupa) bez dodatka CLA. Smeše su bile izbalansirane i u potpunosti zadovoljavale potrebe životinja u svim fazama tova. Na kraju tova životinje su izmerene, izračunata je potrošena količina hrane, a na klanici uzeti uzorci masnog tkiva i mesa za hemijske analze (hemijski sastav mesa, MDA i masnokiselinski sastav) i senzorne analize. Uzorci mesa bataka sa karabatakom za određivanje sadržaja MDA zamrznuti su pri -18oC. Na klanici su posle rasecanja izmerene mase osnovnih delova (grudi, batak sa karabatakom) trupa. Kod izoenergetskih i izoproteinskih smeša za ishranu brojlera utvrđene su statistički značajne razlike između prosečnih sadržaja zasićenih, mononezasićenih, polinezasićenih, n-3 i n-6 masnih kiselina. Utvrđena je statistički značajna razlika između odnosa n-3 i n-6 masnih kiselina. Prosečan ukupan sadržaj konjugovane linolne kiseline u smeši za ishranu oglednih grupa brojlera bio je 4,43 %. U hrani za kontrolnu grupu brojlera nije utvrđeno prisustvo konjugovane linolne kiseline. Na početku tova, a zatim na kraju prve i druge faze tova, kao i na kraju tova nisu utvrđene statistički značajne razlike između prosečnih masa ispitivanih grupa brojlera. Prosečan prirast za ceo period tova bio je najveći kod O-I grupe a najmanji kod K grupe brojlera, dok je ukupna konzumacija bila najveća kod K grupe a najmanja kod O-I grupe. Konverzija hrane bila je najbolja kod O-I grupe a najlošija kod kontrolne grupe brojlera. Prosečne mase trupova pre i posle hlađenja, zatim prosečne mase grudi i prosečne mase bataka sa karabatakom kao i njihova zastupljenost u masi trupa nisu se statistički značajno razlikovale između poređenih grupa brojlera. Takođe nije utvrđena statistički značajna razlika između prosečnih masa, odnosno učešća mesa u grudima, odnosno bataku sa karabatakom ispitivanih grupa brojlera. Između prosečnih pH vrednosti, odnosno prosečnih temperatura mesa merenih nakon 45 minuta, odnosno posle 24 sata od klanja nisu utvrđene statistički značajne razlike...

The main objective of research under this doctoral thesis was to investigate the influence of conjugated linoleic acid (CLA) on performance (feed consumption, weight gain, conversion), the parameters of leanness (pocenat meat in the carcass) and meat quality of broilers (chemical composition, sensory characteristics, fatty acid composition including the content of CLA and content of malondialdehyde). For the experiment used broilers Cobb 500 provenience divided into four groups of 30 animals and fed standard diets as recommended by the manufacturer, provided that the groups differed only in the fact that the experimental group had a meal added to a commercial preparation of conjugated acid, the recommended amount of 2% in the mixture at different stages of production (O-I group 2% CLA since the beginning of the fattening period, O-II group 2% CLA of 11. days of fattening, O-III group 2% CLA of 22.days of fattening) and control (K group) without the addition of CLA. Mixtures were balanced and fully meet the needs of animals in all stages of this. At the end of fattening animals are weighed, calculated the amount of food consumed, and at the slaughterhouse sampled fat and meat for chemical analze (chemical composition of meat MDA and fatty acid composition) and sensory analysis. Samples of drumstick with thigh for determination of MDA were frozen at -18°C. At the slaughterhouse, the meat preservation after the measured weight of the basic parts (breast, drumstickwith thigh) carcass. In meal for broilers, balanced on the energy and protein content,were found statistically significant differences between average content of saturated, monounsaturated, polyunsaturated, n-3 and n-6 fatty acids. There was a statistically significant difference between the ratios of n-3 and n-6 fatty acids. Average total content of conjugated linoleic acid in the mixture for feeding experimental group of broilers was 4.43%. The feed of the control group was not detected conjugated linoleic acid. At the beginning of this, and then at the end of the first and second phases of fattening, as at the end of fattening there were no statistically significant differences between the average mass of examined groups of broilers. Average growth for the whole fattening period was highest in O-I group and the lowest in K group of broilers, while the total consumption was highest in K group and the lowest in O-I group. Feed conversion was the best in O-I group and the worst in the control group of chickens. Average carcass weight before and after cooling, then the average breast weight and the average weight of drumsticks with thighs as well as their representation in carcass weight did not significantly differ between the examined groups of broilers. There was also no statistically significant difference between the average weight and participation in breast meat and drumsticks with thighs examined groups of broilers. Between average pH value and the average temperature of meat measured after 45 minutes and after 24 hours of slaughter were no statistically significant differences...