RESUMO
Meat quality is being increasingly demanded by consumers in recent years. Several factors can affect meat quality, ranging from animal traits such as breed and genetic heritage to pre- and post-slaughter processes. This study investigated the influence of Nellore bulls on carcass and meat quality traits. We used 475 young uncastrated males, the progeny of 54 bulls, to evaluate characteristics of the following carcass traits: hot carcass weight, rib-eye area, and fat thickness. We also evaluated the following beef quality traits: marbling, color, drip loss, cooking loss, and shear force at 0, 7, and 14 days of aging. Bulls had a significant influence (P≤0.05) on rib-eye area, fat thickness, marbling, drip loss at 14 days of aging and color at all aging periods. Based on these results, the use of bulls with high breeding values for these traits can provide important advances in carcass traits and meat quality in breeding programs of Nellore cattle that are raised in tropical conditions.
Assuntos
Peso Corporal/genética , Cruzamento , Carne , Tecido Adiposo/metabolismo , Fatores Etários , Animais , Composição Corporal/genética , Bovinos , Masculino , FenótipoRESUMO
The association between two single nucleotide polymorphisms (SNPs), T945M and UCP1SNP1, with hot carcass weight (HCW, kg, N = 618), longissimus dorsi muscle area (REA, cm(2), N = 633), and backfat thickness (BF, mm, N = 625), measured in Nellore cattle in Brazil, was evaluated. Likelihood ratio tests were used to evaluate reduced (fixed effects of general mean, contemporary group, yearling weight, age at slaughter, and random effect of infinitesimal genetic value) and full model (reduced model effects plus quantitative trait locus effects). Additive and dominance effects were tested for each SNP. Genotypic and gene frequencies were also obtained for the SNPs and a descriptive phenotype analysis was made. Mean values for HCW, REA and BF were equal to 288.13 +/- 0.55 kg, 73.14 +/- 0.27 cm(2), and 4.28 +/- 0.07 mm, respectively; the coefficients of variation were 4.74, 9.24, and 42.43%, respectively. Gene frequencies for T945M and UCP1SNP1 were f(C) = 0.89, f(T) = 0.11, f(C) = 0.81, and f(G) = 0.19. The SNP T945M had a genotypic frequency of only three animals for TT genotype. Additive effects were observed for T945M on REA and BF, while UCP1SNP1 affected HCW and BF. Based on the significant additive effects of the SNPs and the gene frequencies that we found, we can expect genetic gains with marker assisted selection.
Assuntos
Bovinos/genética , Polimorfismo de Nucleotídeo Único , Animais , Marcadores Genéticos , FenótipoRESUMO
We studied the secretory IgA (sIgA) response of the mucosal urinary tract of malnourished children before and after nutritional rehabilitation. sIgA concentration (mg/l) was determined by ELISA in 187 children aged 3 months to 5 years. The children, who frequented a day care center, were divided into four groups, according to nutritional status: 57 were eutrophic, 49 were undergrown, 57 were moderately malnourished and 24 were severely malnourished. In addition, dip slide (Urotube, Roche) and dip-stick (Combur 9-Boehringer) tests showed that children had no bacteriuria or any other urinary abnormalities. Plasma albumin concentration (g/dl) was significantly lower (P<0.005) in the severely malnourished group (mean 3.0 + ou - 0.3 SD) than in the eutrophic group (mean 4.0 + ou - 0.5 SD). When each nutritional state was analyzed, no significant differences in the sIgA were found between the 0 --- 1 and 1 -- 5 year age range. In the moderately and severely malnourished groups, sIgA (0.36 and 0.45, respectively) was significantly lower than in the eutrophic (0.69) and undergrown (0.75) groups. Ninety-five children were included in the 8-month follow-up study; 30 children were excluded from the follow-up because 4 had bacteriuria, 11 had leukocyturia, 8 had proteinuria and 7 had hematuria. Among the malnourished children, 40 per cent showed nutritional improvement (P<0.05) and significantly increased sIgA as compared to reference values for the eutrophic and undergrown groups. These data suggest that malnourished children have a significantly lower urinary sIgA than eutrophic children. After nutritional rehabilitation, they develop local immunity with a significant increase in sIgA.