Resumo em Inglês:

This experiment was carried out in a 104 m² poultry house located between the geographical coordinates 25°45'00" south latitude and 53°03'25" west longitude and an average altitude of 550 m, from September to November, 2008. The chickens were placed in 12 pens measuring 2 m² each at a stocking density of 12 chickens m-2. This study aimed at evaluating the effect of two different initial weights (chick weight on first day of experiment) and two types of litter material on broiler production parameters, litter humidity, as well as on breast and footpad lesions. A total of 240 female Cobb® chickens, derived from the same flock of breeders, was distributed in a completely randomized experimental design with a 2 (initial weight) by 2 (litter material) factorial arrangement with three replicates per treatment. Initial weights were classified as light (34.40 - 35.22 g) or heavy (39.29 - 41.30 g), whereas wood shavings and sawdust were used as litter material. Data were analyzed by ANOVA and means were compared by Tukey's test at 95% confidence level. Initial weight significantly influenced bird performance, as chickens with heavy initial weight presented higher feed intake and body weight. Type of litter did not have any effect on breast injuries and litter humidity. However, the wood shavings litter significantly influenced footpad lesions.

Resumo em Inglês:

The objective of this study was to evaluate the effects of the inclusion of annato (Bixa orellana L.) and turmeric (Turmeric longa L.) in layer feeds on live performance, egg quality, and yolk pigmentation and depigmentation time. A number of 144 layers were distributed in a completely randomized experimental design, with four treatments with six replicates of six birds each. In the basal diet, sorghum replaced 50% of corn, and was supplemented or not with natural pigments to composse the following treatments: Control (0% pigments), AS (2.0% annato), TR (2% turmeric) and ASTR (1% annato and 1% turmeric). Egg weight (g), egg production (%), egg mass (%), feed intake (g), feed conversion ratio (kg/dz and kg/kg) and mortality were evaluated. The following egg quality parameters were evaluated: specific gravity (SG); yolk, albumen, and eggshell percentages, and yolk color. The treatments did not influence layer performance or egg quality parameters, except for egg production and yolk color. The dietary inclusion of 1% turmeric root and 1% annato seed promoted higher egg production. Diets containing annato resulted in more saturated, more intense, and redder yolk color, with increasing pigment deposition after day 10, with maximum values obtained on day 28. Dried turmeric root did not promote good yolk pigmentation, resulting in higher presence of white in the yolk, which was stabilized on day 4. Three days after pigments were withdrawn from the feeds, yolk color faded in the treatments with annato inclusion.

Resumo em Inglês:

In the Brazilian meat production scenario broiler production is the most dynamic segment. Despite of the knowledge generated in the poultry production chain, there are still important gaps on Brazilian rearing conditions as housing is different from other countries. This research study aimed at analyzing the variation in bird skin surface as function of heat distribution inside broiler houses. A broiler house was virtually divided into nine sectors and measurements were made during the first four weeks of the grow-out in a commercial broiler farm in the region of Rio Claro, São Paulo, Brazil. Rearing ambient temperature and relative humidity, as well as light intensity and air velocity, were recorded in the geometric center of each virtual sector to evaluate the homogeneity of these parameters. Broiler surface temperatures were recorded using infrared thermography. Differences both in surface temperature (Ts) and dry bulb temperature (DBT) were significant (p<0.05) as a function of week of rearing. Ts was different between the first and fourth weeks (p<0.05) in both flocks. Results showed important variations in rearing environment parameters (temperature and relative humidity) and in skin surface temperature as a function of week and house sector. Air velocity data were outside the limits in the first and third weeks in several sectors. Average light intensity values presented low variation relative to week and house sector. The obtained values were outside the recommended ranges, indicating that broilers suffered thermal distress. This study points out the need to record rearing environment data in order to provide better environmental control during broiler grow-out.

Resumo em Inglês:

The objective of the presente study was to evaluate the effects on different dietary fiber sources and crude protein levels on the intestinal morphometry of commercial layers. Isa Brown® layers with 48 weeks of age were distributed in a completely randomized experimental design with a 3 x 2 + 1 factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. At the end of the fourth experimental period (28 days each), birds were 64 weeks of age and were randomly chosen (two birds per replicate, totaling 14 birds per treatment), weighed and sacrificed by neck dislocation. Their intestine was dissected and the duodenum, jejunum and ileum were collected for subsequent analysis of intestinal morphometry. Treatments consisted of diets containing three different fiber sources (cottonseed hulls, soybean hulls or rice husks) and two crude protein levels (12% or 16%). Soybean hulls and 16% crude protein level promoted, in general, an increase in villus height and crypt depth in the three intestinal segments. In the duodenum, the control diet resulted in higher villus height and crypt depth relative to the diets containing fiber. In the jejunum, higher crypt depth values. In the ileum, dietary fiber increased villus height as compared to the control diet.

Resumo em Inglês:

The experiment was conducted to evaluate the effects of different dietary vitamin combinations on the egg quality and vitamin concentrations in the eggs of commercial laying hens. A total of 1,800 25-week-old Lohman pink-shell hens were randomly assigned to four dietary vitamin treatments as follows: NRC(1994) level, NRC (1994) level with Hy.D® (25-hydroxy-cholecalciferol), Local level (current average industry level in China) and OVN® level (optimum vitamin nutrition level), with 10 replicates per treatment and 45 layers per replicate. Hens were housed in commercial laying cages with three birds per cage and given ad libitum access to feed. Results showed the hens that received the fortified vitamin levels in the OVN® treatment had a significantly (p<0.05) lower number of cracked (.47%) and dirty eggs (.27%), and increased egg deposition of vitamin B12, folic acid, vitamin A, vitamin D, 25-OH-D3, vitamin E, vitamin B1, biotin and pantothenate (p<0.05). Treatments had no significant effect on egg-shape index, egg specific gravity, Haugh units and eggshell thickness. Hens fed the NRC-Hy.D® combination also experienced a significant decrease in cracked and dirty eggs (.70% and .44%, respectively) and an increased deposition of 25-OH-D3 in comparison with the NRC treatment. Results of the present study suggest that that the Local treatment was able to improve egg quality parameters of laying hens, but resulted in more cracked and dirty eggs. OVN® reduced the number of cracked eggs and dirty eggs, and improved the deposition of several vitamins in eggs. With the addition of Hy.D®, eggshell strength and 25-OH-D3 deposition in eggs were also improved, and cracked and dirty egg rates declined.

Resumo em Inglês:

The effect of cinnamon powder (CNP) feeding on some blood metabolites in broiler chicks was studied in a 49-day experiment. The feeding program consisted of a starter diet until day 21, a grower diet until day 42 and a finisher diet until day 49. There were five treatments: a negative control diet, without the additive (control: T1); 250 mg/kg (T2); 500 mg/kg (T3); 1000 mg/kg (T4); and 2000 mg/kg (T5) of CNP in the diet. A total of 320 one-day-old mixed-sex broilers (Ross 308) were distributed into 16 pens with 20 chickens each, comprising 3 replicates per treatment (except for T1, which had 4 replicates). Serum glucose was measured weekly and reported periodically. At the end of the experiment serum cholesterol, triglycerides, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were determined. There were no significant differences among treatments regarding broiler performance and carcass characteristics, except for the finisher phase, when T2 resulted in a significant decrease in feed conversion ratio and weight gain (p<0.05). In the lowest level of cinnamon supplementation (T2), a significant increase in glucose level in starter, finisher and overall rearing period was observed, as well as an increase in triglyceride levels at the finisher phase as compared to T4 and T5 (p<0/05). However, cholesterol, AST and ALT levels were not statistically different among treatments. Therefore, it was concluded that the use of cinnamon powder can affect on some blood metabolites and broiler performance.

Resumo em Inglês:

In this study, the effects of the inclusion of different vitamin C levels in the diet on bone mineral density (BMD) and eggshell quality was determined. Four experimental diets with four levels of vitamin C (0, 250, 500 and 750 mg/kg) were used. During the experiment, environmental temperature and humidity were 19±1°C and 55±5% respectively. Correlation coefficients of BMD index and shell characteristics with production parameters were also determined. Egg weight, egg mass, hen-day egg production and eggshell quality were not significantly influenced by vitamin C levels. BMD was not affected by vitamin C utilization. A positive correlation was observed between BMD and egg weight and hen-day egg production. A significant positive correlation between specific gravity and eggshell traits was also found. In conclusion, the results of this study have shown that vitamin C does not affect bone mineral density and eggshell quality under lower critical temperature.

Resumo em Inglês:

This study was carried out to evaluate the performance and egg quality of laying hens, in their second laying cycle submitted to different forced-molting methods and three environmental temperatures. Six hundred layers were distributed in a completely randomized experimental design with 15 treatments with five replicates of eight birds each, according to 5x3 factorial arrangement (molting methods vs. temperatures). The following forced-molting methods were applied: 90%, 70%, 50% dietary alfalfa inclusion, addition of 2,800 ppm zinc, and feed fasting. Temperatures were: 20 ºC, 27 ºC and 35 ºC. At the end of each period of the second laying cycle, bird performance and egg quality were evaluated. Data were submitted to analysis of variance and means were compared by orthogonal and polynomial contrasts. The highest alfalfa inclusion level (90% alfalfa and 10% basal diet) proved to be efficient as compared to the other methods, independently of temperature.

Resumo em Inglês:

The present study was carried out to evaluate the effects of alternative feedstuffs as partial substitutes of corn and soybean in free-range broiler diets on performance, carcass yield and technical-economic viability. A total of 400 Pescoço Pelado broilers were distributed in a completely randomized experimental design (CRD), with four treatments (treatment 1:Control; treatment 2: 10% rice bran inclusion; treatment 3: 10% ground cassava leaves; and treatment 4: 10% ground lead tree hay) with four replicates per treatment. Each replicate consisted of a group of 25 birds per paddock, separated per sex. Initial weight (IW), final weight (FW), body weight (BW), daily weight gain (DWG), feed intake (FI) and feed conversion ratio (FCR) were evaluated. Carcass, cuts (breast, thigh, drumstick, back, neck, leg and wings), abdominal fat and giblets (gizzard, heart and liver) yields were determined. The technical-economic viability of each treatment was assessed by determining the cost of feed per kg body weight, economic efficiency index and cost. The highest final weights were obtained with the use of rice bran. Rice bran and cassava leaves promoted higher carcass yield, as well as lower back and abdominal fat yields. The use of cassava leaves showed better economic efficiency among the treatments with alternative feedstuffs. The use of alternative feedstuffs at 10% inclusion in substitution of corn and soybean meal did not not result in major changes in performance and carcass parameters, and economic efficiency, and therefore, their use is recommended when the availability or the price of key ingredients, such as soybean meal and corn, increase.

Resumo em Inglês:

A fibrolytic enzyme complex was added to the pre-starter diet. Broiler chicks were randomly distributed into five treatments, consisting of a diet with no enzyme addition and four test diets supplemented with 100, 200, 300 and 400g/T of an enzyme complex. The dietary inclusion of the enzyme complex increased weight gain, and the dose of 300g/T improved weight gain and worsened feed conversion ratio.