ABSTRACT In order to evaluate the antioxidant effects of barbatimão (BAR) or pacari (PAC) on chicken meat oxidative stability and quality, seven dietary treatments containing in three different BAR and PAC concentrations (200, 400 and 600ppm) plus a negative control (CONT) were fed to 350 broilers from 1 to 41 days of age. Ten birds per treatment were slaughtered to collect breast and thigh meat to evaluate pH, color (L*, a*, b*), cooking weight loss (CWL), and shear force (SF) 24 hours postmortem, and TBARS levels in precooked meatballs stored chilled for 8days. The dietary supplementation with BAR and PAC extracts did not affect pH and color, but reduced (p<0.05) SF in breast meat compared with CONT suggesting improved tenderness. PAC200 increased (p<0.05) L* and protected (p<0.05) yellow pigments (b* values) of thigh meat from degradation compared with the CONT diet. At the end of the chilled storage period, BAR600 and PAC600 significantly reduced (p<0.06) MDA concentrations in breast meatballs compared to the CONT. The dietary supplementation of BAR and PAC improved (p<0.03) oxidative stability of thigh meatballs, except for BAR200. In conclusion, the dietary addition of BAR and PAC extracts may improve meat quality and prevent lipid oxidation in white and dark precooked and chilled chicken meatballs.

ABSTRACT The aim of this study was to evaluate the effect of digestible threonine supplementation in the starter diet on the performance, intestinal parameters, and nutrient metabolism of broilers derived from breeders of different ages. In total, 480 one-day-old Cobb chicks, derived from 38-or 49-week-oldbreeders, were housed in experimental battery cages until 21 days of age and fed four different threonine levels (800, 900, 1,000, or 1,100 mg/kg) in the starter feed. A completely randomized experimental design in a 2x4 factorial arrangement (breeder age x threonine levels) was applied, totaling eight treatments with five replicates of 12 birds each. Broilers from older breeders fed 800 mg digestible threonine/kg of diet presented higher weight gain, with a positive linear effect. There was also an interaction between breeder age and threonine levels for the weight gain of 21-d-old broilers supplemented at maximum level of 1,003 mg Thr/kg diet during the starter phase. There was no effect of breeder age or threonine levels on nutrient metabolism during the period of 17-21 days. There was no influence of breeder age or threonine levels in the starter diet on intestinal morphometric measurements, absorption area, or percentage of goblet cells.

ABSTRACT An experiment was conducted to evaluate the addition of the oil resins ofsucupira (Pterodon emarginatus Vog.) and copaiba (Copaifera langsdorffii) to broiler diets on chicken meat composition, quality, and lipid peroxidation. 350 one-d-old broiler chicks were submitted to seven treatments, consisting of the diets supplemented with copaiba (COP) or sucupira (SUC) resin oils at three different concentrations (500, 900, and 1300 ppm) plus a negative control diet (CONT). At 37 days of age, 10 birds per treatment were selected according to the average weight of the experimental unit and slaughtered to collect breast and thigh meat, which was stored at 4°C for 24 hours to evaluate pH, color (L*, a*, b*), cooking weight loss (CWL), and shear force (SF). Raw meat was vacuum packed and stored frozen until lipid peroxidation analysis. Meat samples were pooled to prepare pre-cooked meatballs (30 ± 0.5g), stored under refrigeration (eight days), and analyzed every two days for TBARS concentration. Results were analyzed using the PROC GLM and MIXED procedures (SAS statistical software). Plant oils increased (p<0.05) breast meat humidity (HU) and crude protein (CP) levels and reduced (p<0.05) total lipid (TLC) and ash (AS) levels when compared with the CONT treatment. Plant oils increased (p<0.05) thigh meat HU when compared with the CONT. High COP dietary levels reduced (p<0.05) breast meat CWL, and increased (p<0.05) thigh meat L* values when compared to CONT, except for SUC500 and SUC900. The dietary inclusion of plant oil resins showed a pro-oxidant effect (p<0.01) on breast meat when compared with the CONT. Low SUC dietary supplementation levels significantly reduced (p<0.01) the concentration of secondary oxidation products in thigh meat.

Feed is responsible for about 70% of broilers production costs, leading to an increasing number of studies on alternative dietary products that benefit bird performance and lower production costs. Since the 1950s, antimicrobial additives are the most frequently used performance enhancers in animal production and their positive results are observed even in high-challenge conditions. Since the 1990s, due to the ban of the use of some antibiotics as growth promoters and the growing trend of the public to consume natural products, plant extracts have been researched as alternatives to antibiotic growth promoters. The first study that evaluated the antibacterial activities of plant extracts was carried out in 1881; however, they started to be used as flavor enhancers only during the next decades. With the emergence of antibiotics in the 1950s, the use of plant extracts as antimicrobial agents almost disappeared. There are several studies in literature assessing the use of plant extracts, individually or in combination, as antimicrobials, antioxidants, or digestibility enhancers in animal feeds. Research results on the factors affecting their action, such as plant variety, harvest time, processing, extraction, as well as the technology employed to manufacture the commercial product and dietary inclusion levels show controversial results, warranting the need of further research and standardization for the effective use of plant extracts as performance enhancers, when added to animal feeds. This article aims at presenting plant extracts as alternatives to antibiotics, explaining their main modes of action as performance enhancers in broiler production.

Two experiments were carried out to assess the efficacy of plant extracts as alternatives for antimicrobial growth promoters in broiler diets. The performance experiment included 1,200 male broilers raised from 1 to 42 days of age. The metabolism experiment used 96 male broilers in the grower phase housed in metabolic cages for total excreta collection. At the end of the metabolism experiment, 24 birds were sacrificed to assess organ morphometrics. In both experiments, the following treatments were applied: control diet (CD); CD + 10 ppm avilamycin; CD + 1000 ppm oregano extract; CD + 1000 ppm clove extract; CD + 1000 ppm cinnamon extract; and CD + 1000 ppm red pepper extract. The microencapsulated extracts contained 20% of essential oil. No significant differences (P>0.05) in the studied performance parameters were observed among treatments. The dietary supplementation of the extracts did not influence (P>0.05) nitrogen-corrected apparent metabolizable energy values. In general, organ morphometrics was not affected by the experimental treatments, but birds fed the control diet had higher liver relative weight (P<0.05) as compared to those fed the diet containing red pepper extract, which presented the lowest liver relative weight. These results showed that there was no effect of the tested plant extracts on live performance or in organ morphometrics.

Two experiments were conducted to evaluate the effects of dietary oxidized poultry offal fat on the performance of broilers and on the oxidative stability of dark chicken meat. One hundred and sixty male chicks were fed a corn-soybean meal diet containing 4% fresh or oxidized poultry fat from 10 to 47 days of age. Fresh fat was stored frozen until diets were produced, and oxidized fat was obtained by electrical heating (110 to 120 ºC). Birds were slaughtered at 47 days of age, and carcass characteristics were measured. Skinless and deboned thigh meat was stored chilled during 12 days, and samples were periodically collected to assess their quality and oxidative stability. Dietary oxidized fat did not affect bird performance or carcass characteristics. During chilled storage, meat color (L*, a* and b*) was not affected by dietary treatments; however, TBARS (Thiobarbituric Acid Reactive Substances) values were higher (P<0.05) in thigh meat from chickens fed the oxidized fat, indicating that oxidative stability was adversely affected.

There are some evidences described in the literature showing reduced energy metabolizability of ingredients for newly hatched chicks. Hence, a metabolism trial was carried out with the objective of determining the metabolizable energy of corn grain, soybean meal and micronized full fat soybean for newly hatched chicks. The method of total excreta collection was used in an experiment with 192 male chicks from one to seven days, distributed in a completely randomized design with four treatments and four replicates of twelve birds. Excreta were collected from four to seven days of age. The treatments included a reference diet, two test-diets consisting of 60% of the reference diet and 40% of the test ingredients: corn grain (CG) and soybean meal (SM), and one test-diet consisting of 80% of the reference diet and 20% of micronized full fat soybean (MFFS). The N-corrected apparent metabolizable energy (AMEn) and the metabolizability coefficient of gross energy (MCGE) of the ingredients determined for the chicks were respectively 3,213 kcal/kg and 81.6% for CG; 2,085 kcal/kg and 49.7% for SM and 4,068 kcal/kg and 74.8% for MFFS.

This study was conducted to determine the effect of microbial or antimicrobial additives on the performance and organ morphology of broilers raised in batteries or in floor pens. The effect of microbial additives on the presence of oocysts in the litter was also studied. Experiments 1 and 2 consisted of four treatments (non-supplemented control diet or diet supplemented with avilamycin, bacitracin methylene disalicylate or enramycin) and six repetitions in a randomized block design. In Experiment 1, 288 day-old chicks were housed in heated batteries in a environmentally controlled room, 12 chicks per cage; in Experiment 2, 1,200 day-old chicks were housed in a curtain-sided experimental house, with concrete floor and rice hulls as litter material, 50 chicks per pen. Experiments 3 and 4 were carried out similarly to Experiments 1 and 2, respectively, but the treatments consisted of microbial additives (non-supplemented control diet or Bacillus subtilis added to the feed plus Lactobacillus reuteri and Lactobacillus johnsonii added to the water, undefined microflora added to the water or live yeast added to the feed). The antibiotics did not affect the performance of birds raised in batteries, but improved feed conversion, weight gain and live weight when chickens were kept on the floor pens. Microbial additives did not affect bird performance in any environment; however, treatments affected liver weight. Microbial agents increased intestinal weight in floor-raised broilers. No relationship was seen between the use of microbial additives and the presence of oocysts in the litter.

Foi realizado um experimento objetivando avaliar os efeitos de promotores de crescimento sobre o desempenho e a temperatura corporal de frangos de corte, no período de 1 a 42 dias de idade. Os tratamentos consistiram de uma ração basal não suplementada (Controle), ou suplementada com 200 mg de Cu/kg de sulfato cúprico pentahidratado (Sulfato), 75 mg de Cu/kg de citrato cúprico anidro (Citrato), 20 mg/kg de virginiamicina (VM), ou a associação Citrato + VM, em um experimento em blocos casualizados com seis repetições de 40 aves, criadas sobre cama reutilizada. Não se observou efeito de tratamentos na fase inicial. Na fase final os tratamentos não afetaram o consumo de ração e o ganho de peso, enquanto a conversão alimentar foi melhor para o VM comparado ao Controle. No período total não houve efeito de tratamentos sobre peso vivo, consumo, ganho de peso e conversão alimentar. No período final e total o Sulfato resultou em menor viabilidade das aves comparado ao Citrato, VM e Citrato + VM. Não foi verificado efeito sinérgico quando se usou VM + Citrato. Os tratamentos não influenciaram a temperatura retal das aves consistentemente. O citrato cúprico não revelou ser mais eficiente que o sulfato cúprico.

An experiment was carried out to evaluate the effects of growth promoters on the performance and body temperature of broiler chickens 1 to 42 days of age. The treatments were a basal diet unsupplemented (Control), or supplemented of 200 mg Cu/kg as copper sulfate pentahydrate (Sulfate), 75 mg Cu/kg as anhydrous copper citrate (Citrate), 20 mg/kg of virginiamycin (VM), or the combination Citrate + VM. The experiment in floor pens with reutilized litter was in randomized blocks and six replicates of 40 birds. There were no treatment effects in the initial period. Treatments did not affect feed intake and weight gain in the final period; VM resulted improved feed conversion compared to Control. In the overall period, liveweight, weight gain, feed intake and feed conversion were not affected by treatments. In the final and overall periods the viability of Sulfate birds was lower than Citrate, VM and Citrate + VM. No synergistic effect was found when VM + Citrate was fed. Rectal temperatures were not consistently affected by treatments. Cupric citrate was not more efficient than copper sulfate.

O experimento avaliou o desempenho de frangos de corte suplementados em 4% na ração com três fontes de gordura: óleo ácido de soja (OAS4) e sebo bovino (SEBO4), óleo de soja (SOJA4) e misturas de 2% entre estas: (OAS2/SEBO2), (OAS2/SOJA2) e (SOJA2/SEBO2). Foram utilizados blocos casualizados, com 6 tratamentos, 6 repetições e 40 aves por parcela. Foram avaliadas as variáveis: consumo de ração (CR), ganho de peso (GP), peso vivo (PV), conversão alimentar (CA), fator de produção (FP) e viabilidade (VB), aos 42 dias de idade. Para análise, foram utilizados contrastes não ortogonais: 1- SOJA4 X (OAS4 + SEBO4 + OAS2/SEBO2); 2- SOJA4 X (OAS2/SOJA2 + SOJA2/SEBO2); 3- OAS2/SOJA2 X SOJA2/SEBO2; 4- OAS4 X OAS2/SOJA2; 5- OAS4 X OAS2/SEBO2. No contraste 1, observou-se um menor CR, melhor CA, superior GP, PV e FP para SOJA4 em relação a média OAS4, SEBO4 e OAS2/SEBO2. A comparação do SOJA4 com (OAS2/SOJA2 + SOJA2/SEBO2) do contraste 2 não foi significativa. O contraste 3 não indicou diferença entre OAS2/SOJA2 e SOJA2/SEBO2, exceto para VB. No contraste 4, OAS2/SOJA2 resultou em maior GP, PV e FP e melhor CA que OAS4. A mistura (OAS2/SEBO2) não foi vantajosa ao OAS4 para as variáveis (contraste 5). A gordura abdominal não foi afetada pelos tratamentos, somente a composição dos ácidos graxos das gorduras. O óleo de soja proporcionou melhor desempenho das aves, tanto em misturas 1:1 quanto como fonte única adicionada à ração. O óleo ácido de soja, o sebo e a mistura destes resultaram em depressão do desempenho das aves.

The objective of this research was to evaluate less expensive fat sources as alternatives to soybean oil in broiler diets. A total of 1,440 day-old male Ross chicks were raised to 42 days of age in a randomized block design of six treatments and six replicates, fed diets containing 4% supplemental fat from the sources: soybean oil (SOY4), beef tallow (TAL4), acidulated soapstock (SOAP4), mixtures 2%:2% (SOAP2/TAL2), (SOAP2/SOY2) and (SOY2/TAL2). Liveweight, weight gain, feed intake, feed:gain ratio and viability were analyzed using non-orthogonal contrasts: 1- SOY4 X (SOAP4 + TAL4 + SOAP2/TAL2); 2- SOY4 X (SOAP2/SOY2 + SOY2/TAL2); 3- SOAP2/SOY2 X SOY2/TAL2; 4- SOAP4 X SOAP2/SOY2; 5- SOAP4 X SOAP2/TAL2. Liveweight, weight gain and feed:gain of SOY4 were better (p<.05) than those devoid of soybean oil in the diet, but feed intake, and viability did not differ. The mixtures containing 2% soybean oil (contrast 2) resulted in performance similar to SOY4 in all variables (p>.05) and soybean oil in the mixture equally improved the results of the alternative sources (contrast 3). The performance of birds fed SOAP4 was inferior to those fed SOAP2/SOY2 (p<.06) but was similar to those fed SOAP2/TAL2 . The abdominal fat did not differ among the treatments, but abdominal fats reflected the composition of the different fats. These results confirmed the superiority of soybean oil relative to the other fat sources fed to broiler and demonstrated that the quality of acidulated soapstock and beef tallow may be improved when used in 1:1 mixtures with soybean oil.

Este estudo foi desenvolvido com a finalidade monitorar a qualidade da farinha de carne e ossos (FCO), durante o armazenamento prolongado (10 semanas), e avaliar os efeitos da adição do BHT (500mg/kg) a esta farinha. Um lote fresco de FCO (41,12% PB e 9,14% EE) foi dividido em seis partes iguais, sendo uma não tratada (CONTROLE) e as demais tratadas com BHT em diferentes tempos de armazenamento (nos dias 0, 7, 14, 21 e 28: BHT/0, BHT/7, BHT/14, BHT/21 e BHT/28, respectivamente). As FCO foram armazenadas em ambiente diariamente monitorado e sua qualidade foi avaliada por amostragens semanais, com determinação do índice de peróxidos, cujo nível máximo obtido foi de aproximadamente 80meq/kg (CONTROLE). A partir da 4ª semana de armazenamento, foi conduzido um experimento com frangos de corte alimentados por 42 dias com rações à base de milho e farelo de soja, contendo cerca de 4% das FCO armazenadas. Foram utilizados 1.440 pintos de um dia, machos, distribuídos num delineamento em blocos casualizados, com 6 tratamentos e 6 repetições. Os resultados médios obtidos para peso vivo, ganho de peso, consumo de ração, conversão alimentar, mortalidade e refugagem e fator de produção foram submetidos à análise da variância e as médias dos tratamentos foram comparadas ao CONTROLE através do teste de Dunnett. As variáveis estudadas, em geral, não foram afetadas pelos tratamentos (p>0,05), indicando que, neste estudo, o uso da FCO oxidada ou das FCO protegidas pelo BHT, não influenciaram o desempenho das aves.

The objectives of this study were to assess the variation in quality of meat and bone meal (MBM) during an extended storage period (10 weeks) and evaluate the effects of the antioxidant BHT on the oxidative stability of MBM and the performance of broilers fed diets containing these MBM. A freshly produced batch of MBM (41,12% protein and 9,12% fat) was divided in six portions. One portion was stored with no BHT added (CONTROL) and the others were treated with 500mg BHT/kg at day 0 (BHT/0), 7 (BHT/7), 14 (BHT/14), 21 (BHT/21) and 28 (BHT/28). The quality of MBM was measured through weekly samplings and the peroxide value (IP) was the main parameter analysed. After four weeks of storage, a feed trial was carried out using 1,440 male RossXRoss day-old chicks raised in floor pens in an experiment with six treatments and six replicates. The birds were fed ad libitum corn-soybean diets formulated to contain 4% MBM. Results of 42d liveweight, feed intake, feed:gain ratio and mortality and culling were submitted to analysis of variance. Treatment means were compared to CONTROL using Dunnett’s test. Although rancidity was observed in MBM during storage, the levels of IP found (maximum 80meq/kg) did not affect bird performance. In general, the performance of broilers was not affected (p>.05) by feeding MBM oxidized or preserved with BHT.