V. M. N. Abreu

Productive and bioeconomical performance of broiler chicks grown under different heating systems

ABSTRACT - This experiment was carried out in two phases to study the effect of different heating systems on the productive and bioeconomical performances in broilers. Five hundred one-day broiler chicks, 50% male and 50% female, in each protected circle, were allotted to a randomized block design with seven treatments and four blocks. The heating systems were: fiber glass plate without plastic sheet cover, fiber glass plate with plastic sheet cover; built-in floor resistance without plastic sheet cover, built-in floor resistance with plastic sheet cover; mortar plate without plastic sheet cover, mortar plate with plastic sheet cover, and brooder heating gas. Heating was maintained up to the 21st days of age, beginning with the temperature of 35oC in the first week with a reducing of 3oC by each week. Live weight, weight gain, feed intake, feed:gain ratio and mortality were evaluated. The electric energy and gas expenditures were recorded during all bird heating period in order to compare the different heating systems cost. The heat electric system with mortar structure plate and plastic sheet cover was the most indicated, by promoting good thermal conditions and higher gross margin at the end of the growing period.

Capacidade de combinação de características de produção de ovos de linhagens de matrizes de frango de corte, usando análise de componentes principais

This study was conducted using data from single crosses (diallel) withim three female lines (PP, KK and VV). A completely randomized block design, with 81 single crosses treatments, three replicales with 81 broilers was used. The twelve production traits were: egg number during the periods of 24th-32nd, 32nd-40th, 40th-48th, 48th-56th, 56th-64th, 22nd-66th, 32nd-66th, 40th-66th, 48th-66th, 24th-40th, 24th-48th and 24th-56th weeks of age. The first two principal components explained more than 98% of total variance of the crosses means. In the study of the general combining ability (GCA), based on the scores of the first two principal componentes, the parent lines PP and VV were selected by GCA, for principal component1, however for the principal component 2 the parent line selected was PP.

Effect of floor type (dirt or concrete) on litter quality, house environmental conditions, and performance of broilers

This study was conducted with the objective of evaluating the use of concrete or hard-packed dirt floor in broiler houses. This experiment was carried out in two different phases. The following performance parameters were studied: live weight, feed intake, feed conversion ratio, and mortality. Litter moisture, pH and temperature were measured. Litter residual contamination after cleaning and disinfection was also evaluated. A dry bulb thermometer, a wet bulb thermometer, and a black bulb thermometer were placed inside each broiler house at bird height and outside the broiler house for data collection. Environmental data were collected at 3h intervals from 00:00 to 24:00 hours during weeks 4, 5, and 6 of the grow-out. Based on the collected data, air relative humidity (RH) was determined, after which wet bulb globe temperature (WBGT) and Radiant Heat Load (RHL) were calculated. There were no differences in live performance parameters. However, total mortality and sudden death were higher in birds raised on dirt floor. On days 0, 14 and 35, litter pH was higher in the dirt floor as compared to the concrete floor, but at the end of the grow-out, this difference disappeared. There was a cubic effect of bird age on litter moisture, which increased up to day 28, and then stabilized or decreased. Litter coliform contamination was higher at the end of the grow-out as compared to that found at housing, but it was not influenced by floor type. The general thermal comfort of broiler raised on dirt floor was similar to that of broilers raised on concrete floor.

Metodologia de Dimensionamento de Sistemas de Aquecimento em Piso, em Função da Temperatura e Espessura de Cama, para Criação de Frangos de Corte

The present study was conducted to evaluate the suitable temperature and thickness of the poultry litter related to the electric heating systems (glass fiber and armed mortar) and regarding the ambient temperature variations. Temperature values were obtained in specific places of the litter each 5 minutes. The system keeps working up to 35oC at the top layer of litter. The suitable system was the one in which the armed mortar and glass fiber thickness were respectively, 0,06 and 0,08 m. In this system, the total thickness outside the brooding area could be maintained at 0,11 m.

Estudo da capacidade de combinação de linhagens de matrizes de frango de corte, por meio da análise de fatores de características produtivas

This study was carried out to study the combining ability of parental broiler lines using factor analysis of production traits. The single crosses (partial diallel) among the male lines of group 1 (LL, TL, ZL, TT, LT, ZT, ZZ, LZ, and TL) and female lines of group 2 (PP, KP, VP, KK, PK, VK, VV, PV, and KV). A completely randomized blocks design, with three blocks, 81 single crosses and nine females per cross was used. The production traits, were fertility at 32nd, 38th , 42nd and 49th weeks of age, hatchability at 32nd, the initial body weights of the chicks, body weight and feed:gain ratio at 42nd days of age, and carcass yield, breast yield and fat pad yield at 42nd day of age of the broiler. Four factors, whose biological meanings were defined after rotation of the factor, were used. The lines that stood out in the factor analysis, for factor 2 (body weight factor at 42nd day) were LT and LZ, in group 1, and VP, KP, KK, KV, PK and VV, in group 2.

Desempenho e Predição de Híbridos e Análise de Agrupamento de Características de Matrizes de Frangos de Corte

This study was conducted using data from single crosses (partial diallel) of male lines, group I (LL, TL, ZL, TT, LT, ZT, ZZ, LZ, TL), female lines, group II (PP, KP, VP, KK, PK, VK, VV, PV, KV), besides two control lines (LLc and PPc). A completely randomized block design, with three replicales, 82 single crosses treatments with nine females for experimental unit was used in the analyses. The production traits analyzed, eleven total, were: fertility at 32nd, 38th, 42nd and 49th weeks of age, hatchability at 32nd, body weight at day of age, body weight and feed:gain ratio at 42nd days of age, and carcass yield, breast yield and fast pad yield at 42nd day of age. The averages and prediction of the hybrid ones showed to be important source of information. Similarity exists among the crossings originating from of the use of the line 1, as progenitor.

Estudo da capacidade de combinação de linhagens de matrizes de frangos de corte, por meio da análise de fatores. Produção de ovos

With the objective to determine the combining ability of broiler matrix lines by means of factor analysis, single crosses (full diallel) within female lines (PP, KK and VV) were used. The evaluated traits were egg numbers from the 24th-32nd(P1), 32nd-40th(P2), 40th-48th (P3), 48th-56th (P4), 56th-64th (P5), 22nd-66th (P6), 32nd-66th (P7)), 40th-66th (P8), 48th-66th(P9), 24th-40th (P10), 24th-48th (P11)) and 24th-56th (P12) week of age. In the factor analysis, two factors were used, with the meaning biological factor defined after the factor rotation. The common factor 1 presented the bigger weight for the characteristic P6, being, then, considered the production factor. In the selection of superior progenitors based on the additive genetic value, the progenitor VV was the one that stood out. The superior hybrid for the two most important traits, peak of egg production and total egg production, involves the same progenitors, the PP and VV. The factor analysis provided factors with biological and economic meaning of easier use and interpretation.