Zinc plays an important role in the organism of animals and human. It’s biological role is connected with activity of ductless glands, where it is mainly concentrated. For today the necessity of Zinc for the function of endocrine glands and it’s participating in the mechanism of cellular division is proved. So, Zinc effect operating on the organism of animals is multifaceted and optimization of rations with this microelement influences on normalization of progress of different metabolic  processes.

The aim is to establish the optimal dose of mixed legade Zinc complex consisting of fodder for young pigs Landrace breeds for fattening that would provide maximum meat productivity.

Scientific and economic research was conducted in conditions of "Elite" Kyiv Region fattening young pigs Landrace breed. Pigs kept for meat production were fed by mixed fodders of own production with the addition of mineral mixture Landmix designed for the manufacture of animal mixed fodder in terms of the economy according to the needs of animals in minerals.

Pigs had free access to food and water, thus ensuring optimum feed intake. Nutritiousness of mixed fodders was the same for animals of all experimental groups and met detailed standards of feeding, but mixed fodders differed on the content of Zinc. Animals eat food with appetite and any changes in the behavior of experimental pigs were not observed.

The nature and feeding and balance of feed and feed additives in the diet depends not only animal productivity and product quality, but also the health and functional activity of internal organs of pigs. Enrichment of rations fattening pigs of Landrace breeds Zinc chelate showed positive impact on slaughter figures.

These data show that pigs mass before slaughter from the 2-nd experimental group exceeded controls by 1.8 %; the 3-d - 2.2; the 4-th - by 3.3 and the 5-th - by 2.1 %. Slaughter mass of animals from the 2-nd experimental group exceeded analogues of control by 2.3 %; the 3-rd - 3.2; the 4-th - 5.0 (r≤0,01); the 5-th - 3.4 % (r≤0,05).

Pigs of experimental groups dominated analogues of control also by slaughter yield. This indicator of animals from the 2-nd experimental group was higher than in the control by 0.4 %; the 3-rd - 0.9;the 4-th - 1.4; 5th - by 1.0 %.

Internal fat weighing results showed that Landrace breed pigs have less fat than young pigs of Great White breed. Most of it’s weight was found in pigs of the 4-th experimental group - 3.9 % more compared to the control, but significant difference in this indicator was not observed. It should be noted that the head mass of Landrace breed pigs was less than the head mass of Great White breed, and this figure was the highest in animals of the 4-th experimental group and it prevailed by 3.1% of  control. According to the mass of head of the 2nd, the 3-rd and the 5-th experimental groups dominated the control animals, by 0.6 %; 1.0 and 2.1 % respectively.

Weighing indicators of feet and pig skin in the 2-nd experimental group did not differ from that of control animals and the 4-th experimental group - dominated control, by 4.5 % and 1.4 % respectively. Pigs of the 3-rd and the 5-th experimental groups dominated control data by mass the feet - 2.3 % by weight of skins - by 0.5 % and 1.0 %, but the difference was statistically improbable.

The thickness of the bacon over 6-7 thoracic vertebrae was similar in all experimental pigs. Area of "muscle cells" in the animals of the 2-nd – the 5-th experimental groups compared with control was higher and amounted to 30.3-30.8 sq.cm that exceeded the date of control by 0,3-2,0 %.

Research of morphological composition of carcasses showed that the yield of meat from animals of experimental groups was high. It should be noted no significant intergroup differences in content of meat, fat and bones in the carcasses. The largest amount of meat in the carcasses of animals was in the 4-th and the 5-th experimental groups respectively by 7.4 % (r≤0.01) and 5.4% (r≤0.05) higher than in control.

In the half carcasses of pigs from the 2-nd and the 3-rd experimental groups weight of meat was higher, respectively, by 1.9 % and 3.9 % compared with the control.

Data of fat content in the half carcasses of pigs from the 2-nd experimental group exceeded the control by 4.0 %; the
3-rd and the 5-th - 5.1 % (r≤0,05) and the 4-th groups - by 6.0 % (r≤0,05).

The least bones were in the half carcasses of pigs from the 4-th and the 5-th experimental groups - by 6.4 % (r≤0,05) and 4.3 % (r≤0,05) less than in the control, and pigs from the 3-d group - 2.2 % less. The content of bones in the half carcasses of pigs from the 2-nd experimental group was at control.

Thus, the enrichment of mixed fodder for young pigs of Landrace breed of experimental groups with chelates of Zinc improves the morphological structure of animals slaughtered and improve performance. Thus the highest rates found in the animals of the 4-th experimental group, mixed legade Zinc Complex was added to the mixed fodder in the amount of 166,4 g/t.

Analysis of the chemical composition of the meat showed that the moisture content in it ranged from 1 %. The difference was statistically improbable. The same mechanism was also set for dry matter content.

The highest protein content was determined in meat of pigs from the 4-th experimental group, this figure is 1 % higher than the control. Protein in the meat of pigs from the 2-nd and the 3-rd experimental groups was higher by 0.3 % and 0.5 %. respectively.

Fat content in the longest back muscle was the largest in the animals from the control group - 4.18 %. This indicator in the animals from the 2- nd, the 3- rd, the 4- th and the 5th experimental group was slightly lower - respectively, 0.26 %; 0.48; 2.13 (r≤0,05) and 1.70 % (r≤0,05). The highest ash content in meat of pigs was in the animals from the 4-th experimental group - 2.65% (r≤0,05). In the animals from the 2-nd, the 3-rd and the 5-th groups ash content was higher than control, respectively, 0.04 %; 0.08; 0.1 % (r≤0,05).

Fat of animals from the control and experimental groups in chemical composition did not differ significantly from controls. The protein content was the highest in the fat of animals from the 4-th experimental group and was 1.95 %, which is 0.30 % (r≤0.05) more compared with analogues of the 1-st control group.

The analysis of mass indicators of liver, heart, lungs, kidneys and spleen testify  positive effect of mixed legade zinc complex on the mass of internal organs of Landrace breed pigs, but significant difference between the control and experimental groups were not established.

As for the digestive system, it should be noted that the pigs who consumed different levels of Zinc chelate had a greater mass of the stomach, small and large intestines. Pigs from the 4-th experimental group that consumed mixed fodder with content of mixed legade Zinc Complex in the amount of 166.4 g/t exceeded control data. Thus, by the mass of the stomach, animals from the 4-th experimental group prevailed control by 10.4 %; by mass of small intestine - 8.7 % and large intestine - 13.5 %.

Feeding young pigs with different levels of Zinc in the form of organic mixed legade Zinc complex in the mixed fodders causes increase of slaughter indices, meat yield and its chemical composition. It should be noted that Landrace breed pigs remarkably exceeded control data at dose of mixed legade of Zinc complex 166.4 g/t.

Prospects for further research is to study the effect of mixed legade Zinc complex in the combination of mixed fodders for young pigs of various breeds and hybrids on productivity, metabolism and accumulation of zinc in products of slaughter.

Key words: pigs, mixed legade Zinc complex, mixed fodder, slaughter weight, slaughter yield, morphological composition of carcass, chemical composition of meat, fat, internal organs.