Haematological response and growth performance of Nile tilapia (Oreochromis niloticus L.) fed diets containing folic acid

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

Beak trimming methods and their effect on the performance and egg quality of Japanese quails (Coturnix japonica) during lay

A total number of 720 Japanese quail females, reared under identical management conditions, and receiving feed and water ad libitum, was used. Quails were housed and reared from 1-35 days of age in litter pens in a rearing house, and then were transferred to a quail layer house. This study aimed at verifying if different beak trimming method could optimize egg production and quality by reducing stress and cannibalism among birds. A completely randomized experimental design was used, with six treatments in a 2x3 factorial arrangement, with two beak trimming ages (14 and 21 days) and three beak trimming variants (non-trimmed, 1/3 of the beak trimmed, or 1/2 of the beak trimmed), 6 replicates of 20 birds each. Performance was evaluated by feed intake, percentage of lay, egg mass, feed conversion ratio per dozen and per kg eggs, and mortality. Performance was influenced by trimming variant, with the best results obtained by birds with intact and those with 1/3 of the beak trimmed. Better specific gravity was in quails submitted to beak trimming at 21 days of age, whereas other egg quality parameters did not present significant results. Based the results obtained in the present study, it is recommended to submit to beak trimming either at 14 or 21 days of age.

Productive consequences of fasting neonatal chicks of different genetic constitutions for growing

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

Beak-trimming methods and their effect on the performance of japanese quail pullets (Coturnix japonica)

This study aimed at verifying if beak-trimming methods in Japanese quail pullets could optimize production by decreasing stress caused by cannibalism. A total number of 816 day-old Japanese quails was distributed in a completely randomized experimental design in a 2 x 3 factorial arrangement, with two beak-trimming ages (14 and 21 days of age) and three beak-trimming sizes (not trimmed, 1/3 trimmed, or 1/2 trimmed), and 4 replicates of 34 birds per replicate. Birds were submitted to the same management and feeding conditions. Weight gain, feed intake, feed conversion ratio, and mortality were evaluated. There was no significant effect of age at beak trimming on the evaluated parameters (P>0.05), as well as no significant interaction between age at beak trimming, and beak-trimming method. There was a significant effect (P<0.01) of trimming size on performance, with the best performance observed in birds not submitted to beak trimming or had 1/2 of the beak trimmed. When the beak was more aggressively trimmed (1/2), parameters were worse. According to the obtained results, it is recommended to trim 1/3 of the beaks, which can be performed either at 14 or 21 days of age.

Effects of dietary calcium levels and limestone particicle size on the performance, tibia and blood of laying hens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Calcium and available phosphorus levels for laying hens in second production cycle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of the calcium level and limestone particle size on the performance of semi-heavy layers in the second cycle of egg production

An experiment was carried out at the Research and Development Unit of Brotas aiming at evaluating dietary calcium level and limestone particle size on the production performance of commercial (Hy-Line Brown) layers in the second lay cycle. Experiment duration was 112 days. A total number of 288 hens, with 83 weeks of age in the beginning of the experiment, were used in a completely randomized experimental design in a factorial arrangement of 2x3, with two calcium levels (3.5 and 4.0%) and three limestone particle size compositions: 100% fine limestone (FL), 30% coarse limestone (CL) + 70% fine limestone (FL), and 50% (CL) + 50% (FL), with six replicates of eight birds each. Egg weight (g), egg production (%), egg mass (%), feed intake (g), feed conversion ratio (kg/dz and kg/kg), mortality (%), and egg loss (%) were evaluated. The analysis of variance did not detect significant differences (p>0.05) among treatments on any of the evaluated performance parameters. It was concluded that the tested calcium levels and limestone particle composition did not influence the performance of semi-heavy layers in second production cycle.

Performance, carcass yield, and meat quality of free-range broilers fed wet grain corn silage

This study aimed at evaluating the effect of total replacement of dry corn by wet grain corn silage (WGCS) in the feed of label broilers older than 28 days of age on performance, mortality, carcass, parts, breast meat and thighs meat yields, and meat quality. A mixed-sex flock of 448 ISA S 757-N (naked-neck ISA JA Label) day-old chicks was randomly distributed in to randomized block experimental design with four treatments (T1 - with no WGCS; T2 - WGCS between 28 and 83 days; T3 - WGCS between 42 and 83 days; and T4 - WGCS between 63 and 83 days) and four replicates of 28 birds each. Birds were raised under the same management and feeding conditions until 28 days of age, when they started to have free access to paddock with pasture (at least 3m²/bird) and to be fed the experimental diets. Feed and water were offered ad libitum throughout the rearing period, which was divided in three stages: starter (1 to 28 days), grower (29 to 63 days), and finisher (64 to 83 days) according to the feeding schedule. During the short periods of WGCS use (group T2 during grower stage and T4 during the finisher stage), performance and mortality results were similar as to those of the control group (T1). At the end of the experiment, it was observed that the extended use of WGCS (T2 and T3) determined a negative effect on feed conversion ratio. However, the best results of breast meat yield were observed with birds fed WGCS since 28 days (T2). It was concluded that WGCS can replace dry corn grain for short periods during the grower and finisher stages with no impairment of meat quality and yield in slow growth broilers.

Morphological asymmetry and broiler welfare

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

Metabolizable energy and oil intake in brown commercial layers

With the objective to establish the best metabolizable energy (ME) intake for layers, and the best dietary vegetable oil addition level to optimize egg production, an experiment was carried out with 432 30-week-old Hisex Brown layers. Birds were distributed into nine treatments with six replicates of eight birds each according to a 3 × 3 factorial arrangement, consisting of three daily metabolizable energy intake (280, 300 or 320 kcal/bird/day) and three oil levels (0.00; 0.75 and 1.50 g/bird/day). Daily feed intake was limited to 115, 110 and 105 g/bird in order to obtain the desired energy and oil intake in each treatment. The following parameters were evaluated: initial weight, final weight, body weight change, egg production, egg mass, feed conversion ratio per dozen eggs and per egg mass and energy conversion. There was no influence of the treatments on egg production (%) or egg mass (g/bird/day). Final weight and body weight change were significantly affected by increasing energy intake. Feed conversion ratio per egg mass, feed conversion ratio per dozen eggs and energy conversion significantly worsened as a function of the increase in daily energy intake. An energy intake of 280 kcal/bird/day with no addition of dietary oil does not affect layer performance.

Growth performance of Nile tilapia, Oreochromis niloticus, fed diets containing levels of pyridoxine and haematological response under heat stress

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

Corn texture and particle size in broiler diets

The objective of this study was to evaluate the effect of corn texture and the particle size on broiler performance, carcass yield, nutrient digestibility, and digestive organ morphometrics. In Experiment I, 720 male Cobb chicks were distributed in a completely randomized experimental design with a 2 x 3 factorial arrangement, consisting two corn textures (dented and hard) and three corn particle sizes, was applied, with four replicates of 30 birds each. Corn particle size was classified according to geometric mean diameter (GMD) as fine - 0.46 mm; medium - 0.73 mm, and coarse - 0.87 mm. In Experiment II, 120 broiler chicks were used to evaluate corn digestibility during the periods of 16 to 22 days and 35 to 41 days of age, using the method of total excreta collection. In Experiment I, corn particle size influenced body weight, average weight gain, feed intake and feed conversion ratio of 21-day-old birds. Corn texture and particle size did not affect the performance of 42-day-old broilers or carcass traits. In Experiment II, there was no influence of corn texture and particle size on digestive organ weights. Dented corn increased nitrogen excretion in the first trial, and hard corn improved dry matter digestibility in the second metabolic trial. Corn with fine particle size promotes better performance of broilers at 21 days of age. Hard corn results in higher dry matter digestibility and lower nitrogen excretion, and consequently higher production factor in 42-day-old broilers.

Overview on the performance of Brazilian broilers (1990 to 2009)

This article describes the genetic evolution of commercial broilers between 1990 and 2009, considering live performance, in particular, in terms of weight gain and feed conversion ratio. In order to determine if the assumption that the relationship between body weight gain and feed conversion ratio is increasing and positive, information on all broiler strains reared in Brazil were collected from several companies present in five Brazilian regions. This survey aimed at evaluating broiler live performance as a function of genetic improvement with time. Broiler performance improved, as shown by the statistical differences obtained for the following parameters: livability, live weight, daily weight gain, feed conversion ratio, and production efficiency index between 1990 and 2009. However, live weight gain and feed conversion ratio are emphasized due to the significant differences found along the studied period.

Fibra solúvel e amido como fontes de carboidratos para terminação de novilhos em confinamento

Avaliou-se o efeito da utilização de duas fontes de carboidratos solúveis, amido ou fibra solúvel em detergente neutro, associadas a dois níveis de FDN, sobre o desempenho de novilhos de corte em confinamento na fase de terminação. Foram confinados 24 novilhos ½ Angus x ½ Nelore, com idade inicial de 18 meses e peso de 329 ± 24 kg. As quatro dietas foram calculadas para fornecer nível de PB suficiente para ganho diário de 1,4 kg. As dietas foram constituídas de 40% de silagem de milho e 60% de concentrado (grão de milho, polpa cítrica e casca de soja), além de minerais e uréia, arranjados de forma a promover nível alto de amido associado a dois níveis de FDN (48 e 39%) ou nível alto de fibra solúvel associado aos dois níveis de FDN. Observou-se que os animais alimentados com a dieta com maior nível de polpa cítrica (45%), com baixos teores de fibra solúvel e FDN, apresentaram consumo reduzido e, conseqüentemente, baixo ganho de peso e pior conversão alimentar. Entre as dietas com maior nível de FDN, verificou-se que os animais alimentados com fibra solúvel apresentaram o melhor ganho de peso (1,435 vs 1,262 kg/dia) e a melhor conversão alimentar (7,494 vs 8,651), mas não diferiram daqueles do tratamento com amido e baixo teor de FDN. Os resultados demonstraram que é possível alterar o desempenho animal manipulando a fonte e a concentração dos carboidratos solúveis.

Níveis de arraçoamento para juvenis de trairão (Hoplias lacerdae)

Com esta pesquisa buscou-se avaliar diferentes níveis de arraçoamento, em porcentagem de peso corporal (PC), para juvenis de trairão em início do período de engorda. Peixes com comprimento de 15,0 ± 1,0 cm e peso de 38,5 ± 8,2 g foram distribuídos em seis aquários com 250 litros de água cada, em densidade de cinco juvenis/aquário. Utilizou-se delineamento inteiramente casualisado com três tratamentos (níveis de arraçoamento diário: 2, 4 e 6% PC) e duas repetições. Os juvenis foram alimentados com ração comercial extrusada (42% PB), às 8 e 13 h. Ao final de 45 dias, avaliaram-se a sobrevivência, a conversão alimentar aparente e os ganhos em biomassa, peso diário e comprimento. Não houve diferença para sobrevivência e ganhos em biomassa, peso diário e comprimento. Houve diferença para a conversão alimentar aparente em função do manejo adotado. Os melhores resultados de desempenho foram encontrados nos peixes alimentados com níveis de 2 e 4% PC de ração por dia. Conclui-se que a melhor taxa de arraçoamento para juvenis de trairão é de 4% PC.