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Carcass quality and intramuscular fat content of castrates and gilts are compared and a possible dependence of intramuscular fat content on sex and slaughter weight is determined in the pig population of the Slovak Republic. A total of 129 pigs of three different genotypes were included in the experiment. After slaughter, the carcasses were weighed and backfat thickness was measured. On the next day, carcass dissection described by Walstra and Merkus (1995) was determined. Four prime cuts (shoulder, loin, ham and belly) were further dissected to meat, bones and fat with skin. Intramuscular fat content was analysed in a laboratory from the samples (100 g) of musculus longissimus dorsi. The results were statistically analysed using SAS/STAT and a linear model was used to find the dependence of intramuscular fat content. Correlation coefficients between carcass traits and intramuscular fat were also calculated. Sex of pigs, and particularly weight of lean meat and weight of fatty parts had a significant effect on intramuscular fat content (P < 0.0001 and P = 0.0022) while no effect of the genotype and slaughter weight was observed. Significant differences between castrates and gilts were found in almost all observed traits, e.g. average backfat thickness (29.01 vs. 25.56 mm), percentage of meat (52.77 vs. 57.68%), intramuscular fat content (2.49 vs. 2.00%). Generally, the intramuscular fat in the pig population is not sufficient (2.25%), therefore it would be desirable to include this trait in selection strategies in pig breeding.

The aim of our study was to compare the hFVIII mRNA expression in different organs, pathological changes and selected haematological and biochemical blood parameters between transgenic and non-transgenic rabbits from F3 generation. Selected physiological parameters of 3- to 4-month-old transgenic rabbits from F3 generation carrying human factor VIII gene (hFVIII) were analysed and compared with those of non-transgenic ones. Before slaughtering, the blood for haematological and biochemical analysis was taken from the central ear artery. Pathological and histological examination of vital organs and RT-PCR analysis of several tissue organs of transgenic and non-transgenic animals were performed after slaughtering. Except for the mammary gland tissue, slight hfVIII mRNA expression in the spleen, lung and brain and none expression in the liver, kidney, skeletal muscle and heart of rabbits were recorded. pathological examination of vital organs showed some pathological changes in both transgenic and non-transgenic rabbits which were confirmed by histological qualitative evaluations. Statistically significant lower values of blood haemoglobin in blood of transgenic (11.86+/-0.86) animals compared with non-transgenic (12.41+/-1.02, P<0.05) ones and lower parameters of HCT (39.22+/-2.44 versus 40.89+/-2.26, P<0.01) in blood of transgenic rabbits were observed. Parameters of WBC, RBC and PLT showed no significant differences between the analysed groups. All biochemical serum parameters of transgenic rabbits were higher in comparison with non-transgenic ones. Significant differences were found in the concentration of the urea, AST and GMT between transgenic and non-transgenic animals (P<0.001) and in the total protein content, the difference was significant at P<0.05. In conclusion, our results showed that no considerable impact on the general health was found in transgenic rabbits.

The objective of this study was to compare some internal and external egg quality traits between two meat lines of Japanese quail (Coturnix japonica). Line 8 was the result of selection for high adult live body mass (three generations). Line 9 was the control. Birds were housed in four-stage cage technology at the NAFC-Research Institute for Animal Production Nitra. Feed mixture contained 11.7 MJ ME and 200.0 g crude protein. Feed and water were given ad libitum. Females of both lines had the same age. Egg-laying traits were observed daily during 5-day period. Eggs were analysed in the laboratory of the Slovak University of Agriculture in Nitra. The egg weight was significantly higher (P ≤ 0.001) in selected line 8: 13.259 g vs. 12.203 g. The egg shell weight, egg width, length and shape index were also higher (P ≤ 0.001) in selected line 8. The shell thickness on egg sharp region differed significantly (P ≤ 0.01) between lines 8 and 9. However, the difference in overall shell thickness was insignificant. Eggshell percentages were 9.128 and 9.200 % in lines 8 and 9. Significant differences (from P ≤ 0.001 to P ≤ 0.05) were found in yolk weight, yolk width, yolk height and yolk percentage. In general, selected line 8 was of higher yolk values, except for yolk percentage 29.358 % vs. 30.292 %. Significant differences in albumen weight (P ≤ 0.001), albumen width (P ≤ 0.01) and albumen height (P ≤ 0.05) were found. There was no significant (P > 0.05) difference in Haugh Unit (89.297 vs. 88.893).

The objective of study was to evaluate the effect of sex and terminal sire line on pork belly composition of commercially produced pigs. The animals were progeny of White Meaty sows and three terminal sire lines: HA × PN, LA and YO × PN. Barrows: gilts ratio was 97:102. Pigs were slaughtered at average carcass weight 85.73-89.0 kg according to genotype. Day after slaughter, the dissection of right half sides was done. After that, the detailed dissection of trimmed belly to individual tissues (bones, meat, fat and skin) was performed. The effect of sex on belly characteristics was significant. Gilts had higher meat proportion in belly than barrows (51.41 vs. 47.21 %), which reached higher content of subcutaneous and intermuscular fat (43.92 vs. 38.83 %). The influence of terminal sire line was also significant. All differences were found between HaxPN genotype and other two terminal sire lines. Progeny of HA × PN sire line had the highest percentage of meat in belly (51.28 %) while progeny of YO × PN had the highest content of fat and skin (42.79 %) and bones in belly (9.48 %). Keywords