Vliv kvality siláže na množství a složení mléka dojnic českého strakatého plemene skotu

The diploma thesis is focused on analysing the impact of the quality of silage on the production and quality of milk of the Czech fleckvieh cattle. For this purpose, a herd of Czech fleckvieh cattle was observed in monthly intervals for the whole year 2016. I focused mainly on assessing the impact of the quality of silage and total mixed ration (TMR) on the components of milk and the milk production. At each observation, was carried out an assessment of the individual TMR fractions using a separator. The detection of cow comfort index (CCI) was followed by monitoring movements of chewing, chewing times and evaluation of condition of selected cows at the first lactation. The structure of the TMR during the year varied widely. The fraction of TMR on the first separator sieve ranged from 4.1% of TMR for cows at the peak of the lactation up to 91.41% of TMR for cows standing dry. The structure of the TMR for cows at the peak of lactation during the year was nearly optimal, since on the bottom of the separator there was only a minimal amount of TMR. The majority of the TMR remained in the second and third sieves. On the first sieve, there was found more than 10% TMR (except month of January - 4.55%), which corresponds to the general requirements of the structural fibre. According to the laboratory analyses the quality of the corn silage had not significantly changed. The dry matter was in the range from 31.78 to 37.91%, crude protein was from 8.3 to 11.04%, starch was from 28.78 to 41.55%, fibre was from 14 to 19.95%, pH from 3.70 to 3 81, NEL 6.60 to 6.81 MJ/kg and acidity of water extract from 1916 to 2211 mg KOH/100 g. CCI during the year ranged from 79.25 to 91.49%. Regarding chewing movements, the cow performed an average of 58 chewing movements in an average time of 58 seconds. Also, an evaluation was carried out of the body condition score of cows at their first lactation. The average value was 3.21 points, which is reported below the minimum threshold which a cow should achieve in this period (3.25 points). Due to the optimized feed rations, whose nutritional content was approaching the optimal values, the impact of variation of these values did not show up either on quantity or quality of milk, or dairy cow welfare parameters