The current modern time brings knowledge that help streamline the efforts of breeders and interfere with the originally untouchable action, fertilization. Genetics and reproduction have become the main interest of biotechnological research. It was develop and operating implementation of biotechnological methods such as artificial insemination, embryo transfer, longterm cryopreservation of semen or sexsorting semen, which became the impetus the topic of this thesis. Milk production performance of cattle is the property caused by a plethora of internal and external influences. Recent interest in professional public switched to other options affecting the milk yield, which is the sex of the calf. The aim of this study, processed in following up on the research GRANT QJ1510139 National information system of genetic evaluation of livestock, was to verify the influence of the sex of the calf on the milk yield of the mothers in our conditions. From previous studies (Hinde et al., 2014; Grasboll et al., 2015), arose the hypothesis, that gender affects the milk yield.
To evaluate the two files have been used the measured data from the 1995-2015 with data on the sex of the calf and milk yields of the holstein dairy cattle in the control days provided by ČMSCH, a.s. From raw data has been created file of cows with three lactations, while each breeding had registered at least 3 control days on lactation. Abnormal data, wrong control days and sires with low number of daughters were eliminated as well. After editing the file contained 4.7 million milk yields from 197 thousends cows. Thesis worked with model based test-day access. Average daily milk yield in the file was 27.29 kg. In the method of least squares for 10 models were used the following effects: HTD (herd test day), Pohl (the effect of gender), Porl (effect of lactation), Skup (group) (for first lactation created by age of calving, calving period, service period and year of calving, for second and third lactations is the intervening period used instead of the age of the calving). Fixed regression the Legendre polynomial (LP) was used with 4 parameters. Milk yield fitted using LP showed normal shape of the lactation curve. According to the approved models is the effect of the sex of the calf on milk yield of the mother of the calf statistically insignificant. Having bulls increase productivity of milk yield about 0.07 kg/day which is about 21 kg per lactation. Genetic parameters were not examined due to the insignificance of the effect.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:259553 |
| Date | January 2016 |
| Creators | Fialová, Zuzana |
| Contributors | Přibyl, Josef, Jiří, Jiří |
| Publisher | Česká zemědělská univerzita v Praze |
| 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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