The aim of the study was the comparison of the physicochemical and sensory characteristics of cap... more The aim of the study was the comparison of the physicochemical and sensory characteristics of capons and cockerels. The experiment involved 80 Rhode Island Red (R-11) cockerels, which were randomly assigned to two groups with 40 birds per group. Group I (control) consisted of uncastrated cockerels, and group II was comprised of birds subjected to castration at 9 weeks of age. The castration was performed under local anesthesia by a veterinary surgeon. The birds received the same diets ad libitum and were kept on litter under optimal environmental conditions, at a stocking density of 7 birds/m2. At the end of fattening, 8 birds whose body weights were similar to the group average were selected for slaughter from each group. After slaughter, the birds were checked for castration success (removal of the testes), analysed for dressing percentage and technological parameters of the meat and subjected to chemical and sensory evaluation of the breast and leg muscles. In summary, the castration of Rhode Island Red cockerels (R-11) had a favourable effect on body weight, feed conversion ratio, dressing percentage and carcass muscling. The breast and leg muscles of the capons were characterised by better water holding capacity, tenderness and sensory score compared to the uncastrated cockerels. In addition, the castration had a positive effect on the content of crude protein in both the breast and leg muscles which, with a higher crude fat content, were characterised by a more favourable profile of fatty acids i.e. lower SFA and higher n-6 and n-3 PUFA content.
Broiler chicken welfare, health and performance are strictly linked with skeleton development. La... more Broiler chicken welfare, health and performance are strictly linked with skeleton development. Lameness compromises welfare of broiler chickens and causes considerable economic loss since lame birds have difficulty accessing feed and water, become dehydrated and eventually die. Leg disorders are therefore considered to be one of the main factors associated with in-field mortalities between 21-42 d in broiler rearing at European poultry farms. In chickens and other farm animals, bone development is strictly correlated with dietary content of inositol hexaphosphate (IP6), as well as calcium and phosphorus availability. However, lameness is also associated with many other factors, such as diseases, genetics, species, gender, growth, aging, as well as physical loading, rearing period and management. Therefore, the aim of the current paper is to review selected non-infectious and infectious factors, which contribute to bone quality in poultry.
A high content of non-starch polysaccharides (NSP), namely arabinoxylans (AX), in rye is a reason... more A high content of non-starch polysaccharides (NSP), namely arabinoxylans (AX), in rye is a reason for the potential adverse effect of this grain on intestinal functions, gut microflora, absorption of nutrients and performance indices. As such, the use of rye grain in intensively producing poultry diets is limited. However, recently developed new types of hybrid rye are characterised not only by increased yield potential, resistance to fungus and pests and low production costs, but also the content of antinutritive substances may be reduced in these varieties. The aim of this paper is to discuss the mechanisms of NSP effects in the digestive tract, as well as to review the results of recent studies on the use of rye in poultry nutrition. Based on the literature data, it can be concluded that the use of new hybrid rye varieties with decreased NSP concentration and NSP-hydrolising enzymes may be a way of increasing the share of rye grain in poultry diets.
Vitamin D plays many important function in the animal organism; among others, it is necessary for... more Vitamin D plays many important function in the animal organism; among others, it is necessary for proper calcium (Ca) absorption and Ca use in different biological processes. The aim of several recent experiments with poultry was to evaluate the efficacy of different forms and levels of vitamin D3 in the diets for broiler chickens and laying hens. The results of these studies are presented and discussed in this review paper. Based on these results, it can be stated that the modern high-performing poultry requirement for supplemental vitamin D to maximise minerals digestibility, performance and immunity indices, bone health, and eggshell quality is about 3,000 IU/kg, i.e. is much higher than NRC (1994) recommendations. The results of several recent poultry studies have also shown that 25-hydroxycholecalciferol (25-OH-D3) is more efficient in commercial poultry nutrition than the basic form of vitamin D3 (cholecalciferol).
Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surfac... more Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surface of the footpads, is commonly observed in fast-growing broiler chickens and turkeys. FPD negatively affects the welfare of birds, performance indices, and the economic profit of poultry meat production. Nutrition is an important factor affecting water intake, excreta moisture and litter quality and, in this way, the occurrence and intensity of FPD in birds. This paper reviews and discusses the recent results published in the literature on the effects of nutritional factors on litter quality and FPD severity in broiler chickens and turkeys. Literature data on the efficacy of nutritional methods on the litter quality and FPD occurrence are not consistent. However, the results of several experiments indicate that the optimal level of crude protein, biotin, and electrolytes (Na, K) in the diet, as well as such feed additives as feed enzymes hydrolisating non starch polysaccharides and organic sources of microelements (zinc) may reduce the litter moisture as well as FPD incidence and severity in broilers chickens and turkey.
the aim of this review is to present and discuss the anatomy and physiology of crop in different ... more the aim of this review is to present and discuss the anatomy and physiology of crop in different avian species. the avian crop (ingluvies) present in most omnivorous and herbivorous bird species , plays a major role in feed storage and moistening, as well as functional barrier for pathogens through decreasing pH value by microbial fermentation. Moreover, recent data suggest that this gastrointestinal tract segment may play an important role in the regulation of the innate immune system of birds. in some avian species ingluvies secretes " crop milk " which provides high nutrients and energy content for nestlings growth. the crop has a crucial role in enhancing exogenous enzymes efficiency (for instance phytase and microbial amylase, β-glucanase), as well as the activity of bacteriocins. Thus, ingluvies may have a significant impact on bird performance and health status during all stages of rearing. Efficient use of the crop in case of digesta retention time is essential for birds' growth performance. thus, a functionality of the crop is dependent on a number of factors, including age, dietary factors, infections as well as flock management. It is important to expand knowledge about the crop functions to use them effectively in poultry production. furthermore , more scientific data is needed in the scope of immunological function of the crop as well as its microecosystem for a better understanding of the avian immune system and enhancing the health of the birds.
Cottonseed meal (CSM) is a by-product of the oil industry, i.e. oil extraction from cotton seeds.... more Cottonseed meal (CSM) is a by-product of the oil industry, i.e. oil extraction from cotton seeds. CSM is a rich source of protein (30 to 50% in dry matter), characterised by a high concentration of amino acids. However, a relatively low concentration of lysine restricts the quality of protein in CSM. The use of CSM as feed material for poultry nutrition is limited mainly by free gossypol presence, as well as a high variability in nutrient concentration. Gossypol is a polyphenolic compound reducing protein digestibility by inhibition of pepsin and trypsin activity in the intestine and binding iron in the diet. High dietary levels of CSM can negatively affect growth performance and egg production and egg quality. Such dietary treatments as increased iron and lysine dietary supplementation can increase the usefulness of CSM in poultry nutrition by alleviating the toxic effect of gossypol. The results of recent experiments on the use of CSM meal as a feed material for poultry are discussed in this review article. Based on the results presented, cottonseed meal is an acceptable ingredient of poultry diets and could be safely fed at a 10-15% dietary level, partially replacing - in a cost effective way - soybean meal.
The consumption of poultry meat and eggs is expected to increase considerably in the nearest futu... more The consumption of poultry meat and eggs is expected to increase considerably in the nearest future, which creates the demand for new poultry feed ingredients in order to support sustainable intensive production. Moreover, the constant improvement of the genetic potential of poultry has resulted in an increased nutrient density in poultry feeds, which limits the possibility to include low quality feed ingredients. Therefore, the feed industry needs new sources of highly digestible protein with a desirable amino acid composition to substitute other valuable but limited protein sources of animal origin, such as fishmeal. With estimated 1.5 to 3 million species, the class of insects harbours the largest species variety in the world including species providing a high protein and sulphur amino acids content, which can be successfully exploited as feed for poultry. The aim of this paper is to review the present state of knowledge concerning the use of insect protein in poultry nutrition and the possibilities of mass production of insects for the feed industry. There is no doubt that insects have an enormous potential as a source of nutrients (protein) and active substances (polyunsaturated fatty acids, antimicrobial peptides) for poultry. It can be concluded, basing on many experimental results, that meals from insects being members of the orders Diptera (black soldier fly, housefly), Coleoptera (mealworms) and Orthoptera (grasshoppers, locust, crickets and katylids), may be successfully used as feed material in poultry diets. However, legislation barriers in European Union, as well as relatively high costs and limited quantity of produced insects are restrictions in the large-scale use of insect meals in poultry nutrition.
Probiotics are widely used in nutrition, and their mode of action is intensively studied in mamma... more Probiotics are widely used in nutrition, and their mode of action is intensively studied in mammals and birds; however, it is almost unknown in reptiles. In the present study, Tra-chemys scripta scripta and Sternotherus odoratus were used to assess the effects of dietary probiotics on chelonian gastrointestinal tract microecology. In the first, 20-week experiment, 40 young T. s. scripta were randomly distributed to four experimental groups: 1 st , (CON)–with no additives; 2 nd , (SSPA) with Bacillus subtilis PB6; 3 rd , (MSP)–with multiple strain probiotic; and 4 th , (SSPB) with Bacillus subtilis C-3102. The first study has shown that SSPA and MSP decreased the numbers of total bacteria, Enterobacteriace, Staphylococcus sp. and Streptococcus sp. excreted to water and increased the villous height and mucosa thickness in duodenum. SSPB improved the duodenal microstructure; however, it also increased numbers of kanamycin and vancomycin resistant bacteria, Staphylococcus sp. and Streptococcus sp., in water. In the second, 52-week experiment, 30 S. odoratus were randomly assigned to three dietary treatments. CON, SSPA and MSP groups. The MSP preparation increased the body weight gain, crude ash, Ca and P share in the turtles' shells. Both probiotics affected duodenal histomorphology. SSPA decreased the villous height, while MSP increased the villous height and mucosa thickness, and decreased the crypt depth. SSPA decreased the concentrations of bacteria excreted to water. In the case of intestinal microbiota, bacteria suppressing effects were observed in the case of both pro-biotics. MSP increased the number of Bifidobacterium sp. and Lactobacillus sp./Enteroc-coccus sp., and decreased the number of Clostridium perfringens and Campylobacter sp. in the small intestine. In the large intestine it lowered, amongst others, Bacteroides–Pervo-tella cluster, Clostridium leptum subgroup and Clostridium perfringens numbers. The above-mentioned results suggest that probiotics are useful in turtle nutrition due to their positive effects on growth performance, shell mineralization, duodenal histomorphology and microbiota.
The objective of the paper was to demonstrate the possibilities of use of Polish native breed of ... more The objective of the paper was to demonstrate the possibilities of use of Polish native breed of chickens for the production of meat for its specific quality features in the light of world-wide researches. The object of the analysis was the quality of meat from slow-growing chicken raised in varied housing systems, including capons and poulards. The findings of studies on the quality of poultry meat from native breeds obtained from post-production cockerels and from hens in their post egg-laying stage have shown that there are chances for their use in meat production. Native breed hens can also be used as foundation material for the production of capons, poulards or international mixed breeds for purposes of extensive farming. The body weight of native breed hens, including their muscle build depend on the bird’s genotype, feeding, length of exploitation and farming system. Meat from native breed hens, raised in free-range systems have less fat, but with higher poly-saturated fatty acids in their meat muscles as well as a healthier ratio of n-6/n-3 PUFA acids. Outdoor free-range access influences the meat colour, i.e., bright coloured breast muscle (L*) as well as increased intensity of red coloration of leg muscles (b*). Caponisation of hens enhances intensified body weight gains along with increased fattening of meat. In comparison with cockerel meat, the meat of capons is more juicy, tender and of better taste, while poulard meat has distinctively favourable sensory values in comparison with broiler chicken meat.
The objective of this study was to determine the influence of limestone particle size in the diet... more The objective of this study was to determine the influence of limestone particle size in the diets with different contents of Ca on the biomechanical and geometrical measurements of tibia and femur bones, digestibility of nutrients, and selected biochemical blood variables. The experiment was conducted with 108 laying hens, allocated to 9 treatments of 6 replicates (cages), with 2 layers in each cage. A 3×3 factorial arrangement, with 3 dietary concentrations of Ca (3.20, 3.70, and 4.20%) and 3 levels of dietary substitutions (0, 25, and 50%) of fine particles of limestone (FPL; diameter, 0.2 to 0.6 mm) with large particles of limestone (LPL; diameter, 1.0 to 1.4 mm), was used. The hens were fed with experimental diets from 25 to 70 wk of age. At wk 45 a balance experiment was conducted, and after termination of the experiment, i.e., at wk 70, tibia and femur bones, and blood samples, were collected for analysis. Neither dietary Ca concentration nor limestone particle size had an effect on dry matter, organic matter, ether extract, N-free extracts, crude fiber, and crude ash digestibility, and P retention and excretion; however, Ca excretion increased linearly and Ca relative retention decreased linearly with increasing Ca dietary concentration (P<0.05). No effect of limestone particle size on tibia and femur biomechanical and geometrical measurements, tibia and femur mineralization, serum alkaline phosphatase activity, and serum Ca and P concentration, was observed. Increased dietary Ca concentration enhanced linearly tibia and femur bone breaking strength, yielding load, stiffness, and Ca concentration (P<0.05). Serum alkaline phosphatase activity decreased linearly with increasing Ca dietary concentration (P<0.05). In conclusion, the results of this study demonstrated that a content of 3.20 to 3.70% Ca in a layer’s diet is not sufficient through the entire laying cycle to maintain optimal bone quality; however, partial substitution of fine- with large-particle limestone does not improve Ca and P retention and bones quality variables.
The aim of this review article is to discuss the results of experiments on the use of microalgae ... more The aim of this review article is to discuss the results of experiments on the use of microalgae as the feed material in poultry nutrition. Microalgae are unicellular, photosynthetic aquatic plants. They are introduced to poultry diets mainly as a rich source of n 3 long chain polyunsaturated fatty acids, including docohexaenoic and eicosapentaenoic acid, but can also serve as a protein, microelements, vitamins, and antioxidants source, as well as a pigmentation agent. The results of the majority of experiments have shown that microalgae, mainly Spirulina and Chlorella, also as defatted biomass from biofuel production, can be successfully used as feed material in poultry nutrition. They can have beneficial effects, mainly on meat and egg quality, i.e. the increased concentration of n 3 polyunsaturated fatty acids and carotenoids in these products, but also in regards to performance indices and immune function. Positive results were also obtained when fresh microalgae biomass was used to replace antibiotic growth promoter in poultry diets. In conclusion, because of their chemical composition, microalgae can be efficiently used in poultry nutrition to enhance the pigmentation and nutritional value of meat and eggs, as well as a partial replacement of conventional protein sources, mainly soybean meal.
The aim of this review paper is to present and discuss the current experimental findings describi... more The aim of this review paper is to present and discuss the current experimental findings describing the effects of dietary oils on the functions of immune cells and the efficacy of different mechanisms of the immune system in poultry and pigs. The majority of experiments of this kind have focussed on dietary sources of n-3 polyunsaturated long-chain fatty acids (n-3 PUFAs). Their results have shown a significant association between dietary fat (i.e., the level of n-3 PUFAs as well as n-6:n-3 PUFAs ratio in the diet) and different mechanisms of immune response. Dietary supplementation with rich sources of n-3 PUFAs, especially with fish oil, can have a beneficial, modulating influence on the immune system; specifically they appear to decrease acute and chronic inflammatory immune reactions and simultaneously to improve indices of specific immune response. However, several studies demonstrated that anti-inflammatory properties of n-3 PUFAs do not always result in improvement of growth or egg performance.
Distillers dried grains with solubles (DDGS), a co-product of the ethanol industry, is often used... more Distillers dried grains with solubles (DDGS), a co-product of the ethanol industry, is often used as feed material in livestock and poultry nutrition. Results of many experiments have indicated, however, that a high dietary level of DDGS can negatively affect the digestibility of nutrients and the performance of monogastric animals due to their high content of non-starch polysaccharides (NSP). Nevertheless, using high levels of DDGS as a protein source in livestock diets can be still economically justifiable in view of the rising prices of soybean meal and other protein sources. The aim of some recent experiments with poultry and pigs was to improve the nutritional efficacy of high-NSP diets through the addition of feed enzymes. As presented and discussed in this review article, the efficacy of feed enzymes added to poultry and pig diets containing DDGS is not consistent and depends on many factors. However, NSP-hydrolysing enzymes generally seemed to be more efficient than phytases in terms of the digestibility of nutrients and the growth performance of poultry and pigs fed high-DDGS diets. For this reason, supplementation with NSP-hydrolysing enzymes could be an efficient way to enable the use of increased levels of DDGS in poultry and pig diets.
The objective of this study was to evaluate the effect of particle size of a dietary Ca source on... more The objective of this study was to evaluate the effect of particle size of a dietary Ca source on egg production and eggshell quality when added to hens’ diets that have different levels of calcium. The experiment was carried out on 216 ISA Brown hens (25 to 70 weeks of age), allocated to 9 groups of 12 replicates (cages), with two birds in each cage. A 3 x 3 factorial arrangement was used, with three dietary levels of calcium (3.20, 3.70 and 4.20 %) and three levels of dietary substitutions (0, 25 and 50 %) of fine particles of limestone (FPL, diameter 0.2–0.6 mm) with large particles of limestone (LPL, diameter 1.0–1.4 mm) as a Ca source.
The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P>0:05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P>0:05); however, it increased (P<0:05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20% Ca in a layer’s diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.
The aim of this study was to investigate, under conditions similar to commercial broiler producti... more The aim of this study was to investigate, under conditions similar to commercial broiler production, the effect of the herbal extract blend (HE) at a quantity of 1g per kg feed (200 mg respectively of herbal extract, Allium sativum, Salvia officinalis, Echinacea purpurea, Thymus vulgaris and Origanum vulgare), used individually or in combination with mannan oligosaccharide (MOS; 1g per kg feed) or chitosan (3ml containing 2% deacetylated chitin per kg feed) on the performance parameters of broiler chickens, the results of the slaughter analysis, litter moisture and the number of oocysts excreted in feces. The experiment was conducted on 4,500 broiler chickens of both sexes kept in straw-bedded pens. Chickens were randomly assigned to 5 experimental treatments with 5 replicates (pens) of 180 birds. The experimental design included negative and positive (diclazuril, 1 mg per kg feed) control groups. The examined herbal extract blend used individually during natural exposure to the coccidia improved, compared to the negative control diet, the performance parameters to a greater extent than coccidiostat, lowered the litter moisture content and reduced the oocyst output. Combined dietary supplementation with a herbal extract blend of chitosan or mannan oligosaccharide did not result in further improvement.
Phytase is well studied and explored, however, little is known about its effects on the microbial... more Phytase is well studied and explored, however, little is known about its effects on the microbial ecology of the gastrointestinal tract. In total, 400 one-day-old female Ross 308 chicks were randomly distributed to four experimental groups. The dietary treatments were arranged as a 2 × 2 complete factorial design, with the factors being adequate (PC) or insufficient calcium (Ca) and digestible phosphor (dP)(NC) and with or without 5000 phytase units (FTU)/kg of Escherichia coli 6-phytase. The gastrointestinal tract pH values, ileal microbial communities and short-chain fatty acid concentrations in the digesta were determined. The reduction in Ca and dP concentration significantly affected pH in the crop and caeca, and addition of phytase to the NC resulted in a pH increase in the ileum. The reduction in Ca and dP concentration significantly lowered, while phytase supplementation increased ileal total bacterial counts. Additionally, the deficient diet reduced butyrate- but increased lactate-producing bacteria. The addition of phytase increased Lactobacillus sp./Enterococcus sp. whereas in case of Clostridium leptum subgroup, Clostridium coccoides - Eubacterium rectale cluster, Bifidobacterium sp. and Streptococcus/Lactococcus counts, a significant Ca and dP level x phytase interaction was found. However, the recorded interactions indicated that the effects of phytase and Ca and dP levels were not consistent. Furthermore, the reduction of Ca and dP level lowered Clostridium perfringens and Enterobacteriaceae counts. The analysis of fermentation products showed that reducing the Ca and dP content in the diet reduced total SCFA, DL-lactate, and acetic acid in the ileum whereas phytase increased concentrations of these acids in the NC group. This suggests that P is a factor which limits fermentation in the ileum. It may be concluded that phytase plays a role in modulating the gut microbiota of chicken, however, this is clearly linked with the levels of P and Ca in a diet.
ANNALS OF ANIMAL SCIENCE, 2015, 15 (2). DOI: 10.1515/aoas-2015-0002
The objective of the study was to determine the effect of caponizing of Greenleg Partridge cocker... more The objective of the study was to determine the effect of caponizing of Greenleg Partridge cockerels on slaughter parameters and meat quality. In total 80 Greenleg Partridge cockerels were assigned to two groups with 40 birds per group. Group I (control) consisted of uncastrated cockerels and group II contained birds that were castrated at 8 weeks of age. Birds were kept until 24 weeks of age and fed the same diet ad libitum. Body weight was recorded at 1, 8, 16 and 24 weeks of age. Dressing percentage, proportion of breast and leg muscles, giblets and abdominal fat, and microstructure of the pectoralis superficialis muscle were determined postmortem. Physicochemical characteristics of meat (pH, CIE L*a*b* colour,
water holding capacity, drip loss, thawing loss, cooking loss, shear force, texture parameters and chemical composition) were determined and sensory evaluation was performed. The castration of Greenleg Partridge cockerels contributed to increases in body weight, dressing percentage, and carcass muscle and fat content, and changed the colour of bird skin and muscles. The leg muscles of capons were characterized by higher pH24h, better water holding capacity, a tendency for higher fat concentration, and better sensory quality. The breast muscles of castrated cockerels lost more water and were tougher than the same muscles from uncastrated cockerels, but received better scores for flavour. In conclusion, the results of this study indicate that the caponized Greenleg Partridge cockerels can be used as a valuable material for production of high quality meat.
The aim of the study was the comparison of the physicochemical and sensory characteristics of cap... more The aim of the study was the comparison of the physicochemical and sensory characteristics of capons and cockerels. The experiment involved 80 Rhode Island Red (R-11) cockerels, which were randomly assigned to two groups with 40 birds per group. Group I (control) consisted of uncastrated cockerels, and group II was comprised of birds subjected to castration at 9 weeks of age. The castration was performed under local anesthesia by a veterinary surgeon. The birds received the same diets ad libitum and were kept on litter under optimal environmental conditions, at a stocking density of 7 birds/m2. At the end of fattening, 8 birds whose body weights were similar to the group average were selected for slaughter from each group. After slaughter, the birds were checked for castration success (removal of the testes), analysed for dressing percentage and technological parameters of the meat and subjected to chemical and sensory evaluation of the breast and leg muscles. In summary, the castration of Rhode Island Red cockerels (R-11) had a favourable effect on body weight, feed conversion ratio, dressing percentage and carcass muscling. The breast and leg muscles of the capons were characterised by better water holding capacity, tenderness and sensory score compared to the uncastrated cockerels. In addition, the castration had a positive effect on the content of crude protein in both the breast and leg muscles which, with a higher crude fat content, were characterised by a more favourable profile of fatty acids i.e. lower SFA and higher n-6 and n-3 PUFA content.
Broiler chicken welfare, health and performance are strictly linked with skeleton development. La... more Broiler chicken welfare, health and performance are strictly linked with skeleton development. Lameness compromises welfare of broiler chickens and causes considerable economic loss since lame birds have difficulty accessing feed and water, become dehydrated and eventually die. Leg disorders are therefore considered to be one of the main factors associated with in-field mortalities between 21-42 d in broiler rearing at European poultry farms. In chickens and other farm animals, bone development is strictly correlated with dietary content of inositol hexaphosphate (IP6), as well as calcium and phosphorus availability. However, lameness is also associated with many other factors, such as diseases, genetics, species, gender, growth, aging, as well as physical loading, rearing period and management. Therefore, the aim of the current paper is to review selected non-infectious and infectious factors, which contribute to bone quality in poultry.
A high content of non-starch polysaccharides (NSP), namely arabinoxylans (AX), in rye is a reason... more A high content of non-starch polysaccharides (NSP), namely arabinoxylans (AX), in rye is a reason for the potential adverse effect of this grain on intestinal functions, gut microflora, absorption of nutrients and performance indices. As such, the use of rye grain in intensively producing poultry diets is limited. However, recently developed new types of hybrid rye are characterised not only by increased yield potential, resistance to fungus and pests and low production costs, but also the content of antinutritive substances may be reduced in these varieties. The aim of this paper is to discuss the mechanisms of NSP effects in the digestive tract, as well as to review the results of recent studies on the use of rye in poultry nutrition. Based on the literature data, it can be concluded that the use of new hybrid rye varieties with decreased NSP concentration and NSP-hydrolising enzymes may be a way of increasing the share of rye grain in poultry diets.
Vitamin D plays many important function in the animal organism; among others, it is necessary for... more Vitamin D plays many important function in the animal organism; among others, it is necessary for proper calcium (Ca) absorption and Ca use in different biological processes. The aim of several recent experiments with poultry was to evaluate the efficacy of different forms and levels of vitamin D3 in the diets for broiler chickens and laying hens. The results of these studies are presented and discussed in this review paper. Based on these results, it can be stated that the modern high-performing poultry requirement for supplemental vitamin D to maximise minerals digestibility, performance and immunity indices, bone health, and eggshell quality is about 3,000 IU/kg, i.e. is much higher than NRC (1994) recommendations. The results of several recent poultry studies have also shown that 25-hydroxycholecalciferol (25-OH-D3) is more efficient in commercial poultry nutrition than the basic form of vitamin D3 (cholecalciferol).
Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surfac... more Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surface of the footpads, is commonly observed in fast-growing broiler chickens and turkeys. FPD negatively affects the welfare of birds, performance indices, and the economic profit of poultry meat production. Nutrition is an important factor affecting water intake, excreta moisture and litter quality and, in this way, the occurrence and intensity of FPD in birds. This paper reviews and discusses the recent results published in the literature on the effects of nutritional factors on litter quality and FPD severity in broiler chickens and turkeys. Literature data on the efficacy of nutritional methods on the litter quality and FPD occurrence are not consistent. However, the results of several experiments indicate that the optimal level of crude protein, biotin, and electrolytes (Na, K) in the diet, as well as such feed additives as feed enzymes hydrolisating non starch polysaccharides and organic sources of microelements (zinc) may reduce the litter moisture as well as FPD incidence and severity in broilers chickens and turkey.
the aim of this review is to present and discuss the anatomy and physiology of crop in different ... more the aim of this review is to present and discuss the anatomy and physiology of crop in different avian species. the avian crop (ingluvies) present in most omnivorous and herbivorous bird species , plays a major role in feed storage and moistening, as well as functional barrier for pathogens through decreasing pH value by microbial fermentation. Moreover, recent data suggest that this gastrointestinal tract segment may play an important role in the regulation of the innate immune system of birds. in some avian species ingluvies secretes " crop milk " which provides high nutrients and energy content for nestlings growth. the crop has a crucial role in enhancing exogenous enzymes efficiency (for instance phytase and microbial amylase, β-glucanase), as well as the activity of bacteriocins. Thus, ingluvies may have a significant impact on bird performance and health status during all stages of rearing. Efficient use of the crop in case of digesta retention time is essential for birds' growth performance. thus, a functionality of the crop is dependent on a number of factors, including age, dietary factors, infections as well as flock management. It is important to expand knowledge about the crop functions to use them effectively in poultry production. furthermore , more scientific data is needed in the scope of immunological function of the crop as well as its microecosystem for a better understanding of the avian immune system and enhancing the health of the birds.
Cottonseed meal (CSM) is a by-product of the oil industry, i.e. oil extraction from cotton seeds.... more Cottonseed meal (CSM) is a by-product of the oil industry, i.e. oil extraction from cotton seeds. CSM is a rich source of protein (30 to 50% in dry matter), characterised by a high concentration of amino acids. However, a relatively low concentration of lysine restricts the quality of protein in CSM. The use of CSM as feed material for poultry nutrition is limited mainly by free gossypol presence, as well as a high variability in nutrient concentration. Gossypol is a polyphenolic compound reducing protein digestibility by inhibition of pepsin and trypsin activity in the intestine and binding iron in the diet. High dietary levels of CSM can negatively affect growth performance and egg production and egg quality. Such dietary treatments as increased iron and lysine dietary supplementation can increase the usefulness of CSM in poultry nutrition by alleviating the toxic effect of gossypol. The results of recent experiments on the use of CSM meal as a feed material for poultry are discussed in this review article. Based on the results presented, cottonseed meal is an acceptable ingredient of poultry diets and could be safely fed at a 10-15% dietary level, partially replacing - in a cost effective way - soybean meal.
The consumption of poultry meat and eggs is expected to increase considerably in the nearest futu... more The consumption of poultry meat and eggs is expected to increase considerably in the nearest future, which creates the demand for new poultry feed ingredients in order to support sustainable intensive production. Moreover, the constant improvement of the genetic potential of poultry has resulted in an increased nutrient density in poultry feeds, which limits the possibility to include low quality feed ingredients. Therefore, the feed industry needs new sources of highly digestible protein with a desirable amino acid composition to substitute other valuable but limited protein sources of animal origin, such as fishmeal. With estimated 1.5 to 3 million species, the class of insects harbours the largest species variety in the world including species providing a high protein and sulphur amino acids content, which can be successfully exploited as feed for poultry. The aim of this paper is to review the present state of knowledge concerning the use of insect protein in poultry nutrition and the possibilities of mass production of insects for the feed industry. There is no doubt that insects have an enormous potential as a source of nutrients (protein) and active substances (polyunsaturated fatty acids, antimicrobial peptides) for poultry. It can be concluded, basing on many experimental results, that meals from insects being members of the orders Diptera (black soldier fly, housefly), Coleoptera (mealworms) and Orthoptera (grasshoppers, locust, crickets and katylids), may be successfully used as feed material in poultry diets. However, legislation barriers in European Union, as well as relatively high costs and limited quantity of produced insects are restrictions in the large-scale use of insect meals in poultry nutrition.
Probiotics are widely used in nutrition, and their mode of action is intensively studied in mamma... more Probiotics are widely used in nutrition, and their mode of action is intensively studied in mammals and birds; however, it is almost unknown in reptiles. In the present study, Tra-chemys scripta scripta and Sternotherus odoratus were used to assess the effects of dietary probiotics on chelonian gastrointestinal tract microecology. In the first, 20-week experiment, 40 young T. s. scripta were randomly distributed to four experimental groups: 1 st , (CON)–with no additives; 2 nd , (SSPA) with Bacillus subtilis PB6; 3 rd , (MSP)–with multiple strain probiotic; and 4 th , (SSPB) with Bacillus subtilis C-3102. The first study has shown that SSPA and MSP decreased the numbers of total bacteria, Enterobacteriace, Staphylococcus sp. and Streptococcus sp. excreted to water and increased the villous height and mucosa thickness in duodenum. SSPB improved the duodenal microstructure; however, it also increased numbers of kanamycin and vancomycin resistant bacteria, Staphylococcus sp. and Streptococcus sp., in water. In the second, 52-week experiment, 30 S. odoratus were randomly assigned to three dietary treatments. CON, SSPA and MSP groups. The MSP preparation increased the body weight gain, crude ash, Ca and P share in the turtles' shells. Both probiotics affected duodenal histomorphology. SSPA decreased the villous height, while MSP increased the villous height and mucosa thickness, and decreased the crypt depth. SSPA decreased the concentrations of bacteria excreted to water. In the case of intestinal microbiota, bacteria suppressing effects were observed in the case of both pro-biotics. MSP increased the number of Bifidobacterium sp. and Lactobacillus sp./Enteroc-coccus sp., and decreased the number of Clostridium perfringens and Campylobacter sp. in the small intestine. In the large intestine it lowered, amongst others, Bacteroides–Pervo-tella cluster, Clostridium leptum subgroup and Clostridium perfringens numbers. The above-mentioned results suggest that probiotics are useful in turtle nutrition due to their positive effects on growth performance, shell mineralization, duodenal histomorphology and microbiota.
The objective of the paper was to demonstrate the possibilities of use of Polish native breed of ... more The objective of the paper was to demonstrate the possibilities of use of Polish native breed of chickens for the production of meat for its specific quality features in the light of world-wide researches. The object of the analysis was the quality of meat from slow-growing chicken raised in varied housing systems, including capons and poulards. The findings of studies on the quality of poultry meat from native breeds obtained from post-production cockerels and from hens in their post egg-laying stage have shown that there are chances for their use in meat production. Native breed hens can also be used as foundation material for the production of capons, poulards or international mixed breeds for purposes of extensive farming. The body weight of native breed hens, including their muscle build depend on the bird’s genotype, feeding, length of exploitation and farming system. Meat from native breed hens, raised in free-range systems have less fat, but with higher poly-saturated fatty acids in their meat muscles as well as a healthier ratio of n-6/n-3 PUFA acids. Outdoor free-range access influences the meat colour, i.e., bright coloured breast muscle (L*) as well as increased intensity of red coloration of leg muscles (b*). Caponisation of hens enhances intensified body weight gains along with increased fattening of meat. In comparison with cockerel meat, the meat of capons is more juicy, tender and of better taste, while poulard meat has distinctively favourable sensory values in comparison with broiler chicken meat.
The objective of this study was to determine the influence of limestone particle size in the diet... more The objective of this study was to determine the influence of limestone particle size in the diets with different contents of Ca on the biomechanical and geometrical measurements of tibia and femur bones, digestibility of nutrients, and selected biochemical blood variables. The experiment was conducted with 108 laying hens, allocated to 9 treatments of 6 replicates (cages), with 2 layers in each cage. A 3×3 factorial arrangement, with 3 dietary concentrations of Ca (3.20, 3.70, and 4.20%) and 3 levels of dietary substitutions (0, 25, and 50%) of fine particles of limestone (FPL; diameter, 0.2 to 0.6 mm) with large particles of limestone (LPL; diameter, 1.0 to 1.4 mm), was used. The hens were fed with experimental diets from 25 to 70 wk of age. At wk 45 a balance experiment was conducted, and after termination of the experiment, i.e., at wk 70, tibia and femur bones, and blood samples, were collected for analysis. Neither dietary Ca concentration nor limestone particle size had an effect on dry matter, organic matter, ether extract, N-free extracts, crude fiber, and crude ash digestibility, and P retention and excretion; however, Ca excretion increased linearly and Ca relative retention decreased linearly with increasing Ca dietary concentration (P<0.05). No effect of limestone particle size on tibia and femur biomechanical and geometrical measurements, tibia and femur mineralization, serum alkaline phosphatase activity, and serum Ca and P concentration, was observed. Increased dietary Ca concentration enhanced linearly tibia and femur bone breaking strength, yielding load, stiffness, and Ca concentration (P<0.05). Serum alkaline phosphatase activity decreased linearly with increasing Ca dietary concentration (P<0.05). In conclusion, the results of this study demonstrated that a content of 3.20 to 3.70% Ca in a layer’s diet is not sufficient through the entire laying cycle to maintain optimal bone quality; however, partial substitution of fine- with large-particle limestone does not improve Ca and P retention and bones quality variables.
The aim of this review article is to discuss the results of experiments on the use of microalgae ... more The aim of this review article is to discuss the results of experiments on the use of microalgae as the feed material in poultry nutrition. Microalgae are unicellular, photosynthetic aquatic plants. They are introduced to poultry diets mainly as a rich source of n 3 long chain polyunsaturated fatty acids, including docohexaenoic and eicosapentaenoic acid, but can also serve as a protein, microelements, vitamins, and antioxidants source, as well as a pigmentation agent. The results of the majority of experiments have shown that microalgae, mainly Spirulina and Chlorella, also as defatted biomass from biofuel production, can be successfully used as feed material in poultry nutrition. They can have beneficial effects, mainly on meat and egg quality, i.e. the increased concentration of n 3 polyunsaturated fatty acids and carotenoids in these products, but also in regards to performance indices and immune function. Positive results were also obtained when fresh microalgae biomass was used to replace antibiotic growth promoter in poultry diets. In conclusion, because of their chemical composition, microalgae can be efficiently used in poultry nutrition to enhance the pigmentation and nutritional value of meat and eggs, as well as a partial replacement of conventional protein sources, mainly soybean meal.
The aim of this review paper is to present and discuss the current experimental findings describi... more The aim of this review paper is to present and discuss the current experimental findings describing the effects of dietary oils on the functions of immune cells and the efficacy of different mechanisms of the immune system in poultry and pigs. The majority of experiments of this kind have focussed on dietary sources of n-3 polyunsaturated long-chain fatty acids (n-3 PUFAs). Their results have shown a significant association between dietary fat (i.e., the level of n-3 PUFAs as well as n-6:n-3 PUFAs ratio in the diet) and different mechanisms of immune response. Dietary supplementation with rich sources of n-3 PUFAs, especially with fish oil, can have a beneficial, modulating influence on the immune system; specifically they appear to decrease acute and chronic inflammatory immune reactions and simultaneously to improve indices of specific immune response. However, several studies demonstrated that anti-inflammatory properties of n-3 PUFAs do not always result in improvement of growth or egg performance.
Distillers dried grains with solubles (DDGS), a co-product of the ethanol industry, is often used... more Distillers dried grains with solubles (DDGS), a co-product of the ethanol industry, is often used as feed material in livestock and poultry nutrition. Results of many experiments have indicated, however, that a high dietary level of DDGS can negatively affect the digestibility of nutrients and the performance of monogastric animals due to their high content of non-starch polysaccharides (NSP). Nevertheless, using high levels of DDGS as a protein source in livestock diets can be still economically justifiable in view of the rising prices of soybean meal and other protein sources. The aim of some recent experiments with poultry and pigs was to improve the nutritional efficacy of high-NSP diets through the addition of feed enzymes. As presented and discussed in this review article, the efficacy of feed enzymes added to poultry and pig diets containing DDGS is not consistent and depends on many factors. However, NSP-hydrolysing enzymes generally seemed to be more efficient than phytases in terms of the digestibility of nutrients and the growth performance of poultry and pigs fed high-DDGS diets. For this reason, supplementation with NSP-hydrolysing enzymes could be an efficient way to enable the use of increased levels of DDGS in poultry and pig diets.
The objective of this study was to evaluate the effect of particle size of a dietary Ca source on... more The objective of this study was to evaluate the effect of particle size of a dietary Ca source on egg production and eggshell quality when added to hens’ diets that have different levels of calcium. The experiment was carried out on 216 ISA Brown hens (25 to 70 weeks of age), allocated to 9 groups of 12 replicates (cages), with two birds in each cage. A 3 x 3 factorial arrangement was used, with three dietary levels of calcium (3.20, 3.70 and 4.20 %) and three levels of dietary substitutions (0, 25 and 50 %) of fine particles of limestone (FPL, diameter 0.2–0.6 mm) with large particles of limestone (LPL, diameter 1.0–1.4 mm) as a Ca source.
The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P>0:05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P>0:05); however, it increased (P<0:05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20% Ca in a layer’s diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.
The aim of this study was to investigate, under conditions similar to commercial broiler producti... more The aim of this study was to investigate, under conditions similar to commercial broiler production, the effect of the herbal extract blend (HE) at a quantity of 1g per kg feed (200 mg respectively of herbal extract, Allium sativum, Salvia officinalis, Echinacea purpurea, Thymus vulgaris and Origanum vulgare), used individually or in combination with mannan oligosaccharide (MOS; 1g per kg feed) or chitosan (3ml containing 2% deacetylated chitin per kg feed) on the performance parameters of broiler chickens, the results of the slaughter analysis, litter moisture and the number of oocysts excreted in feces. The experiment was conducted on 4,500 broiler chickens of both sexes kept in straw-bedded pens. Chickens were randomly assigned to 5 experimental treatments with 5 replicates (pens) of 180 birds. The experimental design included negative and positive (diclazuril, 1 mg per kg feed) control groups. The examined herbal extract blend used individually during natural exposure to the coccidia improved, compared to the negative control diet, the performance parameters to a greater extent than coccidiostat, lowered the litter moisture content and reduced the oocyst output. Combined dietary supplementation with a herbal extract blend of chitosan or mannan oligosaccharide did not result in further improvement.
Phytase is well studied and explored, however, little is known about its effects on the microbial... more Phytase is well studied and explored, however, little is known about its effects on the microbial ecology of the gastrointestinal tract. In total, 400 one-day-old female Ross 308 chicks were randomly distributed to four experimental groups. The dietary treatments were arranged as a 2 × 2 complete factorial design, with the factors being adequate (PC) or insufficient calcium (Ca) and digestible phosphor (dP)(NC) and with or without 5000 phytase units (FTU)/kg of Escherichia coli 6-phytase. The gastrointestinal tract pH values, ileal microbial communities and short-chain fatty acid concentrations in the digesta were determined. The reduction in Ca and dP concentration significantly affected pH in the crop and caeca, and addition of phytase to the NC resulted in a pH increase in the ileum. The reduction in Ca and dP concentration significantly lowered, while phytase supplementation increased ileal total bacterial counts. Additionally, the deficient diet reduced butyrate- but increased lactate-producing bacteria. The addition of phytase increased Lactobacillus sp./Enterococcus sp. whereas in case of Clostridium leptum subgroup, Clostridium coccoides - Eubacterium rectale cluster, Bifidobacterium sp. and Streptococcus/Lactococcus counts, a significant Ca and dP level x phytase interaction was found. However, the recorded interactions indicated that the effects of phytase and Ca and dP levels were not consistent. Furthermore, the reduction of Ca and dP level lowered Clostridium perfringens and Enterobacteriaceae counts. The analysis of fermentation products showed that reducing the Ca and dP content in the diet reduced total SCFA, DL-lactate, and acetic acid in the ileum whereas phytase increased concentrations of these acids in the NC group. This suggests that P is a factor which limits fermentation in the ileum. It may be concluded that phytase plays a role in modulating the gut microbiota of chicken, however, this is clearly linked with the levels of P and Ca in a diet.
ANNALS OF ANIMAL SCIENCE, 2015, 15 (2). DOI: 10.1515/aoas-2015-0002
The objective of the study was to determine the effect of caponizing of Greenleg Partridge cocker... more The objective of the study was to determine the effect of caponizing of Greenleg Partridge cockerels on slaughter parameters and meat quality. In total 80 Greenleg Partridge cockerels were assigned to two groups with 40 birds per group. Group I (control) consisted of uncastrated cockerels and group II contained birds that were castrated at 8 weeks of age. Birds were kept until 24 weeks of age and fed the same diet ad libitum. Body weight was recorded at 1, 8, 16 and 24 weeks of age. Dressing percentage, proportion of breast and leg muscles, giblets and abdominal fat, and microstructure of the pectoralis superficialis muscle were determined postmortem. Physicochemical characteristics of meat (pH, CIE L*a*b* colour,
water holding capacity, drip loss, thawing loss, cooking loss, shear force, texture parameters and chemical composition) were determined and sensory evaluation was performed. The castration of Greenleg Partridge cockerels contributed to increases in body weight, dressing percentage, and carcass muscle and fat content, and changed the colour of bird skin and muscles. The leg muscles of capons were characterized by higher pH24h, better water holding capacity, a tendency for higher fat concentration, and better sensory quality. The breast muscles of castrated cockerels lost more water and were tougher than the same muscles from uncastrated cockerels, but received better scores for flavour. In conclusion, the results of this study indicate that the caponized Greenleg Partridge cockerels can be used as a valuable material for production of high quality meat.
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Papers by Sylwester Świątkiewicz
In summary, the castration of Rhode Island Red cockerels (R-11) had a favourable effect on body weight, feed conversion ratio, dressing percentage and carcass muscling. The breast and leg muscles of the capons were characterised by better water holding capacity, tenderness and sensory score compared to the uncastrated cockerels. In addition, the castration had a positive effect on the content of crude protein in both the breast and leg muscles which, with a higher crude fat content, were characterised by a more favourable profile of fatty acids i.e. lower SFA and higher n-6 and n-3 PUFA content.
The findings of studies on the quality of poultry meat from native breeds obtained from post-production cockerels and from hens in their post egg-laying stage have shown that there are chances for their use in meat production. Native breed hens can also be used as foundation material for the production of capons, poulards or international mixed breeds for purposes of extensive farming.
The body weight of native breed hens, including their muscle build depend on the bird’s genotype, feeding, length of exploitation and farming system. Meat from native breed hens, raised in free-range systems have less fat, but with higher poly-saturated fatty acids in their meat muscles as well as a healthier ratio of n-6/n-3 PUFA acids. Outdoor free-range access influences the meat colour, i.e., bright coloured breast muscle (L*) as well as increased intensity of red coloration of leg muscles (b*). Caponisation of hens enhances intensified body weight gains along with increased fattening of meat. In comparison with cockerel meat, the meat of capons is more juicy, tender and of better taste, while poulard meat has distinctively favourable sensory values in comparison with broiler chicken meat.
The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P>0:05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P>0:05); however, it increased (P<0:05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20% Ca in a layer’s diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.
water holding capacity, drip loss, thawing loss, cooking loss, shear force, texture parameters and chemical composition) were determined and sensory evaluation was performed. The castration of Greenleg Partridge cockerels contributed to increases in body weight, dressing percentage, and carcass muscle and fat content, and changed the colour of bird skin and muscles. The leg muscles of capons were characterized by higher pH24h, better water holding capacity, a tendency for higher fat concentration, and better sensory quality. The breast muscles of castrated cockerels lost more water and were tougher than the same muscles from uncastrated cockerels, but received better scores for flavour. In conclusion, the results of this study indicate that the caponized Greenleg Partridge cockerels can be used as a valuable material for production of high quality meat.
In summary, the castration of Rhode Island Red cockerels (R-11) had a favourable effect on body weight, feed conversion ratio, dressing percentage and carcass muscling. The breast and leg muscles of the capons were characterised by better water holding capacity, tenderness and sensory score compared to the uncastrated cockerels. In addition, the castration had a positive effect on the content of crude protein in both the breast and leg muscles which, with a higher crude fat content, were characterised by a more favourable profile of fatty acids i.e. lower SFA and higher n-6 and n-3 PUFA content.
The findings of studies on the quality of poultry meat from native breeds obtained from post-production cockerels and from hens in their post egg-laying stage have shown that there are chances for their use in meat production. Native breed hens can also be used as foundation material for the production of capons, poulards or international mixed breeds for purposes of extensive farming.
The body weight of native breed hens, including their muscle build depend on the bird’s genotype, feeding, length of exploitation and farming system. Meat from native breed hens, raised in free-range systems have less fat, but with higher poly-saturated fatty acids in their meat muscles as well as a healthier ratio of n-6/n-3 PUFA acids. Outdoor free-range access influences the meat colour, i.e., bright coloured breast muscle (L*) as well as increased intensity of red coloration of leg muscles (b*). Caponisation of hens enhances intensified body weight gains along with increased fattening of meat. In comparison with cockerel meat, the meat of capons is more juicy, tender and of better taste, while poulard meat has distinctively favourable sensory values in comparison with broiler chicken meat.
The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P>0:05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P>0:05); however, it increased (P<0:05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20% Ca in a layer’s diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.
water holding capacity, drip loss, thawing loss, cooking loss, shear force, texture parameters and chemical composition) were determined and sensory evaluation was performed. The castration of Greenleg Partridge cockerels contributed to increases in body weight, dressing percentage, and carcass muscle and fat content, and changed the colour of bird skin and muscles. The leg muscles of capons were characterized by higher pH24h, better water holding capacity, a tendency for higher fat concentration, and better sensory quality. The breast muscles of castrated cockerels lost more water and were tougher than the same muscles from uncastrated cockerels, but received better scores for flavour. In conclusion, the results of this study indicate that the caponized Greenleg Partridge cockerels can be used as a valuable material for production of high quality meat.