Two experiments were carried out at the Poultry Sector of the School of Agrarian Sciences of the Federal University of Grande Dourados to evaluate the incidence of leg problems in broilers reared on two distinct types of bedding material: rice husks or wood shavings, both new and reused. In both trials, a randomized experimental design was applied in factorial arrangement (2 x 2 x 2) using two genetic strains (Cobb ® or Ross ® ); two sexes (male or female), and two litter materials (rice husks or wood shavings). In each trial 1080 one day pullets were reared equally divided in the treatments. The birds were placed in 4.5 m 2 boxes at a density of 10 birds m -2 . All birds were fed diets with equal nutritional density, and water was offered ad libitum. Feeds were divided in three phases: starter diet (1 -21 days), grower diet (22 -35 days), and finisher diet (36 -45 days). On day 45, fifty birds were randomly selected in each experiment to evaluate flock leg problems. The following parameters were analyzed: gait score, incidence of valgus and varus disorder, footpad dermatitis, femoral degeneration, tibial dyschondroplasia, and spondylolisthesis. Ambient temperature during rearing and litter caking and moisture content were recorded in four boxes per treatment. The analytical hierarchy process was used to organize the data into specific criteria. Several criteria, related to the attributes that were determinant according to the statistical analysis, were chosen in order to provide the best input to the process. Results indicated that new wood-shavings bedding was the most appropriate bedding to prevent locomotion problems, followed by new rice husks, reused wood shavings, and reused rice husks. However, when leg problems were associated to sex and genetic strain, male Ross birds strain presented less problems when reared on new rice husks, followed by new wood shavings

Two field trials were conducted to assess locomotor problems in broilers. Males and females broilers were used from two commercial strains reared on two different litter materials, new and re-used. In the first experiment (E1) rice husks and wood shavings were used as new litter, and in the second experiment (E2) the same litter was re-used. A batch of one-day-old chicks (2968) was reared randomly distributed in experimental pens, in a 2¥2¥2 factorial scheme (two genetic strains, two sexes and two litter materials). The same fodder and water were available to all birds ad libitum. Broilers locomotion problems were evaluated using the characteristics of gait score, incidence of valgus and varus, foot-pad lesions, degeneration, femoral, tibial dyschondroplasia, spondylolisthesis and breast calluses. The number of birds with high gait score was less than 30% in the two experiments. Males presented higher gait score (GS) (28.46% GS 1 and 2 compared to females, 20.98%); greater incidence of angular deformities (26.62% with valgus compared to 14.71% of the female); and femoral degenerative joint lesions (70.83% in average, compared to 55.16% of the female), and the correlation between these traits varied from 0.18 to 0.87 (P<0.05). There was an increase of foot-pad lesions in re-used litter leading to poor welfare. The use of rice husks in deep litter for broiler production might be a viable alternative of wood shavings.

The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37-to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers) with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p<0.05). There was no influence (p>0.05) of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p<0.05) under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p<0.05) between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.

<div class="section abstract"><div class="htmlview paragraph">This paper presents the development of a method for the fatigue life analysis in chassis of road implements from power spectral densities, bringing a new possibility for fatigue analysis and reducing the probability of a prototype having fatigue failure. The method was executed by deploying triaxial and uniaxial accelerometers at various points on the road implement chassis, and performing finite element analysis, while it was driven on various road surfaces. Within the proposed method, three types of analyzes were performed: the operational modal analysis; harmonic and modal analysis; and fatigue life analysis. To perform the operational modal analysis, the signals were treated with low-pass and window filters and converted to the frequency domain. As a result, the modal data referring to the implement are inserted as properties of a virtual chassis model in finite elements to obtain frequency response functions through harmonic and modal analysis. A matrix of power spectral densities was also created from the accelerations obtained so that, together with the frequency response functions and, from stress calculation techniques, the spectral moments are obtained. To calculate the fatigue life, the Dirlik or Tovo-Benasciutti methods were employed using spectral moments to obtain the probability density functions. These functions, along with S-N curves, were then utilized to determine the fatigue life. The fatigue life was calculated both in the time and frequency domains for two chassis models, one simplified and the other being a full representation. The simplified model presented approximate results in both domains, in the time domain, the worst life presented itself at 11.200 km and, in the frequency domain, 8.900 km. The complete model showed a variation in the results, 847.000 km in the time domain, and 0.05 km in the frequency domain.</div></div>