Abstract The aim of the experiment was to compare the sensory characteristics of meat from cows of two age categories and depending on to the degree of marbling. Slaughter cows were divided into two age categories: up to 4 years of age and over 4 years of age. Meat samples from m. longissimus dorsi for tasting were taken from the right carcass halves between rib 9 to 11. The marbling degree was evaluated according to a 10 point scale (1 - very strong marbling, 10 - virtually no marbling or only traces). A sensory evaluation of the meat was carried out on day 7 after the slaughter of the animals. Meat samples were stored for 7 days and then they were grilled to evaluate their flavour, taste, tenderness and juiciness (degree 1 - without flavour, taste, tenderness, juiciness, degree 5 - very high flavour, tenderness, taste, and juiciness). We also set a score for the shear force of the grilled meat in our device Texture Analyser. There are no significant differences in sensory evaluation between the categories in relation to meat marbling, which would indicate better or worse sensory evaluation of meat. With the characteristic shear force of the grilled meat there were more favourable results at all levels of marbling in category up to 4 years of age.

Content of free fatty acids, lipolytic bacteria and somatic cells in relation to milking technologyThe contents of free fatty acids (FFA) and counts of total bacteria, psychrotrophic lipolytic bacteria (PLiBC) and somatic cells were determined in 150 samples of cow's bulk raw milk on 20 farms with three different milking technologies in South Bohemia during 2008-10. FFA were determined using an extraction-titration method. Within the compared technologies, the highest mean values of FFA (3.88 mmol 100 g-1; P<0.001) and PLiBC (696 CFU ml-1) were observed on farms with pipeline milking in stalls. The lowest mean FFA level (1.54 mmol 100 g-1) was determined on farms with an automatic milking system. Medium values were determined on farms with parlour milking.

The effects of biological additives on the fermentation process and fibre composition of farm-scale grass silagesThe effects of bacterial and enzymatic additives on the course of fermentation process and on changes in the fibre composition of grass silages were investigated under farm-scale conditions over three years. Fourteen silages were prepared from die back grass stands in each of three variants, with no additive (control), with inoculants of lactic acid bacteria (LAB), and with LAB combined with cellulase and hemicellulase. The content of lactic acid was significantly (P<0.05) elevated, while the degree of proteolysis decreased (P<0.01) in both variants with the additives. The changes in the fermentation processes resulted in pH values about 4.8 and 4.3 in the control and the variants with additives, respectively. The qualitative parameters of fermentation were very similar for both the groups of additives.

Reasons for the culling of dairy cows on low-input mountain farmsReasons for the culling of dairy cows were scrutinized on thirty-four low-input farms in the Šumava mountains in the Czech Republic. An increase in the frequency of the most common culling category - category 58 (other health reasons) - was identified in both the Holstein and Czech Fleckvieh breeds between 2000 and 2007: from 35% to 59% in the Holstein cows and from 19% to 41% in the Czech Fleckvieh cows (X2 test; P<0.001). This brought the Czech Fleckvieh cows to the same level of frequency as in the Czech Republic population, while the frequency among Holstein cows was on average 11% higher than in the Czech Republic population. The frequency of category 58 was higher in the Holstein than in the Czech Fleckvieh cows, but category 52 (low milk production) was more frequent in the Czech Fleckvieh than in the Holstein cows (P<0.001). There is a link between category 58 ‘other health reasons’ and an increase in the milk productivity of the cows; this results eventually in a higher incidence of metabolic disorders and is discussed in this paper.