the objective of the study was to determine the effect of caponizing 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 pH 24h , 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 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 anaesthesia 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/m 2 . 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.Key words: capon, meat quality, fatty acid, sensorial evaluation, spme-GC-ms, chemometricsAccording to the Codex Alimentarius FAO/WHO, meat quality is defined as a combination of attributes that meet specific demands and make meat desirable for food. Over the last several years there has been an increasing number of consum-*This study was financed from statutory activity, project no. 03-010.01.

the aim of the study was to assess the quality of carcasses and meat from selected native breeds and breeding lines of hens after using them for laying eggs in terms of their usefulness as raw material in traditional old polish cuisine. hens included in the programme for the protection of genetic resources were the object of this study. they belonged to the following breeds/breeding lines: greenleg partridge (Z-11), rhode Island red (r-11), new hampshire (n-11) and Barred rock (WJ-44) -30 hens from each line. the hens were kept in a closed hen house under standard raising conditions. eight hens were selected from 56-week-old hens of each line which were subjected to analysis after being slaughtered. as a result of the research conducted, it was found that: -among the hens under study, heavier layers, i.e. Barred rock (WJ-44), new hampshire (n-11) and rhode Island red (r-11), which are characterized by good muscling and dressing percentage similar to that of broiler chickens, proved to be most suitable for use as meat. -the meat from WJ-44 hens contained most cholesterol and least protein, and the meat from Z-11 birds had the least fat compared to the other lines. -at the end of the laying period, meat and broth from WJ-44, n-11 and r-11 hens obtained better sensory scores than those from the carcasses of Z-11 hens, which makes them an attractive raw material for traditional polish cuisine.

The aim of the study was to determine the effect of caponizing on body weight and physicochemical properties of meat of the capons - hybrids obtained from the crossing of hens of the Yellow-Legged Partridge (Ż-33) breed with meat roosters. The study covered 80 roosters - hybrids, which were randomly assigned to two groups of 40 animals each (8 boxes of 10 pcs in each group). Group I (control) consisted of uncastrated roosters while group II included birds, which were castrated in 8th week of age under local anesthesia by a vet. Birds were fed ad libitum with the same standard diets and kept on litter under optimal environmental conditions with a stocking density of 7 animals/m2. At the end of fattening, i.e. in the 20th week of life, 8 birds with a body weight close to the group average were selected from each group for slaughter. After slaughter, the effectiveness of the procedure was checked (lack of testicles), then the slaughter performance of birds, physicochemical parameters of the pectoral and leg muscles were determined, and sensory evaluation was performed. The procedure of castration of roosters - hybrids had a positive effect on body weight, feed conversion ratio and carcass traits. The pectoral and leg muscles of the capons were characterized by better water absorption, brittleness and sensory evaluation compared to roosters. Among the assessed groups of birds there was also a variation in the coloring of whole carcasses and muscles, which were lighter (L*), more yellow (b*) and less red (a*) in caponized birds. In addition, the castration procedure had a positive effect on the total protein content in both the pectoral and leg muscles, which in turn, with a higher raw fat content, were distinguished by a favorable ratio of n-6/n-3 polyunsaturated fatty acids (PUFA). Based on the results, it can be concluded that the hybrids obtained from the crossbreeding of the Yellow-Legged Partridge (Ż-33) and Ross 308 meat roosters are good choice for capon production. They can complement poultry meat production with a niche product for consumers looking for products of exceptional quality.

The aim of this study was to evaluate the effect of algal oil with very high level of docosahexaenoic acid (DHA, C22:6n-3) used as fat source in the diet for laying hens, on egg yolk lipids fatty acid composition, as well as egg production and egg quality indices, in comparison with other dietary fat sources. The experiment was carried out on 168 ISA Brown hens (25 to 60 wks of age), allocated to 7 groups of 12 replicates (cages), with two birds in each cage. The experimental diets were supplemented with 2% of different fat sources, i.e. soybean oil (SO), coconut oil (CO), rapeseed oil (RO), linseed oil (LO), camelina oil (CAO), fish oil (FO), or algal oil (AO). Laying performance indices, i.e. egg production, mean egg weight, feed intake, feed conversion ratio, or egg and eggshell quality parameters were not affected by used fat sources (P>0.05). Dietary fat sources significantly influenced on egg yolk lipids fatty acids composition. Thus, AO addition caused some changes in the yolk lipid profile that were favorable from the dietary perspective, i.e., increased concentration of eicosapentaenoic acid (EPA) and DHA (P<0.05). However, boiled eggs from hens fed a diet with AO were characterized by an inferior flavour and taste to those from other groups. In conclusion, the results of this experiment, have shown that the use of AO in the laying hens nutrition is an efficient way to increase the deposition of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) in eggs, without negative effect on egg performance, however further researches, aiming to establish optimal AO dietary level that does not adversely affect the organoleptic properties of eggs, are needed.