Rangel, Adriano Henrique do NascimentoLima, Tábatta Cristine Chaves de2017-04-262017-04-262014-06-05LIMA, Tábatta Cristine Chaves de. Polimorfismo no gene da beta-caseína em rebanhos zebuínos leiteiros no Estado do Rio Grande do Norte. 2014. 58f. Dissertação (Mestrado em Produção Animal) - Universidade Federal do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, 2014.https://repositorio.ufrn.br/jspui/handle/123456789/22746Various human health problems have been related to the consumption of bovine milk, foremost among them those related to allergenic constituents, caused by the body's immune response to milk proteins. Knowing this and the importance of milk as a source of animal protein, find solutions to minimize the occurrence of such reactions is extremely necessary. Studies indicate that Zebu breeds have a high frequency of A2 allele of β-casein. This allele, homozygous, provides a less harmful to human health milk, showing the physiological importance of their detection. In this context, this study aimed to identify the presence of allelic variants A1 and A2 of the β-casein gene, as well as evaluate the production characteristics in dairy zebu cattle. EMPARN - 156 Zebu dairy animals (68 Gir and 88 Guzera) from the herd of the Experimental Station Felipe Shrimp were used. DNA extractions were made from animal hair follicle. The gene was amplified and sequenced in ABI 3100 automated sequencer, the sequences obtained were subjected to analysis in Geneious 5.6.5® program. Statistical analysis was performed using the Statistical Analysis System (SAS, 2002) program. The ANOVA procedure was used for analysis of variance and comparison of means by Tukey test at 5% significance. The allelic and genotypic frequencies of Gir and Guzera were, respectively, 98% and 97% for the A2 allele; and 0.96 and 0.93 for genotype A2A2. The means of production characteristics of Gir and Guzera are within the values observed for the races, but it differed significantly between them in the protein, lactose, and solids nonfat. For animals Gir, obtained positive correlation with fat and total solids, while for Guzera there were correlations between the following variables: fat and total solids, protein and total solids, and lactose and total solids. The results show the high frequency of the A2 allele in Gir and Guzera, therefore, can be said that for this protein milk from zebu breeds Gir and Guzera in the population studied and is indicative of the milk of these breeds can be more healthy. This work is of great importance for dairy production because very little research carried out in the country on the topic, especially with the zebu breeds, and signals the prospect of selecting these races in order to increase the frequency of desirable allele, emerging as one viable alternative for the production of a non-allergenic milk.Acesso AbertoAlergiaCSN2Leite A2GirGuzeráProdução de leitemasterThesisCNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL