National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Vyhodnocení reprodukčních schopností a růstu potomstva u plemene Masný simentál
Chytka, Vladimír
Beef Simental is a beef breed that is bred almost all over the world. In the Czech Republic there is the third most widespread of meat breeds in the number of cows. Most breeding bulls of this breed act in natural breeding, which confirms its popularity in commercial crosses. This diploma thesis was focused on growth ability and evaluation of reproductive indicators in five breeds dealing with breeding of this breed in performance control. The influence of breeding conditions, sex, breeding method, calving on weight of calf at birth, at 120, 210 and 365 days was monitored. Furthermore, the length of the interim period, the age at the first calving and the order of calving of the cows in the herd of individual breeders were determined. The influence of breeding conditions, breeding method, sex and calving rank was statistically highly significant (p ˂ 0.01). Difference between calves born after insemination bulls and after natural breeding was 25 kg. Bulls had higher weights in all reference periods (120, 210 and 365 days). The difference between the average weight of a bull and a heifer was 146 kg. There was a statistically significant difference (p ˂ 0,01) between the calves from the first calvers and the cows on the second calf and the other calves in weight. The average age at first calving in the evaluated farms is 954 days which confirms the current trend but is in conflict with the breeding goal of this breed.
The Effect of rearing and age at first calving on the performance and longevity of Holstein dairy cattle
SMRČINA, Tomáš
This thesis examines the influence of the level of rearing and age at first calving on performance and longevity of Holstein dairy cattle in the company ZD Krásná Hora nad Vltavou C. The quantity of milk per kg in the first lactation, functional longevity in kg of milk, functional longevity and longevity in days belong among the indicators observed by cows of Holstein cattle. The results of the monitored herds can be concluded that extension of age at first calving is statistically significant on the amount of milk in the first lactation, on functional longevity in kg of milk, on functional longevity and longevity in days. In contrast, no significant influence of the weight was elicited by observed indicators. The highest longevity in the monitored herd was achieved by the cows that were excluded for a difficult birth and also achieved the highest milk yield for functional longevity in kg milk and observation for the highest average in the number of lactations for life.

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