The aim of the present study was to compare the productive performance of single stage versus multiple stage incubation in eggs of broiler breeders of three age groups. In the incubation process was used 21 878 026 eggs from Cobb 500 broiler breeders (slow feather) grouped in three age categories: young (24 to 35 weeks), adults (36 to 50 weeks), and old (51 to 63 weeks) for a period of one year. The results showed lower total embryonic mortality in the single stage as compared to the multi stage incubation system (p<0.05), both in the young (9.55 vs 10.49%), adult (7.06 vs 9.62%) and old breeders (8.31 vs 12.55%) as well as higher total hatchability and hatchability of fertile eggs in the single stage incubation system in the three age groups (p<0.05). In addition, it was found a better utilization of the older breeders under the single stage incubation system.

The aim of the present study was to compare the productive performance of single stage versus multiple stage incubation in eggs of broiler breeders of three age groups. In the incubation process was used 21 878 026 eggs from Cobb 500 broiler breeders (slow feather) grouped in three age categories: young (24 to 35 weeks), adults (36 to 50 weeks), and old (51 to 63 weeks) for a period of one year. The results showed lower total embryonic mortality in the single stage as compared to the multi stage incubation system (p<0.05), both in the young (9.55 vs 10.49%), adult (7.06 vs 9.62%) and old breeders (8.31 vs 12.55%) as well as higher total hatchability and hatchability of fertile eggs in the single stage incubation system in the three age groups (p<0.05). In addition, it was found a better utilization of the older breeders under the single stage incubation system.

The anatomo-histopathological development of the bursa, thymus and spleen of broiler chickens raised in new and reused litter through five campaigns was evaluated. Two hundred and fifty male chickens of the Ross 308 line were raised, half in new and half in reused litter. On a weekly basis, the morphometric indexes of bursa, thymus and spleen, and the relation bursa/spleen were recorded. The lymphoid organs were evaluated by histopathology and ELISA test was used to determine antibody titres for Gumboro, Newcastle, Infectious Bronchitis, Infectious Anemia, and Reovirus at the beginning and end of the study (49 days). Statistical difference was found (p<0.05) for weight and morphometric index of the bursa (6.57 ± 2.07 g and 1.67 ± 0.49 for birds raised on new litter and 2.74 ± 1.35 g and 0.70 ± 0.36 for birds in reused litter), but not on body weight between groups. Better results ...

Se evaluó el desarrollo anátomo-histopatológico de la bursa, timo y bazo de pollos de carne criados en cama nueva y cama reutilizada por cinco campañas. Se criaron 250 pollos machos de la línea Ross 308, la mitad en cama nueva y la otra mitad en cama reutilizada. Semanalmente, se determinaron los índices morfométricos de bursa, timo y bazo, y la relación entre bursa y bazo por grupo. Los órganos linfoides fueron evaluados mediante histopatología, y los títulos de anticuerpos contra las enfermedades de Gumboro, Newcastle, Bronquitis Infecciosa, Anemia Infecciosa y Reovirus, al inicio y final de la crianza (49 días), se determinaron por la prueba de ELISA. Se encontró diferencia estadística (p<0.05) para el peso e índices morfométrico de la bursa (6.57 ± 2.07 g y 1.67 ± 0.49 para pollos en cama nueva y 2.74 ± 1.35 g y 0.70 ± 0.36 en cama reutilizada, respectivamente)...

The objective of the study was to asses the susceptibility, pathological effect and serological response of wild pigeons (Columba livia) to Newcastle virus. A total of 28 adult wild pigeons were captured, 14 were inoculated with a velogenic viscerotropic strain of Newcastle virus by oral and nasal route, and the remaining birds were used as a control group. Clinical signs and mortality were recorded. Blood samples were collected for the hemaglutination inhibition technique. Tissue samples from lung and trachea were collected, and cloacal swabs were harvested for virus recovery and histological studies. Birds of the inoculated group showed clinical signs (64%) and mortality (42.8%). The clinical signs (sneezes, ruffled plumage, isolation and lethargy) started at day 4 after inoculation. The 43% of birds showed nervous signs (opisthotonos and tremors of head and neck) and 21% had diarrhea....

El objetivo del presente estudio fue evaluar el grado de susceptibilidad, efecto patológico y respuesta serológica de la paloma silvestre (Columba livia) frente a la inoculación experimental con una cepa de virus velogénico de la enfermedad de Newcastle. Se capturaron 28 aves, donde la mitad se inoculó vía nasal y oral, y la otra mitad se mantuvo como grupo control. Se registró signos clínicos y mortalidad. Se tomaron muestras de sangre para la prueba de inhibición de la hemaglutinación y muestras de tejidos de aves muertas y del grupo control para su análisis histopatológico. Se tomaron muestras de pulmón, tráquea e hisopado de cloaca para la recuperación viral, durante seis semanas post inoculación. El 64% de aves del grupo inoculado presentó signos clínicos y una mortalidad del 42.8%. Se presentaron estornudos a partir del 4"dia; erizamiento de plumas, aislamiento y ...