Preliminary study on the characterization of Longissimus lumborum dark cutting meat in Angus × Nellore crossbreed cattle using NMR-based metabolomics.

The aim of this preliminary study was to evaluate meat quality properties, muscle metabolite profile and metabolic pathways associated with the occurrence of dark cutting meat in Angus x Nellore crossbreed cattle. After 14 days' ageing, dark cutting meat presented a higher pH, lower cooking loss and colour parameters, and greater tenderness compared with normal meat. Dark cutting meat had a higher ATP level and lower concentrations of glucose-6-phosphate, lactate, glucose, serine, threonine, creatine phosphate, inosine, leucine, methionine, succinate and glucose-1-phosphate compared to normal meat. In dark cutting samples, the ultimate pH was positively correlated with carnitine and negatively correlated with glucose-6-phosphate. However, in normal meat, the ultimate pH presented a positive correlation with arginine, leucine, methionine, proline, threonine, tyrosine and valine. Pathway analysis showed that differentiation of the groups was linked to energetic pathways such as starch and sucrose metabolism, the pentose phosphate pathway, amino sugar, nucleotide sugar metabolism, and glycolysis or gluconeogenesis. In conclusion, the occurrence of dark cutting meat has a notable impact on meat quality attributes and concentrations of post-mortem glycolytic metabolites, appears to be correlated with mitochondrial activity and affects energetic metabolic pathways.

Selection for Growth and Precocity Alters Muscle Metabolism in Nellore Cattle.

To clarify the relationship between beef genetic selection for growth and precocity with muscle metabolism and metabolites, we performed metabolomic analysis using Longissimus lumborum (LL) muscle from Nellore cattle with divergent selection for these traits (high growth, HG; low growth, LG; high precocity, HP; low precocity, LP). Genetic potential for growth affected muscle protein and energetic metabolism. HG animals had a high concentration of arginine, carnosine, and leucine compared to LG animals. HP animals presented a high concentration of glutamine, betaine, creatinine, isoleucine, carnitine, acetyl carnitine, and lower levels of glucose compared to LP animals, affecting protein and fatty acid metabolism. Intensity of selection (high or low) was correlated with changes in protein metabolism, and the type of selection (growth or precocity) affected fat metabolism. In conclusion, both HG and HP appear to be correlated with a high concentration of protein metabolites and changes in protein metabolic pathways, while selection for precocity is more correlated with changes in fat metabolism compared to animals selected for growth.

Morfometria do oviduto de poedeiras comerciais semipesadas submetidas a diferentes métodos de muda forçada / Morphometry of the oviduct of the brown egg layer hens submitted different methods of molt induction

Este experimento foi conduzido com o objetivo de avaliar a morfometria do oviduto de poedeiras submetidas a diferentes métodos de indução de muda forçada. Duzentas e oito aves com 58 semanas de idade foram distribuídas em um delineamento inteiramente casualizado, com quatro tratamentos (método Califórnia, dieta com alto teor de zinco, dieta com baixo cálcio e com baixo sódio) e quatro repetições de 12 aves cada. Avaliou-se a biometria do oviduto no início do experimento, no 28°. dia e em três períodos subseqüentes à realização da muda forçada, analisando-se o peso corporal da ave, a percentagem do oviduto e do ovário, o número de pregas do magno e do istmo e o comprimento das diferentes partes que compõem o oviduto. No período pós-muda, as características macroscópicas do oviduto não sofreram influência dos tratamentos estudados.

This experiment was aimed at evaluating the performance, oviduct morphometric, hormone concentration and bone density in laying hens submitted of the different methods of molt induction. Two hundred-eight laying hens, 58 weeks of age, were randomly divided into four treatments groups (california method, diet of high-zinc, diet of low-calcium and diet of low-sodium) and four replicates. The experiment evaluated biometrics characteristics on day 1, 28 of the experiment and in three periods postmolt: body weight, ovary percentage, oviduct percentage, number of folds of the magnum and isthmus, and length of the different parts of oviduct. In the postmolt period, the morphometric analysis of the birds were not affected by any of the experimental treatments.