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Opis: Fat deposition contributes importantly to various aspects of pig production such as meat and fat quality. It is influenced by various factors, including genetics (i.e. different breeds) and non-genetic factors (e.g. sex). This study aimed to identify mechanisms underlying these differences. The general objective of the present research was to determine how genetic variants and gene expression networks influence lipid-related traits in different metabolic types of pigs (i.e. among local breeds, between local breeds versus modern pig crossbreed and between entire males versus immunocastrated versus surgically castrated pigs). In the first part of the research, 20 European local pig breeds were phenotypically distributed according to stature, growth performance and fatness traits. Principal component analysis of phenotypic data distinguished between larger and leaner breeds with better growth potential from breeds that were smaller, fatter, and had low growth efficiency. The phenotypic data and genetic variants were used for a genome scan for selection signatures associated with phenotype. Several candidate genes were identified that may have adapted to specific phenotypic traits, such as the ANXA4 and ANTXR1 genes for stature, the TLL1 and KCTD16 genes for growth performance, and the DNMT3A and POMC genes for fatness. Several discovered genes in the genotype-phenotype selection scan were further tested for differential gene expression in adipose tissue between the local Krškopolje and the modern crossbreed. However, no significant differences in expression were found between the studied groups. Additionally, the expression of genes involved in lipid metabolism was further investigated in the same groups to discover possible underlying mechanisms for fatty phenotype in Krškopolje pigs. Genes involved in adipogenesis (i.e. PPARγ) and lipogenesis (i.e. FASN, ACACA) were upregulated in Krškopolje compared to modern crossbreed. These results were further supported by a higher quantity of adipose tissue depots together with a higher desaturation capacity in Krškopolje pigs than in modern crossbreed. However, lipogenic enzyme activities of subcutaneous adipose tissue were lower in Krškopolje than in modern pigs. In the second part of the research, male sex categories were compared at different levels. RNA-sequencing analysis revealed 83 differentially expressed genes between entire males and immunocastrated pigs, 15 between immunocastrated and surgically castrated pigs and 48 between entire males and surgically castrated pigs. Upregulated genes in entire males compared to immunocastrated and surgically castrated pigs were related to extracellular matrix dynamics and adipogenesis, whereas downregulated genes were involved in carbohydrate and lipid metabolism. A candidate gene expression approach using quantitative PCR demonstrated that genes involved in lipogenesis (i.e. FASN, ME1, ACACA) were downregulated in entire males compared to immunocastrated pigs. The obtained transcriptomic results were further associated with the phenotype. It was shown that entire males were the leanest compared to castrated pigs, exhibiting the smallest adipocytes and lobulus surface area in the backfat. In addition, activities of lipogenic enzymes in backfat were similar to surgically castrated pigs, while the immunocastrated pigs had increased activity compared to entire males and surgically castrated pigs. The higher activity of lipogenic enzymes in the backfat of immunocastrated pigs was not consistent with the fatty acid composition, as immunocastrates were still similar to entire males (lower saturated and higher polyunsaturated fatty acid content compared to surgically castrated pigs). To conclude, the present study discovered genetic variants and differentially expressed genes responsible for distinct lipid metabolism in different metabolic types of pigs.
Ključne besede: prašič, maščobno tkivo, lipidni metabolizem, lokalne pasme, moderni križanci, nekastrirani prašiči, imunokastrirani prašiči, kirurško kastrirani prašiči, selekcijski podpisi povezani s fenotipom, izražanje genov
Objavljeno v DKUM: 05.10.2022; Ogledov: 692; Prenosov: 6
Celotno besedilo (4,96 MB)

Opis: Magistrsko delo temelji na razvoju večkriterijskega odločitvenega modela za oceno tradicionalnih in avtohtonih pasem konj. Model smo proučeno prilagodili vsem pasmam, saj se te med seboj razlikujejo po načinu življenja, pričakovanjih, zahtevah in predvsem izkušnjah. Tradicionalne pasme so tiste pasme živali, ki po izvoru ne izhajajo iz Republike Slovenije oziroma za katere to ni dokazano. V magistrskem delu so predstavljeni kasaški konj, ljutomerski kasač in haflinški konj. Avtohtone pasme so tiste pasme živali, za katere je na osnovi zgodovinskih virov o pasmah dokazano, da so pasme po izvoru iz Republike Slovenije, torej da je bila Republika Slovenija prvotno okolje za razvoj pasem. Podrobneje smo predstavili pasme lipicanski konj, slovenski hladnokrvni konj, posavski konj in bosanski planinski konj. Na podlagi vhodnih podatkov, da bi zajeli vplive več dejavnikov pasme konj hkrati, smo razvili večkriterijski odločitveni model DEXi za ocenjevanje tradicionalnih in avtohtonih pasem konj, v katerem smo določili glavne kriterije oziroma atribute: (i) zunanjost/temperament/šolanje, (ii) stroški/namenska uporabnost ter (iii) prilagodljivost okolju. Pasme konj smo glede na pridobljene rezultate razdelili v štiri skupine, in sicer: konji, ki imajo ˝neustrezno˝ oceno pasme, konji, ki imajo ˝manj ustrezno˝ oceno pasme, konji z ˝ustrezno˝ oceno pasme in konji, ki imajo lahko ˝zelo ustrezno˝ oceno pasme. V prvo skupino, poimenovano ˝neustrezna˝ ocena pasme, nismo zabeležili nobenega primera konja. V drugo skupino, poimenovano ˝manj ustrezna˝ ocena pasme, spada največ primerkov iz naše raziskave, in sicer: kasaški konji, ljutomerski kasač, lipicanski konj, slovenski hladnokrvni konj, posavski konj in bosanski planinski konj. V tretjo skupino spada samo en primerek, in sicer pasma haflinški konj, z ˝ustrezno˝ oceno pasme. V četrto in hkrati tudi zadnjo skupino konjev z ˝zelo ustrezno˝ oceno pasme pa prav tako nismo zabeležili nobenega primera konja.
Ključne besede: tradicionalne pasme, avtohtone pasme, večkriterijski model, metoda DEXi
Objavljeno v DKUM: 16.04.2021; Ogledov: 1571; Prenosov: 101
Celotno besedilo (1,50 MB)

Opis: V začetku leta 2015 smo križali štajersko kokoš s pritlikavo vijandotsko kokošjo na kmetiji Fijavž v Vitanju. Opazovali smo lastnosti, ki so se pojavljale pri potomcih križanja v zgodnjem stadiju razvoja, od prvega dne izvalitve piščancev do starosti enega meseca. Ker smo pri križanju uporabili dve pasmi z osebki različnih barv, smo dobili barvno zelo različne piščance. V križanje smo vključili štajerske kokoši v jerebičasti barvi in kokoši pritlikave vijandotske kokoši v srebrni, zlati ter rumeni barvi. Oblikovali smo pet skupin s po štirimi kokošmi in petelinom druge pasme. Prve štiri skupine so tako imele po štiri 'štajerke' in 'vijandotskega' petelina, peta skupina pa 'štajerskega petelina' in kokoši pritlikave vijandotske pasme. Pri piščancih smo po izvalitvi opazovali barvo puha in nog ter določili telesno maso. To smo ponovili pri en mesec starih piščancih. Ugotovili smo, da se barva perja, vizualni izgled kokoši, pozna operjenost petelinčkov in greben v večji meri dedujejo po vijandotskih kokoših, velikost, barva nog, priuhek, rep in čopek pa po štajerski kokoši.
Ključne besede: pasme kokoši, barva perja, križanje, greben, masa piščancev
Objavljeno v DKUM: 28.09.2015; Ogledov: 2770; Prenosov: 203
Celotno besedilo (1,12 MB)

Ključne besede: mlečnost ovac, sestava mleka, sistemi pridelave, tehnologija reje, pasme
Objavljeno v DKUM: 10.07.2015; Ogledov: 1394; Prenosov: 95
Povezava na celotno besedilo

Opis: V raziskavi smo proučevali dolžino poporodnega premora in dobe med telitvama na območju Koroške regije. Podatke smo pridobili s Kmetijskega inštituta Slovenije za šest koroških občin, kjer smo izbrali deset največjih proizvajalcev mleka z raznoliko pasemsko sestavo. Podatke smo obdelali za obdobje desetih let (1998–2008). V obdelavo je bilo vključenih 8.264 krav s povprečno 2,86 zaporednih telitev. Največ je črno-bele pasme (5.972), sledita ji lisasta (727) in rjava (859) pasma. V statistični model smo vključili vpliv občine, pasme ter interakcijo med občino in pasmo. Ugotovili smo, da sta poporodni premor (od 96 do 135 dni) in doba med dvema telitvama (od 380 do 416 dni) v nekaterih koroških občinah nekoliko daljša od priporočil v literaturi. Krave imajo v povprečju 6.373 kg mleka v standardni laktaciji glede na občino in 6.096 kg mleka glede na pasmo. Največ mleka v standardni laktaciji imajo krave črno-bele pasme (6.935 kg). Povprečni poporodni premor vseh pasem (120 dni) v obravnavanih koroških občinah (121 dni) je za deset dni krajši od slovenskega povprečja. Glede na občine (404 dni) in pasme (406 dni) je tudi doba med dvema telitvama na Koroškem krajša od slovenskega povprečja (415 dni). Da bi obdržali poporodni premor in dobo med telitvama na Koroškem vsaj v takšnem stanju, ali ju celo skrajšali, bodo rejci morali v večji meri skrbeti za prehrano, odkrivanje pojatev in pravočasno osemenjevanje krav.
Ključne besede: doba med dvema telitvama / poporodni premor / pasme / plodnost
Objavljeno v DKUM: 22.10.2012; Ogledov: 2125; Prenosov: 185
Celotno besedilo (1,31 MB)