Research Note: Basic chemical composition, physicochemical, and textural characteristics of male and female guinea fowl meat.

The purpose of this study was to compare analyze the quality of meat depending on the type of muscle: breast muscles (m. Pectoralis superficialis and m. Pectoralis profundus) and leg muscles (m. Sartorius and m. Femorotibialis) in relation to the sex of the common guinea fowl (Numida meleagris). For the study, pectoral muscles and leg muscles from 10 females and 10 males at 20 wk of age were used to determine their chemical composition, physicochemical properties, and texture characteristics of the pectoral muscle were determined. Overall, pectoral muscles were characterized by higher protein content, lightness (L*), and electrical conductivity (EC24), and lower redness (a*), and pH24 compared to leg muscles. Leg muscles, on the other hand, were characterized by higher, collagen, intramuscular fat and salt content. In terms of pectoral muscle texture characteristics, males were characterized by lower chewiness value and were less gumminess. In conclusion, it can be said that the sex of the birds affected some of the pectoral muscle texture traits, but did not affect the remaining analyzed features of the pectoral and leg muscles. However, from the consumer's point of view, breast muscles contained more protein and less fat, so they are more dietary compared to leg muscles.

Carcass characteristics, physicochemical traits, texture and microstructure of young and spent quails meat.

The purpose of the study was to compare young (6-wk-old) and spent (52-wk-old) Japanese quail in terms of body weight, carcass characteristics, and some meat quality traits. Whole carcasses were dissected, pectoral muscles and leg muscles were sampled for determination of basic chemical composition and L*a*b* color parameters, while m. pectoralis major was sampled for texture and microstructure traits. Age of quails had a significant effect on body weight, carcass weight, carcass yield, pectoral muscle, abdominal fat and skin with subcutaneous fat, and carcass remainders contents in eviscerated carcass. Spent quails had significantly higher intramuscular fat content in pectoral and leg muscles and protein content in breast muscle, and also lower content of water in breast and leg muscles than young quails. Slaughter age significantly affected lightness (L*) and redness (a*) of pectoral muscles, as well as texture traits (except for cohesiveness) and microstructure of m. pectoralis major, except for thickness of perimysium and endomysium. Regardless of age, quail sex had an effect on the carcass traits studied (except for leg muscle content), intramuscular fat content of pectoral and leg muscles, water content of leg muscles and yellowness of pectoral muscle. In addition, a significant effect of quail sex was found on cutting work, springiness, chewiness and marked microstructural characteristics, except for vertical fiber diameter. The interaction between age and sex was significant for most slaughter and microstructural characteristics and also WB-shear force of m. pectoralis major, and L*, b* pectoral muscles. Higher fatness of carcasses, higher intramuscular fat in meat, and poorer textural and microstructural characteristics of m. pectoralis major spent Japanese quail indicate poorer fulfillment of most consumers' requirements compared to carcasses and meat of young quails.

Carcass, Egg Characteristics and Leg Bone Dimensions of Pigeons of Different Origin.

In the past, studies have been conducted on the evaluation of meat traits of pigeons, but the knowledge obtained is incomplete and needs to be expanded. The purpose of this study was to obtain information on the weight and proportion of carcass elements, femur and tibia bone dimensions, and egg characteristics of meat of King breed and carrier pigeons. For this study, 16 carcasses of carrier pigeons and 16 carcasses of King pigeons were used, with 8 carcasses of males and 8 carcasses of females of each breed. Additionally, 20 eggs evaluated were from carrier pigeons and 20 eggs from King breed pigeons. The carcasses and eggs were obtained from birds that were 12 months old. The compared pigeon breeds differed (p < 0.05) significantly in terms of the weight of the eviscerated carcass with the neck; the content of neck, wings, pectoral and leg muscles in the carcass; as well as in terms of all specified dimensions of tibia and femur length and width. The origin of the pigeons had an effect (p < 0.05) on egg weight and dimensions, egg index, and the other studied egg traits, with the exception of eggshell weight and eggshell yellowness, yolk weight, yolk height, yolk diameter, and yolk index. So far, there have been no studies comparing carrier pigeons and King breed pigeons in terms of femur and tibia bone dimensions, morphological composition and egg dimensions, and egg content traits, which adds to the knowledge in this area and indicates the need for continuation in the future.

The Effects of Slaughter Age and Sex on Carcass Traits, Meat Quality, and Leg Bone Characteristics of Farmed Common Pheasants (Phasianus colchicus L.).

The aim of this study was to determine the effects of slaughter age and sex on the carcass characteristics, meat quality parameters, and leg bone dimensions of common pheasants. The study material consisted of 40 common pheasants, including 10 males and 10 females at 12 weeks of age and 10 males and 10 females at 15 weeks of age. The birds were kept on a farm in a semi-intensive system. The slaughter age had significant effects on the eviscerated carcass weight; the percentage of skin with subcutaneous fat; the wings percentage; electrical conductivity (EC24); the work required to cut the samples (cutting work); redness (a*); the intramuscular fat content in the breast meat; and the protein, intramuscular fat, water, and collagen contents in the leg meat. The sex of the pheasants had significant effects on the eviscerated carcass weight; the contents of leg muscles, skin with subcutaneous fat, and wings in the carcasses; and the electrical conductivity, thermal loss, lightness (L*), and redness (a*) of the breast muscles. It also significantly affected the protein and water contents of the pectoral and leg muscles, the intramuscular fat contents of the leg muscles, the texture traits of the pectoralis major muscle, and all femur and tibia bone dimensions. The results indicate a greater influence of sex compared to slaughter age on the pheasant traits studied. We confirmed the occurrence of a clearly marked sexual dimorphism in birds of this species. Both factors (slaughter age and gender) have significant effects on the nutritional and technological value of pheasant meat. The few studies on meat texture and the dimensions of pheasant leg bones indicate a need for continued research in this area in the future.

Effect of housing system on carcass composition, meat quality, digestive morphometry, and leg bone dimensions of Ross 308 parent broilers.

The aim of the present study was to compare the effects of 2 Ross 308 parent broiler housing systems (SLS-slat-litter system vs. LS-litter-based system) in terms of carcass composition, meat quality traits (chemical composition, texture, physicochemical properties), as well as biometric traits of the digestive system and leg bones. The weight of the eviscerated carcass and the proportion of carcass components were determined at the end of the reproductive period (60 wk of life) following slaughter. The lengths and diameters of the individual intestinal segments, the weight of selected internal organs, the acidity (pH24) and electrical conductivity (EC24), as well as the color (L*, a*, b*) of breast and thigh muscles were assessed. The basal chemical composition of the breast and thigh muscles was also determined, texture analysis of the pectoralis major muscle and measurements of the femur and tibia of parent broilers were also carried out. The housing system differentiated the birds in terms of percentage of breast muscle (SLS-27.4% vs. LS-26.0%) and intramuscular fat content in the breast muscle (SLS-1.1% vs. LS-0.7%), spleen weight pH of the breast and thigh muscles and EC of the thigh muscles (SLS-9.3 mS/cm vs. LS-7.0 mS/cm). Differences were also found between the study groups in the color of the breast and thigh muscles. The housing system affected the results of the texture analysis of the pectoralis major muscle. The birds differed significantly (P < 0.05) in terms of gumminess (SLS-11.1 N vs. LS-16.0 N), springiness, chewiness (SLS-17.6 N × cm vs. LS-23.4 N × cm) and cohesiveness parameters. The housing system did not affect the lengths and diameters of the individual intestinal segments, except for the length of the terminal intestine. There was no significant effect of the housing system on the tibia and femur dimensions analyzed. This study provided information about differences in certain carcass characteristics, meat quality, and the digestive system of Ross 308 parent broilers in relation to the maintenance system.

Effect of vaccination program on immune response, production performance, and carcass composition of Ross 308 broiler chickens.

The aim of this study was to compare the effect of 2 different vaccination programs using vaccines against infection bronchitis virus (IBV) and avian metapneumovirus (aMPV) on the humoral immune response, production performance, carcass weight and composition, and the percentage of selected internal organs. During the rearing of broiler chickens, blood was collected for serum samples from randomly selected birds from each experimental group on d 1, 21, 28, and 38. Geometric mean titer (GMT) values were determined for the aforementioned diseases using serological ELISA tests, performed during routine veterinary inspections. During rearing, body weight, mortality, and feed consumption were monitored, allowing the calculation of feed consumption per kilogram of body weight gain (FCR) and the European Production Index (EPI). At the end of rearing, 20 chickens were selected for dissection, 10 birds from each group. After slaughter, the weight of the eviscerated carcass was determined, and the percentages of carcass parts and selected internal organs in the body weight were calculated. The vaccination program exerted a significant (P<0.05) effect on body weight on days 14, 21, 28, 35 and 42, the percentage of wings in the carcass and the proportion (%) of heart, liver and spleen in body weight. ELISA showed no significant effect of the vaccination program on the anti-IBV serological response, and no negative effect of covaccination against both diseases on the anti-aMPV serological response.

Efficacy of Dietary Supplementation with Zinc-Chromium Mixture, Organic Selenium, or Their Combinations on Growth Performance, Carcass Traits, and Blood Profiles of Broilers under Heat Stress Conditions.

To determine the effects of organic selenium (0.0-0.6 mg and 0.9 mg Se/Kg diet) and Zn-Cr mixture (100 mg Zn/Kg diet plus 1.5 mg Cr/Kg diet) on broiler chicken performance, carcass traits, blood hematology, and biochemistry under heat stress conditions, this study was conducted. Under temperatures between 30.21 to 31.82 °C, 240 broiler chickens (Ross-308), which were 7-day-old, were randomly assigned to one of six treatments: T1 (control), T2 (100 mg Zn per kg of diet and 1.5 mg Cr per kg of diet), T3 (0.6 mg Se per kg of diet), T4 (0.9 mg Se per kg of diet), T5 (100 mg Zn, 1.5 mg Cr and (LSe), and T6 (100 mg Zn, 1.5 mg Cr and (HSe)). At 35 days old, the chicks fed a diet containing Zn-Cr with low or high organic selenium (organic-Se) outweighed the control group in terms of live body weight, weight gain, and feed conversion ratio (p < 0.05). In comparison to the control treatment, birds fed diets supplemented with Zn-Cr or organic-Se (LSe, HSe) significantly increased their serum levels of total protein and total antioxidant capacity. However, these additives resulted in a decrease (p < 0.01) in their serum levels of triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol, creatinine, and uric acid. Together, it was found that trace elements (Zn-Cr and organic-Se) may greatly lessen the impacts of heat stress on broilers by promoting growth performance and boosting metabolic processes.

Fatty Acid Profile, Health Lipid Indices, and Sensory Properties of Meat from Pekin Ducks of Different Origins.

Conservation duck flocks are of significant importance to science. Over a number of years, many experiments have been carried out to gain a better understanding of individual duck populations. However, the knowledge obtained is still incomplete. The aim of the present study was to compare three duck strains maintained in Poland and included in the Genetic Resources Protection Programme in terms of the fatty acid profile, health lipid indices, and sensory traits of breast and leg meat. The experimental material consisted of 180 sexed Pekin ducks, 60 ducks each (including 30 males and 30 females) from strain P33 (Pekin of Polish origin), P8 (Pekin of Danish origin), and P9 (Pekin of French origin). During 49 days of rearing, the ducks were kept in an enclosed building with six pens on straw. The duck genotype had a significant effect on the myristic (C14:0), palmitic (C16:0), oleic (C18:1n9), linolenic (C18:2n6), arachidonic (C20:4n6), monounsaturated fatty acid (MUFA), PUFAn6 content, and Peroxidisability Index (PI) values of breast muscle. Ducks from the compared strains differed significantly in C16:0 content and the proportion of unsaturated fatty acids (UFAs), including MUFAs, Nutritive Value Index, and Health-Promoting Index in leg muscles. Ducks from the compared strains also differed significantly in the aroma and juiciness of the heat-treated breast muscles and the tenderness of the leg muscles. The sex of the birds had a significant effect on the C18:1, C22:6n3, MUFA, PUFAn6, PUFAn3, PI, and aroma and taste desirability of the breast muscles, as well as the aroma intensity of the leg muscles.

Efficacy of licorice extract on the growth performance, carcass characteristics, blood indices and antioxidants capacity in broilers.

Some studies have suggested that dietary medicinal plants or herbs may have a variety of biological functions such as anti-inflammatory, antiallergic, antifungal, antioxidative stress, and anticarcinogenic activities. The present study was undertaken to assess the incorporation of the extract of licorice supplementation on the growth performance, carcass yield, blood indices, and antioxidative capacity in broilers. Three hundred twenty unsexed one-day-old Ross 308 broiler chicks were allocated randomly into four groups. Chicks in each group were randomly subdivided into eight replicates of ten chicks. The first group received a basal diet and was considered a control. The respective groups received a basal diet supplemented with 1, 2, and 3 g licorice extract/kg diet. The obtained results indicated that supplementation of licorice extract to broiler chicks resulted in heavier BW and weight gain and a better feed conversion ratio during the experimental periods compared with the control group. However, feed consumption increased during the entire growing period. Supplementing the broiler's diet with licorice extract led to a higher value of erythrocytes, leukocytes, haemoglobin, plasma total protein, albumin, and antioxidant concentration and a low value in plasma cholesterol, triglycerides, uric acid, urea, and total cholesterol. It could be concluded that the dietary addition of licorice extracts 2 and 3 g licorice extract/kg diet improved broiler chicks' growth performance and physiological status.

The Composition of the Carcass, Physicochemical Properties, Texture and Microstructure of the Meat of D11 Dworka and P9 Pekin Ducks.

The aim of the study was to determine the effects of genotype and sex on carcass composition and selected meat quality parameters of Dworka and Pekin ducks after two reproductive seasons. The research material consisted of 24 carcasses of Dworka ducks (breeding strain D11) and 24 carcasses of Pekin ducks from the herd of genetic resources (French Pekin, strain P-9). After cooling the carcasses (18 h, 2 °C), the pH values and electrical conductivity of the pectoral and leg muscles were determined, and then the carcass was dissected using a simplified method. After dissection, the pectoral and leg muscles were sampled for quality characteristics assessment. The Dworka ducks from breeding strain D11 compared to Pekin duck from conservative strain P9 were characterized by significantly (p < 0.05) higher carcass weight, protein and salt content, thermal drip, yellowness, thickness of perymisium and endomysium and lower water content of the pectoral muscle. Dworka ducks were also characterized by higher protein, salt and collagen content and higher electrical conductivity (EC24) of leg muscles than Pekin ducks. Regardless of genotype, male ducks had a higher gutted carcass weight with neck, salt content, muscle fiber cross-sectional area, fiber perimeter and diameters of pectoral muscle, and also higher protein and collagen, and lower fat content, pH24 and electrical conductivity of leg muscles. The genotype by sex interaction was significant (p < 0.05) for water, protein, fat content, perimisium thickness, cohesiveness, springiness of the pectoral major muscle, and for water content and protein of the leg muscles. The results obtained in this study demonstrate the effects of genotype and sex on the nutritional value and some technological parameters of duck meat. The studied ducks after two reproductive seasons satisfactorily meet the requirements of duck meat for consumers and duck meat processing plants.

Carcass Characteristics, Digestive System Traits of Spent Broiler Breeder and Dual-Purpose Hens.

Raising dual-purpose hens for meat is believed to bring more economic benefits to farmers selling products directly to consumers. The aim of the study was to determine the differences between the carcass features and the digestive system of multipurpose hens and spent broiler breeders. In the experiment, 20 carcasses of 70-week-old Rosa 1 dual-purpose hens and 20 carcasses of 62-week-old Ross 308 broiler breeders were used. Measurements of the length of various sections of the intestine and the diameter of individual intestinal segments were made. During the gutting, proventriculus, gizzard, liver, heart, and spleen were separated and then weighed. Dual-purpose hens differed significantly (p < 0.05) from broiler breeders in weight and carcass dimensions. Multipurpose hens were characterized by significantly lower (p < 0.05) percentages of breast muscles, leg muscles, skin with subcutaneous fat, wings, and carcass remainders. Broiler breeders were characterized by significantly longer (p > 0.05) total intestinal length, duodenum, jejunum, ileum, and terminal intestine. Significant differences were confirmed in terms of the diameter of some segments of the intestine. Broiler breeder hens also had a greater mass of internal organs compared to the dual-purpose layer hens.

Carcass characteristics and selected meat quality traits from commercial broiler chickens of different origin.

The aim of the study was to compare carcass and meat quality traits in 42-day-old Ross 308 and Cobb 500 broiler chickens. Forty carcasses were studied. Acidity (pH24 ) and electrical conductivity (EC24 ) of pectoralis major muscle and drumstick were determined 24 h postmortem. After carcass cutting, samples of breast and leg meat were collected for determination of quality traits. Broiler genotype had a significant effect on abdominal fat content in carcass and on water, protein, fat, sodium, and magnesium content in breast meat. Bird origin had an effect on the lightness, yellowness, horizontal diameter of muscle fiber, horizontal:vertical (H:V) diameter ratio, and most textural characteristics of pectoralis major muscle, as well as on the pH (pH24 ), electrical conductivity (EC24 ), and yellowness (b*) of leg muscles. Sex of birds had a significant effect on carcass weight, water, fat and collagen content, L*, a*, b* color attributes, and chewiness and gumminess of breast meat and on water and protein content in leg muscles. The present study provided information on the differences in carcass and meat quality between Ross 308 and Cobb 500 broiler chickens.

Impact of Treating Hatching Eggs with Curcumin after Exposure to Thermal Stress on Embryonic Development, Hatchability, Physiological Body Reactions, and Hormonal Profiles of Dokki-4 Chickens.

This study evaluated the impact of incubation temperature and spraying hatching eggs with curcumin during the early embryogenesis phase on chick embryo developments, hatchability, physiological body reactions, and hormonal profiles of Dokki 4 chickens. A total of 720 fertile eggs were equally distributed into two groups. In the first group, the eggs were incubated at normal incubation temperature/NIT (37.8 °C and 55-60% RH) for up to 19 days of incubation, whereas those in the second group were incubated in the same conditions except from 6 to 8 day, in which they were daily exposed to chronic incubation temperature/CIT (39.0 °C) for 3 h. Each group was classified into four curcumin treatment doses; the 1st treatment (control) was sprayed with distilled water, while the 2nd, 3rd, and 4th treatments were sprayed with 250, 500, and 1000 mg curcumin/liter distilled water. The results indicated that the lowest hatchability of fertile eggs (%) was obtained in the CIT group (p = 0.02), whereas the highest body surface temperature/BST compared in the NIT group (p = 0.01). Regarding curcumin treatments, the percentages of heart, gizzard, spleen, and T3 hormone levels in the treated group were significantly increased, while the H/L ratio was significantly reduced (p = 0.001) compared with the control. At 8 weeks of age, the testes and ovary percentages in treated groups were significantly (p = 0.05) increased compared with the control. In conclusion, exposure of hatching eggs to high thermal stress (39 °C) during the incubation phase had deleterious effects on chick performance and T3 hormone level. Moreover, spraying hatching eggs had beneficial impacts on growth, reproductive organs, T3 hormone level, and reducing H/L ratio.

Effect of Date Palm Pollen Supplementation on the Egg Production, Ovarian Follicles Development, Hematological Variables and Hormonal Profile of Laying Hens.

This experiment studied the effect of DPP supplementation in the laying hens' diet on the ovarian follicle development, hematological variables and hormonal profile of laying hens. Eighty-four, 78-week-old, Lohman LSL hybrids layers were equally divided into four groups (4 groups × 7 replicates × 3 hens); hens in the 1st group were fed a basal diet (control), while those in the 2nd, 3rd and 4th groups, were fed on the same diet and supplemented with 1.25, 2.5 and 5.0 g DPP/kg diet. The results showed that the egg weight, egg mass and laying rate of laying hens treated with DPP levels were significantly increased compared to those of the hens in the control group. Egg weight, egg surface area, albumen quality and percentage of the yolk in treated hens significantly increased compared with controls. The increased DPP levels in laying hens' diet significantly (p < 0.05) increased WBC, Hb and TAC, while heterophil/lymphocyte (H/L ratio) significantly decreased. Additionally, the concentrations of FSH and LH and the weights of ovary and oviduct in the treated hens significantly (p < 0.05) increased compared with the control. In conclusion, the DPP supplementation in the hen diet significantly improved egg production, EW, H/L ratio, ovarian follicles, FSH and LH hormones concentrations.

Effect of probiotic preparations (EM) on productive characteristics, carcass composition, and microbial contamination in a commercial broiler chicken farm.

This experiment evaluated the effect of Pro-Biotyk (Em-15) and EMFarma™ probiotics on body weight, feed intake and conversion, carcass traits, and microbial contamination in a poultry house. The probiotic preparations caused a nonsignificant increase in body weight (42 days), feed intake, and feed conversion ratio (1-42 days) and a nonsignificant decrease in chicken mortality from 4 weeks of rearing. Chickens exposed to probiotics did not differ significantly in preslaughter body weight, carcass weight, dressing percentage, and the content of carcass components. The carcasses from experimental chickens had a lower percentage of breast muscle, leg muscle, abdominal fat, and neck, as well as a higher percentage of skin with subcutaneous fat, wings, and remainder of carcasses compared with the carcasses from control birds. The probiotic preparations used in this study were highly effective as auxiliary disinfectants.

Carcass Characteristics, Physicochemical Properties, and Texture and Microstructure of the Meat and Internal Organs of Carrier and King Pigeons.

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.

Comparison of some meat quality and liver characteristics in Muscovy and mule ducks.

The aim of the study was to compare Muscovy ducks and mule ducks for proximate analysis, colour attributes, sensory properties of the meat, and concentration of some minerals in the meat and liver, with consideration of the effect of sex on the analysed traits. The study used 46 Muscovy and 44 mule ducks. At the end of the rearing period, 40 birds (10 males and 10 females of each genotype) were selected for slaughter. Meat and liver samples were collected from the slaughtered birds to determine quality traits. The analysed ducks of different genotypes differed significantly in the water content, sodium content, and redness of breast muscles; in the water, fat, and zinc content of leg muscles; and in the sodium, iron, and copper content of liver. Regardless of genotype, males had a higher sodium content in breast muscles; contained more protein, sodium, phosphorus, and magnesium and less potassium and copper in leg muscles; and had a significantly higher content of sodium, potassium, phosphorus, magnesium, zinc, iron, and copper in liver compared to females. The genotype-sex interaction was significant for the sodium and potassium content of breast muscles, for the water, protein, sodium, potassium, phosphorus, magnesium, and copper content of leg muscles, and for the copper content of liver. Our study provided information about differences in the quality of meat and liver in Muscovy and mule ducks.

Carcass characteristics, chemical composition, physicochemical properties, texture, and microstructure of meat from spent Pekin ducks.

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.

Growth Performance, Body Measurements, Carcass and Some Internal Organs Characteristics of Pekin 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.

A comparative study of carcass characteristics and meat quality in genetic resources Pekin ducks and commercial crossbreds.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.