Template-Type: ReDIF-Article 1.0 Author-Name: J. Přibyl Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: J. Přibylová Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: H. Krejčová Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: N. Mielenz Author-Workplace-Name: University of Halle-Wittenberg, Halle, Germany Title: Comparison of different traits to evaluate the growth of bulls Abstract: The live weights of 8 243 performance-tested bulls from 100 to 400 days of age were analysed using random regression (RR) and single-trait animal models. Evaluations were done for live weight at 400 days of age and gains from 100 to 400 days of age at various monthly intervals. Estimates of variance components differed depending on the trait definition and model of analysis. Systematic environmental effects explained a higher proportion of variability in the RR for gains than for other definitions of growth. The expected average reliability of estimated breeding values was similar for all methods from 0.42 to 46, but the rankings of animals differed. Determinations (r2) of breeding values between methods ranged from 0.64 to 0.94. Correlations of the breeding values of progeny at performance-test stations with parents were highest for the evaluation of gains in consecutive intervals evaluated by RR. Correlations of the breeding values of sires from their growth at performance-test stations with the breeding values of groups of progeny at progeny-test stations were from 0.26 to 0.38. Correlations were the highest for RR evaluations of gain using consecutive short intervals. Evaluation of the growth of animals according to daily gains in short consecutive intervals was preferred because more animals and more observations per animal were included in the evaluations, and the growth curve was separated into genetic and non-genetic parts. Simple evaluation of growth according to the final weight or daily gain in a long interval is not entirely correct, since environmental compensatory growth can occur. Keywords: bulls, daily gains, random regression, breeding values, variances Journal: Czech Journal of Animal Science Pages: 273-283 Volume: 53 Issue: 7 Year: 2008 DOI: 10.17221/357-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/357-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-200807-0001.txt Handle: RePEc:caa:jnlcjs:v:53:y:2008:i:7:id:357-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: M. Fiedlerová Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: D. Řehák Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: M. Vacek Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: J. Volek Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: J. Fiedler Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: P. Šimeček Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: O. Mašata Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: F. Jílek Author-Workplace-Name: Department of Veterinary Sciences, Czech University of Life Sciences, Prague-Suchdol, Czech Republic Title: Analysis of non-genetic factors affecting calving difficulty in the Czech Holstein population Abstract: The objective of this study was to analyze the effects of non-genetic factors affecting calving difficulty in the Holstein population of the Czech Republic for subsequent compilation of the model for genetic evaluation as well as for herd management practice. Calving difficulty recorded in 1997-2006 was assessed in three categories: 1 = normal, 2 = hard pull, 3 = complicated. The original observations were transformed to an underlying normal scale. A data set containing 409 255 records was analysed by a linear model with fixed effects of season, parity of dam, sex of calf and Holstein gene proportion. All these effects were significant, and their appropriate categorization was considered. Analyses of additional factors such as gestation length, age at first calving and preceding calving interval were performed. The results revealed that gestation length was in a non-linear relationship with calving difficulty. A higher risk of difficult calving was associated with short or long gestation and with a prolonged preceding calving interval in multiparous cows. Calving difficulty should be adjusted for these factors. A decreased risk of difficult calving could be achieved by an altering of calving interval and age at first calving as a management tool. Keywords: calving process, gestation length, age at first calving, preceding calving interval, dairy cattle Journal: Czech Journal of Animal Science Pages: 284-291 Volume: 53 Issue: 7 Year: 2008 DOI: 10.17221/355-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/355-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-200807-0002.txt Handle: RePEc:caa:jnlcjs:v:53:y:2008:i:7:id:355-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: J. Trávníček Author-Workplace-Name: Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic Author-Name: J. Racek Author-Workplace-Name: Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic Author-Name: L. Trefil Author-Workplace-Name: Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic Author-Name: H. Rodinová Author-Workplace-Name: Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic Author-Name: V. Kroupová Author-Workplace-Name: Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic Author-Name: J. Illek Author-Workplace-Name: University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic Author-Name: J. Doucha Author-Workplace-Name: Institute of Microbiology, Academy of Science of the Czech Republic, Třeboň, Czech Republic Author-Name: L. Písek Author-Workplace-Name: Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic Title: Activity of glutathione peroxidase (GSH-Px) in the blood of ewes and their lambs receiving the selenium-enriched unicellular alga Chlorella Abstract: The effect of supplementation of selenium inorganic and organic forms on the activity of glutathione peroxidase (GSH-Px) was investigated for 7-8 months in three groups of ewes (by five animals each) and in born lambs. The basal feed ration contained 55 μg Se, the ewes of experimental group E1 received a supplement of 180 μg Se in sodium selenite, and the ewes of experimental group E2 were administered a supplement of 180 μg selenium bound in the biomass of the alga Chlorella. Control group C was without selenium supplement. The ewes were in the stage of non-pregnancy, pregnancy and lactation during the experiment. The average number of lambs born per ewe was 1.0 in groups C and E1 and 1.8 in group E2. Both forms of selenium supplementation resulted in higher activity of GSH-Px in the whole blood, higher content of Se in the blood serum (P < 0.001) and milk of ewes (P < 0.001). Average activity of GSH-Px in the whole blood of ewes was as follows: C 697.9 ± 179.3; E1 1 147.4 ± 181.5; E2 1 056.1 ± 267.5 U/g Hb (P < 0.001). It reached the highest values in the 5th to 6th month of Se supplementation while the activity decreased after parturition in connection with lactation. Higher utilisation of Se from the organic form, compared to the inorganic form, was reflected in a higher content of Se in the milk of group E2 ewes (P < 0.05). The positive effect of selenium supplementation of ewes contributed to higher activity of GSH-Px in the whole blood of their lambs (P < 0.001) and higher Se concentration in the blood serum (P < 0.01). The organic form of Se (group E2) was more efficient in this case. Average activity of GSH-Px in the whole blood of lambs was as follows: C 434.1 ± 70.6; E1 1 031.6 ± 172.3 and E2 1 055.6 ± 235.1 U/g Hb. Keywords: selenite, organic selenium, blood selenium, urine, milk, pregnancy, lactation, sheep, glutathione peroxidise, Chlorella Journal: Czech Journal of Animal Science Pages: 292-298 Volume: 53 Issue: 7 Year: 2008 DOI: 10.17221/354-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/354-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-200807-0003.txt Handle: RePEc:caa:jnlcjs:v:53:y:2008:i:7:id:354-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: J. Zelenka Author-Workplace-Name: Faculty of Agronomy, Mendel University of Agriculture and Forestry, Brno, Czech Republic Author-Name: A. Jarošová Author-Workplace-Name: Faculty of Agronomy, Mendel University of Agriculture and Forestry, Brno, Czech Republic Author-Name: D. Schneiderová Author-Workplace-Name: Faculty of Agronomy, Mendel University of Agriculture and Forestry, Brno, Czech Republic Title: Influence of n-3 and n-6 polyunsaturated fatty acids on sensory characteristics of chicken meat Abstract: The relationship between different levels of n-6 and n-3 PUFA in chicken breast and thigh meat and sensory characteristics of meat was studied. Chickens were fed diets containing 1, 3, 5 or 7 percent of oil made of seeds either of the linseed cultivar Atalante (A) with a high content of α-linolenic acid or of the cultivar Lola (L) with a predominating content of linoleic acid. The meat of chickens fed L showed better sensory characteristics than the meat of birds fed A. If the tissue contained more than 180 mg/100 g of n-3 PUFA, i.e. the thigh meat when chickens were fed 3% or more A and the breast meat when chickens were fed 7% A, significant fishy odour and taste as well as slight oily aftertaste were recorded. Texture, tenderness and juiciness of breast meat did not differ significantly (P > 0.05) in groups fed different diets. Thigh meat in the group with 1% A was significantly (P < 0.05) more fibrous than in the group with 7% L; however, there were no differences in texture between the other groups. The thigh meat of chickens fed L was tenderer, juicier and tastier than the meat of those fed A. Tenderness and juiciness were the highest in the group fed 7% of L. There is only a limited possibility to increase the intake of n-3 PUFA without any risk of changes in sensory characteristics of meat. If the levels of α-linolenic acid in the diet were 6.5 and 31 g/kg and the n-6/n-3 PUFA ratios in the meat were 3.3:1 and 0.9:1, respectively, the sensory value of TM and BM was not significantly deteriorated. Keywords: chicken meat, organoleptic properties, linseed oil, PUFA Journal: Czech Journal of Animal Science Pages: 299-305 Volume: 53 Issue: 7 Year: 2008 DOI: 10.17221/356-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/356-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-200807-0004.txt Handle: RePEc:caa:jnlcjs:v:53:y:2008:i:7:id:356-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: M. Skřivan Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: G. Dlouhá Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: O. Mašata Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: S. Ševčíková Author-Workplace-Name: Institute of Animal Science, Prague-Uhříněves, Czech Republic Title: Effect of dietary selenium on lipid oxidation, selenium and vitamin E content in the meat of broiler chickens Abstract: An experiment was conducted to compare the effect of dietary sodium selenite and selenomethionine on selenium and α-tocopherol concentration in breast meat, oxidative stability of meat in broilers, and on growth performance, but only as an unimportant criterion in this case. Sexed broiler cockerels Ross 308 were allocated to 3 dietary treatments, each comprising 100 chickens. The basal diet was supplemented with 0 (control) or 0.3 mg/kg Se from sodium selenite (SS) or selenomethionine (SM). Dietary supplementation with SM increased (P < 0.05) body weight, but only by about 3%. Breast muscle Se concentration was increased (P < 0.05) by both Se sources, but more by SM (1.32 mg/kg dry matter; 0.47 mg/kg DM in control). The concentration of Se in excreta was 3 times higher with SS supplement than with SM supplement. Dietary Se supplementation increased (P < 0.05) the α-tocopherol content of breast meat from 25.9 mg/kg DM in the control to 33.2 mg/kg DM when SM supplementation was used. Furthermore, lipid peroxidation decreased compared to the control. The inclusion of SM in the diet reduced (P < 0.05) malondialdehyde (MDA) values in breast samples after 0, 3, and 5 days of cooler storage, whereas SS decreased (P < 0.05) the MDA of breast meat after 0 and 3 days of storage. The results of this experiment indicate that selenomethionine in the diet of broilers is capable of simultaneously increasing the content of selenium and vitamin E in broiler meat plus its stability in storage. Keywords: broilers, sodium selenite, selenomethionine, vitamin E Journal: Czech Journal of Animal Science Pages: 306-311 Volume: 53 Issue: 7 Year: 2008 DOI: 10.17221/358-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/358-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-200807-0005.txt Handle: RePEc:caa:jnlcjs:v:53:y:2008:i:7:id:358-CJAS