Pigeons have been the subject of research in the past, but the knowledge gained is incomplete and must be extended. The aim of the study was to provide information about differences in carcass weight and measurements, carcass composition, proximate chemical composition, acidity, electrical conductivity, color attributes, the texture, rheological properties and microstructure of the meat, and some biometric characteristics of the digestive system in carrier and King pigeons, and also to determine if the two compared breeds meet the expectations of pigeon meat consumers to the same extent. The study involved 40 carcasses from carrier pigeons and King pigeons after three reproductive seasons. The chemical composition was determined by near-infrared transmission (NIT) spectroscopy, color coordinates according to CIELab, the texture according to Texture Profile Analysis (TPA) and Warner–Bratzler (WB) tests, and the rheological properties of meat according to the relaxation test. The compared pigeon groups differed significantly (p < 0.05) in carcass weight and measurements, carcass composition (except breast muscle percentage), chemical composition (except leg muscle collagen content) and electrical conductivity, lightness (L*), yellowness (b*), chroma (C*) and hue angle (h*), textural characteristics (except cohesiveness and Warner‒Bratzler shear force), rheological properties, microstructure of the pectoralis major muscle, as well as the total length of intestine and its segments, duodenal diameter, weight of proventriculus, gizzard, liver, heart, and spleen. The sex of the birds had a significant (p < 0.05) effect on the carcass weight, chest circumference, carcass neck percentage, breast muscle collagen content, and caeca length. The genotype by sex interaction was significant (p < 0.05) for fat content, collagen content, hardness, sum of elastic moduli and sum of viscous moduli of the pectoralis major muscle, protein and collagen content of leg muscles, duodenal and caecal length, jejunal and ileal diameter, and spleen weight. The obtained results show a significant effect of genetic origin and sex on the nutritive and technological value of the meat, and on the digestive system development of the pigeons.

The aim of the study was to determine body weight and dimensions, body conformation, length of the esophagus, length of intestine and its segments, as well as weight of internal organs and their proportions relative the body weight of broiler chickens from three commercial lines - Ross 308, Hubbard Flex and Hubbard F15. At the age of 42 days, Ross 308 chickens had significantly (p≤0.05) shorter trunk, but greater chest circumference and compactness index, as well as shorter esophagus and longer large intestine compared with Hubbard F15. The longest large and total intestine was found in Ross 308 broilers. Chicken genotype had no significant effect on the percentage of the main internal organs, i.e. liver, heart, proventriculus, gizzard, and spleen. In the analyzed broilers, the coefficients of correlation between body weight and dimensions and the length of the esophagus, small intestine, caeca and large intestine were low and not significant. This study provides information relevant to breeding practice, including that the development of internal organs in broiler chickens raised under intensive conditions has an effect on their meat characteristics.

The aim of the study was to compare P33 (Polish Pekin), P8 (Danish Pekin), and LsA (English Pekin) ducks after 2 reproductive seasons for carcass composition and some meat quality traits. A total of 48 duck carcasses (8 male carcasses and 8 female carcasses of each genotype) were studied. Whole carcasses were dissected, and pH and electrical conductivity of the breast and leg muscles were determined 24 h postmortem. After dissection, breast and leg muscles were sampled to determine proximate composition, some minerals, and physicochemical properties. Breast muscles were also analyzed for textural characteristics, microstructural characteristics, and rheological properties. At 112 wk of age, genotype and sex were found to have no significant effect on carcass weight and percentage of carcass components. The genotype of the birds had a significant effect on the water and fat content in the pectoral and leg muscles, as well as protein and collagen in the leg muscles. The origin of the ducks had a significant impact on the magnesium content in pectoral muscles and Warner-Bratzler shear force pectoralis muscle major, as well as the electrical conductivity of the leg muscles. The differences in duck genotype had a significant effect on the sum of elastic moduli, fiber cross-sectional area, fiber perimeter, and vertical fiber diameter of pectoralis major muscle. Regardless of the genetic origin, breast muscles from 112-week-old males had a lower fat content, and male leg muscles contained more water and protein and less fat and collagen than the female muscles. The genotype by sex interaction was significant for the content of breast muscles, skin with subcutaneous fat, and neck percentage and for the water and fat content in breast and leg muscles.

The study was aimed to compare carcass traits, physicochemical and textural properties of meat in two different genotypes of Pekin ducks with regard to sex effect. The study involved 120 Pekin ducks - 30 males and 30 females of strain P33 (Polish native Pekin ducks) and 30 males and 30 females of Star 53 HY (commercial hybrid Pekin ducks). At 49 d of age, 48 birds (12 males and 12 females of each genotype) were selected for dissection. After the dissection, meat samples were collected to determine meat quality traits. The studied Pekin ducks of different genotype showed significant differences in body weight, carcass weight, dressing percentage, as well as percentages of breast muscles, skin with subcutaneous fat, abdominal fat, neck, and remainders of eviscerated carcass with neck. Duck genotype had an effect on the content of crude protein, crude fat, Na, K, P, Zn, pH24, electric conductivity (EC24), cooking loss, L*, a*, most textural traits of breast muscle, and also Na, Mg and Fe content, EC24, drip loss, cooking loss and L*, a* and b* colour coordinates of leg muscles. Regardless of genetic origin, males exhibited higher BW, carcass weight and carcass neck percentage, as well as lower redness, hardness, chewiness and gumminess of breast muscle compared to females. The genotype sex interaction was significant for the crude fat content and cooking loss of breast muscle, and for the yellowness of leg muscle. Star 53 HY ducks are more suited for broiler production due to their higher body weight and dressing percentage. Their breast and leg meat are characterized by more beneficial chemical composition but has poorer sensory and textural properties compared to the meat of P33 ducks.

Native breeds of ducks have been the subject of many studies in the past, yet the relevant knowledge is still incomplete and needs to be further expanded. The objective of this study was to provide information about differences in growth performance, dressing percentage, carcass composition and digestive morphometry among three lines of Pekin ducks from conservation flocks raised in Poland. The study used 180 sexed Pekin ducks—30 males and 30 females of line P33 (ducks of Polish origin), 30 males and 30 females of line P8 (ducks of Danish origin), and 30 males and 30 females of line P9 (ducks of French origin). Throughout the study (49 d), ducks were confined indoors in six pens. Birds were fed complete commercial diets ad libitum and had unrestricted access to water. The compared lines of ducks differed significantly in body weight from 1 to 49 d of age except of ducks of both sexes at 14 d. At 49 d of age, significant differences were observed between the tested ducks in all the body measurements. Duck genotype had a significant effect on preslaughter body weight, carcass weight and breast muscle, neck and remainders contents, caeca length, liver weight and gizzard percentage. The results show that the tested ducks were significantly different and unique, mainly in terms of the body biometric characteristics.

The aim of the study was to compare P33 (Polish Pekin), P8 (Danish Pekin), and P9 ducks (French Pekin) for body weight, dressing percentage, carcass