ABSTRACT Natural antimicrobials, known as phytobiotics, are used in bacterial infections. The objective of this study was to evaluatethe phytobiotic activity, in vitro and in vivo, of an extract and an essential oil of Piper auritum and Ocimum basilicum on avian Eschericia coli serotype O2 in broiler chickens experimentally infected. For the in vitro test, extracts at 4, 8, 12 and 16% in water-based solvent or alcohol at 70% were prepared from leaves of both plants. In the essential oils, solvents at 10% were used. A concentration of 1×108 CFU mL-1 of bacteria was seeded and on each sense disc, 25 µL of the extract or essential oil were poured, except on the positive or negative control. The diameter of the inhibition zone (DIZ) of bacterial growth was measured. In the in vivo test, 40 chickens were inoculated, by intratracheal route, with a bacterial suspension of 1 × 108 CFU mL-1. E. col was identified and isolated from the organs; mortality, morbidity and relative weight of the organs were measured, and postmortem lesions and histopathologic findings were observed. A completely randomized design and the Kruskal-Wallis test for data analysis was used. By increasing the concentration of the extract, DIZ was greater; at the time of slaughter, differences in body weight (p<0.05) were found and the majority of lesions were observed in lungs. It is concluded that leave extracts of P. auritum and O. basilicum had phytobiotic activity on E. col serotype O2.

ABSTRACT Poultry farmers in the southeastern of Mexico consider that the productivity of the hens that comes from rearing on floor has a higher productive performance than reared hens in cages, mainly due to higher percentage of egg laying and lower mortality. The aim of this study was to evaluate the productive performance of the laying hen in relation to the type of rearing. A total of 79680 pullets Bovans White of 17 weeks of age were housed in cages with five pullets cage-1 (405 cm2pullet-1). They were divided in two treatments according to their type of rearing (floor vs cage) with four replicates. The study period was from week 20 to week 40 of age. The variables evaluated were daily (%) and cumulative mortality (%), egg production (%), egg weight (g), feed intake (g pullet d-1), cumulative feed intake (g pullet-1), daily and cumulative egg mass, number of eggs per hen housed, egg loss (%) and productivity index. The variables were analyzed using a randomized block design. It was observed that daily and cumulative mortality, feed intake and egg loss was higher (p< 0.05), while the number of eggs per hen housed and productivity index (p< 0.05) was lower for hens in cages. We conclude that it is possible to associate detriments in the productive performance of laying hens based on the type of housing during its growth phase.