The set includes 1782 heads of culling Czech fleckvieh cattle eliminated from 1 January 2012 to 1 September 2015. Influences on the first calving age, calving interval and lifetime milk yield were detected for data in the set. The following items were integrated among selected lifetime milk yield influences : genotype, herd, first calving age and first calving month. It was also tested whether the age of the first calving of milking cows is influenced by genotype and a herd. The last tested hypothesis was related to the influence of genotype and a herd on the length of the carving interval. The influence of genotype, lactation and the age of first calving cows on the way of elimination was investigated in the set as well. Multi-factor analysis of variance were used for the calculation of differences among the individual tested groups . With respect to statistical significance there was a statistically significant effect (p <0.05)of the herd and genotype on the age of the first calving cows found out. From the set it is evident that cows calved earlier reached better lifetime milk yield than cows calved at the older age (p <0.05). Another statistically significant difference (p <0.05) was found out within the first month of calving. Milking cows calved during colder periods of the year reached the higher lifetime milk yield. The influence of genotype on milk yield was not proved in this set. This also holds to reproductive parametres, there was no influence of genotype and the age of first calving on calving interval. When observing the outcome in terms of how we can positively evaluate the elimination of voluntarily culled milking cows, which is 34% .This situation is significantly lower than it is stated in literature and shows a good zootechnical care of the herds. In terms of elimination method there were the most dairy cows culled because of fertility - 31%. This fact shows that fertility is one of the main factors influencing the managament and profitability of dairy herds of cattle.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:251797 |
| Date | January 2016 |
| Creators | VAFEK, Jan |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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