The aim of the study was to determine the quality and nutritional value of meat originating from pigs of polish native pure breeds -the puławska and Złotnicka spotted as well as the commercial four-breed crossbreds f1 (large white × polish landrace) × f1 (duroc × pietrain). physicochemical properties of meat were evaluated, such as acidity, water holding capacity, tenderness, and color parameters. in addition, functional properties of meat were determined: nutritional value, mineral content and fatty acid profile. the dietetic indices of meat were also determined. the smallest acidity of muscle tissue was characteristic of the meat of the puławska breed and the smallest meat drip loss was found in both native breeds (p≤0.01). this can confirm their greater technological suitability. the most tender was meat obtained from pigs of the puławska breed (36.07 n/cm 2 ). the darker color was characteristic of the pig meat of the Złotnicka spotted breed (l* = 49.19) (p≤0.01). meat of all three groups of the tested pigs had the quality characteristics related to normal meat. the highest content of protein was found in the Złotnicka spotted meat (25.23%) at optimum fat content (2.25%). the high content of ash (1.63%) recorded in the Złotnicka spotted meat meant higher content of macro and microelements, especially iron and zinc, as compared to meat of the four-breed crossbreds (p≤0.01). the highest amount of monounsaturated fatty acids (52.72%) was recorded in porcine meat of the puławska breed, while content of polyunsaturated fatty acids was the highest in meat of the four-breed crossbreds (16.77% vs. 9.32% and 15.19%) (p≤0.01). no differences were found between the groups tested for atherogenic index. in terms of most physicochemical and functional characteristics, meat of native pig breeds was superior to the meat of commercial pigs from mass-production. key words: pigs, native breeds, meat quality, nutritional value *This study was funded from statutory activity.

The aim of the study was to determine the changes in the content of major proteins, glucose and selected hormones in the blood of piglets during the first 7 days of neonatal life. The study involved an entire litter of eight newborn piglets of F1 hybrids (Polish White Large x Polish Landrace) delivered from one sow in the second gestation. In blood samples collected directly after parturition (before colostrum intake), in the 12 JD , 24 JD and 48 JD hour and in 7 JD day of life, the content of total protein and its fractions, glucose concentration and the level of insulin, T ! (total and free), T " (total and free), leptin, resistin and ghrelin (total and active) was determined. In the blood serum of newborn piglets a low content of total protein, albumins, gamma globulins and a high share of alpha-and beta globulins was found. In the 12 JD hour of life, after colostrum intake, a significant (P<0.05) increase in the content of total protein, albumins, beta-globulins and a rapid increase of gamma globulins as well as decrease of alpha-globulins level were observed. In the consecutive periods of postnatal life a significant (P<0.05) decrease of total protein, beta-and gamma globulins as well as a steady increase in the content of albumins in the blood serum of piglets was observed. The content of glucose, insulin, leptin, resistin and ghrelin in the blood serum of neonates increased significantly (P<0.05) after colostrum intake. During the successive experimental periods a progressive increase (P<0.05) of glucose and T ! as well as systematic decrease of insulin, T " , ghrelin and resistin in the blood serum was observed as compared to the 12 JD hour of life.

The effects of reproduction performance of sows may be subject to the degree of progress growth and development of their reproductive system. The aim of the study focused on the effect of the growth rate and meatiness on the potential fertility of gilts. In total, developmental stages of reproductive organs of gilts of two breeds Polish Large White (n = 100) and Polish Landrace (n = 100) were used. The animals were divided into three groups depending on their daily gains (≤ 850 g, 851 -1000 g and > 1000 g). Feed efficiency was similar in each group, and amounted to 2.91, 2.57 and 2.34 kg/kg, respectively. Meat content in carcass demonstrated significant differences (P ≤ 0.01) between three groups for the Polish Landrace breed (61%, 61% and 59.2%, respectively). An adverse effect of a high growth rate was confirmed for uterine weight (P ≤ 0.05), vaginal and cervical length (P ≤ 0.01), total length of the uterine horns (P ≤ 0.01) and uterine capacity (P ≤ 0.01) mainly in the Polish Large White breed. Similarly to ovarian volume, ovarian weight showed significant differences (P ≤ 0.01; P ≤ 0.05), however disproportionately to the rate of growth. The most favourable properties have been demonstrated in the Polish Large White characterized by moderate growth rate (P ≤ 0.01). Research on the scope of the assessment growth and development of the reproductive system of prepubertal gilts is very limited. Thus, this study brings important data about factors affecting morphometrical characteristics of the uteri, ovaries and oviducts of gilts.Female pig, growth rate, carcass musculature, uterus measure, ovary volume

The study involved an analysis of the developmental stage of reproductive organs collected at slaughter from 160 gilts (Polish Large White (PLW), n = 80; Polish Landrace (PL), n = 80) at 100 kg body weight. Due to a large variation in slaughter age (140-190 days), three groups of animals were set up: A (less than 160 days), B (160 to 180 days) and C (more than 180 days). PL gilts reached their slaughter weight earlier than PLW gilts (P≤0.05). Uterine weight increased with the age of animals but due to high variability and large deviations from the mean value, statistically significant differences were demonstrated only between gilt groups A and B for both breeds together (120.57 g vs. 148.83 g; P≤0.05). Larger differences related to the age of the gilts were found for cervical length between the groups compared (P≤0.01). The total length of the right and left uterine horns showed a significant increase with age in PLW gilts (P≤0.05). The ratio between uterine weight without ligament and the length of uterine horns (g/cm) was significantly higher in group B than in group A in gilts of both breeds together (P≤0.05), which might indicate thickening of the uterine walls. Uterine capacity was significantly higher in older animals yet due to a large variability of this trait, no significant differences between the groups were shown. The length and diameter of oviducts, the weight of each ovary, their sum and dimensions did not reveal any consistent changes associated with the age or breed of pigs. However, the size of the ovaries determined volumetrically and reported as the volume of ovaries in gilts of both breeds was significantly larger in group B compared with C (P≤0.01). No significant differences related to the studied traits were stated between PLW and PL prepubertal gilts. However, the effect of age on morphometric development of the reproductive system was more pronounced in PLW than in PL gilts.