Template-Type: ReDIF-Article 1.0 Author-Name: J. Boleckova Author-Workplace-Name: Department of Molecular Biology and Genetics, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark Author-Workplace-Name: Department of Cattle Breeding, Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: O. F. Christensen Author-Workplace-Name: Department of Molecular Biology and Genetics, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark Author-Name: P. Sørensen Author-Workplace-Name: Department of Molecular Biology and Genetics, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark Author-Name: G. Sahana Author-Workplace-Name: Department of Molecular Biology and Genetics, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark Title: Strategies for haplotype-based association mapping in a complex pedigreed population Abstract: In association mapping, haplotype-based methods are generally regarded to provide higher power and increased precision than methods based on single markers. For haplotype-based association mapping most studies use a fixed haplotype effect in the model. However, an increase in haplotype length raises the number of parameters in the model, resulting in low accuracy of the estimates especially for the low-frequency haplotypes. Modeling of haplotype effects can be improved if they are assumed to be random effects, as only one parameter, i.e. haplotype variance, needs to be estimated compared to estimating the effects of all different haplotypes in a fixed haplotype model. Using simulated data, we investigated statistical models where haplotypes were fitted either as a fixed or random effect and we compared them for the power, precision, and type I error. We investigated five haplotype lengths of 2, 4, 6, 10 and 20. The simulated data resembled the Danish Holstein cattle pedigree representing a complex relationship structure and QTL effects of different sizes were simulated. We observed that the random haplotype models had high power and very low type I error rates (after the Bonferroni correction), while the fixed haplotype models had lower power and excessively high type I errors. Haplotype length of 4 to 6 gave the best results for random model in the present study. Though the present study was conducted on data structure more frequent in livestock, our findings on random vs. fixed haplotype effects in association mapping models are applicable to data from other species with a similar pedigree structure. Keywords: association mapping, haplotype, complex pedigree, false positives Journal: Czech Journal of Animal Science Pages: 1-9 Volume: 57 Issue: 1 Year: 2012 DOI: 10.17221/5478-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/5478-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-201201-0001.txt Handle: RePEc:caa:jnlcjs:v:57:y:2012:i:1:id:5478-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: F. Leiber Author-Workplace-Name: ETH Zürich, Institute of Agricultural Sciences, Zurich, Switzerland Author-Name: C. Kunz Author-Workplace-Name: ETH Zürich, Institute of Agricultural Sciences, Zurich, Switzerland Author-Name: M. Kreuzer Author-Workplace-Name: ETH Zürich, Institute of Agricultural Sciences, Zurich, Switzerland Title: Influence of different morphological parts of buckwheat (Fagopyrum esculentum) and its major secondary metabolite rutin on rumen fermentation in vitro Abstract: It was hypothesized that buckwheat, especially its flowers, influences foregut fermentation in ruminant animals because it is rich in phenolic compounds. The entire fresh aerial buckwheat herb, or its parts (leaves, stems, flowers and grain), were incubated for 24 h together with pure ryegrass (1:1, dry matter basis) in an in vitro ruminal fermentation system (Hohenheim Gas Test). Additionally ryegrass, supplemented with 0, 0.5, 5, or 50 mg rutin trihydrate/g dry matter, was incubated. Contents of extractable phenols (g/kg dry matter) were the highest in buckwheat flowers (88), followed by leaves (63), and the lowest in ryegrass (8). The levels of production of total gas and volatile fatty acids demonstrated that the nutritional value of buckwheat was slightly lower than that of ryegrass. Compared to ryegrass alone, ruminal transformation of dietary protein-N into ammonia was lower with 50 mg rutin, buckwheat flowers and buckwheat leaves. Thus, these treatments appeared to have partly protected dietary protein from ruminal degradation. Rutin, at the highest level, buckwheat flowers and the total aerial fraction of the buckwheat plant suppressed methane per unit of total gas by > 10%, either at elevated (rutin) or reduced total gas volume. This indicates that the ways of the influence on the ruminal fermentation pattern differed between pure rutin and buckwheat. In vivo studies have to confirm these potentially beneficial effects of buckwheat if used as forage for ruminants and clarify the role of further phenolic compounds present in buckwheat. Abbreviations: DM = dry matter, HGT = Hohenheim Gas Test, NDF = neutral detergent fibre, TEP = total extractable phenols, VFA = volatile fatty acids Keywords: Fagopyrum esculentum, ruminant feed, rumen fermentation, methane, ammonia, plant secondary compounds Journal: Czech Journal of Animal Science Pages: 10-18 Volume: 57 Issue: 1 Year: 2012 DOI: 10.17221/5479-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/5479-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-201201-0002.txt Handle: RePEc:caa:jnlcjs:v:57:y:2012:i:1:id:5479-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: M. Czauderna Author-Workplace-Name: The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland Author-Name: J. Kowalczyk Author-Workplace-Name: The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland Title: Simple, selective, and sensitive measurement of urea in body fluids of mammals by reversed-phase ultra-fast liquid chromatography Abstract: Ultra-fast liquid chromatography with a photodiode array detector for simple and rapid determination of urea in body fluids of farm animals is described. Blood plasma, milk, and urine samples are treated with trichloroacetic acid and then centrifuged. Supernatants are derivatized at room temperature using p-dimethylaminobenzaldehyde. Samples are separated using a ternary gradient of methanol in buffer and water. Derivatized urea in standards and biological samples is analyzed using a Phenomenex C18-column (Synergi 2.5 µm, Hydro-RP, 100Å, 100 × 2 mm). The photodiode detector is set to 370 and/or 254 nm for detection. Temperature is maintained at 27°C by a column heater. Clear separation of derivatized urea from the endogenous species present in assayed biological samples was achieved in less than 6 min. The urea adduct peak eluted at 4.36 ± 0.05 min. Average recoveries of the urea standards added to assayed biological materials were satisfactory (i.e. 100.2 ± 4.1%). Our chromatographic method with photodiode detection at 370 nm and at 254 nm, in particular, offers low detection (LD) and quantification limits (LQ) (370nmLD = 0.47 ng, 254nmLD = 0.027 ng and 370nmLQ = 1.41 ng, 254nmLQ = 0.080 ng, respectively). Our liquid chromato-graphy based on detection at 370 nm is the most versatile analytical tool that assures sensitive, accurate, and precise analysis of urea in urine, milk, and plasma samples, and selected diets for mammals. The presented chromatographic procedure is especially suitable for preparation of reference sample sets, very accurate and precise research purposes or rapid clinical diagnostic with smaller sample sets. Urea in urine can be also determined using our liquid chromatography with detection at 254 nm. Detection of urine urea at 254 nm is more sensitive and precise compared with monitoring at 370 nm. Our chromatographic method based on photodiode detection at 370 nm and especially at 254 nm is suitable for the non-invasive analysis of urea in only urine of humans and animals. Keywords: Keywords: urea, derivatization, liquid chromatography, milk, blood plasma, urine Journal: Czech Journal of Animal Science Pages: 19-27 Volume: 57 Issue: 1 Year: 2012 DOI: 10.17221/5480-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/5480-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-201201-0003.txt Handle: RePEc:caa:jnlcjs:v:57:y:2012:i:1:id:5480-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: M. Marounek Author-Workplace-Name: Department of Nutrition Physiology and Animal Product Quality, Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: L. Pavlata Author-Workplace-Name: Ruminant Clinic, University of Veterinary and Pharmaceutical Science, Brno, Czech Republic Author-Name: L. Mišurová Author-Workplace-Name: Ruminant Clinic, University of Veterinary and Pharmaceutical Science, Brno, Czech Republic Author-Name: Z. Volek Author-Workplace-Name: Department of Nutrition Physiology and Animal Product Quality, Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: R. Dvořák Author-Workplace-Name: Ruminant Clinic, University of Veterinary and Pharmaceutical Science, Brno, Czech Republic Title: Changes in the composition of goat colostrum and milk fatty acids during the first month of lactation Abstract: Changes in the composition of colostrum and milk fatty acids during the first month of lactation of ten 3-years-old White shorthaired goats fed a winter diet were investigated. Thirty-eight fatty acids (FAs) were identified in the milk fat. Saturated FAs accounted for 67.0% of the total determined FAs in colostrum and 62% at 30 days post partum. Monounsaturated FAs made up 28.2% of the total FAs in colostrum and increased with the progress of lactation at the expense of saturated FAs. The percentage of polyunsaturated FAs varied from 4.4 to 4.8%. The major FAs in colostrum and milk were palmitic and oleic acids, followed by stearic and myristic acids (30.1, 25.3, 11.8, 11.4% and 23.6, 30.3, 13.6, 8.6% in colostrum and milk 30 days post partum, respectively). The levels of palmitic and myristic acids in colostrum were higher than in mature milk, whereas the levels of capric, stearic and oleic acids were lower. The medium-chain FA (caprylic, capric, lauric) content increased from 8.7% of FAs in colostrum to 11.1% on the fourth day of lactation. These acids are efficient antimicrobials, thus may contribute to the protection of young goats from microbial pathogens. Keywords: goat, colostrum, milk, composition, fatty acids, serum Journal: Czech Journal of Animal Science Pages: 28-33 Volume: 57 Issue: 1 Year: 2012 DOI: 10.17221/5481-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/5481-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-201201-0004.txt Handle: RePEc:caa:jnlcjs:v:57:y:2012:i:1:id:5481-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: D. Bureš Author-Workplace-Name: Cattle Breeding Department, Institute of Animal Science, Prague-Uhříněves, Czech Republic Author-Name: L. Bartoň Author-Workplace-Name: Cattle Breeding Department, Institute of Animal Science, Prague-Uhříněves, Czech Republic Title: Growth performance, carcass traits and meat quality of bulls and heifers slaughtered at different ages Abstract: The effects of sex and slaughter age on growth, feed intake, carcass composition and meat quality attributes of musculus longissimus lumborum were investigated in Charolais × Simmental bulls (n = 12) and heifers (n = 12) reared and finished under identical management conditions. The animals entered the experiment at similar age (251 days) and were slaughtered at 14 or 18 months of age. Bulls gained more rapidly (P < 0.001), consumed more dry matter daily (P < 0.05), and had a higher killing-out proportion (P < 0.05). The sex × slaughter age interaction was significant (P < 0.01) for feed conversion ratio, which deteriorated markedly more in heifers than in bulls as slaughter age increased. Bulls produced leaner carcasses with a higher proportion of total meat (P < 0.001). While bulls contributed to high-priced meat by a higher proportion of meat from the shoulder (P < 0.01), heifers had higher proportions of meat from the rump and loin (P < 0.05). Older animals were generally fatter and their carcasses contained lower proportions of high-priced meat (P < 0.01) and bones (P < 0.05). Bulls exhibited lower contents of dry matter (P < 0.001), protein (P < 0.05) and intramuscular fat (P < 0.001), and a higher content of collagen (P < 0.001) in musculus longissimus lumborum than hei-fers. The meat from heifers was assessed by the sensory panel as more tender and, when aged for 11 days, more acceptable than the meat from bulls. Older animals obtained higher scores for beef flavour intensity (P < 0.01), tenderness (P < 0.001), juiciness (P < 0.05), and overall acceptance (P < 0.001). Keywords: beef cattle, sex, slaughter age, growth, carcass composition, meat quality Journal: Czech Journal of Animal Science Pages: 34-43 Volume: 57 Issue: 1 Year: 2012 DOI: 10.17221/5482-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/5482-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-201201-0005.txt Handle: RePEc:caa:jnlcjs:v:57:y:2012:i:1:id:5482-CJAS