A five-year surveillance study of vaccination schedules using viral-vectored vaccines against infectious laryngotracheitis in a high-density layer region / Cinco anos de monitoramento de esquemas vacinais com vacinas virais vetorizadas contra laringotraqueíte infecciosa em uma região altamente povoada por galinhas poedeiras

The effectiveness of vectored recombinant vaccines to control infectious laryngotracheitis (ILT) in chickens from a region (State of Minas Gerais, Brazil) with ~10 million layers was evaluated under field conditions from 2014-2018. During this period, only recombinant turkey herpesvirus (rHVT) or fowl poxvirus (rFPV) vaccines that express antigens of infectious laryngotracheitis virus (Gallid herpesvirus-1; GaHV-1) were used. Layer chickens (n=1,283), from eight different egg-producing companies, were individually sampled and examined (active surveillance), and in instances when government poultry health veterinarians were notified due to respiratory disease (passive surveillance). Clinical, macroscopic, and histopathology examinations were performed to diagnose ILT as well as molecular techniques for the detection and characterization of the GaHV-1 DNA from the trachea and trigeminal ganglia (TG). The layer hens sampled and examined belonged to flocks and farms that used different vaccination protocols (non-vaccinated, single dose vaccination, and prime/ boost vaccination). This is the first long-term field study of the effectiveness of ILT vectored vaccines in a high-density multiple age layer hen region. Using various diagnostic methods, the occurrence of GaHV-1 infection and ILT clinical disease in layer hens vaccinated with vectored recombinant vaccines in one quarantined region of Brazil were investigated. The number of ILTV positive chickens by PCR and ILT clinical disease cases was lower in farms when all chickens were vaccinated with at least one vaccine. However, the difference in the detection rates of GaHV-1 infection was significant only when compared farms with prime/ boost and farms using single dose of HTV-LT.

A efetividade das vacinas recombinantes vetorizadas para o controle da laringotraqueíte infecciosa (LTI) nas aves de uma região (Minas Gerais, Brasil) com aproximadamente 10 milhões de poedeiras foi avaliada em condições de campo, no período de 2014 a 2018. Durante este período, somente as vacinas recombinantes "turkey herpesvirus" (rHVT) ou "fowl poxvirus" (rFPV), que expressam antígenos do vírus da laringotraqueíte (Gallid herpesvirus-1; GaHV-1) foram utilizadas. Galinhas poedeiras (n=1.283), de oito diferentes granjas produtoras de ovos, foram individualmente amostradas e examinadas por monitoramento ativo e, na ocorrência de notificação de doença respiratória aos veterinários do serviço oficial, por monitoramento passivo. Exames clínicos, macroscópicos e histopatológicos foram realizados para o diagnóstico de LTI, bem como técnicas moleculares para a detecção e caracterização do DNA de GaHV-1 da traqueia e gânglio trigêmeo. As galinhas poedeiras pertenciam a lotes e granjas que usavam diferentes protocolos de vacinação (não vacinadas, uma dose ou tipo de vacina e duas doses ou tipos de vacina). Este é o primeiro longo estudo a campo sobre a efetividade das vacinas vetorizadas em uma região com população elevada de poedeiras de múltiplas idades. Utilizando vários métodos de diagnóstico, a ocorrência da infecção por GaHV-1 e a LTI clínica em poedeiras de uma região interditada do Brasil foi investigada. O número de galinhas positivas para o vírus GaHV-1 e para casos clínicos de LTI nas granjas foi menor quando todas as aves estavam vacinadas com, pelo menos, um tipo ou dose de vacina. Entretanto, a diferença na taxa de detecção da infecção por GaHV-1 foi significativa somente quando a comparação foi realizada entre granjas com aves vacinadas com duas doses e aves de granjas vacinadas com uma única dose de HVT-LT.

Calidad durante el almacenamiento de huevos de gallinas alimentadas con dietas con aceite de palma / Egg quality during storage of eggs from hens fed diets with crude palm oil

RESUMEN Objetivo. Evaluar el efecto del aceite crudo de palma (ACP) sobre la calidad del huevo almacenado por varios días a diferentes temperaturas. Materiales y métodos. Un total de 240 gallinas de 28 semanas se alimentaron con dietas con 30g/kg de aceite de soya (AS) o ACP. Después de 12 semanas, muestras de huevos se almacenaron durante 0, 4, 8 y 12 días a 4, 12 y 24°C. Las características de calidad del huevo fueron evaluadas. Resultados. El huevo y la albúmina de gallinas en la dieta con ACP fueron más pesados que aquellos en la dieta con AS (p<0.05). La alta temperatura de almacenamiento redujo el peso del huevo, albúmina y yema, unidades Haugh (UH), altura de la albúmina y la yema, pH y color (p<0.05), pero aumentó el ancho de la albúmina y la yema, y la longitud de la albúmina (p<0.05). A medida que aumentaba el tiempo de almacenamiento, el peso del huevo, el peso y la altura de la albúmina, y la altura de la yema, el pH y el color se redujeron (p<0.05). Sin embargo, el peso y el ancho de la yema, el ancho y la longitud de la albúmina aumentaron (p<0.05). La interacción aceite x tiempo de almacenamiento (p<0.05) indico que la altura de la albumina, UH y el color de la yema de los huevos de la dieta con ACP fueron mejores a los 12 días de almacenamiento que en la dieta con AS. Conclusiones. Las gallinas en la dieta con ACP tuvieron huevos y albuminas más pesadas que las de las de la adieta con AS. La calidad del huevo disminuyó conforme el tiempo y temperatura de almacenamiento se incrementó, pero, los huevos de las gallinas suplementadas con ACP tuvieron mejor calidad en algunas características a los 12 días de almacenamiento.

ABSTRACT Objective. Evaluate the effect of crude palm oil (CPO) on quality traits of eggs stored various days at different temperatures. Material and Methods. A total of 240 hens, 28 weeks of age were fed diets with 30 g/kg of soybean oil (SO) or CPO. After 12 weeks, sample of eggs were stored during 0, 4, 8 and 12 days at 4, 12 and 24 °C. Egg quality traits were evaluated. Results. Egg and albumen from hens in CPO diet were heavier than those in SO (p<0.05). High storage temperature reduced egg, albumen and yolk weights, Haugh units (HU), albumen and yolk heights, pH and color (p<0.05), but increased albumen and yolk widths and albumen length (p<0.05). As storage time increased, egg weight, albumen weight and height, and yolk height, pH and colour were reduced (p<0.05). However, yolk weight and width, albumen width and length increased (p<0.05). Oil x storage time interaction (p<0.05) indicated that albumen height, HU and yellowness of yolk from hens in CPO diets were better at 12 days of storage than for hens fed SO. Conclusions. Hens in CPO diet had heavier eggs and albumen than those in SO diet. Egg quality traits decreased as temperature and days of storage increased, but, eggs from hens supplemented CPO had better quality in some traits at 12 days of storage.

Toxic Effects of Ochratoxin A on Calcium Metabolism during Chick Embryo Developmentand in Hatched Chicks

ABSTRACT The present study was carried out to study the effect of in-ovo ochratoxin A (OTA) injection in Highline layer eggs on calcium metabolism and blood biochemical parameters of embryos and after the hatch. At day 10 of embryonic development, one hundred and sixty-two fertile eggs were individually weighed and divided into two equal treatments. The first treatment (control) consisted of the individual injection of fertile eggs with 50 µL sodium carbonate. In the second treatment (OTA), fertile eggs were individually injected with 12.5 ng OTA dissolved in 50 µL sodium carbonate. On days 12, 14, and 16 of incubation and at the hatch, serum calcium and inorganic phosphorus concentrations were lower (p 0.05), while sodium, alkaline phosphatase and triiodothyronine concentrations were higher (p 0.05) in the OTA-injected eggs compared with the controls. Serum potassium concentration was not affected (p 0.05) by OTA treatment. Lower calcium and phosphorus levels were determined (p 0.05) in the allantoic fluid of OTA-injected eggs compared with the controls. On days 12, 14, and 16 of incubation and at the hatch, lower whole body and yolk calcium and phosphorus, but not sodium levels, were measured (p 0.05) in the OTA treatment compared with the controls. In conclusion, the injection of eggs with OTA reduced blood calcium and phosphorus levels, which were associated with reduced whole body and yolk content from these electrolytes. Therefore, ochratoxin A had a negative effect on calcium metabolism.

Toxic Effects of Ochratoxin A on Calcium Metabolism during Chick Embryo Developmentand in Hatched Chicks

ABSTRACT The present study was carried out to study the effect of in-ovo ochratoxin A (OTA) injection in Highline layer eggs on calcium metabolism and blood biochemical parameters of embryos and after the hatch. At day 10 of embryonic development, one hundred and sixty-two fertile eggs were individually weighed and divided into two equal treatments. The first treatment (control) consisted of the individual injection of fertile eggs with 50 µL sodium carbonate. In the second treatment (OTA), fertile eggs were individually injected with 12.5 ng OTA dissolved in 50 µL sodium carbonate. On days 12, 14, and 16 of incubation and at the hatch, serum calcium and inorganic phosphorus concentrations were lower (p 0.05), while sodium, alkaline phosphatase and triiodothyronine concentrations were higher (p 0.05) in the OTA-injected eggs compared with the controls. Serum potassium concentration was not affected (p 0.05) by OTA treatment. Lower calcium and phosphorus levels were determined (p 0.05) in the allantoic fluid of OTA-injected eggs compared with the controls. On days 12, 14, and 16 of incubation and at the hatch, lower whole body and yolk calcium and phosphorus, but not sodium levels, were measured (p 0.05) in the OTA treatment compared with the controls. In conclusion, the injection of eggs with OTA reduced blood calcium and phosphorus levels, which were associated with reduced whole body and yolk content from these electrolytes. Therefore, ochratoxin A had a negative effect on calcium metabolism.(AU)

Efectos de la alta temperatura sobre la producción en gallinas ponedoras suplementadas con vitaminas C y E / Effects of high temperature on production in layer chickens supplemented with vitamins C and E

Objetive. To determine the effects of high temperature, the high humidity and the index on production performance in layer chickens supplemented with vitamins C and E. Materials and methods. The experiment was carried out from July 14th to August 15th. A total of 720 L33 layer chickens, 39 weeks old, were divided at random into four groups (180 birds/group), by replicates (n=4): Control Group) was fed with a basal diet and treatment groups were fed with the basal diet supplemented with either 150 mg of l-ascorbic acid/g of diet (Group Vit. C) or 150 mg of dl-α-tocopherol acetate /kg, of diet (Group Vit. E), and 150 mg of l-ascorbic acid /kg of diet plus 150 mg of dl-α-tocopherol acetate/kg of diet (Group Vit C + E). Results. Egg/bird were higher (p<0.05) in all treatment groups when compared to control group, but p value was highly significant in vitamin E treated group. Likewise, the laying index was different (p<0.05) in all treatment groups when compared to control, and P value was highly significant in vitamin E treated group. Although, viability was not affected by vitamin C, vitamin E and vitamin C+E groups when compared to control (p>0.05). However, feed consumption and conversion were different (p<0.05) in treatment groups when compared to control group. Conclusions. Dietary supplementation with 150 mg vitamin C and/or 150 mg vitamin E increased production performance in heat stressed layer chickens.

Effects of heat stress on some blood parameters and egg production of Shika Brown layer chickens transported by road

The effects of vitamins C and E on layer chickens transported by road for 6 h during the hot dry season were investigated. Two experimental groups consisting of thirty Shika Brown layers were separately administered vitamins C and E orally just before transportation, while another 30 layers, which were only given sterile water, served as control. Blood samples analyzed before and after transportation in the control layers showed a decrease (p<0.05) in total white blood cell, (p<0.01) lymphocyte and monocyte values, and a signifcant (p<0.05) and (p<0.001) increase in the values of eosinophils and heterophils post-transportation, respectively. In the experimental groups, post-transportation values of total white blood cells, eosinophils and monocytes were not different (p>0.05) from those obtained before transportation. Heterophil/lymphocyte values were highest in the control group. The result showed that transportation was stressful for the control layers. Post-transportation egg production was not signifcantly (p>0.05) different in the vitamin E treated group, but values recorded for the vitamin C and control groups were signifcantly (p<0.05) and (p<0.001) reduced compared to pre-transportation. In conclusion, vitamins C and E administration ameliorated the adverse effect of road transportation stress during the hot dry season.