Analysis of Cluster and Unrest Behaviors of Laying Hens Housed under Different Thermal Conditions and Light Wave Length.

Laying hens are affected by the intensity, wavelength, and duration of light, and the behavioral patterns of these animals are important indicators of stress. The objective of the present study was to evaluate cluster and unrest behaviors of lying hens submitted to three environments with different treatments of monochromatic lighting (blue, green, and red). For 29 weeks, 60 laying hens from the Lohmann variety were divided into three groups and monitored by surveillance cameras installed on each shed ceiling and directed to the floor. Each group was housed in a small-scale shed and maintained under a monochromatic lighting treatment. The recordings were made at two times of the day, 15 min in the morning and 15 min in the afternoon, and the videos were processed, segmented, and analyzed computationally. From the analysis of the images, the cluster and unrest indexes were calculated. The results showed the influence of lighting on these behaviors, displaying that the birds were more agitated in the treatments with shorter wavelengths. Cluster behavior was higher in birds housed under red light. There was an interaction between the lighting treatments and the thermal environment, indicating that more studies should be carried out in this area to better understand these behavioral changes.

HPMCP-Coated Microcapsules Containing the Ctx(Ile21)-Ha Antimicrobial Peptide Reduce the Mortality Rate Caused by Resistant Salmonella Enteritidis in Laying Hens.

The constant use of synthetic antibiotics as growth promoters can cause bacterial resistance in chicks. Consequently, the use of these drugs has been restricted in different countries. In recent years, antimicrobial peptides have gained relevance due to their minimal capacity for bacterial resistance and does not generate toxic residues that harm the environment and human health. In this study, a Ctx(Ile21)-Ha antimicrobial peptide was employed, due to its previously reported great antimicrobial potential, to evaluate its application effects in laying chicks challenged with Salmonella Enteritidis, resistant to nalidixic acid and spectinomycin. For this, Ctx(Ile21)-Ha was synthesized, microencapsulated and coated with hypromellose phthalate (HPMCP) to be released in the intestine. Two different doses (20 and 40 mg of Ctx(Ile21)-Ha per kg of isoproteic and isoenergetic poultry feed) were included in the chick's food and administered for 28 days. Antimicrobial activity, effect and response as treatment were evaluated. Statistical results were analyzed in detail and indicate that the formulated Ctx(Ile21)-Ha peptide had a positive and significant effect in relation to the reduction of chick mortality in the first days of life. However, there was moderate evidence (p = 0.07), not considered statistically significant, in the differences in laying chick weight between the control and microencapsulation treatment groups as a function of time. Therefore, the microencapsulated Ctx(Ile21)-Ha antimicrobial peptide can be an interesting and promising option in the substitution of conventional antibiotics.

Análise de adesão do fungo entomopatogênico Metarhizium anisopliae para o controle de Alphitobius diaperinus (cascudinho) em instalações avícolas / Analysis of entomogenous fungus Metarhizium anisopliae to control Alphitobius diaperinus in poultry buildings

Este trabalho permitiu a construção de um modelo estatístico para a adesão de conídios do fungo Metarhizium anisopliae diante de diferentes níveis de concentração e tempo, além de avaliar seu potencial para o controle do cascudinho (Alphitobius diaperinus), importante praga da avicultura, causadora de danos às aves pelos ferimentos no trato digestivo e pela transmissão de várias doenças. O estudo da adesão sobre o tegumento é de grande importância, pois a adesão representa um evento complexo, sendo o primeiro do ciclo das relações patógeno-hospedeiro que ocorre após a deposição do fungo sobre o inseto e visa a preparação do local para a fase de penetração. Insetos adultos do cascudinho foram expostos a três concentrações do fungo: 1x10 elevado a 3, 1x10 elevado a 6 e 1x10 elevado a 9 conídios/mL, sendo 5, 10 e 15 minutos de exposição em cada concentração. Para verificar o potencial de controle de M. anisopliae, os insetos foram colocados para caminhar sobre uma massa de conídios crescida em meio BDA por 10 minutos, resultando num potencial de inóculo de 8,1x10 elevado a 8 conídios/mL, a mortalidade foi avaliada durante 21 dias consecutivos, onde se verificou uma mortalidade de 74% em larvas após 48h, e 50% de mortalidade em adultos após 15 dias de exposição ao fungo. A análise de variância (ANOVA) mostrou que existe influência e interação de ambos os efeitos: concentração e tempo.

This present research work has allowed a statistical modeling for conidial adhesion and the potential fungus Metarhizium anisopliae ability to lesser the mealworm Alphitobius diaperinus control, that is an important pest of poultry production, which causes damage to the birds by the development of injuries in the digestion tract, and yet it serves as vector of many avian pathogens. The study of the host cuticle adhesion is very important, whereas the adhesion process represents a complex event, as it is the first occurrence in the pathogen-host cycle, taking place after fungus deposition on the insect, aiming the penetration phase. Adult insects of A. diaperinus were exposed to three concentrations of the fungus: 1x10 superscript to 3, 1x10 superscript to 6 e 1x10 superscript to 9 conidia/mL, for 5, 10 and 15 minutes of exposition to each conidial concentration. In order to verify the ability control of M. anisopliae, the insects were forced to the displacement on the conidial mass growth onto PDA medium for 10 minutes, resulting in a 8,1x10 superscript to 8 conidia/mL inocullum potential, and the mortality was monitored during 21 days, obtaining 74% of mortality in larvae after 48h and 50% of mortality in adults after 15 days, under fungus exposition. ANOVA has showed that there is influence and interaction between both effects: concentration and time.

Avaliação de poluentes aéreos em instalações de creche e terminação de suínos / Evaluation of aerial pollutants in nursery and finishing swine housing

Esta pesquisa foi desenvolvida em duas instalações para suínos nas fases de creche e terminação, em duas salas cada, em granjas localizadas no município de Salto, SP, com os objetivos de avaliar a concentração de amônia e poeira e a presença de fungos, além de estimar os riscos de exposição ocupacional a esses agentes ambientais. As avaliações foram realizadas conforme preceituam as normas NR-15, NIOSH e ACGIH. Os resultados indicaram diferença significativa nas concentrações de amônia em relação aos horários, às instalações e aos períodos do dia. Estes também indicam negligência para a questão da ventilação sanitária nas instalações de creche, com conseqüentes teores mais altos de amônia, e que estes estão vinculados à circulação de ar no interior das instalações, ao manejo dos dejetos e da cortina, à tipologia da construção e às condições de clima local, além da lotação e da densidade de suínos. A concentração de poeira total foi mais alta nos prédios de creche (0,84-9,16mg m-3) do que nos de terminação (0,84-3,34mg m-3), enquanto que a poeira respirável foi mais alta na creche, ficando inferior a 3,67mg m-3 e dentro dos limites de insalubridade para o trabalhador. Foram encontrados fungos do gênero Aspergillus, Penicillium e Neurospora em suspensão no ambiente interno das instalações estudadas.

This research was developed in two swine housings in the phases of nursery and finishing: in two pens each, in two farms located at Salto County, SP, with the objective to evaluate ammonia and concentrations, and fungi presence besides estimating the occupational risk of exposure to these environmental agents. The evaluations were done according to recommended by the norms NR-15, NIOSH e ACGIH. Results indicated significant difference in ammonia concentration in relation to the hour, the housing and to the day period. They also indicate negligence to sanitary ventilation matter in nursery housing with consequent higher level of ammonia; which are linked to the air circulation inside housing, the manure and curtain management, housing typology, and to local climate conditions; besides swine crowd and density. Total dust concentration was higher in nursery buildings (0.84-9.16mg.m-3) than in finishing (0.84-3.34mg m-3), while inhale dust was higher in the nursery, however lower than 3.67mg m-3, and within the labor welfare limits. There were found fungi from genus Aspergillus, Penicillium and Neurospora in suspension in the internal environmental of the studied housings.

Efeito das temperaturas de bulbo seco e de globo negro e do índice de temperatura e umidade, em vacas em produçäo alojadas em sistema de free-stall / Evaluating the dry bulb and black globe temperatures and temperature and humidity index effect in dairy cows lodged in free-stall system

O resultado da exposiçäo de vacas em produçäo em ambiente adequado, pode ter reflexo na produtividade leiteira, por permitir o uso correto de equipamentos reduzindo o estresse térmico nos animais, e consequentemente, melhorando a produtividade. No presente trabalho avaliou-se o efeito das temperaturas de bulbo seco e de globo negro, na produçäo de vacas leiteiras alojadas em sistema de freestall, utilizando-se dois grupos de vacas: mais produtivas, com produçäo acima de 29 kg/dia e menos produtivas, com produçäo média abaixo de 14 kgdia-1. Os resultados mostraram os efeitos das variáveis ambientais e do índice de temperatura e umidade regional, no declínio da produçäo de leite. Näo houve correlaçäo significativa entre os valores do índice e o declínio na produçäo de leite, para nenhum dos dois grupos estudados