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ABSTRACT The objective of this study was to evaluate the association of polymorphisms in the diacylglycerol acyltransferase ( DGAT ) and leptin ( LEP ) genes with the performance, carcass characteristics, meat quality, and lipid profile of Nellore cattle. A total of 100 intact male Nelore cattle were used to analyze the performance, carcass, physicochemical and centesimal composition, and fatty acid profile of beef. To identify the polymorphisms, the PCR–single-strand conformation polymorphism (SSCP) technique was applied to genomic DNA extracted from muscle tissue. The SSCP technique revealed the presence of four band patterns for the DGAT gene (AC, AD, AE and BB) with five alleles (A, B, C, D and E). For the LEP gene, five band patterns (AA, AB, AC, BB and BC) with three alleles (A, B and C) were observed. For the LEP gene, the AB genotype was associated with higher backfat thickness and ribs weight, while the BB genotype was associated with lower ribs yield; higher hindquarter yield was associated with AC and BB genotypes. Higher contents of C17:0, C18:0 and lower contents of C18:2ω6C, total polyunsaturated fatty acids, total ω6 and ratio of polyunsaturated and saturated fatty acids (PUFA/SFA) were verified for the AC genotype of the LEP gene. The AC and AA genotypes of the LEP gene were associated with higher means of C15:0 and C18:1ω9t. For the DGAT gene, the highest C24:0 content was associated with the AE genotype and the lowest with the AD and BB genotypes. Polymorphisms in the DGAT and LEP genes influence carcass parameters and the lipid profile of the meat of Nellore cattle.

This study aimed to characterize the quality of the meat from Rodhe Island Red poultry, considering the type of cut and sex. We used 30 birds in a completely randomized design in a factorial arrangement (2 x 2), two cuts (breast and thigh) and both sexes, with five replicates per treatment. The birds were slaughtered at 105 days to carry out the physical and chemical analysis, chemical composition and lipid profile of breast and thigh. The thigh showed the highest mean final pH, redness (a*) and shear force (SF). For brightness (L*), the breast had the highest average as well as females presented the highest SF average. The thigh presented the highest amount of ether extract (EE) and humidity. The breast presented the highest amount of saturated fatty acids. Females showed the highest amount of ω3 and the lowest ω6 / ω3 relation. There was a higher thrombogenicity index in breast meat. The thigh showed the lowest content of saturated fatty acids and a lower thrombogenicity index. Females had higher content of ω3. The cut showed greater influence then sex on the studied parameters and the thigh showed better physical and chemical aspects and lipid profile for poultry meat in such production system regarding the meat quality as desirable by the consumers. Keywords: atherogenicity; color; fatty acids; shear force; thrombogenicity.

Objetivou-se caracterizar a qualidade da carne de aves da raça Rodhe Island Red em função da diferença do tipo de corte e sexo. Foram utilizadas 30 aves em delineamento inteiramente casualizado em esquema fatorial (2 x 2), sendo dois cortes (peito e coxa) e dois sexos, com cinco repetições por tratamento. As aves foram abatidas aos 105 dias para realização das análises físico-químicas, composição centesimal e perfil lipídico do peito e coxa. A coxa apresentou maior média de pH final, teor de vermelho (a*) e força de cisalhamento (FC). Para luminosidade (L*), o peito obteve a maior média e as fêmeas maior média de FC. A coxa apresentou maior teor de extrato etéreo (EE) e umidade. O peito apresentou maior média de ácidos graxos saturados. As fêmeas obtiveram maior quantidade de ?3 e menor relação ?6/?3. Foi observado maior índice de trombogenicidade no peito. A coxa mostrou menor conteúdo de ácidos graxos saturados e menor índice de trombogenicidade. As fêmeas apresentaram maior teor de ?3. O tipo de corte demonstrou maior influência que o sexo sobre os parâmetros estudados e a coxa apresentou melhores aspectos físico-químicos e de perfil lipídico para carne de aves neste sistema de produção relacionados à qualidade de carne desejável pelos consumidores. Palavras-chave: ácido graxo; aterogenicidade; cor; força de cisalhamento; trombogenicidade.