Effect of ultrasonic, thermal and ozone pre-treatments on waste activated sludge solubilisation and anaerobic biodegradability

In order to enhance the efficiency of anaerobic digestion, the effects of ultrasounds, ozonation and thermal pre-treatment have been studied on waste activated sludge. The feature of this study was to carry out the comparison of the three pre-treatments in the same conditions and on the same sludge sample. Each treatment was tested in two conditions close to optimum conditions to maximise batch anaerobic sludge biodegradability. All treatments led to chemical oxygen demand and matter solubilisation and had little influence on mineral matter. In terms of solubilisation thermal pre-treatment was better than sonication or ozonation. But, in terms of batch anaerobic biodegradability, best results were obtained with ultrasounds with an energy of 6250 or 9350 kJ/kg TS and a thermal treatment at 170 or 190°C. Moreover, treatments had effects on physicochemical characteristics of sludge samples: apparent viscosity decreased after all treatments but the reduction was more important with thermal treatment. Median diameter of sludge flocs were reduced after sonication, increased after thermal treatment and did not change after ozonation. Finally, capillary suction time (CST) increased after ozonation, increased highly after sonication and was reduced after thermal treatmen

Growth, carcass value and blood biochemical parameters of Czech Genetic Resources of nutria (Myocastor coypus)

The aim of the study was to evaluate the effect of colour type and sex of nutrias on growth, carcass composition, weight of organs and biochemical parameters of blood. One hundred and twenty nutrias (Bohemian type of Standard -ST, Moravian Silver - MS and Prestice Multicolour - PV) from weaning age at 2 month till 8 months were studied. Growth of nutrias was affected by significant interaction of the colour type and sex till the age of 6 months. The sex had effect from the age of three months with more intensive growth in males. Dressing out percentage was unaffected by any of the observed factors and ranged from 56% to 59%. The weight of the hind leg meat was affected by interaction of colour type and sex (P≤0.009) whereas weight of the loin (P≤0.03) and the weight of the hind leg meat (P≤0.01) by colour type. The weight of the internal organs was affected by sex. In the case of blood biochemical characteristics, the interactions of colour type and sex were found in total protein (P≤0.013) and glucose (P≤0.012). The effect of the colour type was in total protein (P≤0.017), urea (P≤0.001), triacylglycerol (P≤0.011) and glucose (P≤0.001). In conclusion, the results of the study show that sex of nutrias had a higher impact on growth, carcass composition and blood biochemistry than colour type

Differences in carcass composition of males and females of two turkeys hybrids

DOI: 10.15414/afz.2014.17.03.72–74Received 7. May 2014 ǀ Accepted 27. May 2014 ǀ Available online 27. August 2014The objective of this study was to evaluate the effect of hybrid and sex on carcass composition in turkeys. A total of 240 turkeys (males and females) of two different hybrids (BUT Big 6 and Converter) were used in experiment. Birds were housed in housing conditions suitable for turkeys. Turkeys were fed ad libitum with commercial feed mixture for given category of turkeys. Six males and six females of each genotype were slaughtered at 17th weeks of age. Live weight and carcass composition were determined. The significant interactions between hybrid and sex were detected in live weight (P≤0.001), carcass weight (P≤0.001) and liver percentage (P≤0.006). The highest live weight and carcass weight was observed in Converter males (17410 g, 13360 g, respectively), while the lowest was detected in Converter females (12115 g, 9390 g, respectively). Converter females had the highest liver share (1.47%), whereas the lowest liver share was noted in BUT Big 6 females (1.20%). The significant effect of hybrid was found in live weight, carcass weight and thigh percentage.  The significantly higher live weight (P≤0.003), carcass weight (P≤0.002) and share of thigh (P≤0.010) was detected in BUT Big 6 compare to Converter. Males had significantly higher (P≤0.001) live weight, carcass weight and share of thigh than females.Keywords: turkeys, hybrids, sex, carcass trait

The effect of housing conditions on Biceps femoris muscle fibre properties, fatty acid composition, performance and carcass traits of slow-growing rabbits

The aim of the present work was to evaluate the effect of stocking density on the biceps femoris (BF) muscle fibre properties, meat quality, the growth performance and carcass traits of Czech White rabbits.  A total of 20 rabbits (40 days old, 10 rabbits per treatment, sex ratio 1/1) were reared in cages at different stocking densities (10 rabbits/m2 or 4 rabbits/m2) for 49 days. Stocking density had no significant effect on the growth performance. There were no significant differences between groups with regard to hot carcass weight (HCW) or dressing-out percentage. The proportions of both perirenal (9.5 vs. 15.9 g/kg HCW; P=0.010) and total dissectible fat (14.9 vs. 25.1 g/kg HCW; P=0.001) were lower in rabbits reared at the lower stocking density. No significant differences in ultimate pH values, meat colour or proximate composition were observed. The hind leg meat of rabbits reared at the lower stocking density contained significantly less lauric (4.6 vs. 6.7 mg/100 g of muscle; P=0.008) and myristic acid (52.2 vs. 64.4 mg/100 g of muscle; P=0.033). Significantly higher percentages of βR fibres (16.3 vs. 6.5 %, P=0.001) and αR fibres (24.5 vs. 14.2 %; P=0.001) and a significantly lower percentage of αW fibres (59.2 vs. 79.3 %; P=0.001) were also observed in these rabbits. The mean cross-sectional area (1882 vs. 2744 μm2; P=0.001) and diameter (47.9 vs. 58.5 μm; P=0.001) of βR fibres were smaller in rabbits reared at the lower stocking density. Thus, the lower stocking density favourably affected the medium-chain fatty acid profile of meat and fibre characteristics of the rabbits' biceps femoris muscle

The effect of housing conditions on Biceps femoris muscle fibre properties, fatty acid composition, performance and carcass traits of slow-growing rabbits

[EN] he aim of the present work was to evaluate the effect of stocking density on the biceps femoris (BF) muscle fibre properties, meat quality, the growth performance and carcass traits of Czech White rabbits. A total of 20 rabbits (40 days old, 10 rabbits per treatment, sex ratio 1/1) were reared in cages at different stocking densities (10 rabbits/m2 or 4 rabbits/m2) for 49 days. Stocking density had no significant effect on the growth performance. There were no significant differences between groups with regard to hot carcass weight (HCW) or dressing-out percentage. The proportions of both perirenal (9.5 vs. 15.9 g/kg HCW; P=0.010) and total dissectible fat (14.9 vs. 25.1 g/kg HCW; P=0.001) were lower in rabbits reared at the lower stocking density. No significant differences in ultimate pH values, meat colour or proximate composition were observed. The hind leg meat of rabbits reared at the lower stocking density contained significantly less lauric (4.6 vs. 6.7 mg/100 g of muscle; P=0.008) and myristic acid (52.2 vs. 64.4 mg/100 g of muscle; P=0.033). Significantly higher percentages of βR fibres (16.3 vs. 6.5 %, P=0.001) and αR fibres (24.5 vs. 14.2 %; P=0.001) and a significantly lower percentage of αW fibres (59.2 vs. 79.3 %; P=0.001) were also observed in these rabbits. The mean cross-sectional area (1882 vs. 2744 μm2; P=0.001) and diameter (47.9 vs. 58.5 μm; P=0.001) of βR fibres were smaller in rabbits reared at the lower stocking density. Thus, the lower stocking density favourably affected the medium-chain fatty acid profile of meat and fibre characteristics of the rabbits' biceps femoris muscle.This study was supported by the Ministry of Agriculture of the Czech Republic (Project No. QI101A164).Volek, Z.; Chodova, D.; Tumova, E.; Volkova, L.; Kudrnová, E.; Marounek, M. (2014). The effect of housing conditions on Biceps femoris muscle fibre properties, fatty acid composition, performance and carcass traits of slow-growing rabbits. World Rabbit Science. 22(1):41-49. https://doi.org/10.4995/wrs.2014.1176SWORD414922