Anna Rekiel

Expression of apoptosis-related proteins in involuting mammary gland of sow.

The expression of apoptosis-related proteins: TGF-beta1 (local inductor), TGF-beta-receptor, Bax (promoter), Bcl-2 (inhibitor) and CPP-32 (executor of apoptosis); the subcellular distribution of Bax; as well as the number and morphology of apoptotic cells in low-, moderate-, and high-involuted mammary glands of sow (four to six days after weaning) were investigated. The immunohistochemical study demonstrated a statistically significant increase in the integrated optical density (IOD) of lobuloalveolar mammary tissue labelling with anti-Bax antibody from low- through moderate-, to high-involuted glands. The immunoelectron microscopy revealed that Bax was localised in the cytosol, on the membranes of mitochondrium and rough endoplasmic reticulum, in nuclear envelope pores, and over heterochromatin of mammary epithelial cells. The increase in Bax/Bcl-2 ratio (2.3, 2.6 and 5.6 for low-, moderate-, and high-involuted glands, respectively) indicated the increasing susceptibility of mammary epithelial cells to apoptosis in the course of involution. The highest Bax/Bcl-2 ratio in high-involuted glands coincided with the highest expression of CPP-32 (caspase 3), TGF-beta1 and TGF-beta1 receptor. The number of apoptotic cells (simultaneous TUNEL and Hoechst 33342 staining) was 2.7, 3.4 and 3.8% for low-, moderate-, and high-involuted glands, respectively. The ultrastructural evaluation showed characteristic morphological features of apoptosis such as: margination and condensation of chromatin; pyknosis and fragmentation of the nucleus; and formation of apoptotic bodies. Phagocytosis of apoptotic cells by macrophages was also documented. The results of the present study suggest the involvement of Bax/Bcl-2 check-point in the regulation, CPP-32 in the execution, but TGF-beta1 in the induction of apoptosis of mammary epithelial cells in the involuting mammary gland of sow.

Effect of restricted feeding and realimentation periods on pork quality and fatty acid profile of M. longissimus thoracis.

An experiment with 94 fattening pigs (48 gilts and 46 barrows) was conducted to determine the effect of feeding 25% restricted diets at different body weights on meat quality and fatty acid profile of M. longissimus thoracis (LT). During the 84 days of the experiment (4 periods, 21 days each), animals with an initial weight of about 31 kg were fed in different periods of observation ad libitum (A) or restricted diets (R) in groups AAAA, AARA, RAAA and RARA. After 21 days of the experiment, the restricted-fed pigs, compared to those fed ad libitum, had a lower total fat content of M. longissimus thoracis (P<0.05), higher shear force (P=0.068), and lower proportions of SFA (C14:0, C18:0 P<0.05) and MUFA and higher proportions of PUFA (C20:4, C22:4 P<0.05) in the fatty acid profile. Three weeks after the restricted feed supply was lifted, the total fat content in LT muscle was higher than in animals fed ad libitum throughout (2.34 vs. 2.02), very close after the next 3 weeks of realimentation (3.16 vs. 3.15) and lower after another 3 weeks (3.19 vs. 3.49). Regardless of the time at which restricted feeding was started and the number of restricted feeding periods, the total fat content in the LT muscle at the end of the experiment was similar or lower in groups RAAA, AARA and RARA, compared to group AAAA. The coefficient of correlation between the total fat content in LT and the shear force was -0.36 (P<0.01). Colour, pH and drip loss did not depend on the level of nutrition. After 84 days of observation, animals from groups RARA and AARA, compared to pigs from groups AAAA and RAAA, were characterized by a slightly higher shear force of LT, lower SFA and MUFA (P<0.001), and higher n-6 PUFA (P<0.01) and n-3 PUFA (P<0.01) proportions in the fatty acid profile. The fatty acid profiles of AAAA pigs and pigs undergoing a 63-day realimentation period (RAAA) were similar. Regardless of the feeding scheme, the n-6:n-3 ratio exceeded 10 in all the groups.

Effect of sow prolificacy and nutrition on preand postnatal growth of progeny – a review

Abstract Weakened growth and development of embryos as well as of fetuses or their organs (IUGR) show a relationship with increasing sow fertility. When aiming to increase birth weight in piglets and reduce within-litter variation in piglet body weight, efforts should be made to maintain a favourable maternal environment (uterus-placenta-embryo). Intrauterine undernutrition can be limited through the hormonal and/or nutritional treatment of pregnant sows. This has an effect on prenatal myogenesis, resulting in better development of skeletal muscles, higher birth weight of piglets, and progression in postnatal growth rate.

Effect of Sex Ratio in the Litter in Which Polish Large White and Polish Landrace Sows were Born on the Number of Piglets Born and Reared

Effect of Sex Ratio in the Litter in Which Polish Large White and Polish Landrace Sows were Born on the Number of Piglets Born and Reared The aim of the study was to determine the effect of sex ratio in the litter in which Polish Large White (PLW) and Polish Landrace (PL) sows were born on the number of piglets born and reared to 21 days of age. Results obtained in nucleus herds from one breeding region were analysed. A total of 518 multiparous sows (179 PLW and 339 PL) were evaluated based on data from their litters (790 PLW and 1540 PL litters). The proportion of females in the litter in which the sow was born served as a basis for dividing the females into groups: group 1 <40%, group 2 - 40-50%, group 3 - 50-60%, group 4 - 60-70%, group 5 >70%. Significant differences in the average number of piglets born were found between the groups for PLW sows; compared to sows from groups 1, 2 and 3, females from group 5 gave birth to 8.0% (P≤0.05), 9.4% (P≤0.01) and 6.6% more piglets (P≤0.01), respectively, and compared to sows from group 2, those from group 4 gave birth to 5.1% more piglets (P≤0.05). The average number of piglets born and reared to 21 days by PL sows did not differ significantly between groups. The greater the proportion of females in the litter in which the PLW sow was born, the greater the preweaning mortality of piglets: 0.79, 0.87, 0.99, 1.02 and 1.24 piglets in groups 1 to 5, respectively. Preweaning mortality of PL piglets (0.93, 0.89, 0.81, 0.76 and 0.65 in groups 1 to 5, respectively) decreased with increasing proportion of females in the litter of origin and was lower than that of PLW piglets. It seems appropriate to account for the sex ratio of the litter in which the gilts were born when selecting them as mothers of the next generation as part of herd replacement; this parameter may improve fertility and production efficiency. Wpływ udziału płci w miocie pochodzenia loch rasy wielkiej białej polskiej i polskiej białej zwisłouchej na liczbę prosiąt urodzonych i odchowanych Celem pracy była ocena wpływu udziału płci w miocie pochodzenia loch rasy wielkiej białej polskiej i polskiej białej zwisłouchej na liczbę prosiąt urodzonych i odchowanych do 21. dnia życia. Analizowano wyniki uzyskane w stadach zarodowych z jednego rejonu hodowlanego. W ocenie loch wieloródek - 179 rasy wbp i 339 rasy pbz - podstawą były informacje pozyskane dla pochodzących od nich miotów; łącznie było to 790 miotów wbp i 1540 pbz. Udział osobników płci żeńskiej w miocie pochodzącym od lochy-matki był podstawą podziału samic na grupy: grupa 1 <40%, 2 - 40-50%, 3 - 50-60%, 4 - 60-70%, 5 >70%. Dla loch wbp wykazano między grupami istotne różnice w średniej liczbie prosiąt urodzonych; samice z grupy 5 w porównaniu do loch z grup 1, 2 i 3 urodziły więcej prosiąt, odpowiednio o: 8,0% (P≤0,05), 9,4% (P≤0,01), 6,6% (P≤0,01), a z grupy 4 vs. 2 o 5,1% (P≤0,05). Średnia liczba prosiąt urodzonych i odchowanych do 21. dnia przez lochy pbz nie różniła się istotnie pomiędzy grupami. Im większy był udział samic w miocie pochodzenia loch rasy wbp, tym większe były upadki prosiąt w czasie odchowu; w grupach 1-5 odpowiednio: 0,79, 0,87, 0,99, 1,02, 1,24 szt. Dla rasy pbz przy zwiększającym się udziale samic w miocie pochodzenia upadki prosiąt podczas odchowu przy matkach malały, przy czym ich poziom był mniejszy niż dla rasy wbp; w grupach 1-5 wyniosły odpowiednio: 0,93, 0,89, 0,81, 0,76, 0,65 szt. Wydaje się uzasadnione uwzględnienie udziału płci w miocie pochodzenia loszek przy ich wyborze na przyszłe matki w ramach prowadzonego remontu stada; cecha ta może poprawiać płodność i efektywność produkcji.

Effect of restricted feeding and realimentation periods on compensatory growth performance and physiological characteristics of pigs

An experiment with 94 growing pigs was conducted to determine the effect of a feed restriction of 25% on performance, carcass quality, organ weight, blood hormone levels and some biochemical parameters. The experiment consisted of four periods of 21 days each. In the different periods animals (initial BW about 31 kg) were fed ad libitum (A) or restrictively (R), resulting at day 84 in Groups AAAA, AARA, RAAA and RARA. During Period I, the daily gain of restrictively fed pigs (Group R) was about 22% lower than from Group A (p < 0.01). During realimentation, compensatory growth was observed in Period II for Group RA, and in Period IV for Group RARA. No compensatory growth was observed for Group AARA, which was fed restrictively in Period III only (day 43 to 63). For the whole experiment (day 1 to 84), BW gain and feed conversion amounted to 830 g/d and 3.03 kg/kg, 798 g/d and 2.99 kg/kg, 813 g/d and 2.86 kg/kg, and 800 g/d and 2.78 kg/kg for Groups AAAA, AARA, RAAA and RARA, respectively. The decrease of liver and kidney weights as a result of restricted feeding was not significant and after three weeks of realimentation these differences almost disappeared. At day 3 after realimentation of restrictively fed pigs (Group RA) the growth hormone level was significantly increased, but at day 14 of realimentation this level turned out to be lower (p < 0.01) than in pigs fed ad libitum (Group AA). This was considered as a further indication of compensatory growth.

Effect of Piglet Birth Weight on Carcass Muscle and Fat Content and Pork Quality – A Review

Abstract Piglet birth weight is determined by the maternal environment, intrauterine crowding, and nutrition, which influence embryonic and fetal survival and, as a result, fertility. The internal environment regulates prenatal myogenesis and muscle fibre number nutritionally and hormonally. The growth and metabolic differentiation of muscle fibres take place during the postnatal period. The effect of intrauterine undernutrition on myogenesis and on fetal growth and development (IUGR) is reflected in the low piglet birth weight and its high within-litter variation. Slaughter traits are determined by many factors, including genetic (breed), environmental (nutrition) and preslaughter handling. Slaughter traits and the physico-chemical and sensory characteristics of meat are dependent on prenatal myogenesis and neonatal weight. Optimized body weight of newborn piglets is conducive to improving quantitative traits (meatiness, fatness) and qualitative traits. However, slaughter traits are also influenced by many other differentiating factors, which is reflected in research results. Muscle fibres become metabolically differentiated during postnatal development, and one of the factors of large variation in pig meat quality traits is variation in the proportions of different fibre types in mature muscle. Considering the divergent opinions among scientists about the effect of prenatal myogenesis and piglet birth weight on slaughter value and pork quality, as well as the existence of areas that have received little investigation, it is justified to continue research in this area.

Effect of Piglet Birth Weight on Selected Characteristics of Pork

Abstract The objective of the study was to determine how different birth weights of piglets influence some chemical and physical characteristics of pig meat. Piglets were grouped according to birth weight: ≤1.30 kg (group I), 1.31-1.70 kg (group II), ≥1.71 kg (group III). Animals were reared and fattened under standardized housing and feeding conditions. Tests were conducted with 60 samples of meat (20 per group) collected from the right side of the carcasses (M. longissimus lumborum) of threebreed crosses of (Polish Landrace × Polish Large White) × Duroc (barrows to gilts, 1:1), which were slaughtered at about 180 days of age. Determinations were made of basic chemical composition, colour of meat, drip loss, shear force value, and fatty acid profile. It was found that the birth weight of the piglets affects meat colour (redness), crude fat content and the proportion of some fatty acids (C16:1, C20:1 n-9, C20:2 n-6, C20:5 n-3).

Comparison of changes in fatness of sows in high pregnancy and at weaning and determination of their association with reproduction results and rearing of piglets

Sixty crossbred sows were investigated for the effect of the level of fat reserves in high pregnancy and pre-weaning changes in lipid reserves on reproductive performance of sows and rearing of piglets. At 104 days of pregnancy and at weaning, sows were analysed for body weight, P2 and P4 backfat thickness and M. Longissimus dorsi (MLD) thickness at P4M (Piglog 105). Sows were grouped according to mean backfat thickness (P2 + P4)/2 at 104 days of pregnancy into primiparous (P2 + P4)/2>18 mm (group I), primiparous (P2 + P4)/2≤18 mm (group II), multiparous (P2 + P4)/2>20 mm (group I) and multiparous (P2 + P4)/2≤20 mm (group II). The body weight of sows from group I was higher than sows from group II at 104 days of pregnancy (P ≤ 0.05) and at weaning (P ≤ 0.01). As assumed in the experiment, fatness in high pregnant sows (points P2 and P4) was significantly higher in group I than in group II (P ≤ 0.01), and the differences between the groups persisted when piglets were weaned (P ≤ 0.01). At weaning, sows from group II had a significantly greater P4M thickness compared to sows from group I. The differences in backfat thickness in late-pregnant sows in groups I and II and in the loss of fat reserves during a 21-day lactation had no effect on reproduction results and rearing of piglets. Sows lost body weight to a small extent and fat reserves to a moderate degree; the changes were greater in primiparous than multiparous sows, regardless of the group (I or II).

Developments in pig production in the Podlasie region the years 1970–2010

The aim of the study was to determine the changes that have occurred in pig breeding on family farms in the Podlasie region. The questionnaire survey was conducted in 140 farms representative for the whole region and covered three study periods: I – the years 1970–1985, II – the years 1986–2000, III – the years 2001–2010; this revealed changes that have taken place in pig farming, feeding, management, scale of production, and slaughter. It was found that pigs were shifted from conventional diets consisting primarily of farm-produced feeds to more efficient diets based on grains and extracted meals and/or concentrates as well as premixes. Livestock buildings housing several Anna Rekiel, Marcin Sońta, Andrzej Ryczko, Justyna Więcek 94 PDGR – PSAH different species of animals were replaced with piggeries housing only pigs. The animal management system has also changed and the pig-on-litter system was partly replaced with the less labour-intensive non-litter system. As indicated by the survey respondents, the increased supply of pigs for fattening as well as the increased scale of home slaughters have made the production more competitive and profitable. The changes in pig production in the Podlasie region were part of nationwide changes.

The effect of carcass weight on chemical characteristics and fatty acid composition of Longissimus dorsi and Semimembranosus muscles of European wild boar (Sus scrofa scrofa) meat

Abstract: The objective of this study was to investigate the effect of carcass weight on chemical characteristics and fatty acid composition of m. longissimus dorsi and m. semimembranosus of European wild boar (Sus scrofa scrofa) meat. The research was carried out on 50 wild boars shot during four battues at hunting reserves in the central part of Poland. The carcasses were divided into three groups: ≤30 kg (G1), 31–45 kg (G2), and >45 kg (G3). The protein concentration increased with carcass weight (P ≤ 0.01). The concentration of saturated fatty acids was influenced by carcass weight and was higher when weight increased. A significantly higher level of monounsaturated fatty acids (MUFA) was found in the carcasses of wild boars from G3 compared with G1 group (P ≤ 0.01). The content of C18:2n-6 was significantly lower in the lightest carcasses compared with the heaviest (P ≤ 0.05). Statistical analysis confirmed that carcasses weight significantly affected polyunsaturated fatty acids (PUFA) n-3 content. The lightest carcasses contained a significantly higher concentration of PUFA n-3 (P ≤ 0.01). In addition, in G3, the amount of C22:5n-3 was two-fold lower (P ≤ 0.01) than in G1. The research has shown that the meat quality was affected by the carcass weight, resulting better parameters in the lighter than in the heavier carcasses. Therefore, most of the culled wild boars should be squeakers and young boars after the first year of life.