Fatty acid profile of duodenal digesta and of meat of feedlot beef cattle fed diets containing different levels of concentrate

The objective of this study was to evaluate the fatty acid profile of duodenal digesta (experiment I) and of meat of beef cattle (experiment II) fed diets containing different levels of concentrate (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The experiment I was conducted with four Charolais-Nellore steers (460 ± 18.2 kg of BW), with a T-shaped duodenal cannula, using a double 4 × 4 Latin square as an experimental design. In experiment II, 16 crossbred Charolais-Nellore young bulls (192.44 ± 18.2 kg of BW) were randomly distributed in the experimental treatments (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The diets were isonitrogenous (120 g of crude protein/kg of dry matter). The intramuscular fat content was used as a covariant for the statistical analysis of the meat fatty acid profile. The duodenal content of fatty acid C17:0 decreased with increase of concentrate levels, while its content in the meat presented a quadratic variation with the increase of the concentrate levels of the diets, being the lowest values observed for the diet with 400 g of concentrate. The duodenal content of fatty acid C18:1 trans-11 decreased, whereas the content of this fatty acid in the meat increased with the increase of the dietary concentrate levels. The increase in the level of concentrate reduced the content of polyunsaturated fatty acids C18:3 n-3, C20:3 n-6, C20:4 n-6, and C20:5 n-3 EPA in both the duodenal digesta and meat. No difference was observed in the n-6/n-3 fatty acids ratio (mean of 13.96) of the meat between diets. The elevation of the level of concentrate in confinement diets reduces the nutraceutical quality of the meat of Charolais-Nellore young bulls slaughtered at 14-16 months of age due to the reduction of the polyunsaturated fatty acids content important for human health.

Effects of doe-litter separation on intestinal bacteria, immune response and morphology of suckling rabbits

Gut development is stimulated by exposure to microorganisms, especially early-life microbial exposure. This study aimed to investigate whether doe-litter separation, which is performed in many rabbit farms, affects this exposure and therefore inhibits the development of intestinal system in suckling rabbits. Immediately after parturition, Rex rabbit does (n=16) were adjusted to 8 kits per litter and divided into doe-litter separation (DLS) group and doe-litter together (DLT) group based on the conditions of the does. One healthy kit per litter was selected and sacrificed at 7 d, 14 d, 21 d and 28 d of age, and the number of total bacteria, Escherichia coli and Bacteroides-Prevotella, expression of interleukin 6 (IL-6) and interleukin 10 (IL-10) in duodenum and caecum were investigated by real-time polymerase chain reaction. The morphological parameters of duodenum and vermiform appendix were also measured. Our results showed that doe-litter separation affected the number of intestinal bacteria. At 7 d of age, except for caecal Escherichia coli, the number of the investigated bacteria was decreased by doe-litter separation (P<0.05). But 1 wk later, only the number of total bacteria and Bacteroides-Prevotella in caecal content (P<0.05) and Escherichia coli in duodenal content from DLS kits (P<0.05) were still lower than those from DLT kits. After being provided with supplementary food for 7 d, DLS kits had fewer total bacteria in caecal content (P<0.05) and fewer E. coli in duodenal content (P<0.01) than DLT kits. After growing to 28 d of age, kits in DLS group still tended to have fewer total bacteria in caecal content, and expression of IL-10 and secretion of secretory IgA (sIgA) in vermiform appendix in DLS group was obviously lower than kits in DLT group (P<0.05). The villus height:crypt depth ratio in duodenum at 3^rd wk and 4^th wk was decreased by DLS (P<0.05). Kits in DLS group had shorter villus height (P<0.05), higher crypt depth (P<0.05) and shorter vermiform appendix (P<0.05) at the end of the trial. Furthermore, separating kits from the doe had a negative effect on their average daily gain at 3^rd wk and 4^th wk (P<0.05). Limiting the microbiological contact with the mother during suckling period affected the kits’ intestinal flora and could negatively affect the development of intestinal digestive and immune system and growth performance of kits.

Lipolysis In Lacto Trophy Of Newborn And 1-Year Infant

Lipolysis is accomplished sequentially and simultaneously by lipase in saliva and gastric juice in the infant’s stomach as inductors in autolytic digestion by bile-dependent lipase in breast milk and colipase-dependent pancreatic lipase in the ileum. Lipase was determined in blood serum of women in labor, in umbilical cord blood, in water, and in infant gastric content. According to the data obtained, the initial lipolysis potential of newborns is significantly lower than that of the mothers. It is developed during the first half of pregnancy so gestation period does not have a significant effect on it. Over a year of lactation period, the breast milk steatolytic activity decreases, with a lower rate compared with other breast hydrolytic activities. If the steatolytic activity is low during the first month of lactation, it increases during the succeeding 4–5 months. In cases when steatolytic activity is high initially, it decreased during the following months. This indicates that the lipase content level has an effect on lipolysis at lactotrophy. Additional food and specifically bottle feeding strongly increased the steatolytic activity of duodenal content because of lipase exosecretion stimulation in the pancreas. In contrast, the steatolytic activity is decreased when mixed feeding is introduced. Assessment of lipolysis potential is important in choosing the feeding type for newborns and infants.

Expression of COX2 and p53 in Rat Esophageal Cancer Induced by Reflux of Duodenal Contents

Aim. Reflux of duodenal contents can induce mucosal injury, stimulate cell proliferation, and promote tumorigenesis. We examined the expression of COX2 and p53 in rat esophageal lesions induced by duodenal content reflux. Methods. Thirty 8-week-old male Wistar rats were exposed to duodenal content esophageal reflux. All animals underwent an esophagoduodenal anastomosis (EDA) with total gastrectomy in order to produce chronic esophagitis. Ten rats were the sham. Control. They were sacrificed at the 40th week. Their esophagi were examined for HE, COX2, p53, and proliferating cell nuclear antigen (PCNA). Results. After 40 weeks of reflux, dysplasia, squamous cell carcinoma (SCC), and adenocarcinoma (ADC) were found. PCNA labeling index was higher in dysplastic and cancer tissue than that in normal. Overexpression of COX2 was shown in ADC and SCC. Wild-type p53 accumulation was found in ADC, and not in SCC. Conclusion. Reflux of duodenal contents into the esophagus led to ADC and SCC in rats. COX2 may play an important role in esophageal cancer by duodenal content reflux. Our present results suggest an association between wild-type p53 accumulation and COX2 expression in ADC, with no such relation seen in SCC.

APPLICATION OF KJELDAHL AND DUMAS COMBUSTION METHODS FOR NITROGEN ANALYSIS

O método padrão de Kjeldahl vem sendo substituído pelo método de combustão Dumas na determinação do nitrogênio total (NT) em alimentos. Estes procedimentos foram utilizados para avaliar amostras de rotina em laboratórios de nutrição animal (concentrados, forragens, excreta e conteúdo duodenal). A covariável nitrato (N-NO3) interferiu na determinação do NT em função da metodologia empregada. Foi observada uma correlação positiva entre os métodos utilizados para cada grupo avaliado: ingredientes volumosos, Kjeldahl-N = 1.1661 + 0.9216 Dumas-N (R2=0.99); alimentos energéticos, Kjeldahl-N = 0.6376 + 0.9445 Dumas-N (R2=0.72) e alimentos protéicos, Kjeldahl- N = 6.5638 + 0.8615 Dumas-N (R2=0.97). As médias para NT dos alimentos, ajustadas para a covariável, não diferiram entre os métodos (P > 0,05). O desvio padrão do teor de N dentro e entre os métodos utilizados estão dentro dos intervalos permitidos pela literatura, o que, associado ao fato da metodologia de Dumas consistir em uma técnica não poluente ao ambiente, indica ser esta metodologia capaz de substituir com vantagens o procedimento de Kjeldahl em análises de rotina em laboratórios de nutrição animal. Abstract The Kjeldahl procedure has been replaced by Dumas combustion procedure for total N determination in feeds. These methods were compared using routine samples in the animal nutrition laboratory (concentrates, forages, excreta and duodenal content). NO3-N covariate interfered on total N determination according to the procedure used. A significant correlation for crude protein (CP) content was observed between methods used for each group: grass silage component, Kjeldahl-N = 1.1661 + 0.9216 Dumas-N (R2=0.99); energy feeds, Kjeldahl-N = 0.6376 + 0.9445 Dumas-N (R2=0.72) and protein feeds, Kjeldahl-N = 6.5638 + 0.8615 Dumas-N (R2=0.97). Means for total N contents from components, adjusted by covariance, were not different (P > 0.05) between both methods. Considering that the standard deviation for N content obtained by the two methods stayed within the intervals observed in the literature, corroborated by the fact that Dumas combustion procedure using the analyzer LECOFP 528 LC is not harmful to the environment it was concluded, that this method can replace with advantages the Kjeldahl procedure in routine animal nutrition N analyzes.