In this review, we highlight information on microRNA (miRNA) identification and functional characterization in the beef for muscle and carcass composition traits, with an emphasis on Qinchuan beef cattle, and discuss the current challenges and future directions for the use of miRNA as a biomarker in cattle for breeding programs to improve meat quality and carcass traits. MicroRNAs are endogenous and non-coding RNA that have the function of making post-transcriptional modifications during the process of preadipocyte differentiation in mammals. Many studies claim that diverse miRNAs have an impact on adipogenesis. Furthermore, their target genes are associated with every phase of adipocyte differentiation. It has been confirmed that, during adipogenesis, several miRNAs are differentially expressed, including miR-204, miR-224, and miR-33. The development of mammalian skeletal muscle is sequentially controlled by somite commitment into progenitor cells, followed by their fusion and migration, the proliferation of myoblasts, and final modification into fast- and slow-twitch muscle fibers. It has been reported that miRNA in the bovine MEG3-DIO3 locus has a regulatory function for myoblast differentiation. Likewise, miR-224 has been associated with controlling the differentiation of bovine adipocytes by targeting lipoprotein lipase. Through the posttranscriptional downregulation of KLF6, miR-148a-3p disrupts the proliferation of bovine myoblasts and stimulates apoptosis while the miR-23a~27a~24-2 cluster represses adipogenesis. Additional to influences on muscle and fat, bta-mir-182, bta-mir-183, and bta-mir-338 represent regulators of proteolysis in muscle, which influences meat tenderness.

This review considers the unique characteristics of Chinese cattle and intramuscular fat content (IMF) as factors influencing meat quality, including tenderness, flavor, and juiciness of meat. Due to its nutritional qualities, meat contributes to a healthy and balanced diet. The intramuscular fat content and eating quality of beef are influenced by many factors, which can generally be divided into on-farm and pre-slaughter factors (breed, sex of cattle, age at slaughter, housing system, diet, and pre-slaughter handling) and postmortem factors (post-slaughter processing, chilling temperature, and packaging). Meat quality traits can also be influenced by the individual genetic background of the animal. Worldwide, the function of genes and genetic polymorphisms that have potential effects on fattening of cattle and beef quality have been investigated. The use of DNA markers is recognized as a powerful and efficient approach to achieve genetic gain for desirable phenotypic characteristics, which is helpful for economic growth. The polymorphisms of the SIRT4, SIRT6, SIRT7, CRTC3, ABHD5, KLF6, H-FABP, and ELOVL6 genes for body and growth characteristics of cattle, and also for beef quality, are considered with the aim of highlighting the significance of beef intramuscular fat content, and that growth, body, and meat quality characteristics are polygenically regulated.

Istraživanje autohtone proizvodnje Livanjskog i Travničkog sira ima za cilj očuvanje tradicije, organizirane proizvodnje i plasmana na tržišta izvan domicilne regije. Autohtoni sirevi su raznovrsnijeg okusa, arome i konzistencije u odnosu na industrijski proizvedene sireve, gdje je tehnologija definirana, a uvjeti proizvodnje kontrolirani. Nadmorska visina, kvalitetna voda i hrana nisu dovoljni čimbenici za trajno održavanje kvalitete autohtonih sireva. Na osnovi standardizacije tehnoloških postupaka proizvodnje može se proizvesti sir specifičnog obilježja. Cilj istraživanja bio je odrediti i komparirati ukupni dušik i dušične frakcije u dva autohtona sira – Livanjskom i Travničkom, ovisno o terminu uzorkovanja (srpanj, kolovoz i rujan). Za anlizu su uzorci sira uzeti nakon 90 dana zrenja u izvornim uvjetima okoline. U uzorcima sira određivan je ukupni dušik i dušične frakcije. Određivanje sadržaja ukupnog dušika (TN), kao i dušika topljivog u vodi pri pH 4,6 (SN-4,6) i 12% trikloroctenoj kiselini (TCA-SN) provedeno je metodom po Kjeldahlu. Vrijednosti TN, SN-4,6 i TCA-SN u uzorcima Travničkog sira bile su niže u odnosu na uzorke Livanjskog sira pri svakom terminu uzorkovanja. Najveće vrijednosti indeksa SN-4,6/TN i TCA-SN/TN kod oba ispitivana sira utvrđene su u sirevima proizvedenim od mlijeka prikupljenog tijekom rujna. Indeksi zrenja su bili viši u uzorcima Travničkog sira, što ukazuje na povećanu primarnu proteolizu u odnosu na Livanjski sir, to može biti rezultat specifičnosti biljnog pokrivača i ispaše ovaca na nižoj nadmorskoj visini.

The study included a total of 127 sheep milk samples from two different areas (Livno and Travnik) in summer feeding period (July, August and September). Fatty acids in milk were determined by gas chromatography (GC). The animals were marked with the appropriate number of ear tags on the basis of which we always took samples from the same animals through different periods. Fatty acids in milk were determined by gas chromatography and the following fatty acids composition: butyric acid, caproic acid, caprylic acid, capric acid, stearic acid, oleic acid, linoleic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, rumenic acid. The fatty acid content of sheep's milk in this study showed a tendency of variation, both within and between sampling areas, and characterized by its relatively high content of saturated fatty acid (SFA) during the period of harvest.