The main objective of this thesis is to assess the influence of condition of Holstein cattle during the dry period on the quality of colostrum and on the milk yield. The assessment is based on Body Condition Score (BCS) performed on dairy cows during the dry period and, subsequently, after calving. The experiment was carried on from December 2015 to October 2016 in Mléčná farma Lubina, s. r. o. farm. The Body Condition Score was assessed in the dry period and then within a week after calving. The overall number of examined animals is 384 cows in the dry period and 384 cows after calving. An hour after calving, a sample of colostrum was taken and its quality was assessed by a manual refractometer ATC (with automatic temperature compensation). The parameters of milk yield were obtained from the milk yield examination of each dairy cow 100 days after calving. The experiment showed that the physical condition of dairy cows in the dry period was highly influential (P is smaller than 0,01) in the average BCS in component ranges and that the physical condition after calving was also highly influential (P is smaller than 0,01) in the average BCS in component ranges. Furthermore, the conclusive impact (P is smaller than 0,05) on the contents of proteins in milk of dairy cows with BCS is smaller or equal than 3 (3,77 %) and of dairy cows with optimum BCS of 3,25 to 3,75 (3,89 %) was proved. In case of succession of lactation periods, the conclusive impact (P is smaller than 0,01) was proved on milk yield of cows in their 2nd lactation period (38,16 kg) and cows in their 3rd lactation period (41,17 kg), as well as on cows in their 4th lactation period (38,59 kg). Also, the statistically conclusive impact (P is smaller than 0,01) on the contents of proteins in milk and of lactose of dairy cows in their 2nd lactation period (3,71 % a 5,03 %) and of dairy cows in their 4th lactation period and latter (4,10 % a 4,96 %) was proved. Other results weren´t statistically significant.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:430183 |
| Date | January 2017 |
| Creators | Křístková, Jana |
| 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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