ABSTRACT This study aimed to evaluate different n6:n3ratios on performance, serum biochemical variables, and egg quality in 81-week-old laying hens. A total of 224 laying hens, 81-week-old Hysex White, were utilized and distributed in a completely randomized design consisting of seven treatments and eight replications of four birds per cage, totaling 56 cages. The experimental treatments consisted of seven different n6:n3fatty acid ratios: 1.0:1.0, 2.0:1.0, 4.0:1.0, 8.0:1.0, 16.0:1.0, 32.0:1.0, and 64.0:1.0. For diet formulation, sunflower oil, rich in omega-6, and linseed oil, rich in omega-3, were used. Productive performance, egg quality and serum biochemical variables of laying hens were evaluated at the end of the cycle at 26, 27, and 28 days. Analysis of variance (ANOVA) was conducted and orthogonal contrasts were used to obtain the sum of squares of the treatment of the analysis of variance in polynomial regression effects. Egg quality variables did not vary significantly between the diets. Therefore, diet supplementation with polyunsaturated fatty acids at different ratios was possible without altering egg quality. The only exception was Haugh unit, which displayed a quadratic effect indicating that the best value was the n6:n3ratio of 32, according to data significance. It was concluded that an increase in n6:n3ratios decreases laying hens’ feed intake. The n6:n3 ratio of 34.64 provides greater eggs’ Haugh units, decreasing from that value on. The ratios of n6:n3 did not influence the hens’ serum biochemical variables.

ABSTRACT Butyric acid has been studied and utilized intensively in broiler chicken production in order to substitute growth-promoting antibiotics. However, the comprehensive literature on this topic makes it difficult to understand overall results, since there is a noticeable number of studies with conflicting conclusions. Although several research studies have shown that butyric acid may increment broiler chicken’s performance, several other studies show the opposite. This work aimed to organize information to understand, through a meta-analysis, whether butyric acid can be used as a performance-enhancing additive for broiler chickens, and whether it can replace growth-promoting antibiotics. It was clear from the results that the effect of butyric acid depends on the microbiological challenge that broilers receive. When broilers are raised without health challenge, butyric acid and even antibiotics do not influence growth performance. However, when broilers are challenged, butyric acid provided an increase in weight gain and a significant improvement in feed conversion, matching the results of antibiotics. We conclude that butyric acid improves broiler performance and can be used to replace growth-promoting antibiotics.

ABSTRACT The aim of this study was to evaluate diets supplemented with probiotic (Bacillus amyloliquefaciens) and organic acids (lactic, acetic and butyric acid) in attempt to replace the antibiotics and anticoccidial (avilamycin + sodium monensin) growth promoters on performance and economic viability of broilers challenged by Eimeria acervulina, E. maxima and E. tenella. A total of 900 male Cobb® chickens, with a mean weight of 39.90g, were distributed in a completely randomized design in a 2 × 2 + 1 factorial arrangement: supplementation or not of probiotic and organic acids and a treatment with inclusion of antibiotics, comprising five treatments with six replicates. For the studied performance variables, there was no effect of the isolated additives and no interaction between them (p>0.05). Only the antibiotics promoted better results for weight gain (WG), feed intake (FI) and feed conversion rate (FCR). Therefore, the use of organic acids and probiotic, isolated or associated, provided lower performance to those receiving antibiotics, not improving the performance of chickens under the imposed challenge conditions. The highest revenues were generated with the use of antibiotics, providing greater profits.

ABSTRACT Among the several factors required in breeding laying hens, debeaking is a factor that interferes with batch performance and affects animal welfare. Thus, the objective of this study was to evaluate three different debeaking procedures and to verify the best technique to be used. For this, the performance of the birds, the incidence of cannibalism, and in rearing phase, the quality of the eggs were evaluated. Dekalb White birds were distributed in a completely randomized design with three treatments, T1 (infrared radiation debeaking) T2 (hot blade debeaking) and T3 (V debeaking).The data was submitted to Analysis of Variance and compared by Tukey’s test (95%), using statistical software R. The frequencies of mortality and cannibalism were submitted to the Chi-Square test (Software R). It was observed that mortality was lower with IR debeaking in the breeding phase. Already in the rearing phase, the mortality was similar between the debeaking techniques and the cannibalism was null. The final mean weight (g), mean weight gain (g) and average daily weight gain in the rearing and egg quality variables were higher for V debeaking when compared to other techniques. It is concluded that V-debeaking provides better bird performance, resistance and shell thickness when compared to the infrared radiations and hot blade debeaking, in addition to subjecting the birds to less stress.

ABSTRACT The objective of this study was to investigate the influence of two cleaning and disinfection programs on broiler performance and on the microbiological status of the facilities. This trial was an observational study of comparative character. Two experiments were conducted, with 960 birds each. Both experiments were carried out in a positive-pressure broiler house. Broilers were distributed in pens equipped with a bell drinker and a tube feeder each. In the first experiment, new wood shavings were used as litter material, and in the second, reused wood shavings were used. Two treatments with16 replicates of 30 birds each were evaluated. The regular treatment consisted of dry and wet organic matter removal, followed by washing. The European treatment consisted of dry organic matter removal, humidification, washing with water under high pressure, detergent application, rinsing, and application of two combined disinfectants: glutaraldehyde 250g/L + formaldehyde 185g/L; p-chlor-m-cresol 210 g/L. Biosecurity measures were adopted during daily management tasks to prevent cross contamination between treatments. The effectiveness of the treatments was evaluated by microbiological analysis performed before and after treatment applications, as well as by broiler performance results. Live performance results were similar between both treatments when broilers were reared on new litter. When reused word-shavings were used as litter material, the European treatment promoted better broiler performance. The European treatment was more effective than the regular treatment in reducing total microbial counts in the facilities when reused wood shavings were used as litter material, and positively influenced broiler performance.

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.

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>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.

This study aimed to evaluate diets supplemented with prebiotic, probiotic and symbiotic as an alternative to antibiotics on the performance and immune response against the virus of Newcastle disease in broiler chickens. 1,400 one-day old male Cobb 500 chicks were raised until 42 days old in a completely randomized design with 2x2+1 factorial scheme with seven replications. The treatments were: diet without supplementation (base diet - BD), BD + prebiotic, BD + probiotic, BD + symbiotic (prebiotic + probiotic), and BD + antibiotic. The parameters evaluated were performance and antibody serum titers against Newcastle disease. No antibiotic effect was observed on performance. The symbiotic provided better results for weight gain and feed:gain ratio until 21 days old than isolated additives. At 28 days old, the broilers fed diets with prebiotic presented better feed: gain ratio. In the same period (28 d-old), there was an antibody production increase against the Newcastle disease virus in the group supplemented with prebiotic. It can be concluded that the utilization of symbiotic in broiler chickens' diets can substitute performance enhancing antibiotics. The inclusion of prebiotic in the diet improves feed: gain ratio at 1-28 days old. The chickens' immune response increases at 28 days against the Newcastle disease virus in the group supplemented with prebiotic.

Brazil must comply with international quality standards and animal welfare requirements in order to maintain its position as world's largest exporter of poultry meat. With the scenario of global climate change there is the forecast of occurrence of extreme events with characteristics of both excess cold and heat for several regions of the country. This study aimed to evaluate the effectiveness of using images of infrared thermography to evaluate the loss of sensible heat in young broilers fed different dietary energy levels. Twenty birds were reared in a house with appropriate brooding using infrared lamps. Birds were distributed in a completely randomized experimental into two treatments: T1 (control diet with 2950 kcal ME/kg-1), and T2 (high-energy diet with 3950 kcal ME/kg-1). Infrared thermographic images of the birds were recorded for four consecutive days. One bird was randomly chosen per treatment, and had special images taken and analyzed. Average surface temperature of the body area was calculated using the surface temperature recorded at 100 spots (50 at the front and 50 at the lateral side of the bird's body). Mean surface temperature of the flock was calculated recording 100 spots on the group of birds. Total radiant heat loss was calculated based on the average data of surface temperature. The results indicated that the young broilers fed the high-energy diet presented a metabolic energy loss equivalent to 0.64 kcal h-1, while the birds fed with the control diet lost 2.18 kcal h-1. This finding confirms that oil supplementation to the diet reduces bird heat loss. The infrared camera was able to record young broilers' surface temperature variation when birds were fed diets with different energy contents.

The objective of this study was to evaluate the internal quality of eggs of Japanese quails fed diets supplemented with chelated selenium and zinc. The experiment was carried out for 120 days, and 144 birds were divided in random blocks into four treatments (control; 0.3 ppm Se; 60 ppm Zn and 0.3 ppm Se + 60 ppm Zn). Ten, 14, 18, and 22 weeks after the beginning of lay, eggs were collected and stored under two different temperatures (environmental temperature or refrigeration) and for 10, 20, and 30 days. Eggs were analyzed for: Haugh units (HU), albumen height (AH), yolk index (YI), and albumen index (AI). Parameters were only statistically influenced by the interaction between dietary treatment and storage time. It was concluded that the addition of organic Se and Zn influenced internal egg quality when eggs were stored up to 20 days, independently of storage temperature, suggesting that the combined supplementation of organic Se and Zn improve internal egg quality and extend egg shelf life.