The aim of the study was to determine the effect of age of slow-growing broiler chickens on growth performance and meat quality. Subjects were hybrids between Hubbard meat-type cockerels and Yellowleg Partridge Polish native hens. Chickens were raised indoors to 56, 70 or 84 days of age on deep litter under the same environmental conditions and fed ad litibum complete starter, grower and finisher diets containing 20, 18, 15 CP and 2825, 2825 and 2740 ME/kg feed, respectively. At the end of the experiment, 5 cockerels and 5 pullets were selected for slaughter from each age group and subjected to a simplified carcass analysis. Breast muscles and leg muscles were evaluated for technological properties such as pH, colour, water holding capacity, drip loss, cooking loss and shear force. The results were analysed statistically using analysis of variance and Duncan’s multiple range test. The duration of rearing had an effect on carcass and meat quality. The highest, statistically significant differences in the analysed traits were found between chickens slaughtered at 56 and 84 days of age. The highest dressing percentage was obtained in birds raised until 84 days of age. Youngest birds were characterized by the poorest muscle content of the carcass and the least favourable technological properties of meat. The highest growth efficiency was obtained when the hybrids were raised to 70 days of age.

The aim of the study was to determine slaughter yield and meat quality of native Zatorska (ZG) goose and compare them to those of commercial hybrid White Koluda® goose (WKG) after fattening in an intensive production system. The experiment was carried out on 500 birds of each group and lasted up to 10 wk of age. The birds were kept on deep litter with access to free range and were fed with the same complete feed mixtures, according to dietary requirements for broiler geese. Body weight, carcass composition, and technological properties of breast and thigh muscles were evaluated (pH24, L*a*b* color, water holding capacity, thermal loss, drip loss, and shear force). In addition, chemical composition of breast and thigh muscles, fatty acid profile of muscle lipids, and amino acids of proteins were determined. The body weight, weight of eviscerated carcass, and dressing percentage of ZG were lower (P < 0.05) than those in WKG. However, breast and thigh muscles of both groups of geese were characterized by similar technological and nutritive values. The differences in meat quality traits concerned only the shear force of breast muscles, with higher values (P < 0.05) for WKG. Moreover, dry matter content in breast muscles of ZG was higher than that in WKG. The effect of goose genotype on the level of oleic acid and monounsaturated fatty acids in breast muscles was shown. Also, the amino acid proportion of meat protein depended on goose breed. Breast muscles of ZG were characterized by higher (P < 0.05) content of some nonessential (Glu, Asp, Ala) and essential amino acids (Val, Thr), and thigh muscles contained less (P < 0.05) Gly, Lys, and Leu and more Pro and Ile than WKG. The present results indicate that the meat of both ZG and WKG broilers showed good technological properties and basic chemical composition and fatty acid profile, and the protein was characterized by high nutritional value. Moreover, the smaller carcasses produced from ZG can better meet the needs of the current market.

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 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 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/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.