Chemical сomposition of broiler chickens meat and liver with protoryzyn enzyme
The importance of studying the chemical composition of meat products as one of the human nutrition priorities is proved by numerous theoretical studies and syntheses of both national and foreign scientists, including the works by S. Merzlov, I. Ibatullin, I. Egorov, P. Shmakov, R. Temirayev, but with the advent of new feed additives it is necessary to study their impact on the quality of poultry meat. The purpose of the work was to study the effect of Protoryzyn enzyme on the chemical composition of white and red meat with experimental birds. The object of the research is chicken broilers of Cobb-500 cross. Research Methodology. The experiment was conducted at the researching farm of Vinnytsya National Agrarian University. Subject chickens were kept in cages in compliance with the zoo hygienic requirements. The duration of the experiment was 42 days. To study 200 chickens selected, of which on the principle of analogues there were formed 4 groups 50 heads each. The birds were fed twice a day with mixed fodder (base diet) supplemented with enzyme in experimental diet groups. At the end of the experiment there was conducted teh controlling slaughtering of broiler chickens, four heads with each group. Statistical analysis was performed on a PC using the method suggested by M. O. Plohinskiy. The contents of moisture, protein, fat, ash and BER in meat were determined by standard methods. Feeding with the enzyme does not significantly affect the dry matter content in the white meat of experimental poultry. There has been found that the protein level was the lowest in the 2 <sup>nd</sup> experimental group (2.1% less than control analogues). However, the birds of the 3 <sup>rd</sup> and 4 <sup>th</sup> experimental groups had protein content by 1.8% and 2% (P<0.05), respectively, greater than in chickens of group 1. The amount of fat in muscle tissue increased in broilers of the 3 <sup>rd</sup> group by 0.6% (P<0.01) and poultry of the 4th group - by 0.4% if compared with the control group. The index of ash content in the 1st control and 2nd experimental groups was at the same level, while its level in the 3rd and 4th experimental groups decreased to the control level by 0.8% (P<0.05) and by 0.6% (P<0.001), respectively. The content of nitrogen-free extractive substances in chickens of the 2 <sup>nd</sup> group was higher than with the control analogues by 2%, while in the 3 <sup>rd</sup> and 4 <sup>th</sup> groups this indicator decreased by 1.4% and 2%, but significant difference between the control and experimental groups were not found. There have been observed no significant differences in broiler experimental groups if compared with the control on the content of dry matter in the leg muscles. The level of protein deposition by feeding with the smallest dose of the enzyme (2 <sup>nd</sup> group) was lower than the control analogues by 3.5% (P<0.05), while in the 4 <sup>th</sup> experimental group this indicator exceeded that of group 1 by 0,4%. The results of the studies proved an increase in the fat content of red meat in the second group by 1.8% (P<0.05), in the third group - by 1.6% (P<0.05) and in the fourthgroup - by 1.7% if compared with the first control group. The level of ash in the leg muscle of the 1 <sup>st</sup> control and 4 <sup>th</sup> experimental group remained at the same level, while with the birds of the 2 <sup>nd</sup> and 3 <sup>rd</sup> groups it was higher than in control analogues by 0.4% and by 0.9 % (P<0.01), respectively. The content of nitrogen-free extractive substances in the meat of the 2 <sup>nd</sup> group increased by 1.2%, while with the birds of the 3 <sup>rd</sup> and 4 <sup>th</sup> groups it was lower by 2.7% (P<0.01) and by 2.5% (P<0.05) than in the 1 <sup>st</sup> group. By feeding wtih enzyme in chickens of the 2 <sup>nd</sup>, 3 <sup>rd</sup> and 4 <sup>th</sup> experimental groups there increased the dry matter content in the liver by 0.7% (P<0.05), by 0.6% (P<0.05) and by 1% (P<0.01), respectively, if compared with the control group. Birds which consumed an average dose of the new feed factor showed the increase of protein content by 2.2% (P<0.01) if compared with the first group. In chickens of the second and fourth experimental groups this indicator also increased by 0.5% and by 1.3%. The fat content in the liver of broilers in the 1 <sup>st</sup> control and the 2 <sup>nd</sup> experimental group was almost at the same level, but with chickens of the 3 <sup>rd</sup> and 4 <sup>th</sup> groups it was significantly higher than the benchmark by 1% (P<0.05) and by 1,7% ( P<0.01). The level of ash in the liver declined in the 2 <sup>nd</sup> experimental group by 0.6% (P<0.01) and in the 3 <sup>rd</sup> group - by 0.5% of the contents of this indicator in the control group. The intake of average and the highest dose of additive nitrogen-free extractive substances content in the liver of chickens decreased by 1.9% (P<0.01) and by 1.6% (P<0.01) if compared with the control group. Introduction of enzyme in the diets of the 3 <sup>rd</sup> and 4 <sup>th</sup> experimental groups promotes increasing of protein and fat in white and red meat. The use of average and highest dose in the liver increased the content of dry matter, protein and fat, but the level of nitrogen-free extractive decreased.