Érika Salgado Politi Braga Saldanha

Avaliação do desempenho e do rendimento de carcaça de quatro linhagens de frangos de corte em dois sistemas de criação

The objective of this work was to evaluate performance and carcass and dressing yields of four broiler chicken lineages raised in confined and semi-confined systems. It was used 1,440 chicks distributed in a random block design with a 4 o 2 factorial scheme, composed of lineage types (Ross 308, Master Griss, Label Rouge and Vermelhao Pesado) and two production systems (confinement and semi-confinement), each one with four replications with 45 birds. At 84 days of age, four birds of each repetition were slaughtered, totaling 128 birds, for evaluation of carcass and dressing yields. Access to the paddock (semi-confinement) did not affect performance neither the yield of the carcass of the lineages, except abdominal fat yield, which was the lowest in the semi-confined birds. Considering only birds of colonial lineage, Master Griss and Vermelhao Pesado showed the best results for weight and Label Rouge, the best feed intake. Broilers of Master Griss, Label Rouge and Vermelhao Pesado, compared to the Ross commercial lineage, showed the highest dressing yield, except for breast and breast meat, which were the highest in Ross lineage. Choice of lineage must be done accordingly to the market interest, since there are differences on performance and yield of dressing and carcass.

Efficiency of prebiotics and probiotics on the performance, yield, meat quality and presence of Salmonella spp in carcasses of free-range broiler chickens

Two trials were carried out in the present study. Trial I evaluated the performance, carcass yield and breast meat quality, whereas Trial II evaluated the efficacy of utilizing prebiotics + probiotics on the control of Salmonella spp incidence in the carcasses of free-range broilers. In Trial I, 688 one-day-old male chicks of the Naked Neck Label Rouge strain were used, distributed in a randomized block design arranged according to a 2 x 2 factorial: control diet or diet supplemented with probiotics and prebiotics; and two rearing systems (confined or with access to paddocks - 3m2/bird), using four replicates with 35 birds each. The birds were reared until 84 days of age following the recommendations of management and nutrition for free-range strains, and had access to paddocks after 35 days of age. Water and food were given inside the experimental poultry house. Birds fed probiotics and prebiotics in the diet and the confined birds showed better performance, carcass yield and meat quality compared to the birds of the other treatments. In Trial II, 128 one-day-old male chicks of the free-range Naked Neck Label Rouge strain were used. The birds were distributed into four treatments: NCC (non-challenged control), NCS (non-challenged supplemented), CC (challenged control) and CS (challenged supplemented). There were no significant effects of adding probiotics and prebiotics in the diet in regard to Salmonella enteritidis recovery from the carcasses.

Morfologia das fibras musculares esqueléticas de frangos de corte de diferentes linhagens criados em sistemas de confinamento e semiconfinamento

The effect of strain, breeding system and sex on body weight, carcass and leg yield, and morphologic aspects of skeletal muscle fibers of flexor hallucis longus muscle of broiler chickens was evaluated in this study. The experiment consisted of a 4x2x2 factorial arrangement of treatments, with four strains (Ross-308, Naked Neck Label Rouge, Caipirinha and Paraiso Pedres), two breeding systems (confinement and semi-confinement) and two sexes, with two replicates per treatment, considering each bird selected randomly at 56 days of age an experimental unit, with a total of 64 birds. Ross strain had the highest values of body weight, weights of legs and meat of legs and weight of flexor hallucis longus muscle and highest values of carcass yield and meat of leg yield. The higher muscle mass of birds selected for high growth is related to an increase in the area of the three types of muscle fibers evaluated (SO, FOG and FG). Males presented higher muscle mass and a musculature higher in fast-glycolityc-type fibers than females. Semi-confined system modified the composition of skeletal muscle fibers of males, increasing the oxidative-type fibers. However this effect was not observed in females.

Influência de métodos de debicagem e do tipo de bebedouro no desempenho e na qualidade dos ovos de codornas japonesas

A total of 672 one day old- female quails was allotted to a completely randomized experimental design, with three treatments (non-trimmed birds; 1/3 of the beak trimmed and cauterized beak), 8 replicates of 28 birds to evaluate the effect of beak trimming and drinking system on productive performance. The birds were beak trimmed at 21 days of age, and at day 35 the weight gain, feed intake, feed conversion and mortality were evaluated. At day 39, 576 quails were transfered to laying cages, and assigned to a 3x2 factorial arrangement, to evaluate three beak trimming methods and two drinking systems (cup and nipple) by using four replicates of 24 birds each. The production phase started when the birds reached 50% egg production, at 60 days of age. The quails submitted to beak trimming by cauterization showed smaller weight and lower feed intake during the initial period. Stress pain due to the cauterized beak can justify not only lower feed intake and lower weight gain, but also increased mortality. It can be inferred that once this method takes more time it has caused more pain and higher levels of stress, worsening the performance of birds. The trimmed to 1/3 of the beaks cut can have caused stress to the birds less intense, without effect on performance. No differences on bird performance and egg quality were observed between drinking systems and beak trimming during the laying phase. In the initial phase, beak trimming system reduced performance, however, during the production phase, both drinking and beak trimming systems do not affect performance and egg quality of Japanese quails.

Limestone and oyster shell for brown layers in their second egg production cycle

This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 %) and four combinations of calcium sources (1- 100% fine limestone (FL), 2- 50% FL + 50% coarse limestone (CL), 3- 50% FL and 50% oyster shell (OS), 4- 50% FL and 25% CL+ 25 %OS), with six replicates of eight birds each. Calcium sources were analyzed for geometric mean diameter (GMD) and in-vitro solubility. The following performance and egg quality parameters were evaluated: egg weight (EW, g), egg production (% Eggs), egg mass (EM %), feed intake (FI g), feed conversion ratio (FCR kg/dz and FCR kg/kg), mortality (% Mort.), specific egg gravity (SG), percentages of yolk (Y%), albumen (Alb%) and eggshell (ES%), eggshell thickness (EST), eggshell breaking strength (BS), eggshell weight per surface area (EWSA), Haugh unit (HU), yolk index (YI) and yolk color. Performance and internal egg quality were not affected by the treatments (p>0.05). Blocks had a significant effect on (p<0.05) FI and FCR (kg/dz and kg/kg). Treatments significantly influenced external egg quality, which improved as dietary calcium levels increases and when up to 50% fine limestone was replaced by combinations of coarse limestone with oyster shell.

Maize replacement with sorghum and a combination of protease, xylanase and phytase on performance, nutrient utilization, litter moisture and digestive organ size in broiler chicken

Abstract We investigated the effects of a combination of protease, xylanase, and phytase in maize- or sorghum-based diets for broilers. Two experiments were conducted with male chicks randomly distributed in a 3 × 2 factorial arrangement with three replacement levels of maize with sorghum (0%, 50%, and 100%) with or without enzymes. In the first trial, 1152 chicks were allotted to 36 floor pens to determine performance, relative organ weight, and litter moisture. A second trial was performed with 150 and 120 chicks allotted in 30 cages with five and four broilers per cage to determine nutrient and energy utilization from 11 to 21 d and from 25 to 35 d, respectively. Enzyme supplementation improved body-weight gain and feed conversion ratio. Total maize replacement with sorghum compromised body-weight gain from 1 to 14 d and from 1 to 35 d. Nitrogen retention was reduced by partial and total maize replacement with sorghum at starter phase and by total replacement at grower phase. Enzyme supplementation improved nitrogen retention at starter phase and apparent metabolizable energy at starter and grower phases. Therefore, partial maize replacement with sorghum is viable and on top application of an enzyme blend containing protease, xylanase, and phytase improves performance and nutrient retention of broilers.

Tipos de miosinas de linhagens de frangos de corte criados em sistemas de confinamento e semiconfinamento

The objective was to evaluate body weight, leg weight and morphologic aspects of the muscle fibers of the flexor hallucis longus muscle and electrophoretic profile of myosin heavy chain of four strains of broilers, reared in confinement and semi-confinement systems. 1440 chicks were randomly assigned in a 4 × 2 factorial arrangement: four strains (Ross 305, Master Gris, Label Rouge and Vermelhao Pesado), two production systems (confinement and semi-confinement), with four replicates for each treatment. Four birds were sacrificed for each treatment, at 28 and 84 d, totaling 64 animals. Electrophoresis technique identified the presence of three myosin heavy chain types: MyHC-I, MyHC-IIa and MyHC-IIb, in the flexor hallucis longus muscle of the broilers. There was increase in MyHC-II and decrease in MyHC-I, as age passed. Only at 84 days-old was the MyHC-II expression influenced by strain, confirming a response of selection in Ross lineage on a more glycolytic muscle. The Ross lineage has higher live weight, leg weight, weight and area of the flexor hallucis longus, compared to different chicken strains.