21 research outputs found
Nitrogen fertilization time affects the root reserves of tropical grasses
Grass regrowth can reduce root mass, delaying reestablishment and grazing periods by reducing the nutrient absorption from the soil by plants. This study aimed to determine the optimal intervals for harvest and nitrogen fertilization in Urochloa brizantha cv. BRS Piatã and Megathyrsus maximuscv. BRS Quênia, as well as to investigate whether the flexibility of the fertilization time is related to the accumulation of water-soluble carbohydrates (WSC) and nitrogen in the roots. The experiment was conducted in a greenhouse, using a completely randomized design, with five treatments (nitrogen fertilization after harvest: 0, 2, 4, 6 and 8 days) and ten replicates. The nitrogen fertilization time linearly reduced the forage and root mass for the BRS Piatã, but had no effect on the BRS Quênia guinea grass. For the BRS Piatã, the WSC and starch concentrations in the roots showed a quadratic response, decreasing from harvest to day 2 and increasing until the day 8. However, the delayed fertilization led to a linear reduction in the root nitrogen content. The nitrogen fertilization time had a quadratic effect on the WSC concentration for the BRS Quênia roots. For the BRS Piatã, the nitrogen fertilization immediately after harvest improves the forage and root masses, WSC and nitrogen reserves. In contrast, the BRS Quênia exhibited a greater flexibility, concerning the nitrogen fertilization time. The interval between harvest and nitrogen fertilization is primarily depended on root mass, which influences the nitrogen accumulation in the roots
EFEITO DA FORMA FÍSICA DA RAÇÃO SOBRE O DESEMPENHO DE FRANGOS DE CORTE
Um experimento foi conduzido com o objetivo de avaliar o efeito de diferentes formas físicasde rações sobre o desempenho de frangos de corte, lote misto, nas fases pré-inicial (1 a 7 dias deidade), inicial (8 a 21 dias de idade), de crescimento (22 a 42 dias de idade), final (43 a 49 diasde idade) e período total (1 a 49 dias de idade). Foram distribuidos 2.880 frangos de corte emum delineamento inteiramente casualizado, com oito tratamentos e seis repetições, totalizando48 parcelas. Os tratamentos utilizados foram: ração farelada; ração expandida - triturada; raçãoexpandida - peletizada - triturada; ração expandida e 50% peletizada; ração expandida e 60%peletizada; ração expandida e 70% peletizada; ração expandida e 80% peletizada; e, ração expandidae 90% peletizada. Os dados obtidos foram submetidos à análise de variância pelo programaSAS ® e as médias comparadas pelo teste Student-Newman-Keuls em um nível de 5% de probabilidade.De acordo com os resultados, recomenda-se para as fases pré-inicial, inicial e final autilização de ração farelada e, para a fase de crescimento, recomenda-se o uso de ração expandidae peletizada (a partir de 60%) para lotes de frangos de corte mistos.Palavras-chave: Ração expandida. Ração farelada. Ração peletizada. Ração triturada
Tolerância de híbridos de braquiária ao estresse hídrico
O conhecimento sobre a tolerância ao estresse hídrico é importante para escolher adequadamente o capim conforme às diversas condições edafoclimáticas. Diante disso, o objetivo com esta pesquisa foi verificar a tolerância de híbridos de Brachiaria spp. ao estresse por déficit hídrico e alagamento. O experimento ocorreu em casa de vegetação, em delineamento experimental inteiramente casualizado, com doze tratamentos, em esquema fatorial 4x3, e três repetições. Os tratamentos adotados foram quatro capins, sendo três híbridos de braquiária (Camello, Cayana, Cayman) e B. humidicola cv. Llanero, que foram submetidos a três condições hídricas (déficit hídrico, sem estresse hídrico e alagamento). As gramíneas foram submetidas ao estresse hídrico por 47 dias e neste período foram realizadas duas avaliações. Para todos os capins, o déficit hídrico acarretou redução no número de perfilhos e o déficit hídrico e o alagamento promoveram redução no número de folhas, com maior impacto para o déficit hídrico. O alagamento não comprometeu a massa de forragem da Brachiaria humidicola cv. Llanero, o que demonstrou a tolerância deste capim a este estresse hídrico. Para todos os híbridos, houve a redução da produção de massa de forragem quando submetidos ao estresse hídrico (déficit e alagamento). O deficit hídrico promoveu menor massa de forragem que o alagamento para todos os híbridos estudados, com exceção do Cayana, que foi afetado de modo igual pelo déficit hídrico e alagamento. O déficit hídrico reduziu a massa de raízes de todos os capins, enquanto o alagamento reduziu a massa de raízes dos capins Camello e Cayana. Observou-se que a Brachiaria humidicola cv. Llanero e o capim Cayman apresentam maior tolerância ao alagamento, visto que nesta condição não houve redução na massa de raízes. Por isso, nenhum dos híbridos tem tolerância ao déficit hídrico e o Cayman é o híbrido com maior tolerância ao alagamento
Biogas production: litter from broilers receiving direct-fed microbials and an enzyme blend
Lisina e metionina+cistina digestíveis sobre o desempenho, rendimento, qualidade e morfometria do músculo peitoral (Pectoralis major) de frangos de corte
Two experiments were conducted to evaluate different levels of digestible lysine and methionine+cystine on growth performance, carcass yield, morfphometry of breast fillet and muscle fibers and meat quality of pectoral muscle (Pectoralis major) of broilers at 1 to 21 (first experiment) and 22 to 42 (second experiment) days of age. A total of 4,800 one-day-old male Cobb® 500 chicks were used, distributed in a completely randomized design with ten treatments (factorial arrangement 2x5) and eight replicates of 30 birds each. Treatments had two digestible lysine levels (experiment 1: 1.253 and 1.378%; experiment 2: 1.100 and 1.210%) x five digestible methionine+cystine levels (experiment 1: 0.812, 0.857, 0.902, 0.947 and 0.992%; experiment 2: 0.724; 0.764; 0.804; 0.844; 0.884%). For the experiment conducted during initial phase, it is concluded that the use of different levels of digestible lysine and methionine+cystine in diet had influenced on meat quality and morphology of Pectoralis major muscle fibers. Regarding the performance and carcass yield, lower levels of digestible lysine (1.253%) and methionine+cystine (0.812%) achieved bird's requirements at 1 to 21 days old. For the experiment conducted during the growth phase, it is concluded that different digestible lysine and methionine+cystine levels had influenced the morphology of Pectoralis major muscle fibers. Regarding the performance, meat quality and carcass yield, lower digestible lysine (1.100%) and methionine+cystine (0.724%) levels achieved bird's requirements. However, for better thighs and drumsticks ...Foram conduzidos dois experimentos, um durante a fase inicial (1 a 21 dias de idade) e um durante a fase de crescimento (22 a 42 dias de idade), com o objetivo de avaliar o efeito de diferentes níveis de lisina e de metionina+cistina digestíveis sobre o desempenho zootécnico, rendimento de carcaça e suas partes, biometria do filé de peito, morfometria das fibras musculares e qualidade do músculo Pectoralis major de frangos de corte. Utilizou-se um total de 4800 pintos machos de um dia de idade, da linhagem Cobb® 500, em um delineamento inteiramente casualizado em esquema fatorial 2x5, com oito repetições de 30 aves cada, para cada experimento. Os tratamentos consistiram de 2 níveis de lisina digestível (fase inicial: 1,253 e 1,378%; fase de crescimento: 1,100 e 1,210%) x 5 níveis de metionina+cistina digestíveis (fase inicial: 0,812; 0,857; 0,902; 0,947; 0,992%; fase de crescimento: 0,724; 0,764; 0,804; 0,844; 0,884%). Para o experimento conduzido durante a fase inicial, conclui-se que, a utilização de diferentes níveis de lisina e metionina+cistina digestíveis na dieta influenciou os resultados de qualidade e morfometria de fibras do músculo Pectoralis major. Com relação ao desempenho e rendimento de carcaça, os menores níveis de lisina (1,253%) e metionina+cistina (0,812%) digestíveis atenderam as exigências das aves de 1 a 21 dias de idade. No experimento conduzido durante a fase de crescimento conclui-se que diferentes níveis de lisina e metionina+cistina influenciam a morfometria das fibras do músculo Pectoralis major. Com relação ao desempenho, qualidade e rendimento de carcaça, os menores níveis utilizados de lisina (1,100%) e metionina+cistina (0,724%) digestíveis atenderam as exigências das aves, entretanto para o rendimento de coxa e sobrecoxa o nível de 1,210% de lisina digestível promoveu o melhor resultado em frangos de corte aos 42 dias de idad
Analyzing the importance of attributes for Brazilian consumers to replace conventional beef with cultured meat.
Cultured meat has been proposed as an alternative source of protein to overcome the environmental and ethical problems associated with conventional meat production. However, the lack of consumers' acceptance could be a major barrier to the introduction of cultured meat on a large scale. Despite Brazil being one of the countries that consumes the most meat per capita, little is known about Brazilian consumers' preferences for alternative meat. The objective of this study is to identify which attributes influence consumers to possibly replace conventional beef meat with cultured meat in Brazil. An online survey was conducted, and Best-worst scaling methodology was applied to a sample of 225 consumers. The sampling leaned towards educated and employed residents of the southeast region of Brazil, which might not fully represent the Brazilian population. Despite limitations in terms of the sampling demographic, overall, Brazilians appear to be willing to consume cultured meat: 80.9% of the sample would be willing to try it, 61.3% would be willing to eat it regularly, and 56.9% would be willing to eat cultured meat as a replacement for conventionally produced beef. Despite the focus of this study being on attributes of a hypothetical product that is not commercially available, which might pose difficulty to consumers to predict their future consumption behavior, results show that the most important attributes influencing consumers to possibly replace conventional beef meat by cultured meat in Brazil are anticipated risk of zoonotic diseases, anticipated healthiness and anticipated food safety conditions. Attributes related to benefits at a global societal level and intrinsic characteristics of cultured meat were less important
Impact of objective knowledge and self-assessed knowledge on the population’s attitudes towards the Brazilian agribusiness
In Brazil, positive and negative information is spread about agribusiness. In this context of positive and negative information, the population forms its attitudes towards Brazilian agribusiness. Attitudes are related to objective knowledge, that is, accurate scientific information or consolidated data the individual has in his/her memory, and self-assessed knowledge, that is, what the individual thinks she or he knows. The objective was to identify the impacts of objective knowledge and self-assessed knowledge about Brazilian agribusiness on the population’s attitudes. Data were collected through the application of questionnaire to a sample of 468 participants. Data were analyzed using descriptive statistics, and an ordinal logistic regression model. The results show that the greater the objective knowledge and the greater the self-assessed knowledge, the greater the probability of an individual having a more positive attitudes towards Brazilian agribusiness. The results also show that the further to the right on the political spectrum the individual declared himself/herself, the greater the probability of showing more positive attitudes towards the Brazilian agribusiness
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Impact of objective knowledge and self-assessed knowledge on the population’s attitudes towards the Brazilian agribusiness
In Brazil, positive and negative information is spread about agribusiness. In this context of positive and negative information, the population forms its attitudes towards Brazilian agribusiness. Attitudes are related to objective knowledge, that is, accurate scientific information or consolidated data the individual has in his/her memory, and self-assessed knowledge, that is, what the individual thinks she or he knows. The objective was to identify the impacts of objective knowledge and self-assessed knowledge about Brazilian agribusiness on the population’s attitudes. Data were collected through the application of questionnaire to a sample of 468 participants. Data were analyzed using descriptive statistics, and an ordinal logistic regression model. The results show that the greater the objective knowledge and the greater the self-assessed knowledge, the greater the probability of an individual having a more positive attitudes towards Brazilian agribusiness. The results also show that the further to the right on the political spectrum the individual declared himself/herself, the greater the probability of showing more positive attitudes towards the Brazilian agribusiness