13 research outputs found
Resíduo de acerola em dietas para codornas
RESUMO Objetivou-se avaliar a inclusão do resíduo da acerola em dietas de codornas de corte sobre o desempenho produtivo, rendimento de carcaça, biometria intestinal e viabilidade econômica das aves, aos 42 dias de idade. Foram utilizadas 400 codornas europeias, não sexadas, de um dia de idade, distribuídas em delineamento experimental inteiramente ao acaso, com cinco níveis de inclusão (0,0; 3,0; 6,0; 9,0 e 12,0%) de resíduo da acerola, com oito repetições e 10 aves por unidade experimental. Não foram observadas diferenças significativas (P>0,05) para o ganho de peso, o consumo de ração, a conversão alimentar, os pesos absolutos e os rendimentos de carcaça e os cortes nobres (peito, coxa e sobrecoxa). Houve efeito (P0,05) influenciada pelos níveis de inclusão do resíduo de acerola. O resíduo de acerola pode ser utilizado como ingrediente alternativo nas dietas de codornas europeias, até o nível de 12% de inclusão, sem comprometer o desempenho produtivo, o rendimento de carcaça das aves e a viabilidade econômica
Potential conservation gains from improved protected area management in the Brazilian Amazon
Protected areas (PAs) are important policy instruments for forest conservation, but it is unclear if improved management can increase PA effectiveness. In Brazil, formal management plans are required to be in place shortly after the creation of a PA. This requirement is rarely enforced and, as a result, several PAs undergo many years without approved plans. We take advantage of this variation among PAs to study the impact of management plans on deforestation. We provide estimates from two quasi-experimental evaluation approaches based on the generalization of the difference-in-differences estimator: (1) matching-based methods for time-series cross-sectional data analysis and (2) the generalized synthetic control (GSC) method. We find weak, yet generally consistent, evidence across these two methods suggesting that PAs with approved management plans protect forests more effectively over time. Significant impact estimates from the matching-based approach ranged more widely than the GSC method (0.01%–0.09% versus 0.04%–0.05% of avoided deforestation per year, respectively). The effect size of these impacts is relatively substantial given that the average annual forest loss from our PA sample was 0.07% (±0.40%). To the extent that PAs with approved management plans reflect actual differences in PA management quality, our findings suggest that investments in improving PA management could result in positive conservation gains over time
Potential conservation gains from improved protected area management in the Brazilian Amazon
Protected areas (PAs) are important policy instruments for forest conservation, but it is unclear if improved management can increase PA effectiveness. In Brazil, formal management plans are required to be in place shortly after the creation of a PA. This requirement is rarely enforced and, as a result, several PAs undergo many years without approved plans. We take advantage of this variation among PAs to study the impact of management plans on deforestation. We provide estimates from two quasi-experimental evaluation approaches based on the generalization of the difference-in-differences estimator: (1) matching-based methods for time-series cross-sectional data analysis and (2) the generalized synthetic control (GSC) method. We find weak, yet generally consistent, evidence across these two methods suggesting that PAs with approved management plans protect forests more effectively over time. Significant impact estimates from the matching-based approach ranged more widely than the GSC method (0.01%–0.09% versus 0.04%–0.05% of avoided deforestation per year, respectively). The effect size of these impacts is relatively substantial given that the average annual forest loss from our PA sample was 0.07% (±0.40%). To the extent that PAs with approved management plans reflect actual differences in PA management quality, our findings suggest that investments in improving PA management could result in positive conservation gains over time
Exigências de lisina digestível para aves de corte da linhagem ISA Label criadas em semiconfinamento Digestible lysine requirements for ISA Label broilers reared in free-range system
Foram realizados três experimentos para determinar as exigências de lisina digestível para aves da linhagem ISA Label, de ambos os sexos, criadas em semiconfinamento durante as fases: inicial (1 a 28 dias), de crescimento (28 a 56 dias) e final (56 a 84 dias). Em cada experimento, foram utilizadas 480 aves, alojadas em 24 piquetes, cada um contendo abrigo coberto de 3,13m² e área de pastejo de 72,87m². O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 4x2 (níveis de lisina e sexo) com três repetições de 20 aves cada. Os níveis de lisina digestível avaliados foram: 0,850; 0,970; 1,090 e 1,210% na fase inicial; 0,750; 0,870; 0,990 e 1,110% na fase de crescimento e 0,640; 0,760; 0,880 e 1,000% na fase final. Foram mensuradas as variáveis de desempenho, característica de carcaça, deposição de proteína e gordura corporal, peso e teor de proteína das penas. Com base nos resultados de desempenho, recomendam-se 1, 041; 1,006 e 0,760% de lisina digestível em rações para aves ISA Label nas fases inicial, de crescimento e final, respectivamente.<br>Three assays were carried out to determine digestible lysine requirement for ISA Label, both genders, in free-range system on starter (1 to 28 days), growing (28 to 56 days) e finishing phases (56 to 84 days). A total of 480 birds were distributed into 24 pens, each one composed by shelter (3.13m²) and pasture (72.87m²). The experimental design was a completely randomized in factorial arrangement (four levels of lysine and two genders) with three replicates of 20 birds. The digestible lysine levels were 0.85, 0.97, 1.09, and 1.21% for starter; 0.75, 0.87, 0.99, and 1.11% for growing; and 0.64, 0.76, 0.88, and 1.00% for finishing phases. The analyzed parameters were performance, carcass yield, protein and fat deposition, weight, and protein in the feathers. Based on bird performance the estimated digestible lysine level, was 1.041, 1.006, and 0.760% for the starter, growing and finishing phases, respectively
Níveis de lisina com dois balanços eletrolíticos para frangos de corte na fase de crescimento (22 a 40 dias) Lysine level with two electrolytes balance for broiler chickens in the growing phase (22 a 40 day)
Objetivou-se avaliar os níveis de lisina para frangos de corte na fase de crescimento (22 a 40 dias de idade) utilizando-se dois balanços eletrolíticos. Foram utilizados 640 frangos de corte machos de 21 dias de idade, linhagem Cobb, distribuídos em delineamento inteiramente casualizado, em esquema fatorial 5 × 2, composto de cinco níveis de lisina (1,062, 20, 40 e 60% acima e 20% abaixo do recomendado) e dois balanços eletrolíticos (190 e 255 mEq/kg), com quatro repetições e 16 aves por unidade experimental. Não foi observada interação das variáveis estudadas, porém, os níveis de lisina influenciaram o peso final, o ganho de peso e a conversão alimentar e afetaram de forma linear o consumo de ração. Os melhores ajustes foram observados quando se utilizou o modelo descontinuo LRP, no qual valores acima de 1,089 e 1,14% de lisina não melhoraram o ganho de peso e tampouco a conversão alimentar. Entre os parâmetros sangüíneos avaliados, apenas o ácido úrico foi influenciado pelos níveis de lisina. Os rendimentos de carcaça e de cortes nobres não diferiram significativamente entre os níveis de lisina e os balanços eletrolíticos, contudo, a gordura abdominal foi influenciada pelo balanço eletrolítico da dieta. Níveis acima de 1,089 e 1,14% de lisina, respectivamente, não melhoram o desempenho das aves. Os níveis de lisina testados não influenciaram o rendimento de carcaça nem de cortes nobres.<br>The lysine levels for chickens in the growing phase (22 to 40 days of age) by using two different electrolytes balance were evaluated. Sixty-four hundred Cobb broiler male of 21 days old were allotted to a completely randomized design as a factorial arrangement of treatments, five lysine levels (1.062, 20, 40, and 60% above and 20% below of recommended levels) and two electrolytes balance (190 and 255 mEq/kg), with four replicates and 16 broilers for experimental unit. There was no interaction among the variables studied, however the lysine levels affected final weight, weight gain and the feed:gain ratio and feed intake, however, the best adjustments were observed when the discontinue LRP model was used, where values above 1.089 and 1.14% of lysine did not increase weight gain and feed:gain ratio. Concerning the blood parameters, only uric acid was affected by lysine levels, but no difference was observed for carcass and prime cuts yield, the abdominal fat was influenced by the dietary electrolyte balance. Lysine levels above 1.089 and 1.14 for weight gain and feed:gain ratio, respectively, did not impair broiler performance. The lysine levels affected neither carcass yield and nor prime cuts yield