Czech Journal of Animal Science, 2007 (vol. 52), issue 11
The role of nitric oxide in parthenogenetic activation of pig oocytes: A review
J. Petr, E. Chmelíková, L. Tůmová, M. Ješeta
Czech J. Anim. Sci., 2007, 52(11):363-377 | DOI: 10.17221/2323-CJAS 
Parthenogenetic activation of mammalian oocytes with artificial stimuli is commonly applied in various reproductive biotechniques, e.g. cloning using nuclear transfer. For this reason, many studies focus on oocyte activation in vitro. Recently we have described the activation of pig oocytes using nitric oxide. This activating stimulus is very specific in many aspects. However, it does not provide an adequate stimulus for parthenogenetic development. It was shown that nitric oxide stimulated some signalling pathways which are inactive in conventional treatments for parthenogenetic activation, e.g. the cGMP-dependent signalling cascade. On the...
Nitrogen degradability and intestinal digestibility of rumen undegraded protein in rapeseed, rapeseed meal and extracted rapeseed meal
P. Homolka, J. Harazim, J. Třináctý
Czech J. Anim. Sci., 2007, 52(11):378-386 | DOI: 10.17221/2320-CJAS
In this study, nutritive values of rapeseed (R), rapeseed meal-expeller A (RM-A), rapeseed meal-expeller B (RM-B) and extracted rapeseed meal (ERM) were compared. The trials were performed using the in sacco method with three steers of the Czech Fleckvieh breed, which were fitted with a permanent ruminal cannula. Nylon bags with samples were incubated in the rumen for 2, 4, 8, 16, 24 and 48 hours. The effective degradability (ED) of crude protein (CP) was calculated at 0.08, 0.06 and 0.04 1/h of rumen particulate outflow rates (k), and the obtained ED values were 65.4, 70.8 and 77.4% for R, 86.7, 88.1 and 89.7% for RM-A, 82.2, 84.4 and...
Contamination of cow's raw milk by psychrotrophic and mesophilic microflora in relation to selected factors
R. Cempírková
Czech J. Anim. Sci., 2007, 52(11):387-393 | DOI: 10.17221/2325-CJAS
The objective of the paper was to analyse the influence of dairy cow management technology, milking method, predipping and summer grazing on the contamination of cow's raw milk by mesophilic (TBC), psychrotrophic (PBC), lipolytic (PLiBC) and proteolytic (PPrBC) bacteria. The values of TBC, PBC, PLiBC and PPrBC in bulk milk samples were determined by the culture method according to IDF standards. Investigations were carried out in nine stables of seven dairy farms from January 2005 to June 2006. Summer grazing has the most marked influence on the values of studied parameters. Farms with summer grazing had a lower microbial contamination of milk compared...
Freezing point of raw and heat-treated goat milk
B. Janštová, M. Dračková, P. Navrátilová, L. Hadra, L. Vorlová
Czech J. Anim. Sci., 2007, 52(11):394-398 | DOI: 10.17221/2324-CJAS
The freezing point (FP) was established in 48 bulk tank samples of raw and 48 samples of pasteurized goat milk that were collected in the course of lactation. Alongside, non-fat solids (NFS) content was monitored. Milk freezing point measurements were carried out using the thermistor cryoscope method in compliance with the standard CTS 570538 (1998). The mean freezing point of raw milk was found to be in an interval of -0.5513 ± 0.0046°C, variation ranged from -0.5466°C to -0.5567°C, with higher values in the spring months and a drop at the end of lactation. FP corresponded to the NFS content. The average freezing point of goat milk heat-treated...
Fatty acid profiles of rumen fluid from sheep fed diets supplemented with various oils and effect on the rumen ciliate population
Z. Váradyová, S. Kišidayová, P. Siroka, D. Jalč
Czech J. Anim. Sci., 2007, 52(11):399-406 | DOI: 10.17221/2322-CJAS
The profile of trans-fatty acids and the protozoan population were evaluated in four ruminally fistulated sheep fed a diet with meadow hay: barley grain ratio (80:20%) plus sunflower oil (SO), rapeseed oil (RO) or linseed oil (LO) (5% wt/wt). The concentrate was daily mixed with individual oils and offered at 07.00 h. A 4 × 4 Latin square with 4-week periods was used. The concentration of trans-vaccenic acid (TVA) was the highest 4 h after feeding (36.1 g/100 g FA with SO; 34.5 g/100 g FA with RO) and then decreased with the time after feeding (P < 0.05). The concentration of cis9, trans11 conjugated linoleic acid (c9,t11-CLA) with...
Supplemental wheat bran and microbial phytase could replace inorganic phosphorus in laying hen diets
J.H. Yao, J.C. Han, S.Y. WU, M. XU, L.L. Zhong, Y.R. Liu, Y.J. Wang
Czech J. Anim. Sci., 2007, 52(11):407-413 | DOI: 10.17221/2321-CJAS
An experiment was conducted to determine effects of wheat bran (WB) phytase on production performance and nutrient utilization in laying hens. Three hundred and seventy-five Lohmann hens at 32 weeks of age were randomly allotted to treatments of fifteen hens per pen with five pens per treatment. Five experimental diets were formulated. Diet one (control) contained 0.19% inorganic phosphate (Pi) from dicalcium phosphate. On the basis of diet 1, diet 2 and 3 were formulated to contain WB 5% and 10%, respectively. In diet 4 and 5, the WB was fixed at the level of 10% with Pi level adjusted to 0.14% in diet 4 and completely replaced with 500 U/kg microbial...