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.

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.

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.

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.

Effect of different vaccination programs on production parameters, carcass, leg bones, and digestive system characteristics of broilers

The purpose of the present study was to compare the effects of two commercial vaccination programs using Prevexxion or Vaxxitek vaccines on production parameters, carcass weight and composition, and selected anatomical characteristics of Ross 308 broiler chickens. During the rearing period of broiler chickens, body weights were determined at 1, 10, 35, and 42 d of age, and feed intake and mortality of birds were recorded each day. On d 42 of the rearing period, 20 chickens were selected for dissection, 10 birds from each group. After slaughtering, the weight of the eviscerated carcass and the proportion of carcass elements, the lengths and diameters of individual intestinal segments, the weight of selected internal organs, and the dimensions of the femur and tibia were determined. The Prevexxion vaccination program had a positive significant effect on eviscerated carcass yield, dressing percentage, breast meat, wing and carcass remains content, as well as duodenum length, proventriculus content of slaughter weight and smallest breadth of the corpus of tibia bone. Broiler chickens treated with Prevexxion vaccines had higher European Production Index. The results indicate that Prevexxion vaccines have a more favorable effect on the production performance and slaughter characteristics of Ross 308 broiler chickens than with the use of Vaxxitek vaccines.

Effects of sex on carcass composition and physicochemical, textural and rheological properties of meat from grey partridge

The study aimed to determine the effects of sex on bodyweight (BW) and dimensions, carcass weight, dressing percentage, percentage of carcass components, chemical composition, mineral content, acidity and electrical conductivity of the breast and leg muscles of grey partridges (Perdix perdix L.). The experiment also determined the colour attributes, textural and rheological characteristics, and mineral content in the liver of the grey partridge. Fifteen males and 15 females were examined. Carcasses were weighed on electronic scales, then dissected. The chemical compounds in the breast and leg muscles were determined with a near-infrared spectrophotometer. To ascertain the contents of minerals, the meat samples were analysed by spectrometry. The textural and rheological properties were established with the TPA double compression test, Warner-Bratzler (WB) test, and the relaxation test. At 36 weeks, males had significantly longer keels and shanks than females. Males and females did not differ significantly in the weight of the eviscerated carcass, dressing percentage, and percentage of carcass components. There were no significant differences between males and females in the chemical composition of meat from breasts and legs, and in the mineral contents of the breast and leg muscles and the liver. Bird sex had no significant effect on acidity and electrical conductivity of the breast and leg muscles or on the lightness (L*), redness (a*), and yellowness (b*) of the Pectoralis major muscle. No significant differences were established between 36-week-old males and females in textural and rheological characteristics. Thus, there was scant evidence for sexual dimorphism in this species.

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.

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.

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

Simple Summary

The tradition of pigeon meat consumption dates back to ancient civilizations. Today, pigeons are a popular meat in the cuisines of China, North America, North Africa, and some European countries. The aim of this study was to compare carrier pigeons and pigeons of the King breed after three reproductive seasons for carcass weight and measurements, carcass composition, physicochemical characteristics, the texture, rheological properties and microstructure of meat, and some biometric characteristics of the digestive system. Significant differences (p < 0.05) were observed between the pigeon groups in terms of the carcass weight and measurements, carcass composition (except for breast muscle percentage), physicochemical (except for pH₂₄ and redness of breast muscles) textural (except for cohesiveness and shear force), rheological, and microstructural characteristics, and more digestive system characteristics. These differences result primarily from the type of use. King pigeons are raised for meat, and carrier pigeons are used for flying.

Abstract

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, physicochemical and sensory characteristics of meat from genetic reserve ducks after two reproductive seasons

The aim of the study was to compare carcass composition and meat quality of i) Pekin ducks of French origin (P9), ii) crosses of wild mallard and Pekin duck (K2), and iii) crosses of Khaki Campbell drakes and Orpington Fauve ducks (KhO1). Twenty carcasses from 110-week-old ducks of each genetic group were used. Carcass weight of P9 was significantly higher than that of K2 and KhO1. Carcasses of K2 ducks had a significantly lower percentage of neck and leg muscles and giblet weight compared with P9 and KhO1 ducks, while carcasses of KhO1 ducks had a significantly higher percentage of wing meat compared with K2 and P9, and a significantly lower percentage of breast muscles compared with P9 ducks. Breast and leg muscles of P9 contained significantly more water than those of K2 and KhO1, and the breast muscles of P9 ducks had more protein and less fat than those of KhO1 birds. The leg muscles of KhO1 contained significantly more protein, and those of K2 had significantly more fat than the other duck groups. Breast muscles of P9 and KhO1 ducks had significantly more collagen but had less in leg muscles compared with K2. Breast fillets from P9 ducks showed higher L*, a*, and b* colour values and shear force than K2 and KhO1 ducks. Keywords: carcass composition, conservation flocks, meat quality, spent duck

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.

Growth performance, carcass composition, leg bones, and digestive system characteristics in Pekin duck broilers fed a diet diluted with whole wheat grain

A total of 270 Pekin ducks were reared for 49 d to determine the effect of feeding a diluted complete commercial wheat grain diet on live weight, feed intake and conversion, carcass, leg bone, and digestive system traits. Different feeding regimes had a significant effect on the body weight of the ducks aged 35 d and the feed conversion ratio in the period between days 22 and 35 of rearing. Dilution of a complete commercial diet with whole wheat grain had no significant influence on the final live weight (day 49), feed intake, and feed conversion ratio during the entire rearing period. Ducks fed a diet with whole wheat grain had a significantly higher dressing percentage after higher percentage of pectoral muscles, skin with subcutaneous fat, abdominal fat, as well as a significantly lower percentage of carcass remainders at the age of 49 d. Dilution of a complete commercial diet with whole wheat grain had no impact on the length of the respective intestinal sections nor on the weight and percentage share of gizzard, liver, heart, and spleen. However, it significantly lowered the fracture strength of the tibiotarsus, and decreased some dimensions of the femur and tibiotarsus.

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

Simple Summary

The protection and conservation of native poultry breeds, including ducks, is important for biological, cultural, emotional and scientific reasons. The objective of this study was to compare three lines of Pekin ducks for growth performance, body measurements, carcass and digestive system characteristics. The results showed significant differences between the tested lines of ducks in body weight and body measurements, as well as a small number of significant differences in carcass and digestive system characteristics. This may suggest that the tested lines of ducks are different and distinct, mainly in terms of growth and body measurements.

Abstract

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 influenced 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.

Digestive tract morphometry and breast muscle microstructure in spent breeder ducks maintainedin a conservation programme of genetic resources

Abstract. The objective of this study was to compare three genetic groups of ducks: P9 (French Pekin), K2 (bred from wild mallards – Anas platyrhynchos L. and Pekin duck), and KhO1 (hybrid of Khaki Campbell drake and Orpington Fauve duck) after two breeding seasons for body weight and length, length of intestine and its segments, percentage of other internal organs, and breast muscle microstructure. The study used 60 ducks, 20 birds (10 males and 10 females) from each genetic group. At 110 weeks of age, P9 ducks exhibited significantly (p<0.05) greater body weight and length, and length of intestine and its segments (except for colon length) compared to K2 and KhO1 ducks. KhO1 ducks had significantly shorter jejunum and ileum compared to K2 birds. The lighter K2 and KhO1 ducks had significantly greater relative length of intestine and its segments. In P9 ducks, liver, heart, and gizzard were heavier and spleen percentage in body weight significantly lower than in K2 and KhO1 birds. KhO1 ducks had a significantly higher percentage of proventriculus compared to the other duck groups. The different genetic origins of the ducks had no effect on microstructural characteristics of m. pectoralis superficialis except for perimysium and endomysium thickness. Our study provided information about differences in the digestive tract morphometry and breast muscle microstructure of ducks from three genetic groups after two reproductive seasons, which are maintained in a conservation programme of genetic resources in Poland.

Effect of corn silage and quantitative feed restriction on growth performance, body measurements, and carcass tissue composition in White Kołuda W31 geese

The objective of this study was to determine the effect of corn silage and quantitative feed restriction on BW, ADG, feed conversion, and carcass composition of White Kołuda W31 geese. Two diets were fed during the rearing period from 22 to 98 d of age: 1) a commercial diet ad libitum, and 2) restricted amounts of a commercial diet and corn silage ad libitum. Each treatment had 2 replicates of 16 birds each. From 99 to 119 d of age, all birds were fattened with whole oat grain alone. Incorporation of corn silage reduced weight gains and caused statistically significant differences in BW at the end of the rearing period (14 wk, 6,625.0 vs. 6,050.0 g; P < 0.05). Experimental geese showed compensatory growth during the oat fattening period and the BW of geese from both groups was similar at the end of the study (17 wk, 7,675.1 vs. 7,467.9 g; P > 0.05). Daily weight gains varied with week of growth, being lowest at 12 wk of age. Birds fed the commercial diet and corn silage had a significantly longer trunk (29.2 vs. 31.0 cm, P < 0.05) and shorter shanks (10.0 vs. 9.4 cm, P < 0.05) at 8 wk, and significantly smaller chest circumference (54.7 vs. 51.9 cm, P < 0.05) at the end of 14 wk. At the end of oat feeding (17 wk), geese receiving silage had significantly longer trunk and drumstick compared with geese fed commercial diets alone. The carcasses of 17-wk-old experimental geese contained more breast and leg muscles (%), and less skin with subcutaneous fat from breast and legs compared with control birds. Significant differences were only noted between the groups in dressing percentage (65.0 vs. 74.7%, P < 0.05) and proportion of skin with subcutaneous fat from breast (8.9 vs. 7.8%, P < 0.05). Dilution of the diet for young fattening geese with whole-crop corn silage had a positive effect on production economics and carcass composition.

Prolactin (PRL) and prolactin receptor (PRLR) genes and their role in poultry production traits

Prolactin (PRL), secreted from the anterior pituitary, plays extensive roles in osmoregulation, corpus luteum formation, mammogenesis, lactogenesis, lactopoiesis, and production of crop milk. In birds, prolactin (PRL) is generally accepted as crucial to the onset and maintenance of broodiness. All the actions of prolactin (PRL) hormone are mediated by its receptor (PRLR), which plays an important role in the PRL signal transduction cascade. It has been well established that the PRL gene is closely associated to the onset and maintenance of broody behavior, and could be a genetic marker in breeding against broodiness in chickens. Meanwhile, the prolactin receptor (PRLR) gene is regarded as a candidate genetic marker for reproductive traits. PRLR is also an important regulator gene for cell growth and differentiation. The identified polymorphism of this gene is mainly viewed in terms of egg production traits. Due to different biological activities attributed to PRL and PRLR, they can be used as major candidate genes in molecular animal breeding programs. Characterization of PRL and PRLR genes helps to elucidate their roles in birds and provides insights into the regulatory mechanisms of PRL and PRLR expression conserved in birds and mammals.

Carcass composition and breast muscle microstructure in guinea fowl (Numida meleagris L.) of different origin

Evaluation of dressing percentage and postmortem traits in 14-week-old white and grey guinea fowl, extended with evaluation of breast muscle microstructure, was the aim of the study. Subjects were two varieties of guinea fowl kept in an environmentally controlled house. Birds received complete commercial feeds. At 14 weeks of rearing, their whole carcasses were dissected postmortem. Diameters and percentages of white (alphaW) and red muscle fibres (betaR) were determined based on histological analysis of the musculus pectoralis superficialis. Similar dressing percentage was found in both guinea fowl varieties. At 14 weeks of age, grey guinea fowl had greater body weight, and weight and proportion of leg muscles and wings compared to white guinea fowl. Females of the white variety had greater weight of breast muscles than males. Breast muscle microstructure showed significantly (P < or = 0.05) greater content and diameter of white fibres in grey guinea fowl, and of red fibres in white guinea fowl.

Growth and development of young game pheasants (<i>Phasianus colchicus</i>)

Abstract. Fifty game pheasants were kept to 8 weeks in confinement housing and later maintained outdoors in a partially roofed aviary. Pheasants received commercial feed mixtures ad libitum. Body weight and dimensions were determined every 4 weeks. Ten pheasants were selected for slaughter at the end of 18 and 20 weeks each. After slaughter, their heads, shanks, feathers, blood, inedible viscera and major internal organs were weighed and digestive tract separated and measured. The carcasses were dissected. Higher body weights and daily gains were found in males than in females on all test days during rearing to 20 weeks of age. Compared to females, males had significantly longer keel from 4 weeks, longer lower thighs and shanks from 8 weeks, and longer trunk with and without neck and greater chest circumference from 12 weeks of age. Older pheasants had a significantly lower proportion of feathers and blood, and higher content of inedible viscera, with significantly relatively shorter (cm 100 g b.w.−1) small intestine, caecum and rectum in males than in females. With advancing age, there was a decrease in the proportion of gizzard (significant) and liver, and in males a significant increase in the proportion of testicles.

Comparison of some meat traits in ducks from two conservative flocks

Abstract. Eighty Pekin ducks from P11 and P22 conservative flocks (40 birds of each strain, including 20 males and 20 females) were investigated. Ducks were raised in a confinement building and fed ad libitum standard diets for waterfowl. At 7 weeks of age, 5 males and 5 females from each strain were slaughtered and dissected. Breast and leg muscles were sampled to determine fatty acid profile and selected minerals. Compared to P22 ducks, P11 ducks showed higher body weight at 7 weeks of age and higher rate of growth paralleled by better feed conversion ratio (kg feed/kg gain), higher dressing percentage, lower proportion (%) of leg muscles and lower proportion of all carcass muscles. Differences in these traits were not significant. Breast muscles of P11 ducks had significantly more C24:0 and C20:4 acids and leg muscles contained significantly more C14:0, C16:1, C18:1 and C24:0 acids compared to P22 ducks. In addition, leg muscles of P11 ducks had a significantly lower proportion of C17:0, C18:0, C24:0 and C22:4 compared to the same muscles of P22 birds. Leg muscles of P11 ducks had significantly more monounsaturated fatty acids (MUFA), higher unsaturated to saturated fatty acid (UFA/SFA) and polyunsaturated to saturated fatty acid ratios (PUFA/SFA), and significantly less saturated fatty acids (SFA) compared to P22 ducks. The Na, K, Mg, Fe, Cu and Zn content of duck muscles was similar in both lines. Compared to leg muscles, breast muscles of P11 and P22 ducks were found to contain significantly more iron (Fe) and copper (Cu), and less zinc (Zn).

The effect of using whole wheat grain in the diet of game pheasants on their body weight, dimensions and development of some internal organs

The supplementation of game pheasant diet from 5 weeks of age with 30% whole wheat grain instead of feed mixture did not significantly affect their body weight nor most body dimensions. Female and male pheasants fed a diet containing wheat grain had smaller body and trunk lengths, greater chest circumference and greater length of breastbone, and lower thigh and shank size. Female pheasants were characterized by higher indices of compactness and long-leggedness, whereas male pheasants had higher indices of massiveness, compactness and long-leggedness than pheasants fed only feed mixtures. Cock pheasants receiving the wheat diet also had a statistically shorter trunk, however, hens possessed a statistically longer lower thigh. Length of intestine (174.2 cm) and individual parts of the intestine (small intestine 119.9 cm; caeca 43 cm; rectum 11.3 cm) was greater in cocks fed whole wheat grain compared to cocks receiving only feed mixtures (156.1; 107.6; 38.8; 9.7 cm, respectively). An opposite cocks was found in hens. Supplementation of whole wheat grain in the diets significantly (P < or = 0.05) increased liver weight and percentage in females and significantly decreased testicular weight and percentage in males. It was also found that females of both feed-treatment groups had significantly lower weights ofheart, liver and spleen, and hens fed only feed mixtures were also characterized by a significantly lower weight of the proventriculus.