RESUMO
The objective of this study was to evaluate the possibility of prediction of intramuscular fat (IMF) in live pigs using ultrasound method. Moreover, the accuracy of prediction at five different ultrasound intensity levels was investigated. Cross-sectional images of longissimus dorsi muscle (LD) at right last rib area, from hybrid pigs, were taken. Each pig was scanned at the same frequency (3.5 MHz) and at the five different ultrasound intensity levels 70%, 75%, 80%, 85% and 90% of total amplifying of sonograph, using the device ALOKA SSD-500. The video image analysis was used to predict IMF content (ultrasound intramuscular fat (UIMF) 70 to UIMF90). The second day after slaughter, the dissection of right half carcass was done. A sample of LD at the last rib was taken for laboratory analysis of IMF content (LAIMF). Scatter plots with UIMF on the x-axis and LAIMF on the y-axis were constructed to account for individual variability within and between intensity levels. Correlations between LAIMF and UIMF were significantly different from zero (r = 0.40-0.52), except for correlation between LAIMF and UIMF90 (r = 0.14). Statistical model with LAIMF (the dependent variable), UIMF (the same model for each intensity level), live weight (the covariates) and sex (the fixed effect) was developed. Coefficients of determination (R2) were 0.33, 0.38, 0.34, 0.25 and 0.17 with UIMF at the intensity level 70%, 75%, 80%, 85% and 90%. Root mean square errors ranged from 0.516% to 0.639%. Standard errors of individual prediction ranged from 0.523% to 0.649%. Goodness-of-fit of the model was also justified by testing the residuals for normality. Although the results are not quite unequivocal in favour of the one intensity level, it seems that intensity levels 75% and 80% are the most suitable to predict IMF in live pigs. Further research is needed, mainly to increase accuracy of collecting, processing and evaluating the sonograms using video image analysis.
RESUMO
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.