Evaluation of strain, dietary energy level and stocking density on broiler feathering

This study evaluated the effects of strain, stocking density and dietary energy level on the feathering of broiler chickens. Four trials were carried out between September 2000 and April 2002. There were 10,685 broiler chicks from the strains Ross 308, Cobb 500, Hybro PG, Hubbard, MPK, and Isa Vedette. The bids were reared at stocking densities varying between 10 and 16 birds/m² and were given diets containing different metabolizable energy levels. Broiler feathering was evaluated either by atrributing scores from 1 to 10 to feather covering along the thigh and back (visual inspection), or by determining the percentage weight of the feathers at 28 and 42 days of age. Increasing rearing densities resulted in poorer feathering, mainly if 12 or 13 birds/m² were compared with 16 birds/m². The strains showed different feathering; it was better in Cobb 500 and MPK birds, whereas Hubbard birds showed poorer feathering, mostly along the back. The energy level in the diet has also affected feathering scores. Medium energy level resulted in better feathering along the back at 28 days, and the low level, in better feathering along the thigh at 35 days of age. Finally, feather scores were better in females than in males.

Tibial dyschondroplasia and bone mineral density

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, UNESP, Botucatu-SP, Brazil. The aim was to establish the normal values of bone mineral density (BMD) expressed in millimeters of aluminum in the tibia of broiler chickens using optical densitometry of radiographs. Four hundred Cobb male chicks were reared from 1 to 40 days of age, when 40 of them were selected and the right femur-tibia articulation was radiographed. Radiographs were taken with the X-ray equipment calibrated for 45 kvp and 3.2 mAs and a focus-to-film distance of 90 cm. An aluminum phantom ASTM-6063 consisting of 20 ladder steps with graduate density was placed parallel to the area to be radiographed and used as a densitometry reference standard. Radiograph images were analyzed using the software ATHENA - SIA. The proximal growth plate of the right tibia epiphysis was used as the standard reading region. The inclination axis of the reading window was 0 and the window was 10 mm high and 40-45 mm wide, depending on the bone size. Optical densitometry values of the radiographs ranged from 1.46 to 1.77 mmAl, and the coefficient of variation was 9.93%. It was concluded that densitometry values beyond the range established in the present study might indicate the presence of bone alteration in the tibia of broilers.

Quantitative trait loci associated with chemical composition of the chicken carcass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

QTL for percentage of carcass and carcass parts in a broiler x layer cross

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Quantitative trait loci for performance traits in a broiler x layer cross

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da idade da matriz sobre o rendimento e qualidade da carne de frangos de corte

O experimento foi conduzido na Faculdade de Medicina Veterinária e Zootecnia da UNESP, Campus de Botucatu, para avaliar o efeito da idade da matriz no desenvolvimento, rendimento e qualidade da carne de frangos de corte. Ovos de matrizes da linhagen Ross x Ross provenientes de lotes com 29, 41, 58, 68 e 98 semanas de idade foram selecionados e incubados em idênticas condições. Após a eclosão, três mil e seiscentos pintinhos de um dia foram alojados, ao acaso, em um esquema fatorial 5 x 2, ou seja, 5 idades e 2 sexos, e criados até 49 dias de idade. Com 21, 28, 35, 42 e 49 dias de idade, 25 aves de cada tratamento foram selecionadas e abatidas após um período de 8 horas de jejum alimentar. de acordo com resultados obtidos, a idade da matriz afetou (P<0,05) a espessura do filé do peito e o rendimento de carne de peito aos 49 dias de idade, com melhores resultados para frangos originados de matrizes com 29 semanas de idade. O pH do peito e da perna sofreu uma variação bastante acentuada, sendo menor nas aves oriundas de matrizes mais velhas e maior nas aves oriundas de matrizes mais novas. Já a perda de peso por cozimento e a força de cizalhamento não foram afetados pela idade da matriz.

Resistência à Síndrome Ascítica, Competência Homeotérmica e Níveis de Hsp70 no Coração e Pulmão de Frangos de Corte

Como em outros seres vivos, também nas células das aves ocorre a síntese das proteínas de baixo peso molecular (Hsp), cujo aumento é induzido sob condições de estresse. As Hsps têm um papel importante na manutenção da integridade celular, questiona-se o seu envolvimento no mecanismo de proteção celular de órgãos alvos na ocorrência da síndrome ascítica (SA). Este trabalho objetivou avaliar a temperatura corporal e os níveis da Hsp70 no coração e pulmão de frangos de corte Hubbard (sensível à SA) e caipira de pescoço-pelado (resistente), criados em termoneutralidade (25°C) e frio (16°C) entre 10 e 45 dias de idade. Foram utilizados 192 pintos machos, 96 de cada linhagem. Não houve mortalidade por SA nas aves caipiras. Nas aves Hubbard, a mortalidade devida à SA foi de 4% e 41% em ambiente termoneutro e frio, respectivamente. em ambiente frio, a temperatura corporal das aves Hubbard foi menor que a das caipiras. A temperatura corporal e o nível de Hsp70 do coração das aves Hubbard diminuíram com o aumento da idade, mas não nas aves caipiras, os quais se mantiveram constantes, inclusive a Hsp70 do pulmão. Independente da idade ou da temperatura, o nível de Hsp70 no pulmão das aves caipiras era superior ao das aves Hubbard. em relação às aves Hubbard, as caipiras são homeotérmicas mais competentes e apresentam uma maior indução de Hsp70 nos órgãos primariamente afetados na SA, mas este não parece ser o sistema de proteção contra SA, a qual as aves de pescoço pelado são resistentes.

Mapping quantitative trait loci in Gallus gallus using principal components

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da Densidade de Criação e do Sexo Sobre o Empenamento, Incidência de Lesões na Carcaça e Qualidade da Carne de Peito de Frangos de Corte

O experimento foi conduzido nas instalações experimentais da Faculdade de Medicina Veterinária e Zootecnia - UNESP, Campus de Botucatu, SP, Brasil, com o objetivo de avaliar o efeito da densidade de criação e do sexo sobre o empenamento, incidência de lesões na carcaça e a qualidade de carne de peito de frangos de corte. Foram utilizados 1950 pintos de corte sexados, da linhagem Ross, distribuídos em um delineamento inteiramente casualizado, com esquema fatorial com 3 densidades (10, 13 e 16 aves/m²) e dois sexos com 5 repetições, sendo que uma foi destinada exclusivamente para reserva, criados até os 42 dias de idade. Aos 28, 35 e 42 dias foram amostradas 3 aves por repetição para a determinação do empenamento através da porcentagem de penas e 10 aves para a determinação do escore de empenamento. Também aos 42 dias de idade todas as aves foram identificadas na pata com anilhas numeradas e submetidas à avaliação da incidência de lesões na pele. Foram escolhidas ao acaso 5 aves por repetição para a determinação da qualidade da carne de peito. Pode-se concluir que o aumento na densidade de criação promoveu uma diminuição na velocidade de empenamento e, conseqüentemente, uma maior incidência de lesões na carcaça. O comprimento, a largura e a espessura do peito foram menores para as aves criadas na maior densidade, e a perda de peso por cozimento foi maior para as aves criadas na maior densidade.

A double antibody sandwich ELISA for rapid diagnosis of virus infection and to measure the humoral response against infectious bursal disease on clinical material

A double antibody sandwich ELISA (DAS-ELISA) was developed and employed for simultaneous direct detection of infectious bursal disease virus (IBDV) from bursal samples and to measure the humoral response, using the same basic immunoreagents, the purified and non-purified antigen, capture antibody and chicken hyperimmune sera were prepared, and standardized for this purpose, the DAS-ELISA was applied to both 80 bursal suspensions and 224 corresponding serum samples from vaccinated and non-vaccinated commercial hocks, Bursae samples were collected at 2 weeks of age, and submitted to histological examination, virus isolation in specific pathogen-free chickens embryos, and the DAS-ELISA technique, Serum titres obtained in indirect ELISA and serum neutralization test were compared with those in DAS-ELISA, the agreement was 80% between DAS-ELISA, and the conventional techniques, with high sensitivity (87%) and specificity (90%).

A liquid phase blocking ELISA for the detection of antibodies against infectious bronchitis virus

A liquid phase blocking ELISA (LPB-ELISA) was developed for the detection and measurement of antibodies against infectious bronchitis virus (IBV). The purified and nonpurified virus used as antigen, the capture and detector antibodies, and the chicken hyperimmune sera were prepared and standardized for this purpose. A total of 156 sera from vaccinated and 100 from specific pathogen-free chickens with no recorded contact with the virus were tested. The respective serum titers obtained in the serum neutralization test (SNT) were compared with those obtained in the LPB-ELISA. There was a high correlation (r2 = 0.8926) between the two tests. The LPB-ELISA represents a single test suitable for the rapid detection of antibodies against bronchitis virus in chicken sera, with good sensitivity (88%), specificity (100%) and agreement (95.31%).

Pathology and Tissue Distribution of Turkey Coronavirus in Experimentally Infected Chicks and Turkey Poults

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biological studies and molecular characterization of a Cryptosporidium isolate from ostriches (Struthio camelus)

There are many reports of cryptosporidial infection in ostriches, but none with molecular characterization of the isolates. A study was undertaken for the characterization of a Brazilian Cryptosporidium sp. ostrich isolate by using molecular phylogenetic analysis of fragments of the 18S ribosonial DNA. heat-shock Protein (lisp) 70 coding gene, and actin coding gene. Biological studies were accomplished by the experimental inoculation of chickens via oral or intratracheal routes with fresh ostrich Cryptosporidium sp. oocysts. Molecular analysis of nuceotide sequences of the 3 genes by using neighbor-joining and parsimony methods grouped the ostrich isolate as a sister taxon of Crypiosporidium badeyi and showed that the os(rich isolate is genetically distinct from all other known Cryptosporidium species or genotypes. None of the inoculated chickens developed infection as determined by mucosal smears. histology, and fecal screening for oocysts. Although biological and molecular Studies indicate that the ostrich Cryptosporidium is a new species, further Studies regarding morphological. biological, and molecular characteristics of other ostrich isolates are required to confirm the species status of the ostrich Cryprosporidium.

Traceability of animal by product meals in broilers fed sugarcane yeast using stable isotopes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Unpalatability of Hyla semilineata tadpoles (Anura) to captive and free-ranging vertebrate predators

This study examines the unpalatability of Hyla semilineata tadpoles, relating this possible defence mechanism to their black, presumably aposematic, colouration. Bullfrog tadpoles (Rana catesbeiana), similar in size to the H. semilineata larvae, were used as controls in the experiments. The palatability of H. semilineata tadpoles was tested by offering the tadpoles to Fish (Hoplias malabaricus), free-ranging passerine birds (Pitangus sulphuratus) and hawks (Buteo magnirostris), and domestic chickens (Gallus domesticus). All predators showed a significant preference towards the control R. catesbeiana tadpoles. However, in experiments with fish, this preference was not significant for tadpole capture, only for their ingestion, suggesting that the fish could not distinguish between the two species before tasting them. Although great kiskadees (P. sulphuratus) preferred the control R. catesbeiana tadpoles, they promptly ingested more than half of the test H. semilineata tadpoles when these were offered alone. The chickens, used as naive predators, clearly learned to avoid the black H. semilineata tadpoles after a few trials. The conspicuous colouration and unpalatability of H. semilineata tadpoles may benefit the individual as well as the group, depending on the predator involved.