Povezanost koncetracije ureje u kravljem mlijeku s proizvodnim i reproduktivnim pokazateljima mliječnih krava

master's thesis

• Title (english): Correlation of urea concentration in cows milk with production and reproductive indicators of dairy cows
• Author: Martina Runje
• Mentor: Ante Ivanković (mentor)
• Committee member: Ante Ivanković (predsjednik povjerenstva)
• Committee member: Miljenko Konjačić (član povjerenstva)
• Committee member: Nikolina Kelava Ugarković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Animal Science and Technology); Zagreb
• Defense date and country: 2020-09-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Ureja je uobičajeni metabolit koji nastaje razgradnjom proteina u probavnom sustavu krava. Dio ureje iz organizma mliječne krave izlučuje se mlijekom. Koncentracije ureje u mlijeku krava indikator je opskrbljenosti organizma energetskom i proteinskom komponentom obroka odnosno njihovom ravnotežom u obroku preživača. Na koncentraciju ureje u mlijeku osim hranidbe utječu i brojni drugi čimbenici kao što su pasmina, stadij i redoslijed laktacije, tjelesna masa, dnevna proizvodnja i kemijski sastav mlijeka, somatske stanice, sezona i mužnja. Cilj diplomskog rada je utvrditi povezanost koncentracije ureje u mlijeku sa količinom proizvedenog mlijeka, sadržajem mliječne masti i proteina mlijeka te dužinom servis perioda i intervala teljenja kao reproduktivnim pokazateljima. Prosječna koncentracija ureje u mlijeku krava Holstein, simentalske i smeđe pasmine kretala se od 18,65 mg/mL do 24,11 mg/mL. Utvrđena je pozitivna povezanost koncentracije ureje u mlijeku sa sadržajem mliječnih proteina (P<0,01) i laktoze (P<0,05) te negativna povezanost koncentracije ureje u mlijeku sa visinom dnevne proizvodnje mlijeka (P<0,01). Nije utvrđena značajna povezanost koncentracije ureje u mlijeku sa dužinom servis perioda i intervala teljenja.

Abstract (english)

Urea is a common metabolite formed by the breakdown of proteins in cow the digestive system. Part of the urea from the body of a dairy cow is excreted in milk. It has been observed that the indicator of urea concentration in cow´s milk isan indicator of the body´s supply of energy and protein components of the meal, i.e. their balance of rations in ruminants. In addition to nutrition, the concentration of urea in milk is influenced by numerous other factors such as breed, stage and order of lactation, body weight, daily production and chemical composition of milk, somatic cells, season and milking. The aim of the thesis is to determine the relationship between the concentration of urea and milk production, milk fat and protein content and length of service period and calving interval as reproductive indicators. The average concentration of urea in the milk of Holstein, Simmental and Brown Swiss cows ranged from 18,65 mg/mL to 24,11 mg/mL. A positive correlation was determined between milk urea the concentration and content of milk proteins (P<0,01) and lactose (P<0,05) and negative correlation between the milk urea concentration and the amount of daily milk production (P<0,01). No significant correlation was found between the concentration of urea in milk and the length of the service period or calving interval.

• Keywords: ureja; proizvodnja mlijeka; kemijski sastav; reprodukcija
• Keywords (english): urea; milk production; chemical composition; reproduction
• Language: croatian
• URN:NBN: urn:nbn:hr:204:065405
• Study programme: Title: Production and Processing of Milk; Study programme type: university; Study level: graduate; Academic / professional title: magistar / magistra inženjer/inženjerka proizvodnje i prerade mlijeka (magistar / magistra inženjer/inženjerka proizvodnje i prerade mlijeka)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2020-10-07 12:43:20