Maria Bocian

Polymorphism in Coding and Non-coding Regions of the MyoD Gene Family and Meat Quality in Pigs*

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 pH1 and pHu 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.

Influence of rearing system, diet and gender on performance, carcass traits and meat quality of Polish Landrace pigs

Forty-eight Polish Landrace pigs (initially 32.43 ± 0.70 kg live weight) were assigned to a 2 × 2 × 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 m2, and the outdoor-reared animals had access to a paddock of 24 m2. Pigs were fed a diet computed according to standard requirements and supplied on a basis of 9% of metabolic weight (live weight0.75). Pigs were slaughtered at 110.69 ± 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 = 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.

THE EFFECT OF H-FABP GENE POLYMORPHISM ON CARCASS AND MEAT QUALITY IN THE POLISH NATIVE ZŁOTNICKA SPOTTED PIG

To estimate the relationships between the H-FABP/HinfI genotype and quality of carcass and meat traits, a total of 30 pigs Zlotnicka Spotted breed were investigated. Blood samples were taken during slaughter into test tubes containing anticoagulant K3EDTA and stored at -25oC until analysed. The H-FABP genotypes were identified with PCR-RFLP method using HinfI restriction endonuclease. Meat physico-chemical traits were determined in the longissimus lumborum (LL) muscle. Two alleles (H and h) and three genotypes (HH, Hh and hh) were identified within studied pig sample. The effect of H-FABP gene polymorphism was showed on body weight at slaughter and cold carcass weight, where both weights of body were higher in hh group (113.33 kg and 84.27 kg) than in Hh (106.06 kg and 76.40 kg) and HH (103.75 kg and 73.40 kg); P≤0.05 and P≤0.01. Differences between the means of backfat thickness for three genotype groups were not significant. However, significant relations were found between the polymorphism at locus H-FABP/HinfI and basic chemical meat composition. The pigs meat with genotype hh were marked by a higher intramuscular fat content (2.64%) compared to HH group (1.99%); P≤0.05. Values of all analysed traits were within ranges indicating good meat quality of the Polish native Zlotnicka Spotted pigs.

Morphometric Characteristics of the Reproductive System in Polish Large White and Polish Landrace Gilts at 100 Kg Body Weight / Charakterystyka morfometryczna układu rozrodczego loszek wielkiej białej polskiej i polskiej białej zwisłouchej przy masie ciała 100 kg

Abstract 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. STRESZCZENIE W niniejszej pracy oceniano u 160 loszek (wbp n = 80; pbz n = 80) stan rozwoju narządów rodnych pobranych przy uboju przy masie ciała 100 kg. Ze względu na duże zróżnicowanie wieku przy uboju (140-190 dni) utworzono trzy grupy zwierząt: A (poniżej 160 dni), B (od 160 do 180 dni) i C (powyżej 180 dni). Nieco wcześniej osiągały masę ubojową loszki rasy pbz niż rasy wbp (P≤0.05). Masa macicy zwiększała się wraz z wiekiem zwierząt, jednak ze względu na dużą zmienność i dużą wartość odchylenia od średniej, statystycznie istotne różnice wykazano tylko między grupą loszek A i B obu ras łącznie (120.57g wobec 148.83 g; P≤0.05). Większe różnice związane z wiekiem loszek wykazano dla długości szyjki macicy między porównywanymi grupami (P≤0.01). Długość prawego i lewego rogu macicy podana łącznie wykazała istotny wzrost wraz z wiekiem zwierząt u loszek rasy wbp (P≤0.05). Proporcja masy macicy bez więzadła do długości rogów (g/cm) była istotnie większa w grupie B, niż w grupie A u loszek obu ras łącznie (P≤0.05), co może wskazywać na pogrubienie ścian macicy. Pojemność macicy była wyraźnie większa u zwierząt starszych, lecz ze względu na dużą zmienność tej cechy nie wykazano istotności różnic między grupami. Długość i średnica jajowodów, masa poszczególnych jajników, ich suma i wymiary nie wykazały systematycznych zmian związanych z wiekiem i rasą świń. Jednak wielkość jajników określona metodą wolumetryczną i podana jako objętość jajników u loszek obu ras była istotnie większa w grupie B w porównaniu z C (P≤0.01). Nie wykazano istotnych różnic związanych z rasą w morfometrycznej budowie układu rozrodczego niedojrzałych płciowo loszek wbp i pbz. Jednak wpływ wieku na badane cechy był bardziej wyraźny u loszek rasy wbp niż pbz.

Differences in piglets sex proportion in litter and in body weight at birth and weaning and fattening results.

The aim of the study was presentation the differences in piglets sex proportion in litter and its effect weaning and fattening results. The study was carried out on 133 piglets belonging to 10 litters being progeny of PLW breeding sows and PL boars. Individual piglets growth rate from 1 to 28 day and also during fattening period were recorded. Obtained results were statisticaly analysed including sex proportion. It was showed that in litters was born more gilts (54.89%) than boars (45.11%). Results of weaning piglets to 28 day of life showed higher survival rate of gilts during the weaning period (87.67% vs. 76.67%). Gilts were born heavier as compared to boars (1.35 kg vs. 1.23 kg) and during fattening they achieved higher body weight than barrows (104.48 kg vs. 101.17 kg) (P ≤ 0.05).

Backfat thickness during gestation and lactation period in respect to reproductive performance of primiparous and multiparous sows.

The aim of the study was to determine the effect of backfat thickness measured during gestation and after lactation of primiparous and multiparous sows on the value of reproductive traits. Backfat thickness was determined at mating, at 105 day of gestation and after weaning and were correlated with selected reproductive indicators including placenta weight. The study was carried out 20 primiparous and 20 multiparous sows of Polish Landrace breed. The nutrition and housing conditions were the same for all pigs. Backfat and loin depth (P2, P4 , P4 M) were measured using PIGLOG 105 device. The evaluation of reproductive performance included the weight of placenta at parturition, the number of born piglets, litter weight, piglet body weight at birth, at 21 and at weaning (28 days). Multiparous sows were characterized by greater fatness than primiparous sows in all periods of use. In all examined sows the backfat depth during gestation increased and decreased after lactation. Those changes were more pronounced in multiparous sows than in primiparous sows (P ≤ 0.01). Multiparous sows born and reared more piglets to 21 and 28 days of life (P ≤ 0.01). There have not been dead piglets in primiparous litters. Litters weight from multiparous sows were higher than from primiparous sows only at birth (P ≤ 0.01) and similar in rest periods of rearing. Individual body weight of piglets from primiparous was higher than that from multiparous sows at 21 and 28 days of life (P ≤ 0.01). Fatness changes during lactation, particularly in multiparous sows, were positively correlated with litter weight at birth and negatively correlated with piglet’s weight at 21 and 28 days of life and their daily gains (P ≤ 0.05). Correlations between placenta weight and backfat thickness during lactation were positive in both groups of sows (P ≤ 0.01).

Polymorphisms of the osteopontin gene and level of its expression in the reproductive tract of sows.

Abstract The aim of the study was to find osteopontin gene (OPN) polymorphisms as potential mutations affecting the expression level of genes in the ovaries, uterus and oviduct of sows. The material consisted of 71 F1 sows (Polish Large White × Polish Landrace). In the first stage several polymorphisms in the promoter region, intron 6, exon 6 and 7 of the OPN gene were found. The parameters estimated were the frequency of alleles and genotypes, observed heterozygosity and gene diversity, PIC, and chi2 factors. Chi2 values allow for assessment of genetic equilibrium in the population. Thus, the loci OPNp3-4 and OPNe6-1 were in genetic disequilibrium while locus OPNe6-Knoll showed genetic equilibrium. Also real-time PCR analysis to determine the expression dynamics of the OPN gene in examined tissues was performed in relation to “housekeeping” genes. A comparison was made for relative expression in different tissues and different mutations. The highest expression pattern was observed in the oviduct. Based on the novel polymorphisms a significant correlation between the OPN genotype and OPN expression (mRNA) level in the ovary, oviduct, uterine body and uterine horn was observed. In the second stage, the levels of expression of the OPN gene in individual tissues, traits of reproductive performance and reproductive tract traits of sows were also compared. The expression levels in the uterine body and oviduct were related to the age of mating, cervical length, litter weight at birth, number of active nipples, age at slaughter and body weight at mating. Streszczenie Celem badań było znalezienie polimorfizmu genu osteopontyny (OPN) jako potencjalnego miejsca mutacji mającej związek z ekspresją tego genu na poziomie mRNA w jajnikach, macicy i jajowodzie. Materiał stanowiło 71 loch ras wbp × pbz. W pierwszym etapie badań opracowano kilka polimorfizmów w obrębie promotora, intronu 6 oraz eksonów 6 i 7 genu osteopontyny. Oszacowano frekwencję genotypów i alleli, heterozygotyczność oczekiwaną i spodziewaną,, współczynniki PIC oraz chi2. Stwierdzono, że w obrębie dwóch loci badana populacja nie znajdowała się w stanie równowagi genetycznej, natomiast w trzecim locus, tj. OPNe6-Knoll taka równowaga została zachowana. Wykonano również analizę real time PCR w celu określenia poziomu ekspresji w badanych tkankach w odniesieniu do genów ulegających stabilnej ekspresji w układzie rozrodczym. Dokonano porównania poziomu relatywnej ekspresji w różnych tkankach i w odniesieniu do różnych mutacji. Najwyższy poziom ekspresji odnotowano w jajowodzie. Bazując na nowo opracowanych mutacjach zaobserwowano wiele istotnych zależności pomiędzy genotypem OPN a poziomem ekspresji w jajniku, jajowodzie, rogach i trzonie macicy. W drugim etapie badań porównywano poziom ekspresji w poszczególnych częściach układu rozrodczego i poziom cech związanych z rozrodem i budową układu rozrodczego. Poziom ekspresji w jajowodzie miał związek z wiekiem krycia, liczbą aktywnych sutków, długością szyjki macicy, masą miotu przy urodzeniu, i masą ciała przy uboju. Natomiast poziom ekspresji w trzonie macicy miał związek z długością szyjki macicy, masą miotu przy urodzeniu i wiekiem uboju, a także wiekiem krycia i masą ciała przy kryciu.

Pork quality with special emphasis on colour and its changes during storage

The aim of the study was to evaluate the quality of pork meat, including its colour after 24, 48, and 72 hours from the slaughter and its changes during storage. The meat was obtained from 52 crossbreed porkers F1 (Polish Large White x Polish Landrace), gilts and hogs in equal amounts. The assessment of the quality of the meat was performed in 48 hours after slaughter on the samples of the longissimus lumborum muscle. The meat was analysed in respect to its acidity (pH45 and pH48h), technological properties, and the level of the muscle colours. The sensory evaluation of the meat was conducted in terms of the intensity of colour, marbling, and firmness. The chemical composition of the meat and its tenderness was also evaluated. The colour of meat was measured by the use of the Minolta CR-300 apparatus in CIE L*a*b* system (L* - lightness, a* - participation of redness, b* - participation of yellowness), where the saturation of colour C* was calculated as well as the hue angle ho after 24, 48, and 72 hours from the slaughter. The changes (∆) of colour parameters after 24 h and 48 h of storage were calculated. Results demonstrated that the examined pork had the proper technological properties, it was tender (41.93 N/cm), and low in collagen (0.89%). During the storage of meat after 24, 48, and 72 hours from the slaughter, many significant changes appeared in the parameters of meat colour that is in L*, a*, b*, in saturation with C* and in the hue h° (P<0.01). The values of colour L* were changing into lighter (P<0.01), whereas the participation of colour red a*, yellow b* and the saturation of colour C* and its hue ho showed an increasing trend during storage (P<0.01). It was noticed that there are significant correlation coefficients between the colour parameters L*, a*, b*, its saturation C*, and hue ho, and the technological quality characteristics, the sensory intensity of colour, the content of muscle pigments at 24, 48 and 72 h after slaughter (P<0.01; P<0.05).

Influence of age at first farrowing of maternal breed sows on their reproductive performance

The aim of the study was to determine the relationship between the age of the first farrowing of maternal breed sows Polish Large White (PLW) and Polish Landrace (PL), and the parameters of the previously conducted life performance test and the results of the reproductive performance. Offspring of 4-5 litters born in 2009-2014 years from 564 PLW and 300 PL sows were subjected to the analysis. A total of 4,064 litters. In the performance test took into the consideration the body weight on the day of the assessment, standardized daily gains, and standardized thickness of backfat, the percentage of meat content in a carcass and the value of the selection index. In the reproductive assessment took into account the age of the first farrowing, the number of alive and dead piglets in a litter, the number of piglets in 21st day of life, the mortality rate of piglets, the percentage of gilts in a litter. The obtained results were compiled and analyzed in three groups of sows formed according to the age of the first farrowing: group I ≤ 340 days, II 340-380 days and III > 380 days. The age of the first farrowing varied between the groups of sows and ranged from 322 to 400 days. It was shown that the gilts demonstrating in the performance test the greatest body weight, the largest gains, and the smallest meatiness obtained the highest index value and were characterized by the youngest age of the first farrowing (P<0.01 and P<0.05). The number of born and reared piglets till 21st day, was not significantly related to the age of the first farrowing.

Quality and dietary value of pork meat of the Puławska and Złotnicka Spotted breeds, and commercial fattening pigs

Abstract 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/cm2). 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.