ABSTRACT This study aimed to evaluate the hematological profile, hepatic function, and histopathology of mixed-sex broilers fed rations supplemented with microencapsulated essential oils from Cymbopogon flexuosus (lemon grass) and Lippia rotundifolia (chá-de-pedestre). One hundred and fifty Cobb chicks were housed in cages from 1 to 42 days of age in a completely randomized design, with six replicates with five chickens in each of five treatments (150 total chicks): basal diet without antibiotic growth promoter (negative control), diet with enramicina and salinomycin (positive control), diet with lemon grass essential oil, diet with L. rotundifolia essential oil, and diet with a mixture of lemon grass and L. rotundifolia essential oils. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly lower in untreated broilers (negative control group). Gender was not associated with erythrogram values, but aspartate aminotransferase activity (AST) was higher in females. Gamma-glutamyl transferase (GGT) was higher in chicks in the group that received rations with lemon grass oil. Broilers that received L. rotundifolia oil developed more hepatic lesions, although no effect of sex was observed related to the lesion score. Biliary hyperplasia and fibroplasias were observed in all groups, with higher histopathology scores in broilers that received diets containing L. rotundifolia oil. Mixed-sex broilers fed rations supplemented with lemon grass and L. rotundifolia essential oils have normal complete blood counts and unspecific hepatic lesions and are characterized by lipidosis, hyperplasia of the bile ducts, and fibroplasia.

RESUMO O presente estudo investigou o efeito da desinfecção de ovos férteis de aves caipiras com o uso de óleos essenciais de capim limão (Cymbopogon flexuosus) e chá-de- pedestre (Lippia rotundifolia). Aplicaramse os seguintes tratamentos nos ovos selecionados: 1% (v/v) óleo essencial de capim limão (CL), chá-de-pedestre (CP), associação (CL + CP) e 0,1% (v/v) de amônia quaternária (AQ) (controle positivo). Os ovos foram distribuídos em incubadora e após 21 dias, as aves eclodidas foram contadas e pesadas e os ovos não eclodidos foram quebrados e examinados macroscopicamente para a determinação da fertilidade e o momento da morte embrionária. Determinou-se a ação antimicrobiana dos óleos através das análises quantitativas de mesófilos aeróbios, fungos filamentosos e leveduras e coliformes totais. A mortalidade foi elevada nos tratamentos, a distribuição de mortes nas classes foi superior no tratamento com capim limão. A maior eclodibilidade ocorreu no tratamento com a amônia quaternária. Evidenciou-se a redução na contagem microbiana na aplicação do óleo essencial individualmente ou em associação, superando a aplicação com AQ. Os óleos essenciais de capim limão (Cymbopogon flexuosus) e chá-de-pedestre (Lippia rotundifolia) promoveram a redução da carga microbiana de ovos férteis de aves caipiras.

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.

ABSTRACT The influence of fasting and vaccination against infectious bronchitis (IB) on growth, gastrointestinal development, and morphometric parameters of the small intestine of newborn broiler breeders was investigated. Weight gain (WG), feed conversion ratio (FCR), gastrointestinal visceral growth, residual yolk sac, and morphometric parameters of the small intestine were measured in chicks aged up to 21 d. We showed that WG was lowest in chicks exposed to longer fasting periods (72 h), although compensatory gains with increasing age were also observed. Unvaccinated chicks performed better at seven days; however, at 21 d of age, a compensatory response led to better FCR in vaccinated birds. Allometric growth of the gastrointestinal tract was affected following longer fasting periods, but this effect occurred predominantly in younger birds (three days). Compared with non-fasted, birds fasted for 72 h had lower villus height and crypt depth along the small intestine at three days and lower villus height in the duodenum and jejunum at seven days. However, at 14 and 21 days of age, the previous changes in intestinal morphology imposed by fasting had been offset. The IB vaccine, applied in the first day of life, does not affect the allometric growth of the gastrointestinal organs, but causes momentary loss in the intestinal morphometry, which contributes to the reduction of WG at seven days. Our results suggest that long fasting periods after hatching (48 and 72 h) should be avoided in broiler breeders due to the resulting delay in gastrointestinal organ development and growth impairment up to 21 d of life.

RESUMO No trabalho foi avaliado o efeito antimicrobiano do óleo capim limão (Cymbopogon citratus) microencapsulado frente a cepas de Escherichia coli (ATCC8739), Staphylococcus aureus (ATCC 6538) e Salmonella enterica subsp. enterica (ATCC 6017), e a estabilidade do óleo em ração de frangos de corte. O teste de Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) do óleo essencial de capim-limão microencapsulado foi determinado pelo método de macrodiluição (tubo) utilizando as concentrações de 160μL/mL, 80μL/mL, 40μL/mL, 20μL/mLe 10μL/mL. A concentração do óleo de 80μL/mL apresentou melhores resultados frente às três bactérias. Para a avaliação da estabilidade foram separados e armazenadas porções de 200g de ração misturadas com o óleo essencial de capim limão na dosagem de 120μL/g de ração, foram preparadas porções de ração sem a presença do óleo essencial para teste controle, os resultados mostraram que o óleo permaneceu ativo até sete dias, com redução significativa de 3,08 UFC para S. aureus, 3, 01 para E. coli e 3,10 S. entérica. Conclui-se que, óleo essencial de capimlimão microencapuslado tem atividade antibacteriana na concentração de 80 μL/mL frente à Escherichia coli, S. entérica e S. aureus e promove a estabilidade da ração no período de sete dias mesmo na presença da matéria orgânica que é fonte de nutrientes para patógenos.

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.

ABSTRACT 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.