Effect of arginine, glycine + serine concentrations, and guanidinoacetic acid supplementation in vegetable-based diets for chickens.

The study investigated guanidinoacetic acid (GAA) supplementation with varying dietary digestible arginine (Arg) and glycine+serine (Gly+Ser) concentrations in the starter phase, exploring respective carry-over effects on growth performance, blood chemistry, incidence of pectoral myopathies and proximate composition in broilers. A total of 2,800 one-day-old male broiler chicks were distributed in a central composite design with 2 factors and double experimental mesh, represented by supplementation or omission of 0.6 g per kg of GAA, with a central point represented by 107% of Arg and 147% of Gly+Ser, 4 factorial points (combinations of Arg/Gly+Ser concentrations: 96.4/132.5%; 117.6/132.5%; 96.4/161.5%, and 117.6/132.5%), and 4 axial points (combinations of axial points estimated for Arg and Gly+Ser, with the central points of 92/147%; 122/147%; 107/126.5, and 107/167.5%), totaling 18 treatments, 4 repetitions to factorial and axial points, 24 replicates to the central point, and 25 birds per pen. Feed conversion ratio (FCR) from d 1 to 10 had a linear response (P = 0.009) for the decreasing Arg content and a quadratic response (P = 0.047) for Gly+Ser concentrations. Broilers supplemented GAA had lower FCR compared with nonsupplemented groups from d 1 to 10 (P = 0.048) and d 1 to 42 (P = 0.026). Aspartate aminotransferase (AST) exhibited increasing and decreasing linear effects as a function of Arg (P = 0.008) and Gly+Ser (P = 0.020) concentrations, respectively. Guanidinoacetic acid decreased serum AST (P = 0.028). Guanidinoacetic acid reduced moderate + severe (P = 0.039) and mild (P = 0.015) Wooden Breast scores. The occurrence of normal White Striping increased (P = 0.002), while severe score was reduced (P = 0.029) with GAA supplementation. In conclusion, increased digestible Arg:Lys and 14% and 6% above the recommendations (107% and 147%), respectively, provided improved FCR during the starter phase. Dietary GAA supplementation (0.6 g per kg) improved FCR, reduced severity of breast myopathies and appears to have reduced muscle damage in broilers fed plant-based diets.

Alternative to antimicrobial growth promoters in the diets of broilers challenged with subclinical necrotic enteritis.

Necrotic enteritis (NE) is a disease of worldwide distribution, which affects young broilers and causes economic losses on a scale of 6 billion dollars per year. For decades, NE was controlled in poultry flocks by dietary administration of low doses of antimicrobial growth promoters (AGPs). However, an increase in NE incidence was noted after the AGP ban. This study aimed to compare the effect of an antibiotic (Enramycin) diet to a combination of sodium butyrate, hydrolyzed yeast, and zinc proteinate (ViligenTM) on broiler diets regarding performance, blood parameters, intestinal permeability, morphology and lesions, and carcass yield of broilers challenged with Eimeria spp. and Clostridium perfringens to simulate subclinical necrotic enteritis. A total of 1,150 one-day-old male broiler chickens with an initial average weight of 43.9 ± 0.65 g were allocated to 50 experimental pens. Animals were divided into 5 groups: Negative control (NC) without additives; Positive control (PC) with 0.12 g/ton of Enramycin (8%); V500, V1000, and V1500 with the addition of 500, 1.000, and 1.500 g/ton of Viligen, respectively. All animals were challenged by Eimeria spp. at 7 d of age and by C. perfringens at 17, 18, and 19 d for induction of subclinical NE. The broilers fed with all concentrations of Viligen showed similar performance, blood parameters, intestinal permeability, and carcass yield compared to PC broilers. However, NC broilers showed higher FCR compared to PC broilers from 1 to 33 d (1.42 vs. 1.39) (P = 0.048) and from 1 to 42 d (1.51 vs. 1.49) (P < 0.001). V1500 broilers had fewer intestinal lesions at 28 d when compared to the PC treatment (P < 0.05) and showed that higher Viligen inclusion resulted in lower intestinal damage. At 21 d, the V500 group showed higher intestinal morphology characteristics (VH:VD 4.9 vs. 3.5) compared to the PC treatment (P < 0.001). Thus, in this study, the dietary addition of Viligen to broilers challenged by an experimental model of subclinical NE resulted in lower intestinal damage and similar performance to that obtained by the addition of Enramycin.

Effects of feeding diets with zinc-l-selenomethionine on growth performance of broilers subjected to cyclic heat stress.

Limited information exists on the use of zinc-l-selenomethionine (Zn-L-SeMet) in broiler diets and its effects on the growth performance, body temperature, mortality rates, blood profile, and gene expression, especially when animals are reared under cyclic heat stress conditions. This study aimed to investigate the impact of Zn-L-SeMet in broiler diets from 1 to 42 days of age reared under cyclic heat stress and its effects on growth performance, cloacal temperatures, mortality rate, blood parameters, and insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR) gene expression in the breast muscle. A total of 1000 male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg/kg of Zn-L-SeMet. Each treatment consisted of 10 replicates with 20 birds each. No statistically significant differences in growth performance were observed from 1 to 21 days of age (P > 0.05). However, from 1 to 42 days, feed intake (FI) and feed conversion ratio (FCR) decreased linearly (P < 0.05). Cloacal temperatures showed no significant effects (P > 0.05), while overall mortality rate exhibited a quadratic response (P < 0.05), with the optimal inclusion level predicted to reduce broiler mortality at 0.71 mg/kg. Triglyceride (TRG) levels increased with 0.97 mg/kg (P < 0.05), and gama-glutamil transferase (GGT) levels decreased with the inclusion of 1.19 mg/kg (P < 0.05). No significant effects on IGF-1 and GHR gene expression were found (P > 0.05). In conclusion, the inclusion of 1.30 mg/kg of Zn-L-SeMet in diets of heat-stressed broilers improved growth performance from 1 to 42 days of age. An inclusion of 0.71 mg/kg reduced mortality rate, while 0.97 mg and 1.19 mg increased and reduced TRG and GGT levels, respectively.

Zeolite and corn with different compositions in broiler chickens feeding.

The objective of this work was to evaluate the behavior of zeolite against different types of corn in broiler chickens' diets. 1,200 male broiler chickens were assigned to 6 diets in a completely randomized design and a 2 × 3 factorial arrangement, consisting of 2 types of corn (higher or lower mycotoxin contamination) and the inclusion of zeolite (0; 5,000 and 10,000 g ton-1). In the period from d 1 to 21, there was an interaction (P = 0.0040) between types of corn and the inclusion of zeolite for feed conversion ratio (FCR). In the phase from 1 to 42 d, there was an interaction (P = 0.0322) on the serum levels of creatinine (CREA) and digestible gross energy (dGE); corn with lower mycotoxin level contamination (LMLC), caused a reduction in body weight gain (BWG) (P = 0.0046) and increase in the relative weight of abdominal fat (P = 0.0256). Inclusion rates of zeolite promoted an increase in the digestible CP (P = 0.0477) and digestible ash (P < 0.0001), as well as an increase (P < 0.0001) in hot carcass yield (P = 0.0433). The results indicate that the inclusion of zeolite, in the amounts used, did not alter the performance, serum levels, intestinal development and litter quality of the birds at 42 d of age. However, it was responsible for the improvement in the percentage of digestible nutrients (CP, GE, and MM).

Influence of dietary corn distillers' dried grains with solubles on nutrient digestibility, growth performance, and carcass traits in rabbits.

Two experiments were performed to evaluate the digestibility and growth performance of New Zealand White rabbits fed corn distillers' dried grains with solubles (DDGS). For the digestibility trial, 20 rabbits were housed in metabolic cages. The animals were distributed in two treatments, T1 (control diet without inclusion of DDGS) and T2 (control diet + 300 g kg-1 DDGS). For the growth performance trial, 100 rabbits (50 males and 50 females) were assigned in a factorial design 2 × 5 (2 gender × 5 inclusions of DDGS) and five replicates. The treatments were composed of diets with inclusions of 0, 60, 120, 180, and 240 g kg-1 of DDGS. The rabbits were housed at 35 days old, and the experiment lasted 35 days. The DDGS showed high digestibility for protein (74.10%) and lipids (81.51%) and a high content of digestible energy (2979 kcal kg-1). In the second trial, growth performance and carcass yield and organ relative weights were evaluated. There were no interactions between gender and DDGS inclusions (P > 0.05). A linear decrease was observed for feed intake (FI) for the period from days 35 to 50 (FI, P = 0.001) and FI and FCR from days 35 to 70 (FI, P = 0.004; FCR, P = 0.001) with the increasing levels of DDGS. Rabbits supplemented with 240 g kg-1 had lower (P < 0.05) whole carcass yield (WCY) and carcass without head yield compared with the control rabbits. DDGS is highly digestible in rabbits, and when supplemented up to 240 g kg-1 in diets, it improved FCR but reduced FI and WCY.

Performance, metabolism, and meat quality of broilers fed dry brewery residue.

A study was conducted to assess the chemical composition and apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and their respective coefficients of dry brewery residue (DBR) for broilers. A second study was conducted to evaluate the increasing inclusions of DBR in broiler diets and its effects on growth performance, carcass traits, blood metabolites, and meat quality. In the first trial (metabolism assay), a total of 250 male broilers were assigned to 5 diets (0, 100, 200, 300, and 400 g DBR/kg) composed by 5 replications with 10 animals per cage in a completely randomized design in the period from days 11 to 21. There was an increasing linear effect for AME, AMEn, metabolizable coefficient of gross energy (MCGE), and MCGE corrected for N (MCGEn). In the second experiment, a total of 840 one-day-old male broiler chickens were assigned to 6 treatments (0, 20, 40, 60, 80, and 100 g DBR/kg) with 7 replications and 20 animals per pen, from days 0 to 42. Growth performance was determined at days 21 and 42. There was an increasing linear effect for weight gain in the period from days 0 to 21 and for feed intake from days 0 to 42. A linear decreasing effect was observed at day 21 for cholesterol and quadratic effect for uric acid (UA), aspartate aminotransferase, and albumin. At day 42, there was a quadratic effect for UA and creatinine. At day 21, an increasing linear effect was observed for protein deposition rate. In conclusion, the inclusion of DBR up to 100 g/kg improved WG in the starter phase and did not negatively affect the productive parameters of broilers from days 0 to 42.

Effects of vitamin A on carcass and meat quality of broilers.

This study evaluated the level and length of time of vitamin A supplementation and its effects on carcass and cuts yield, meat quality, and myopathies in 42-day-old broilers. A total of 1,920 birds were divided into 6 groups, and each group received a different level of vitamin A: 0; 6,000; 16,000; 26,000; 36,000 and 46,000 IU/ kg. From d 1 to 21, the treatments were distributed among 16 replicates with 20 birds. From the 22nd d on, 8 repetitions remained with the initial treatment and the others received diets with no vitamin A supplementation. Twelve birds were slaughtered per treatment to evaluate carcass and cuts yield, shear force, cooking loss, water holding capacity, and the presence of substances reactive to thiobarbituric acid. The remaining birds were slaughtered and evaluated in loco for Wooden Breast (WB) and White Striping (WS). Wings weight was affected by vitamin A levels. The duration of the vitamin A supplementation process had effects on the weight of breast, legs with a dorsal portion, and meat color in the yellow intensity (b*). Incidence of WB had higher scores in birds supplemented until 42 d of age. WS showed a quadratic response and a lower response with supplementation of 29,700 IU/ kg. Even for WS, a higher occurrence of the normal score was found in birds supplemented until 21 d of age. Minimal quadratic responses were obtained for normal, moderate, and severe scores, in supplementations of 29,301; 29,959, and 29,827 IU/ kg, respectively. WB had lower occurrence rates in birds supplemented until 21 d of age. Consequently, the severe score was more frequent when supplementation was provided until 42 d of age. The level of vitamin A and the length of time during which this supplementation was provided had influence on cuts yield, meat color and the incidence of WB and WS of the 42-day-old birds.

Daily practices, consumption and citizenship

This paper promotes a reflection on the relationship between daily practices and consumption. Understanding how conflicts, resistance and consensus are generated from daily consumption practices opens up possibilities for reflecting on the construction of sustainability in the context of diversity, one of the landmarks of the globalized world. Within this socio-cultural context, the central issue is: can consumption generate citizenship practices? The concepts of subject and agent help one think about collective action and subjectivation processes and their interferences on the collective consuming behavior. Based on empirical data from a research carried out in the municipality of Estrela in 2007, in the Taquari Valley - Rio Grande do Sul (Southern Brazil) on local reality consumption practices, it was possible to conclude that various reasoning mechanisms and values underlie the daily consumption practices. Citizenship construction, based on consumption practices, depends on the subject's reflection capacity on his/her daily practices or on what goes through the circulation of environmental information based on sociability spaces.

O artigo reflete sobre as relações entre as práticas cotidianas e o consumo. Compreender como se geram os conflitos, as resistências e os consensos a partir das práticas de consumo no cotidiano abre possibilidades para refletir sobre a construção da sustentabilidade no contexto de diversidade, uma das marcas do mundo globalizado. Neste contexto sociocultural, a questão central que surge é: o consumo pode gerar práticas de cidadania? As noções de sujeito e de agente ajudam a pensar a ação coletiva e os processos de subjetivação e suas interferências no comportamento coletivo de consumir. A partir de dados empíricos da pesquisa realizada em 2007 no município de Estrela, na região do Vale do Taquari - RS (Sul do Brasil), sobre práticas de consumo de uma realidade local, foi possível concluir que diferentes lógicas e valores permeiam as práticas cotidianas de consumo. A construção da cidadania a partir das práticas de consumo depende da reflexividade do sujeito sobre suas práticas cotidianas, o que passa pela circulação de informação ambiental com base nos espaços de sociabilidade.

Daily practices, consumption and citizenship.

This paper promotes a reflection on the relationship between daily practices and consumption. Understanding how conflicts, resistance and consensus are generated from daily consumption practices opens up possibilities for reflecting on the construction of sustainability in the context of diversity, one of the landmarks of the globalized world. Within this socio-cultural context, the central issue is: can consumption generate citizenship practices? The concepts of subject and agent help one think about collective action and subjectivation processes and their interferences on the collective consuming behavior. Based on empirical data from a research carried out in the municipality of Estrela in 2007, in the Taquari Valley - Rio Grande do Sul (Southern Brazil) on local reality consumption practices, it was possible to conclude that various reasoning mechanisms and values underlie the daily consumption practices. Citizenship construction, based on consumption practices, depends on the subject's reflection capacity on his/her daily practices or on what goes through the circulation of environmental information based on sociability spaces.