The effect of replacing corn with low-tannin sorghum on broiler performance, carcass yield, integrity of mucosa of small intestine segments, and activity of membrane enzymes of the jejunum is investigated. A total of 594 male Cobb-500 broiler chicks were randomly assigned to 3 dietary treatments: 100% corn (control), 50% corn replacement with low-tannin sorghum (low sorghum), and 100% corn replacement with low-tannin sorghum (high sorghum). Body weight gain, feed consumption, feed conversion, and carcass yield were determined at 7, 21, and 42 d, and segments of the small intestine were collected. Feed conversion and weight gain were impaired at d 42 in broilers fed the high-sorghum diet, but no differences were observed for carcass yield among the treatments (P > 0.05). Crypt cell mitotic index of the jejunum and ileum at d 21 and 42 was lower in broilers fed the control diet than in those fed low- and high-sorghum diets (P < 0.05). Aminopeptidase activity was higher in broilers fed the control diet than in those fed low- and high-sorghum diets irrespective of age (P < 0.05). Conversely, intestinal alkaline phosphatase activity in the small intestine did not differ among the dietary treatments (P > 0.05). Our results indicate that 50% corn replacement with low-tannin sorghum is suitable for broiler diets, whereas 100% corn replacement with low-tannin sorghum had negative effects on the intestinal mucosa and performance of broilers at 42 d.

-This study investigated the effects of Cymbopogon flexuosus and Lippia rotundifolia microencapsulated essential oils on broiler performance and carcass yield. One hundred and fifty mixed-sex Cobb broiler chicks were used, from one day up to 42 days of age, in a completely randomized design, with five treatments and three replicates of ten birds each. The treatments were: negative control (basal diet), positive control (diet with enramycin and salinomycin), and three diets with microencapsulated essential oils from lemongrass, L. rotundifolia, and combination with 50% of both. The performance and carcass yield were not affected by the treatments. The intestine absolute weight was lower in the combination treatment compared with the negative control treatment and the lemongrass essential oil. The intestine relative weight was higher in the treatments with lemongrass and L. rotundifolia essential oils in relation to the combination. The liver relative weight was lower with the lemongrass essential oil and the combination compared with the treatment with the L. rotundifolia essential oil. The trial could not find results enough to recommend the use of the lemongrass and L. rotundifolia essential oils as an additive in broiler diets.

The effect of alternative sources of nutrients was evaluated on yield, nutrition and fruit quality of tomato cv Santa Clara in an agro ecological system, under natural conditions in Montes Claros, Minas Gerais State, Brazil. The experimental design was of completely randomized blocks with seven treatments and four replications, using eight plants per experimental plot. The treatments comprised of 1) conventional fertilization with NPK; 2) organic compost + natural phosphate + rock dust, applied separately; 3) organic compost produced from the addition of natural phosphate and rock dust + green manure; 4) organic compost produced from the addition of rock dust + natural phosphate + green manure; 5) organic compost produced from the addition of natural phosphate and rock dust + green manure; 6) natural phosphate + rock dust; and 7) organic compost + natural phosphate + rock dust + green manure. The highest production was obtained using chemical fertilizers. There was no difference among the treatments regarding the content of foliar nutrients and fruit diameter, pH and total soluble solids. The use of mineral and organic fertilizers significantly reduced the incidence of soft rot and pests in comparison to the use of chemical fertilizers.

O uso de antimicrobianos como melhoradores de desempenho tem representado um risco à saúde pública devido à associação destes com o surgimento de resistência bacteriana e resíduos nos produtos. Como alternativa, pesquisas têm indicado a utilização de aditivos alimentares naturais, como o óleo essencial de capimlimão. Objetivou-se neste artigo avaliar a atividade antimicrobiana do óleo essencial de capim-limão (Cymbopogon flexuosus) frente a Staphylococcus aureus e Escherichia coli entéricas isoladas de aves de postura (Gallus gallus domesticus). Foram preparadas cinco concentrações do óleo essencial (160; 80; 40; 20 e 10 µL mL-1) e então realizados testes in vitro de difusão em disco e determinação da Concentração Inibitória Mínima (CIM) e da Concentração Bactericida Mínima (CBM). Os resultados indicaram que a concentração de 160 µL mL-1 propiciou os maiores diâmetros de halos de inibição na difusão em disco, diferindo-se estatisticamente das demais concentrações (p < 0,05). Houve efeito inibitório (CIM) a partir da concentração de 80 µL mL-1 de óleo para todas as bactérias mas a CBM não foi detectada. Conclui-se que o óleo essencial de capim-limão apresenta atividade antimicrobiana in vitro frente a S. aureus e E. coli isoladas de aves na concentração de 160 µL mL-1. Novos estudos são necessários para avaliar a eficácia do uso de doses superiores e indicar esse óleo como aditivo em dietas de aves.

SUMMARY The antibacterial effect of microencapsulated lemon grass (Cymbopogon citratus) essential oil on strains of Escherichia coli (ATCC8739), Staphylococcus aureus (ATCC 6538) and Salmonella enterica subsp. enterica (ATCC 6017), and the stability of this oil in feeds for broiler chickens were evaluated. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined by the macrodilution method, using the microencapsulated lemon grass essential oil at concentrations of 160 μL mL−1, 80 μL mL−1, 40 μL mL−1, 20 μL mL−1, and 10 μL mL−1. The oil concentration of 80 μL mL−1 presented the best results against the three bacteria evaluated. Samples of 200 g of feed mixed with 120 μL g−1 of the microencapsulated lemon grass essential oil was stored to evaluate the oil stability. Feed without microencapsulated lemon grass essential oil was prepared as control. The oil remained active for seven days, with significant reduction of S. aureus (3.08 CFU), E. coli (3.01 CFU), and S. enterica (3.10 CFU). The microencapsulated lemon grass essential oil at concentration of 80 μL mL−1 had antibacterial effect against the E. coli, S. enterica and S. aureus, and maintained stability of the feed for seven days, even with presence of organic matter, which is source of nutrients for pathogens.

No abstract

No abstract

SUMMARY The effect of the disinfection of fertile eggs of free-range poultry with essential oils from Cymbopogon flexuosus and Lippia rotundifolia was evaluated. The treatments applied to the eggs were (v v-1): 1% essential oil from C. flexuosus (CF), 1% essential oil from L. rotundifolia(LR), 0.1% CF + LR, and 0.1% quaternary ammonia (QA) (positive control). The eggs were incubated for 21 days, the birds from hatched eggs were counted and weighed, and not hatched eggs were opened and examined macroscopically to determine egg fertility, and embryonic death time. The antimicrobial action of the essential oils was determined through quantitative analyses, considering aerobic mesophylls, filamentous fungi, yeasts, and total coliforms. Mortality was high in the treatments, especially in the treatment with essential oil from C. flexuosus. The highest hatchability was found in the treatment with QA. The treatments with singly or combined essential oils were more efficient in decreasing microbial count than QA. The essential oils from C. flexuosus and L. rotundifolia reduced the microbial load of fertile eggs of the free-range poultry evaluated.