Procjena utjecaja uzgoja u srodstvu na svojstva mliječnosti istarske ovce

master's thesis

• Title (english): The impact of inbreeding on dairy traits of istrian sheep breed
• Author: Ana Kurelović
• Mentor: Ante Kasap (mentor)
• Committee member: Ante Kasap (predsjednik povjerenstva)
• Committee member: Jelena Ramljak (član povjerenstva)
• Committee member: Milna Tudor Kalit (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Animal Science and Technology); Zagreb
• Defense date and country: 2024-09-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Utjecaj uzgoja u srodstvu (kvantificiran koeficijentom F) na svojstva mliječnosti je nedovoljno istražen kod ovaca, a budući da je u većini stada istarske ovce mlijeko glavni proizvod, cilj rada bio je utvrditi kako F utječe na 1) količinu proizvedenog mlijeka i 2) udjele masti i bjelančevina u mlijeku. Istraživanje je provedeno na proizvodnim podacima prikupljenim u uzgojno valjanoj populaciji istarske ovce rutinskim kontrolama mliječnosti propisanim nacionalnim uzgojnim programom. Analiza je izvršena multi-faktorijalnim statističkim modelom (metoda ANCOVA) u kojeg je uz ostale izvore fenotipske varijabilnosti (veličina legla, redoslijed laktacije, sezona, stado te trajanje sisanja i mužnje) uključen prethodno procijenjeni koeficijent uzgoja u srodstvu temeljem podataka iz rodovnika (Fped). Prosječni Fped populacije je bio 9%. Regresijom fenotipskih vrijednosti na Fped utvrđena je pozitivna povezanost Fped s količinom proizvedenog mlijeka, a negativna sa sadržajem mliječne masti i bjelančevina (P>0,05). Za generalizaciju utjecaja Fped na svojstva mliječnosti kod ovaca potrebna su dodatna istraživanja.

Abstract (english)

The impact of inbreeding (measured by coefficient F) on dairy traits has been insufficiently researched in sheep, and since milk is the main product of Istrian sheep, the aim of the study was to determine how level of the F affects 1) milk yield and 2) fat and protein content in milk. The research was conducted on "field" data collected in nucleus flocks during milking controls that are obligatory according to the national breeding program. The analysis was performed using a multifactorial statistical model (ANCOVA method). The coefficient of inbreeding, previously estimated from the pedigree (Fped), was included the statistical model together with other sources of phenotypic variability (litter size, parity, season, flock, and duration of suckling and milking periods). The average Fped of the population was 9%. The regression of phenotypic values on Fped revealed a positive relationship between Fped and the milk yield (P>0.05), and a negative relationship between Fped and content of fat and protein (P>0.05). Additional research is needed in the future to generalize the impact of Fped on dairy traits in sheep.

• Keywords: istarska ovca; mlijeko; uzgoj u srodstvu
• Keywords (english): Istrian sheep; milk; inbreeding
• Language: croatian
• URN:NBN: urn:nbn:hr:204:205697
• 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: Open access
• Created on: 2024-09-20 12:12:37