Scielo RSS <![CDATA[Revista Brasileira de Ciência Avícola]]> vol. 16 num. 4 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Influence of artificial lighting on the performance and egg quality of commercial layers</b>: <b>a review</b>]]> In Brazil, the egg production chain produces fresh eggs for the consumer market and for processing. Layers are housed in battery cage systems. Rearing and development farms are separate from egg-production farms. Considering the recent advance of Brazilian chicken egg production, scientific knowledge on management practices are required to disseminate and to consistently apply this knowledge to improve such practices. Artificial lighting is widely used in poultry reproduction, both in the production of hatchable eggs and of commercial eggs. Light is required for the release of hormones responsible for reproduction; however, the best lighting practices to stimulate laying poultry during the reproductive period still need to be determined, with the aim of saving electric energy, and therefore, to dilute production costs and comply with environmental sustainability requirements. This review showed that layers are indeed photostimulated with more than 12 hours of light, independently of the artificial lighting program applied. Results demonstrate that artificial lighting programs influence egg production, but not egg quality parameters. Intermittent lighting programs are good alternatives when layers are housed in open-sided houses, which are typically used in Brazil. Transcranial light reception is the most important route for the stimulation of reproduction in poultry. <![CDATA[<b>Corn replacement by broken rice in meat-type quail diets</b>]]> An experiment was conducted to evaluate the effects of broken rice inclusion as substitute for corn in the diet on the performance, carcass yield, and economic viability of meat-type quails between 7 and 49 days of age. A number of 288 quails was distributed according to a completely randomized design into six treatments with six replicates of eight birds each. Treatments consisted of increasing levels of broken rice (0, 20, 40, 60, 80 and 100%) in replacement of corn. Increasing levels of corn substitution by broken rice in the diet of 7- to 49-day-old meat-type quails did not affect feed intake, weight gain or feed conversion ratio (p>0.05). Relative to carcass traits, the inclusion of broken rice in the diets did not influence (p>0.05) dressing percentage or breast, leg (thigh+drumstick), liver, and gizzard yields. Moreover, feed cost per kilogram of live weight gain, cost index, and economic efficiency index were not influenced by the replacement of corn by broken rice in the diets. The performance, carcass traits and economic viability of broilers fed the different levels of broken rice inclusion were not different from the control group (p>0.05). These results indicate the economic viability of total replacement of corn by broken rice in the feeding of meat-type quails. <![CDATA[<b>Mixed crude glycerin in laying hen diets</b>: <b>live performance and egg quality and fatty acid profile</b>]]> This study evaluated the performance and the quality and fatty acid profile of eggs from laying hens fed diets containing mixed crude glycerin (MCG; 80% vegetable fat + 20% animal fat). A total of 240 39-week-old Hy-Line W36 laying hens were distributed according to a completely randomized experimental design into six treatments consisting of graded MCG dietary inclusion levels (0, 1.5, 3.0, 4.5, 6.0, and 7.5%), with five replicates of eight birds each. Feed intake linearly decreased (p<0.05) with increasing MCG inclusion levels. The percentages of myristic, palmitic, and α-linolenic acids in the eggs linearly decreased as MCG dietary levels increased (p<0.05), while α-linoleic acid, polyunsaturated fatty acids (PUFA) and ω-6/ω-3 ratio linearly increased. Excreta moisture linearly increased with increasing levels of MCG inclusion (p<0.05). MCG may be included in up to 7.5% in layer feeds without impairing performance or egg quality, but levels up to 5.54% reduce SFA egg content. However, the inclusion of MCG in layer diets increases ω-6/ω-3 ratio in the eggs. <![CDATA[<b>Pathological, immunohistochemical, and molecular findings in commercial laying hens and in backyard chickens naturally infected with the infectious laryngotracheitis virus</b>]]> Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread. <![CDATA[<b>Impact of particle size, thermal processing, fat inclusion, and moisture addition on starch gelatinization of broiler feeds</b>]]> The present study evaluated the effect of feed particle size, thermal processing different levels of fat inclusion and of moisture addition on the amount of gelatinized starch in a corn-soybean broiler diet. The different processing factors were combined in a 2 x 4 x 4 x 2 factorial arrangement in a three randomized block design consisting of three production series: two particle sizes (coarse: 1041 microns and medium: 743 microns), four fat inclusion levels at the mixer (15, 25, 35, and 45 g/kg of feed), four moisture addition levels in the conditioner (0, 7, 14, and 21g/kg of feed), and two thermal processing treatments (conditioning-pelleting or conditioning-expanding-pelleting) which resulted in 64 different processed feeds. For the determination of the amount of gelatinized starch one feed sample was collected per treatment in each of three production series, totaling three replicates/treatment. Data were transformed using a variation of Box-Cox transformation in order to fit normal distribution (p&gt;0.05). Adding moisture up to 21g/kg of feed in the conditioner linearly increased the amount of gelatinized starch (p<0.05). The conditioner-expander-pelleting treatment of the diets (at 110°C) increased (p<0.05) the degree of starch gelatinization from 32.0 to 35.3 % compared with the conditioner-pelleting treatment (at 80-82°C). The gelatinized starch content increased from 30.2 to 37.2% in the feed (p<0.05) as the particle size increased from medium to coarse. Fat inclusion had a quadratic effect (p<0.05) on starch gelatinization. The degree of starch gelatinization was significantly reduced with fat inclusion levels higher than 35 g/kg of diet. The factors evaluated in this study resulted in interactions and significant effects on degree of starch gelatinization. <![CDATA[<b>Correlations between endogen amylin hormone and some hormonal, biochemical and bone parameters in pullets</b>]]> The objective of this study was to assess the correlations of amylin (a pancreatic polypeptide hormone) with some hormonal, biochemical and bone parameters in pullets. Forty 18-week-old pullets were used. Plasma amylin, CT (calcitonin), 1,25 (OH)2 vitamin D (1,25 dihydroxycholecalciferol ), serum osteocalcin, glucose, ALP (alkaline phosphatase), cholesterol, and triglycerides, as well as weight, length and total volume of tibiotarsi were measured. Plasma amylin concentration was negatively correlated with serum cholesterol (p<0.05) and triglycerides (p<0.05) concentrations. Plasma amylin concentration was significantly and positively correlated with plasma calcitonin concentrations (p<0.001). Serum ALP and plasma amylin concentrations were positively correlated (p<0.01). There were no correlations between amylin hormone and other parameters. Based on these results, it is possible to conclude that endogen amylin may effect cholesterol, triglycerides, calcitonin, and ALP levels in pullets without changing some other hormonal, biochemical and bone parameters related to calcium and lipid metabolism. <![CDATA[<b>Effect of dietary energy concentration on performance parameters and egg quality of white leghorn laying hens</b>]]> An experiment was carried out with 1200 23-week-old white Dekalb commercial laying hens to investigate production responses, egg quality, and energy utilization of laying hens fed different dietary energy levels at the beginning of lay. Birds were housed and divided in five groups of 240 birds according to dietary apparent metabolizable energy corrected for nitrogen (AMEn): 2700 kcal/kg; 2775 kcal/kg; 2850 kcal/kg; 2925 kcal/kg; and 3000 kcal/kg, with six replicates of 40 birds each. Birds were fed the experimental diets based on corn and soybean meal for 17 weeks. Diets were iso-nutritive, except for energy level. Increasing AMEn levels had a negative effect on egg production and egg mass (p≤0.05). AMEn levels did not influence body weight, egg weight, or livability (p>0.05). Increasing AMEn levels increased (p≤0.05) feed intake and AMEn conversion ratio and feed conversion ratio. AMEn intake remained constant, independently of dietary AMEn level (p>0.05). There were no differences in albumen height, yolk total solids content, or egg component percentages (p>0.05). Egg specific weight improved with increasing AMEn levels (p≤0.05). Therefore, the energy level of 2700 kcal/kg of feed may be fed to young laying hens. <![CDATA[<b>Sources of trophic action on performance and intestinal morphometry of broiler chickens vaccinated against coccidiosis</b>]]> The aim of this experiment was to evaluate the effect of sources of trophic action (glutamine alone, glutamine associated with glutamic acid and yeast) associated with vaccination against coccidiosis on the performance and morphometry of the small intestine of broilers. In the trial, 1,200 broiler chicks were distributed according to a completely randomized design with a 3 x 2 + 2 (trophic action x vaccination or not + control - free trophic factor) factorial arrangement, with five replicates of 30 birds each. Vaccination negatively affected performance parameters and the morphometry of the intestinal mucosa, but at the end of the experimental period, among the broilers vaccinated against coccidiosis, the group fed glutamine presented better recovery from epithelial losses of the intestinal mucosa compared with the control groups. Therefore, the dietary supplementation with the evaluated sources of trophic action could be a strategy to enhance the development of broilers submitted to vaccine stress, also considering the economic viability of the productive segment. <![CDATA[<b>Feeding management strategy for male broiler breeders and its effects on body weight, hatchability and fertility</b>]]> The objective of the present study was to evaluate the supply of a specific-male diet on rooster body weight, hatchability, and fertility. Two diets were supplied during the egg production period: treatment 1, diet formulated for females and containing, in average, 2,830 kcal ME/kg and 15% CP; and treatment 2, diet specifically formulated for male broiler breeders, containing 2,750 kcal ME/kg and 13.5% CP. In the experiment, 26 flocks, with approximately 7,000 females and 840 males each, belonging to the same broiler breeder commercial strain, were distributed into 26 houses (1200m²) on the same farm, and submitted to the same management practices. Body weight was evaluated in 13 flocks per treatment and for five weeks (45, 50, 55, 60, 65), and hatchability and fertility in four incubation lots per treatment and for the same weeks. Data were evaluated by the analysis of mixed models for repeated measurements, using the PROC MIXED of SAS 9.3 (SAS Institute Inc., Cary, NC, USA), and means were compared by the test of Tukey-Kramer at 5% significance level. The specific-male diet allowed body weight control during all analyzed weeks and promoted high hatchability and egg fertility. The increase in the number of chicks hatched demonstrates the economic viability of feeding a specific diet for male broiler breeders. <![CDATA[<b>Comparing the profitability of organic and conventional broiler production</b>]]> Organic broiler chicken production has recently received more attention worldwide. This study carried out an economic analysis to compare the profitability of organic versus conventional growing systems per unit of broiler meat production. In this study, 400 slow-growing broilers (Hubbard Red-JA) were reared in an organic production system and the same number of fast-growing broilers (Ross-308) were reared in a conventional system. Profitability was deduced from an economic analysis that compared total costs and net income. Results showed that organic broiler meat can cost from 70% to 86% more with respect to variable and fixed costs when compared with conventional production. The main reasons for the higher cost of organic broiler meat were feed, labor, certification, and outdoor area maintenance. The proportion of fixed costs in total costs was 1.54% in the conventional system and 7.48% in the organic system. The net income per kg of chicken meat in the organic system was €0.75, which is 180% higher compared with the conventional system (€0.27); however, organic broiler meat was sold at a twice as high price than the conventional one. In conclusion, organic broiler meat production was more economical than conventional rearing. <![CDATA[<b>Metabolizable energy of different glycerine sources derived from national biodiesel production for broilers</b>]]> The objective of the present study was to evaluate the quality of different glycerine sources produced in Brazil and to analyze their metabolizable energy levels and digestibility for broilers. Firstly, the composition of 10 samples of glycerine from different sources was analyzed. Secondly, glycerine from four different sources presenting contrasting compositions were selected to determine their metabolizable energy levels and digestibility in metabolism assays using 200 broilers between 21 and 29 days of age, applying the method of total excreta collection. The values of apparent metabolizable energy corrected for nitrogen balance of the four glycerine sources were 3145, 5026, 2828, and 2892 kcal/kg. <![CDATA[<b>Intestinal integrity and performance of broiler chickens fed a probiotic, a prebiotic, or an organic acid</b>]]> This study aimed at evaluating the intestinal integrity, using light and scanning electron microscopy (SEM), and the performance of broiler chickens fed additives alternative to antimicrobials. A total of 1080 male chicks were distributed according to a completely randomized experimental design, with six treatments with six replicates of 30 birds each. The following treatments were evaluated: basal diet (control), basal diet supplemented with an antimicrobial, basal diet supplemented with a probiotic, basal diet supplemented with a prebiotic, basal diet with a symbiotic, and basal diet supplemented with organic acids. Weight gain, feed intake, feed conversion ratio and livability were recorded when broiler chickens were 10, 21, 35, and 42 days old. On day 42, 72 birds were individually weighed and sacrificed. In order to evaluate the morphometrics of the different intestinal wall layers, segments of the small intestine and the cecum were collected from two birds per replicate, and intestinal integrity (SEM) was evaluated in the same segments of two birds per treatment. During the starter period (1-21 days old), birds fed the alternative additives presented similar weight gain as those fed the antimicrobial product, but were not different from control birds. Feed conversion ratio of birds fed alternative additives was better than that of the control birds from one to 10 days of age, but not during the remaining rearing period, and was similar to the birds receiving the antimicrobial. The morphometric parameters of the different intestinal wall layers was not influenced by the treatments. During the total rearing period, the evaluated alternative additives did not improve intestinal integrity or broiler performance. <![CDATA[<b>Effects of dietary lysine on broiler performance and carcass yield - meta-analysis</b>]]> There has been a great evolution and improvement in the nutrition of poultry and lysine has been used the reference amino acid to increase animal protein deposition. Therefore, a meta-analysis was performed with the objective of studying the effect of different dietary lysine levels on the performance and carcass yield of broiler chickens. In total, 21 studies published in Brazil since 1999 were included. Bird performance considered daily weight gain (178 observations) and feed conversion ratio (188 observations) results. Carcass quality was evaluated relative to carcass yield (24 observations), abdominal fat (24 observations) and breast meat yield (30 observations). Data were checked for normality and were submitted to analysis of variance. Weight gain and carcass yield increased with the addition of 1.05% of lysine to the diet, whereas feed conversion ratio and abdominal fat were reduced as dietary lysine concentration increased. The results, therefore, indicate that lysine is essential in bird nutrition and significantly affects bird performance and carcass yield. <![CDATA[<b>Options, challenges and potentials of poultry meat</b>: <b>an empirical investigation on european consumers</b>]]> Agricultural market developments have attracted considerable attention recently, due to increasing consumer food prices and sharp short term price fluctuations of agricultural commodity prices. This medium term outlook provides a projection for major EU agricultural commodity markets and agricultural income until the year 2022, based on a set of coherent assumptions. Under these assumptions, agricultural commodity prices are expected to stay firm over the medium term, supported by factors such as the growth in global food demand, the development of the biofuel sector and a prolongation of the long-term decline in food crop productivity growth. EU commodity markets are projected to remain balanced on average over the outlook period, without the need for market intervention. Prospects for agricultural income grow at EU level during the outlook period, resulting from continuing decline in labor input rather than from income increases at sector level (European Commission, 2012). The article concentrates on the prospects for European meat market trends and on results of the primary quantitative research which was carried out in four countries EU member state. <![CDATA[<b>Energy utilization of by-products from the soybean oil industry by broiler chickens</b>: <b>acidulated soapstock, lecithin, glycerol and their mixture</b>]]> Acidulated soy soapstock (ASS) and lecithin (LEC) are by-products from processing soy oil (SO) for human consumption, whereas glycerol (GLY) can be obtained through the transesterification of vegetable oils during the production of biodiesel. These are valuable by-products for poultry feeds that have been underutilized in many parts of the world. One study was conducted to estimate the AMEn of ASS, LEC, GLY as well as of their mixture (MIX: 85% ASS, 5% LEC and 10% GLY). Two hundred and sixty Cobb 500 female broilers of 20 days of age were housed in steel wire battery cages in a controlled temperature room for broilers. A completely randomized (energy sources x fat inclusion level) factorial design was applied, with 4 replicates of three birds per treatment. Birds were fed a corn-soybean meal control diet without supplemental fat or with the addition of 2, 4, or 6 % of the four energy sources. Total excreta collection was performed from 26 to 28 days. The AMEn values of by-products were calculated using regression analysis as well as by the difference method. The average AMEn values calculated by regression analysis were: 9,232, 7,502, 5,447 and 8,404, whereas results with the difference method were: 7,951, 6,579, 3,979 and 8,101 kcal/kg for, in both cases for ASS, LEC, GLY and MIX, respectively. It is concluded that these energy sources can be for broilers and that there are significant differences between the methods used to estimate AMEn of fats. <![CDATA[<b>Performance and carcass yield of broilers supplemented with plant extract during the finisher phase</b>]]> In this study, 600 one-day-old male Cobb 500 broilers were distributed according a completely randomized experimental design into the different dietary treatments. Broilers were fed the following dietary treatments: positive control diet (PC), containing 54 ppm zinc bacitracin; negative control diet (NC), with no inclusion of performance enhancers and 3% reduction in metabolizable energy, crude protein, and amino acid levels; PC up to 33 days and then NC, with the dietary addition of 75, 150, or 225 ppm plant extracts, until day 42 days of age. Broiler performance and carcass yield were evaluated. Data were analyzed using the Statistical Analysis System package (SAS Institute Inc., 2008), and submitted to polynomial regression analysis using the GLM procedure at 5% significance level. There was no influence of treatments on feed intake or weight gain, but feed conversion ratio of the broiler fed the plant extract was significantly higher (p<0.05) compared with those fed the antibiotic. There was no significant effect (p&gt;0.05) of the applied treatments on carcass yield. We concluded that the replacement of performance-enhancing additives by plant extracts, at the evaluated inclusion levels, does not promote positive performance results. <![CDATA[<b>Feeding high-moisture corn grain silage to broilers fed alternative diets and maintained at different environmental temperatures</b>]]> The effects of the dietary substitution of dry corn by high-moisture corn grain silage (HMCGS) were evaluated on the performance, nutrient digestibility and serum biochemical parameters of broilers reared in an alternative production system and submitted to different environmental temperatures. A total of 288 one-day-old male Cobb chicks were distributed according to a randomized block design in a 3x4 factorial arrangement: three environmental temperatures (hot, thermoneutral or cold) and four levels of HMCGS in substitution of dry corn (0%, 20%, 40% or 60%). The acid analysis showed that the evaluated HMCGS contained average percentage values of ethanol, lactic acid, and acetic acid (expressed in 100% of dry matter) of 0.7690, 2.7320 and 0.0249%, respectively. Propionic and butyric acids were not detected. Dry corn and HMCGS presented pH values of 5.8 and 3.3, respectively. The inclusion of HMCGS reduced dietary pH, as shown by the values of 5.7, 5.4, 5.1 and 4.8 recorded for the diets containing 0%, 20%, 40% and 60% of HMCGS, respectively. There was no significant interaction between diets and environmental temperature. HMCGS may replace up to 40% dry corn in broiler diets when performance, triglyceride levels, and HDL-cholesterol ratio is considered, and up to 60% when nutrient digestibility is evaluated. High environmental temperature impairs broiler performance, nutrient digestibility, and serum biochemistry, demonstrating the influence of environmental temperature on broiler metabolism and performance.