Broiler meat quality: Proteins and lipids of muscle tissue

Proteins and lipids of muscle tissue are important meat quality parameters. They contribute substantially to the nutritional characteristics of meat. A number of studies has been conducted on the effect of different factors on the protein and lipid content of broiler meat. Given the above, the subjectmatter of the present paper was to provide a review of latest research results on the said quality traits as affected by the most commonly tested factors. The results were grouped and presented in terms of the effect of nutrition, genotype, sex, age and rearing system. The objective of the paper was to review major previous studies on the subject in an attempt to define a future research pathway and facilitate the promotion of scientific findings towards wider practical implementation.Keywords: Broilers, meat quality, proteins, lipid

Changes in Blood Values of Glucose, Insulin and Inorganic Phosphorus in Healthy and Ketotic Dairy Cows after Intravenous Infusion of Propionate Solution

The aim of the present study was to determine the degree of blood glucose utilization by peripheral tissue on the basis of changes in blood concentrations of glucose, insulin and inorganic phosphorus in healthy (n = 10) and ketotic cows (n = 10) after intravenous infusion of propionate solution. Blood samples were taken in both groups of examined cows at the following time intervals: just before (time 0) and 8, 30, 60, 120, 180, 240 and 480 min after the intravenous infusion of 1.84 mol l-1 solution of propionate in the amount of 1 ml kg-1 of body weight. Glucose and insulin blood serum values in both groups of cows increased significantly within 120 min of the experiment (p p p p < 0.05) in blood value of inorganic phosphorus in ketotic cows in comparison with healthy ones. This is linked with the active entry of glucose into glucolytic pathway of peripheral tissues. It can thus be concluded that there is a higher degree of blood glucose utilization by peripheral tissues in ketotic cows

Uticaj genotipa i uzrasta na proizvodne osobine lakih linijskih hibrida kokoši

The aim of this work was parallel investigation of the producing characteristics of light line hen hybrids. Investigation enclosed two hen proveniences: Hisex Brown and Shawer 579. Within the period of 19 up to 63 weeks we followed next parameters: egg-laying hen body mass, mortality, food consumption and egg-laying capacity. Hens body mass on the beginning of the examination, within the 19 weeks of growth was, for Hisex Brown provenience 1607g, and for Shawer 579 provenience 1563g. Hisex Brown provenience achieved about 250 g higher body mass on the end of investigation. During the experiment, mortality at Hisex Brown egg-laying hen was a little bit smaller (5,40%), while the Shawer 579 had 5,56% of dead hens. Globally, the mortality at both hen hybrids was in the range of technological normative. The average consumption of the food at Hisex Brown provenience was higher and it was 127,28g, and at Shawer 579 provenience 125,14g. The average consumption of the nutrition for egg production at both provenience was the same (150g).Cilj ovog rada bio je da se izvrši uporedno ispitivanje proizvodnih sposobnosti lakih linijskih hibrida kokoši. Ispitivanjima su obuhvaćene dve provenijence kokoši: Hisex Brown i Shawer 579. U periodu od 19. do 63. nedelje starosti praćeni su sledeći parametri: telesna masa nosilja, mortalitet, utrošak hrane i nosivost. Telesna masa kokoši na početku ispitivanja, sa 19 nedelja uzrasta, za provenijencu Hisex Brown, iznosila je 1607 g, a za provenijencu Shawer 579-1563 g. Veću telesnu masu na kraju eksperimenta, za oko 250 g postigle su nosilje provenijence Hisex Brown. U toku ispitivanja, mortalitet kod Hisex Brown nosilja je bio nešto manji (5,40%), dok je Shawer 579 imao 5,56% uginulih nosilja. Posmatrano u celini, mortalitet nosilja kod oba hibrida, bio je u granicama tehnoloških normativa. Prosečna dnevna potrošnja hrane kod provenijence Hisex Brown je veća i iznosila je 127,28 g, a kod Shawer 579-125,14 g. Prosečna potrošnja hrane za proizvodnju jajeta kod obe provenijence je bila ista (150 g)

Efekat proteaze na proizvodne i klanične osobine tovnih pilića

Carcass conformation is a very important parameter in assessing the overall appearance and meatiness of broilers. This study evaluates the effect of protease supplemented to reduced protein diets on production traits, dressed carcass weight and conformation measures in fast-growing Cobb 500 and slow-growing Master Gris broilers over a fattening period of 49 days. At slaughter, the following measurements were taken: pre-slaughter body weight (BW), conventionally dressed carcass weight and abdominal fat weight. Following carcass dissection into primal cuts, absolute conformation values, including metatarsus length (ML), keel length (KL), breast depth (BD), breast angle (BA) and thigh girth (TG), were determined. For carcass conformation evaluation purposes, index values of carcass conformation measures BW/ML, BW/KL, BW/BD and BW/TG were identified. Genotype and sex had a significant effect on dressed carcass weight and all conformation measures, whereas the effect of different protein levels in protease-supplemented diets was significant only in Master Gris, for metatarsus length and the following indices: BW/ML, BW/KL and BW/TG.Konformacija trupova pilića predstavlja vrlo važan parametar za ocenu opšteg izgleda i mesnatosti pilića. U radu je analiziran efekat enzima proteaze, uz snižen nivo sirovih proteina, na proizvodne osobine, masu obrađenog trupa i mere konformacije kod brzorastućeg-Cobb 500 i spororastućeg hibrida - Master Gris. Tov pilića trajao je 49 dana. Na liniji klanja izmerena je telesna masa pilića pre klanja, masa klasično-obrađenog trupa i masa abdominalne masti. Nakon rasecanja trupova na osnovne delove izmerene su apsolutne mere konformacije: dužina piska, dužina kobilice, dubina grudi, grudni ugao i obim bataka. Za bolju ocenu konformacije trupova izračunati su indeksi mera konformacije: telesna masa/dužina piska, telesna masa/dužina kobilice, telesna masa/dubina grudi i telesna masa/obim bataka. Značajan je bio uticaj genotipa i pola na masu obrađenih trupova i sve ispitivane mere konformacije, dok je uticaj različitih nivoa proteina, uz dodatak enzima proteaze, bio značajan samo kod hibrida Master Gris, i to za dužinu piska i indekse telesna masa/dužina piska, telesna masa/dužina kobilice i telesna masa/obim bataka

PHYTASE IN DIET FOR FATTENING CHICKENS, INFLUENCE ON BONE’S QUALITY**

Abstract: The influence of phytase added in diet for fattening chickens on the meat quality, was examined during the feed experiment. The experimental examinations were done on the chickens of Arbor Acres strain. There were 440 chickens in the experiment, divided into the 4 experimental groups considering the levels of mineral sources of phosphorus and phytase added into the diet. Control group K (110 chickens) dicalcium phosphate 2%, O-I group (110 chickens) monocalcium phosphate 1,4%; O-II group (110 chickens) dicalcium phosphate 1 % + 0,1 % phytase; O-III group (110 chickens) monocalcium phosphate 0,7 % + 0,1 % phytase. The feeding experiment lasted for 42 days. The chemical analyzes of white and red meat of experimental chickens that the meat of the chickens that gained phytase by diet with lower level of mineral source of phosphorus have more proteins and less fat phytase by diet (P&lt;0,05). Key words: chickens, phytase, sources of phosphorus, meat, quality

THE AGE AND HOUSING SYSTEM EFFECTS ON THE GROWTH OF BROILERS**

**Original scientific paper Abstract: Bearing in mind certain established European Union regulations on the conventional extensive broiler rearing system as well as poultry breeding specificities of our country, experimental investigations were organised with the aim of making a comparison between broiler growth in two different non-industrial rearing systems. The systems included extensive fattening in a poultry house and free-range rearing. The fattening period in both rearing systems lasted up to the 63 rd day of broiler age. During the fattening period chicken growth was controlled by individual chicken weighing on a weekly basis. Based on the research results it was determined that the growth of broilers in both rearing systems was similar up to the 49 th day of age. The differences established were small and statistically insignificant (P&gt;0.05). The controls at 56 and 63 days of age showed somewhat higher differences in mean body weights of chicks. The difference determined on the 63rd day was statistically significant (P&lt;0.05). From the results mentioned it could be concluded that the differences in broiler growth between the rearing systems examined increased with the prolongation of the fattening period. Key words: chickens, rearing systems, age, body weight