Object of work. 1. To review and compare the productivity qualities of the pig breeds bred in Vilnius zone (Lithuanian white, Yorkshyre, Landrace, and Pjetren); 2. To determine the impact of the age, sex, and breed on the pig muscularity. Conclusions. 1. The highest muscularity within the weight limit 95-100 kg makes 53.1 percent, and at the weight of 110-115 kg the muscularity amounts to only 47.5 per cent. While the weight of piglets is increasing, the amount of muscles decreases but the amount of fat increases. It was established that at every 5 kg the fat thickness increases by 1 mm. 2. The weight had the highest influence on the piglets of the Landrace and Pjetren breeds. Based on the research, it can be stated that while the weight increases from 90 kg to 110 kg, the fat layer of the Landrace piglets decreases from 16.1 mm to 14.4 mm, and the fat layer of the Pjetren piglets, on the contrary, increases from 11.1 mm to 14 mm. 3. The highest muscularity is achieved when the age of the Pjetren and Landrace piglets is within 175-190 days, making respectively 59.9 percent and 56.2 percent. The lowest muscularity in Pjetren piglets standing at 58.5 percent is found at the age of 205-220 days. Among Landrace, the lowest muscularity of 52.4 percent is fixed at the age of 220-235 days. 4. The muscularity of the Yorkshire piglets is the highest at the weight level of 85-90 kg by making respectively 55.6 percent and 54.9 percent. While the weight is increasing, as provided by the... [to full text]

Novelty of the research. The effect of genetic and environmental factors on the lean meat quantity in the carcass and the growth rate has been determined by the method of ANOVA for the first time in the country, LW and other breed improvers were highlighted. Statistically reliable regression equations of ham muscle output prediction were drawn. Relations of four main parts of the carcass and their interaction with the carcass quality indexes was defined. Influence of bone fibre myocytes towards the lean meat in the carcass, and the relation between the pH and carcass quality, were analysed.

Novelty of the research: 1. Using pure and cross breeding methods competitive genotype of Lithuanian White pig was formed. 2. Method of mixed linear model multivariate analysis was used and heritability of pig productive traits was evaluated in one farm conditions. 3. Genetic evaluation of Lithuanian White breed structure – boars’ lines and sows’ families- was performed as well as their productive traits correlations were determined for the first time in country. 4. For the first time in Lithuanian pig husbandry computerized method for determination of „muscle eye“ area was used. Practical meaning of the work: Using advantages of pure breeding and applying Large White breed „blood infusion“ was created consolidated meat genotype of Lithuanian White pig with high heritability of muscularity, which is used for genetic improvement in other Lithuanian White pig breed farms. At the moment 90 % of best BLUP method evaluated Lithuanian White pig breed boars and sows are kept in UAB „Berka“.