The present study evaluated the dietary supplementation with essential oil of Lippia alba on the hemato-immunological parameters of Nile tilapia (Oreochromis niloticus) submitted to acute inflammation induced by carrageenin injection in the swim bladder. For a period of 45 days, 96 fish were divided in four treatments in triplicate, as follows: fish fed supplemented diet with essential oil of L. alba (4 mL kg-1 dry ration) injected with carrageenin; fish fed supplemented diet with cereal alcohol injected with carrageenin; fish fed unsupplemented diet with essential oil injected with carrageenin; fish fed unsupplemented diet and noninjected. Cortisol levels, erythrogram, leukogram and the inflammatory infiltrate were analyzed 6 h after inflammatory stimulus. Carrageenin-injected fish showed acute inflammatory reaction in the swim bladder characterized by higher infiltrate of neutrophils and monocytes. The circulating neutrophils number was significantly higher in fish fed L. alba when compared to other treatments. No difference in cortisol levels was found. For dose, time and administration form tested, supplementation with essential oil of L. alba did not present anti-inflammatory activity. On the other hand, influence of dietary supplementation was observed on the neutrophils number after induced aerocystitis highlighting its immunomodulatory characteristic.

Brazil is the world’s largest exporter and third largest producer of chicken meat. To maintain competitiveness, the productive sector must always be alert to consumer demands, and concern about animal welfare is a growing tendency. Aspects involving animal welfare are especially critical in the slaughter of broiler chickens. This study evaluated the stunning of chickens in a CO2-enriched atmosphere chamber to reduce bird stress, comparing with electrical water bath stunning, the most usual desensitization method used in chicken slaughter. The reaction of birds when exposed to a high CO2 concentration (30%) and to a 10% initial CO2 level, gradually elevated to 30% was compared. The effect of mixing argon with CO2 was also evaluated, always aiming to reduce the discomfort of birds. In all the gas stunning parameters evaluated, evident discomfort reactions before stunning were observed in about two thirds of the birds, but the blood levels of corticosterone and glucose, used as stress indicators, indicated that gas increased the birds’ welfare. Gas exposure time required to stun the birds and time to regain consciousness after exiting the gas chamber presented a wide variation. Controlled atmosphere stunning method facilitated bird handling during slaughter, but more studies will be necessary to develop this technological alternative and make it viable for industrial use.

Surgical procedures in pet animals are usually associated with some degree of stress and pain. Hospitalization is one stress-triggering factor. The present study aimed to evaluate the degree of stress and pain during hospitalization of female dogs submitted to elective ovariohysterectomy (OVH) and to investigate the influence of hospitalization on the stress of these animals. Fifteen young adult crossbreed female dogs were divided into two groups: eight animals without surgery (Group 1 - control) and seven animals submitted to surgery (Group 2 - OVH). Pain and stress were evaluated. Visual analogue scale (VAS), simple descriptive pain scale (SDS) and modified Glasgow pain scale (MGPS) were used. Serum cortisol (μg/dL) and glucose (mg/dl) were also measured. No statistical difference was observed for cortisol (μg/dL) between the two groups. Despite the absence of statistical difference between groups and times, mean serum cortisol (μg/dL) values exceeded the normal values for the canine species at various times evaluated. Hyperglycemia was only observed at T4 in the OVH group. It was concluded that the hospitalization of animals was more relevant in the establishment of stress than the surgical procedure and associated pain. The influence of stress was a relevant factor in the results of assessments carried out using the MGPS.