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  • Factors affecting the efficiency of superovulation and embryo transfer. Season and hormonal background
    73-76
    Views:
    235

    Success of the embryo transfer programs is affected by many factors (breed, type, season, treatment). We assume, that periferical blood level of some metabolic hormones (IGF-1, thyroid hormones, leptin, insulin) affects the success of superovulation and ET. According to our results, there is a
    significant difference between the in and out of season periferial blood level of IGF-1 and insulin. Furthermore, decrease in the periferic blood levels of IGF-1 and insulin is less drastic in the pregnant recipients.

  • Biotechnological methods for improving reproduction on sheep breeding program using laparoscopic artificial inseminations in Debrecen, Hungary
    193-200
    Views:
    84

    The aim of this study was to evaluate the results of the LAI method in different types of breeds and seasonal variations. Analysing n=536 LAI in 7 years, there were no significant differences observed in the breed in lambing rates. Although the lambing rate of Prolific Merino (F+) was better than any other breed (45.3%). We found significant differences between breeds of Tzigaia, its pregnancy rate was 19.2%. In the case of prolificacy there were significant differences between breeds: Prolific Merino’s (FF) was the highest (2.38) and, Indigenous Tzigaia’s was the lowest (1.4) from all of them. The obtained results showed that summer inseminations were the most effective in concern of pregnancy rate (49.5%). The results are based on use of the types of semen, showed that using frozen semen was most effective than fresh semen in both parameters, however there were no significant differences. Summarising all tested conditions in our study breeds, seasons and type of semen using LAI the total results of pregnancy rate was 40.3% and the prolificacy was 1.78, respectively. Follow up the out-of-season ovarian, progesterone level of n=36 Prolific Merino were examined and insulin, IGF-1, leptin, T3, and T4 hormones as well, to evaluate the energetic status of the flock. Progesterone analysis showed 43% of examined ewes had a cyclical ovarian function in April and a cyclical ones had good reaction for estrus-induction hormonal treatment. Our results showed that valuable information can be obtained about energy supply from the determination of some metabolic hormones as IGF-1, insulin, leptin.

  • Polymorphism of the bovine GH and LEP genes in a population of Slovak spotted bulls
    19-23
    Views:
    98

    The aim of this study was the detection of polymorphism in the bovine growth hormone and leptin genes using the PCR-RFLP method. A
    polymorphic site of the growth hormone gene (Alul loci) that results in amino acid change at position 127 of the protein chain (leucine, L to
    valine, V) has been linked to differences in circulating metabolites, metabolic hormones and to milk yield. The polymorphism in bovine leptin
    gene is situated in the intron between two exons, which results in an amino acid change at position 2059 of the protein chain (cytosine, C to
    thymine, T). The polymorphisms were studied in a group of 58 bulls of the Slovak spotted breed. A strategy employing PCR was used to amplify 428 bp (GH gene) and 422 bp (LEP gene) products from blood samples. Digestion of PCR products with restriction enzymes AluI and Sau3AI revealed alleles: L and V; A and B for GH gene and LEP gene, respectively. The growth hormone gene is a candidate gene for body weight gain in cattle, since it plays a fundamental role in growth regulation. Leptin plays an important role in the regulation of feed intake, energy metabolism, growth and reproduction of cattle; therefore, animals with higher leptin gene expression will probably have lower daily weight gain than others with similar forage offer and nutritional condition and will also likely have longer calving intervals.