| Sažetak | Govedarska proizvodnja najvažnija je grana stočarske proizvodnje u Republici Hrvatskoj. Zadnjih nekoliko godina dolazi do pada brojnog stanja goveda uz istovremeni uvoz različitih pasmina i genotipova koji trebaju zadovoljiti potrebe i preferencije potrošača ponajprije u pogledu kvalitete mesa (svježe, meko i ružičasto meso). Polimorfizam diacilglicerol-O-aciltransferaze (DGAT1) odgovoran je za neka ekonomski važna svojstva kao npr. udiointermuskularne masti, koji doprinose mekoći, sočnosti i okusu mesa. Stoga je cilj rada bio genetska karakterizacija polimorfizma DGAT1 gena u muških i ženskih križanaca simentalske i Holstein pasmine goveda te povezanost genotipova s odlikama kvalitete trupova (zamašćenost trupova, EUROP klasa, kemijski sastav mišića) obje skupine. U križanaca simentalske i Holstein pasmine goveda utvrđen je polimorfizam DGAT1 gena. Frekvencije alela K su bile veće u odnosu na frekvencije alela A u omjeru 0,64 : 0,36. Također, utvrđena su samo dva genotipa KA i KK s frekvencijama 0,71 i 0,27, dok genotiip AA nije utvrđen. Polimorfizam DGAT1 gena imao je utjecaj na odlike kvalitete trupova križanaca simentalske i Holestein pasmine. Križanci KK genotipa imali su veću porodnu masu (+0,22 g) i masu klanja (+102,8 g), kalo (0,59 kg; 0,05%), veći bruto (+51,30 g) i neto (+26,41 g) dnevni prirast od križanaca KA genotipa koji nije bio statistički značajan (P<0,05). Meso križanaca KA genotipa bilo je jače zamašćeno (0,33 g), imalo je veću debljinu masnog tkiva (0,95 mm) te topli (0,41%) i hladni (0,43%) randman od križanaca KK genotipa,no bez statističke značajnosti. Kemijski sastav mesa križanaca simentalca i Holsteina oba genotipa bio je vrlo sličan. Iako bez utvrđene statističke značajnosti,veće vrijednosti za sadržaj pepela, kolagena, masti, proteina te udjela vlage utvrđene su u mesu križanaca KK genotipa. Nadalje, utvrđen je utjecaj DGAT1 gena i spola na odlike kvalitete trupova križanaca simentalske i Holestein pasmine goveda pri čemu su muški križanci KK genotipa imali statistički veću masu klanja (634,67 kg, P<0,01), bruto i neto dnevni prirast (bruto: 1183,03 g; neto: 691,76 g; P<0,05; P<0,01) ) u odnosu na muške križance KA i ženske križance (KK, KA) genotipa. Također, meso muških križanca KK genotipa bilo je znatno bolje klasificirano (3,83; P<0,05), dok je stupanj zamašćenosti (3,23) i debljina masnog tkiva MLD (4,09) utvrđena u ženskih jedinki KA genotipa bez statističke značajnosti. Kemijski sastav muških i ženskih trupova križanaca simentalca i Holsteina bio je sličan za pokazatelje pepela, kolagena i proteina, dok je udio vlage bio veći kod muških križanca KK genotipa (72,19%, P<0,05), a udio masti (6,55%; P<0,05, P<0,01) u ženskih križanaca KA genotipa. |
| Sažetak (engleski) | Beef production is the most important branch of livestock production in the Republic of Croatia. In recent years, there has been a decline in the number of cattle, simultaneously importing different breeds and genotypes that need to meet the needs and preferences of consumers, especially in terms of meat quality (fresh, soft and pink meat). The polymorphism of diacylglycerol-O-acyltransferase (DGAT1) is responsible for some economically important traits such as share of intermuscular fat, which contributes to softness, juiciness and taste of meat. Therefore, the aim of the study was genetic characterization of DGAT1 gene in male and female crosses of Simmental and Holstein cattle and correlation of genotypes with the carcass quality (EUROP class, chemical composition of the muscles) of both groups. Crosses of Simmental and Holstein breeds contain polymorphism of the DGAT1 gene. The frequencies of alleles K were higher than the frequencies of alleles A(0.64 : 0.36). Also, only two genotypes KA and KK were determined with the frequencies 0.71 and 0.27, while the genotype AA was not found. The DGAT1 gene polymorphism had influence on the quality of the carcasses of Simmental and Holestein crossess. Animals with KK genotype had a higher birth weight (+0.22 g) and slaughter weight (+102.8 g), cooling loss (0.59 kg, 0.05%), higher gross (+51.30 g) and net (+26.41 g) daily gain compared to the crosses of KA genotype which was not statistically significant (P<0.05).Meat from crosses of KA genotype was greasy (0.33 g), had higher fat thickness (0.95 mm), and warm (0.41%) and cold (0.43%) dressing percentage than KK crossbreeds without statistical significance. The chemical composition of the Simmental and Holstein crossbreeds of both genotypes was very similar. Although without static significance, higher values for ash, collagen, fat, protein and moisture content were found in the KKcrosses. Furthermore, the influence of DGAT1 polymorphism and sex on the quality of carcasses of Simmental and Holestein cattle was determined, where male crossesof KK genotype have a statistically higher slaughter mass (634.67 kg, P<0.01), gross and net daily gain (gross: 1183.03 g; net: 691.76 g; P<0.05; P<0.01) than male crosses of KA and female crosses (KK, KA) genotypes. Also, meat of male with KK genotype was significantly better classified (3.83, P <0.05), while the higher degree of greasy (3.23) and fat thickness of the MLD (4.09) was determined in female KA genotypes without statistical significance. The chemical composition of male and female carcasses of Simmental and Holstein crosses was similar regarding ash, collagen and protein indicators, while the moisture content was higher in KK male crosses (72.19%, P<0.05), and fat content (6.55%, P<0.05, P<0.01) in female crosses of the KA genotype. |
