The article presents the results of studies of fattening and meat qualities of young white pigs of different white breeds of different intensity of formation (Δt) in early ontogeny, biochemical parameters of blood serum (aspartate aminotransferase activity, alanine aminotransferase, alkaline transferase, alkaline phosphatase. It is established that according to the main indicators of fattening and meat qualities (age of reaching live weight of 100 kg, days; thickness of the sleeve at the level of 6-7 thoracic vertebrae, mm; length of chilled carcass, mm) young pigs of the controlled herd belong to the first class and class elite, and serum biochemical parameters are consistent with the physiological norm of clinically healthy animals. Taking into account the class of distribution by intensity of formation (Δt), a significant difference was established between animals of I (Δt = 0.795–0.832) and III (Δt = 0.660–0.703) groups on the average daily gain of live weight and age of reaching live weight of 100 kg. The relationship between the biochemical parameters of serum, fattening and meat characteristics of young pigs ranges from -0.250 to +0.385 and is unlikely. We offer in breeding and breeding work, along with the traditional methods of evaluation and selection of high-yielding animals use the method of evaluation and breeding indices.

The aim of the study was to investigate the effect of the feed additive “Butaselmevit-plus” on the state of the antioxidant defense system of piglets during weaning. The experiments were conducted on the basis of the LTD “KOSHET” Mukachevo district of Zakarpattia region. Two groups of piglets were formed – control and experimental, in the amount of 10 individuals in each group, selected on the principle of analogs – age, breed and body weight. Animals were fed according to the norms for this age of pigs. On the 28th day of life, the piglets were weaned from the sow and regrouped from different nests for further maintenance during fattening and rearing with a change in the structure of the diet, which served as technological stress for the animal's body. Piglets of the experimental group, from 21 to 40 days of age, were additionally fed the feed additive “Butaselmevit-plus” at a dose of 100 mg/kg body weight per day. The material for the study was blood, which was taken in the morning before feeding the animals by puncture of the cranial vena cava for 20 days of life (the period before weaning), for 25 days of life (the period before weaning), for 30 days of life (2 days after weaning), for 35 days of life (7 days after weaning), 40 days of life (12 days after weaning). It is proved that feeding piglets feed additive “Butaselmevit-plus” enhanced the antioxidant status of piglets after weaning. It was found that under conditions of technological stress, the use of feed additive “Butaselmevit-plus” in the amount of 100 mg/kg body weight per day improves the antioxidant defense of the body, as evidenced by an increase in blood 35-day-old piglets superoxide dismutase activity by 26.7 % (P < 0.001), catalase – by 39.5 % (P < 0.001), glutathione peroxidase – by 51.7 % (P < 0.05), glutathione reductase – by 52.9 % (P < 0.05), the content of reduced glutathione – at 58.3 % (P < 0.001). These results confirm the effectiveness of the use of milk thistle, methionine, selenium, and vitamins A, E, and D3 in the feed additive “Butaselmevit-plus” to piglets in the period before and after weaning to activate the protective systems of their body.

One of the conditions for obtaining high-quality pig products is the use of feed additives, which contain all the necessary biologically active substances, eliminating their deficiency in feed and acting as catalysts for metabolic processes in pigs. That is why the aim of the study was to study the effect of feed additive “Sylimevit” on the enzymatic and non-enzymatic parts of the antioxidant system of piglets after weaning. Two groups of piglets were formed – control and experimental, in the amount of 10 individuals in each group, selected on the principle of analogues – age, breed and body weight. During the weaning period, the piglets were kept under the sow in special machines, had constant access to the mother, and from the age of 5 days – free access to concentrated feed. Feeding of animals was carried out in accordance with the norms for a given age of pigs. Prior to the study, a clinical and physiological examination of the piglets was performed. Their general condition and activity when eating food were taken into account. On the 28th day of life, the piglets were weaned from the sow and regrouped from different nests in order to be further maintained during the period of fattening and rearing with a change in the structure of the diet, which served as technological stress for the animals. From the age of 5 days, piglets of all groups were fed pre-starter feed. Piglets of the experimental group, from 21 to 40 days of age, were additionally fed the feed supplement “Sylimevit” at a dose of 100 mg/kg body weight per day. Feeding piglets Silimevit feed enhances their antioxidant status. The use of this feed additive in piglets contributed to the activation of both enzymatic and non-enzymatic parts of the antioxidant defense system of piglets after weaning, as indicated by an increase in blood 35-day-old piglets superoxide dismutase activity by 26.9 % (P < 0.001), catalase – 41.1 % (P < 0.001), glutathione peroxidase – by 52.7 % (P < 0.05), glutathione reductase – by 53.5 % (P < 0.05), the content of reduced glutathione – by 75 % (P < 0.001). This is due to the fact that silimevit contains active substances such as milk thistle and vitamins, which are strong direct-acting antioxidants and directly interact with free radicals and reactive oxygen species.

The results of studies of fattening and meat qualities of young pigs of different origin and intensity of formation in early ontogenesis are presented.  The economic efficiency of the results of the studies is calculated. The study was conducted under the conditions of pedigree reproducer for breeding pigs of the large white breed of LTD “Druzhba-Kaznacheevka” of Dnipropetrovsk region. The object of study was young pigs of English and Hungarian origin, as well animals of varying intensity of formation in early ontogenesis. Estimation of young pigs by absolute and integrated indicators of fattening and meat qualities was carried out taking into account the following quantitative characteristics: average daily weight gain for the period of control fattening, kg, age of reaching live weight of 100 kg, days, thickness of the lard at the level of 6–7 thorax , mm, length of cooled carcass, cm, length of bacon half carcass, cm, index “intensity of formation” (∆t), selection index (SI) and “T-factor”. The economic efficiency of the results of the research was calculated according to the indicator "average daily increase of live weight during the period of control fattening, kg". The analysis of the results of the research shows that the young pigs of the large white breed of the control herd by the age of reaching the live weight of 100 kg were outweighed by the minimum requirements of the Instruction for pig testing by 9.78%, by the thickness of the lard at the level of 6–7 thoracic vertebrae – by 30.33% and by length of the cooled carcass – by 3.52%. Taking into account the class of origin and index “intensity of formation, points” (∆t), the difference between the groups by age of reaching live weight of 100 kg, the thickness of the pelvis at the level of 6–7 thoracic vertebrae and the length of the cooled carcass ranges from 2.24 to 8.03%. It was found that in terms of the main indicators of fattening and meat quality, the young pigs of the large white breed of Hungarian breeding are more consolidated (К1 = 0.085–0.344, К2 = 0.086–0.338). The maximum increment of additional production (average daily weight gain during the control fattening period, kg) was obtained from young pigs of large white breed of English origin (2.39%) and animals with index ∆t at the level of 0.619–0.748 points (1.38%). To evaluate the animals of the main herd (brood boars, sows) according to the fattening and meat characteristics of their offspring, we suggest the use of SI and T-factor breeding indices.

The study presents the results of research on fattening and meat qualities of store pigs of large white breed of different intra-breeding differentiation by the gene of melanocortin-4 receptor (MC4R). The study calculated the economic efficiency of animals of different genotypes. The following fattening and meat qualities were evaluated: average daily increase in live weight during the period of control fattening, g; age of live weight 100 kg, days; fat thickness at the level of 6-7 thoracic vertebrae, mm; the length of the cooled carcass, cm; length of bacon half of chilled half-carcass, cm. It was established that store pigs of controlled population at the age of reaching live weight of 100 kg, fat thickness at the level of 6-7 thoracic vertebrae, and length of chilled carcass exceed the minimum requirements of the elite class by 13.69%. A significant difference between animals of different genotypes by the gene of the melanocortin-4 receptor (MC4RAA, MC4RAG) was established according to the average daily live weight gain during the control fattening period (4.24%, P <0.01), the age of reaching a live weight of 100 kg (2.18%, P <0,01), fat thickness at the level of 6–7 thoracic vertebrae (8,45%, P <0,05), length of chilled carcass (2,26%, P <0,001), length of bacon half of chilled half carcass (3.36%, P <0.001) and selection index (SI) (18.92%, P <0.05). Significant correlations in animals of different genotypes by the melanocortin-4 receptor gene (MC4RAA, MC4RAG) were identified regarding the following features: average daily live weight gain during the control period of fattening × age of 100 kg live weight (-0.475 – -0.853), average daily live weight for the period of control fattening × SI (+0.686 - +0.770), SI × age of reaching live weight 100 kg (+0.515 – -0.721), SI × fat thickness at the level of 6-7 thoracic vertebrae (-0.944 – -0.885), length of chilled carcass × length of bacon half of chilled carcass (+0.899 – +0.861). The maximum increase in additional products was obtained from the sale of young pigs by the gene for the melanocortin-4 receptor MC4RAG – +2.02%.