Abstract This study evaluated the effect of increasing the nutritional plane in finishing diets on meat quality traits of culled adult goats. Forty-one crossbred does were divided into four groups: baseline diet formulated to meet 100% of the nutritional requirements (BD); BD + 30% (BD30); + 60% (BD60); + 90% (BD90) of the nutritional level of BD. The goats received the experimental diets for 28 days. The protein profile of the longissimus lumborum muscle was evaluated using 1D SDS–PAGE and mass spectrometry. Cholesterol and albumin concentrations were highest in the BD group. There were no alterations in loin proximate composition or tissue composition. However, there was a significant reduction in the PUFA content in groups BD60 and BD90 compared with the group fed the baseline diet. Of 37 protein bands identified, 35 showed lower intensities in group BD90 than in BD and 22 bands showed lesser expression in groups BD60 and BD90 than in BD. The multivariate model identified 14 band proteins involved in group-diet segregation. Therefore, increasing the nutrient supply for finishing goats did not have marked positive effects on carcass. A lower expression of these proteins can have a profound impact on the qualitative aspects of the meat product.

ResumoObjetivou-se avaliar a diversidade genética de ovinos Santa Inês em fazendas no Estado do Piauí, utilizando marcadores RAPD. Foram analisados 164 espécimes pertencentes a seis municípios das mesorregiões Centro-Norte e Sudoeste. Após a obtenção do DNA, avaliou-se o potencial de 34 iniciadores, dos quais apenas cinco mostraram bandas passíveis de análise. Foram amplificados 37 locos distintos, sendo 36 polimórficos. Apesar do alto polimorfismo geral (97,2%) a taxa de polimorfismo intrapopulacional foi reduzida (média = 69,82%/população), mostrando que o conjunto dos rebanhos apresenta alta diversidade, mas que cada população isolada pode estar sofrendo efeitos da endogamia. Os índices de diversidade genética (Hs) e de endogamia (f) apresentaram, respectivamente, valores de 0,289 e 0,172. Ambos indicaram excesso de homozigotos e consanguinidade positiva dentro das fazendas. A composição dos rebanhos amostrados quase exclusivamente por fêmeas pode ser a justificativa para esses resultados, onde as proles são compostas principalmente por meio-irmãos. Os resultados acima citados foram confirmados pelos testes de AMOVA (ΦST= 0,199), que mostrou diferenças genéticas significativas entre fazendas, e pelas análises do programa Structure, que indicaram a presença de três grupos genéticos distintos, podendo esta ser uma evidência da presença de animais pertencentes ao “Novo Santa Inês”, entre os ovinos amostrados.

AbstractThis study aimed to evaluate the genetic diversity of Santa Inês sheep in Piauí state farms using RAPD markers. A total of 164 specimens belonging to six cities of Central-Northern and Southwestern regions were analyzed. After isolating the DNA, we assessed the potential of 34 primers, of which only five showed bands with sufficient resolution. Thirty-seven distinct loci were amplified, of which 36 were polymorphic. Despite the overall high polymorphism (97.2%) the rate of polymorphism within each population was reduced (mean = 69.82%/population), showing that all the herds have a high diversity but that each isolated population may be suffering the effects of inbreeding. The indices of genetic diversity (Hs) and inbreeding (f) showed, respectively, values of 0.289 and 0.172. Both showed homozygote excess and positive consanguinity within the farms. The composition of the sampled herds almost exclusively by females may be the explanation for these results, where half-brothers compose most of the offspring. The above results were confirmed by AMOVA tests (ΦST = 0.199), which showed significant genetic differences between farms. Also, the analysis of Structure software indicated the presence of three distinct genetic groups, which may characterize the occurrence of animals belonging to the "New Santa Inês" among the sampled sheep.