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 evaluate the relations between genotype effects at porcine loci MYF3, MYF4, MYF5 and MYF6 on meat quality traits in pigs of the CC genotype at the RYR1 locus. Meat traits were analysed in longissimus lumborum muscle in 98 pigs (75 of PLW´PL and 25 [PLW´PL]´Pietrain crosses). The determined meat characteristics covered the pH 1 and pH u records, visual assessment of colour and exudation on fresh meat samples, water holding capacity, drip loss, spectrophotometric measurements of dominant wavelength, colour saturation and lightness, L, a*, b* values according to the CIE system, basic chemical constituents (water, protein, intramuscular fat and ash) and soluble protein fraction in meat. The distribution of animals within particular MyoD genotypes only in the MYF4 and MYF5 genotypes were spread uniformly. The gene effects at particular MyoD loci on studied meat traits were significant. The most pronounced effect on meat quality was exerted by the myogenin gene (MYF4). Individuals of the BB genotype in respect to the MYF4 locus showed a better water holding capacity (P<0.01), lower drip loss (P<0.05), darker colour score (P<0.01) and better wateriness score (P<0.01), darker and more desirable colour characteristic (P<0.01) than pigs with the AA genotype, whereas AB genotype animals had intermediate values. In respect to meat protein solubility the AA genotype pigs had a significantly lower level of soluble protein in meat than AB and BB (P<0.01). On basis of the present study it may be inferred that mutations in coding and the non-coding regions of MyoD genes exert significant effects on muscle traits related to oxidative metabolism, as well as related to glycolysis and contractile muscle properties, and thereby on meat quality.

The paper presents the results of a study on the relationship between acidification (pH) and standard quality characteristics of the meat of Polish Large White × Polish Landrace pig crossbreds. The meat for the study was obtained from 184 F1 Polish Large White × Polish Landrace fatteners from a herd free of the stress-sensitivity gene. The obtained results were analysed in groups formed according to the meat’s measured pH45 values (≤ 6.3; 6.3–6.7; > 6.7) and pHu values (≤ 5.3; 5.3–5.6; > 5.6). Increasing measured pH45 values were paralleled by greater water-holding capacity and plasticity, lower drip loss, darker colour L* as assessed visually and with equipment, and greater content of muscle pigments (P < 0.01) of the evaluated meat. Higher pHu values had a more pronounced impact on WHC, free drip loss, tenderness, water content, and colour parameters: a*, b*, chroma C* (P < 0.01), and hue angle ho (P < 0.05). The obtained simple correlations between pH45 and pHu acidity and meat-quality characteristics indicate that the measured pH45 value was correlated more closely than ultimate acidification (P < 0.01) with visually assessed colour intensity, tactilely assessed meat hardness, colour lightness L* (P < 0.01), hue angle ho (P < 0.05), and muscle pigment content. On the other hand, pHu was more strongly correlated with water-holding capacity, drip loss, meat tenderness as well as water and protein content (P < 0.01).

Carcass, meat quality and muscle fibre traits of m. longissimus lumborum were studied in 61 Z³otnicka Spotted (ZS) pigs and 35 commercial crossbred (Polish Large White × Polish Landrace) pigs. The animals received organic feed ad libitum and were slaughtered at 210 days of age. The current findings indicate that both slaughter weight and cold carcass weight were significantly lower, and backfat thickness higher for ZS pigs compared to commercial pigs, while the commercial pigs exhibited longer carcasses and greater area, height and width of the loin eye. No significant differences were found in IMF content between the analysed groups. Moreover, the percentage of type I fibres was higher and their diameter was larger in m. longissimus lumborum of ZS compared to commercial pigs, whereas the opposite occurred for type IIB fibre percentage and diameter, and that concurred with markedly higher pigment content and higher pH K , redness (a*), plasticity values, and significantly lower drip loss, WHC-loose water, and colour lightness (L*) values in ZS pigs than those found in commercial pigs. Also, sensory assessment of raw meat confirmed that m. longissimus lumborum of ZS pigs was characterized by more favourable colour and less exudative meat.

Forty-eight Polish Landrace pigs (initially 32.43 6 0.70 kg live weight) were assigned to a 2 3 2 3 2 factorial arrangement in order to assess the effects of the rearing system (outdoor v. indoor), diet (with corn grain silage v. without corn grain silage) and gender (barrows v. gilts) on performance, carcass traits, meat quality and intramuscular collagen (IMC) characteristics. During the trial period of 14 weeks, each group was housed in a pen of 12 m 2 , and the outdoor-reared animals had access to a paddock of 24 m 2 . Pigs were fed a diet computed according to standard requirements and supplied on a basis of 9% of metabolic weight (live weight 0.75 ). Pigs were slaughtered at 110.69 6 0.85 kg. The rearing system did not significantly affect growth, hot and cold dressing, meat quality of m. longissimus lumborum or IMC. Outdoor pigs had less (P , 0.05) backfat thickness, slightly higher (P 5 0.082) lean percent and a meat with lower pH and fat than the conventional system. In light of these results, alternative pig rearing systems with indoor space and free outdoor access could be an interesting production system for the pigs. Compared with the pigs fed diets with corn grain silage, those fed diets without corn had higher (P , 0.05) lean, ham percentage and IMC content, lower (P , 0.05) neck percentage but similar main tissue components of the ham and meat quality. Compared with the gilts, barrows were fatter and showed a meat with different physico-chemical traits, which was slightly more tender and had similar IMC properties.

Streszczenie. W pracy przedstawiono wyniki badań dotyczących zależności między obiektywną oceną barwy i jej zmianami (∆) po 48 h przechowywania a standardowymi wyróżnikami jakości mięsa wieprzowego. Mięso do badań pozyskano od 30 tuczników F1 (wbp × pbz) pochodzących ze skupu na terenie woj. kujawsko-pomorskiego. Na próbach pobranych z mięśnia longissimus lumborum, 48 h po uboju, zmierzono zakwaszenie (pH), oznaczono intensywność barwy, zawartość barwników mięśniowych oraz określono właściwości technologiczne mięsa, tj.: wodochłonność, swobodny wyciek soku, wyciek termiczny. Barwę mięsa mierzono 48 i 96 h po uboju w systemie CIE L*a*b*, wyliczono nasycenie barwy C* i ton barwy h°. Wykazano istotne zmiany barwy mięsa w czasie 48 h jego przechowywania w wartościach parametrów barwy a*, b* i h° (p ≤ 0,01). Największe zmiany stwierdzono w udziale barwy żółtej (∆b*) i tonie barwy (∆h°). Uzyskano znaczące zależności pomiędzy parametrami barwy mięsa L*, a*, b* i tonu barwy h° w czasie 48 i 96 h po uboju a kwasowością mięsa (pH48), intensywnością barwy, barwnikami mięśniowymi oraz swobodnym wyciekiem soku (p ≤ 0,01; p ≤ 0,05). Uzyskane wartości korelacji prostej między parametrami barwy a cechami jakości mięsa mierzonymi 48 h po uboju wskazują na istotną rolę cech jakości mięsa w kształtowaniu parametrów jego barwy. Słowa kluczowe: mięso wieprzowe, cechy fizyczne, jakość mięsa Wstęp Jednym z ważniejszych wyróżników jakości technologicznej i konsumpcyjnej mięsa wieprzowego jest jego barwa (Karamucki, 2008). Obiektywna ocena barwy w skali CIE L*a*b* i CIE L*C*h° pozwala na niezależne określenie parametru L*, tj. jasności barwy, zawierającej się między bielą (100%) i idealną czernią (0%), parametru a*, będącego miarą czerwoności, parametru b*, będącego miarą żółtości, oraz nasycenia C* i tonu barwy h° (Karamucki, 2008).

SummaryBackground. More restrictive requirements concerning food production safety will bring about the process of withdrawing GM plants, including soya, from animal feed mixtures starting in 2017. At present, imported extracted soya meal is the base to make complete-portion mixtures used in pig feed. The soybean meal will have to be replaced by legumes produced in Poland. The aim of the research was a comparison of meat quality coming from pigs fed on complete-portion mixtures on the base of soya meal and complete-portion mixtures with an addition of pea and with an addition of lupine. Material and methods. Meat of 32 crossbred fatteners (plw × pl) was tested. Half of them were fed a soya-share diet (K) and the other (D) a 20-38.5% pea and lupine share diet. In the longissimus lumborum muscle the pH45 and pH48h values and basic chemical composition were determined, as well as technological properties of the meat. The colour of the meat was also analysed with Minolta CR 310 apparatus, as well as sensorially, while its marbling and firmness were tested only sensorially. Results. The assessed meat from both groups, i.e. control (K) and experimental (D), displayed good technological and sensorial properties and colour parameters. Moreover, the meat was tender with a beneficial protein and intramuscular fat content. Conclusion. No negative influence on obtaining good quality meat without any significant differentiation in its parameters was observed from substituting soybean meal for legume seeds in feed mixture.

The aim of the study was to examine the effect of gene polymorphism on the development of the reproductive system in 100 Polish Large White and 100 Polish Landrace gilts. Gilts were slaughtered when they reached 100 kg, and their uterus weight and length, as well as the ovary weight and volume were evaluated. Differences between gilts of both breeds were observed in some traits of the reproductive system, such as the uterine weight without the broad ligament (P ≤ 0.05) and the uterine capacity (P ≤ 0.01). Polish Landrace gilts were characterized with higher uterine weight and higher uterine capacity; they were also younger at the time of slaughter (P ≤ 0.05). No BB homozygote relative to the oestrogen receptor gene was found in the examined populations of Polish Landrace gilts. Also, a very low number of gilts with the AA genotype relative to follicle stimulating hormone gene was observed in both populations. Polymorphism of the examined genes had an effect on numerous traits which define the size of particular uterine sections, and thus it influenced the development of potential fertility of gilts before they entered the reproductive cycle. Based on our results we can conclude that genetic determination of reproductive potential occurs already in prepubertal gilts. The results may be used for the prognosis of fertility potential in gilts.