Veterinarija ir Zootechnika

The aim of this study was to investigate the prevalence of polymorphisms of STAT5 and GH genes and to determine their influence on the productivity traits in beef cattle. A total of 95 animals were genotyped, belonging to the breeds Angus, Limousin, Galloway and Simmental. Polymorphisms of STAT5 and GH locus were identified using a PCR-RFLP method. The evaluation of the STAT5 gene polymorphism (7 exon, 6853C> T) demonstrated that C allele (frequency 0.959) and CC genotype (frequency 0.918) were the most common in beef bull populations reared in Lithuania. This polymorphism had a statistically significant effect on the live weight index of animals. The examination of the GH gene polymorphism (5 exon, 2141C> G) revealed that the G gene allele (frequency 0.612) and heterozygous CG genotype (frequency 0.424) were the most common. This polymorphism had a statistically significant effect on daily bull weight and live weight. Bulls of the homozygous CC genotype exhibited better economic characteristics. In conclusion, our results demonstrated the potential of polymorphisms of GH and STAT5 genes as candidates for the investigation of quantitative traits in cattle.

The aim of the present study was to investigate phenotype resistance profiles and some

The deficiency of tick control causes large economic losses for the health of animals and the risk of transmission of zoonotic diseases. Their control is based on the use of acaricides such as organophosphates, synthetic pyrethroids, amidines and macrocyclic lactones; however, its inappropriate use has favoured the presence of populations resistant to the main families of acaricides. This study was conducted with the objective to evaluate the resistance of Rhipicephalus (Boophilus) microplus against three widely used ixoidicides in Nicaragua, namely coumaphos, amitraz and cypermethrin, applied in the concentrations indicated by the manufacturer. For this, the techniques of Adult Immersion Test (AIT) and Larval Package Test (LPT) were applied, for which ticks were collected from farms in Western Nicaragua. The results obtained through the AIT show that coumaphos has a higher percentage of oviposition inhibition of 86%, while cypermethrin only demonstrated an oviposition of 12.9%. Mortality in adults treated with coumaphos was 97.72%, and in those treated with amitraz it was 48.8%, while cypermethrin only provided a mortality of 14.71%. In this study, the Rhipicephalus (Boophilus) microplus ticks collected from cattle were determined to have elevated levels of resistance to cypermethrin but low resistance to coumaphos.