Effect of genotype and sex on carcase composition, physicochemical properties, texture and microstructure of meat from geese after four reproductive seasons.

1. The objective of this study was to compare carcase weight and composition and meat quality traits of Landes, Slovak White and Kuban geese after four reproductive seasons. A total of 42 goose carcases (seven males and seven females from each breed) were assessed.2. After four reproductive seasons, the breeds differed in eviscerated carcase weight. Slovak White geese showed more breast muscle with a cooking loss, whereas Kuban geese had a higher percentage of neck and carcase discards compared to the other breeds. The breeds differed in the chemical composition of breast and leg muscles, except for collagen in breast muscles and protein in leg muscles.3. Regardless of breed, males had heavier carcase weight and higher breast muscle, leg muscle, neck and wings and lower percentages of skin with subcutaneous fat and abdominal fat relative to body weight compared to females. Sex had a significant effect on the fat and salt content, meat lightness, most textural characteristics and endomysium thickness of breast muscle. The same differences in leg muscles for chemical composition (except for protein percentage) and lightness were recorded.4. Breed x sex interactions were significant for the proportion of leg muscle, chemical composition of breast and leg muscles (except for leg protein content), muscle fibre cross-sectional area and fibre perimeter of pectoralis major muscle.5. The results showed that the carcases and meat of the goose breeds after four reproductive seasons were suitable for consumers and meat processors, due to favourable composition, high nutritive value and good technological properties.

The use of two staining methods for identification of spermatozoon structure in roosters.

Many of the methods used to stain semen result in very pronounced coloring of the sperm, but unfortunately they do not distinguish their individual structures, which play a key role in the fertilization process. Hence the aim of this study was to identify sperm structures using two staining techniques in the semen of roosters from breeding flocks. The subject of the study was the sperm of roosters from a Ross 308 breeding flock. To capture the differences in the dimensions of sperm subjected to the effect of different chemical substances in dyes, microscope slides were stained by two techniques: with an AgNO3 solution and by a differential method (eosin-nigrosin test). Assessment was made of the degree of coloration and the number of details that could be identified in the morphological structure of the sperm. The use of AgNO3 allowed accurate identification of the acrosome, nucleus, and midpiece, which were visible in the slides stained with eosin-nigrosin, but only in dead spermatozoa. The AGNO3 staining technique used in this study reveals the cell nucleus within the head and can be an alternative method to analysis with a scanning electron microscope. This staining technique can be used to stain sperm structures that cannot be seen in other methods of slide preparation, which means that it can be considered for routine use in assessing the fertility of roosters in breeder flocks.