Blaptica dubia: estudo preliminar do efeito da composição das dietas no crescimento de ninfas
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2015
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Devido ao aumento da população, um dos desafios enfrentados pelo homem é assegurar recursos suficientes para o futuro. Com a escassez que se tem vindo a verificar em fontes de proteína, consequentemente os preços praticados são cada vez mais elevados. Sendo a proteína um componente de extrema importância na alimentação animal, refletiu-se na procura de novas fontes alternativas mais sustentáveis. Destacam-se assim os insetos, com facilidade reprodutiva e, considerados uma fonte com elevado valor nutricional. As baratas Blaptica dubia ganharam popularidade entre os criadores de répteis devido ao elevado valor proteico e baixo teor em gordura, a relação cálcio:fósforo e as vantagens da criação em relação ao grilo (Acheta domesticus), que é, atualmente, o inseto com maior taxa de utilização como alimento. O objetivo do estudo foi a avaliação do efeito da composição das dietas, nomeadamente do nível da proteína (20, 30 e 40%) em dietas práticas no crescimento de ninfas de Blaptica dubia, com o objetivo de determinar um nível ótimo de inclusão. Durante o ensaio, foram utilizadas três dietas experimentais (D20, D30 e D40) com níveis de proteína em cerca de 22, 33 e 42%, respectivamente. Foram formados nove grupos homogéneos de vinte ninfas com peso médio individual de 0,12 ± 0,03g e um comprimento médio de 14 ± 0,09mm, constituindo três unidades experimentais por tratamento. As dietas foram distribuídas de forma aleatória pelos nove grupos, de modo ad libitum, sendo realizada a respetiva contabilização de alimento ingerido a cada dois dias. O ensaio durou cento e vinte dias, onde foram realizadas pesagens mensais de grupo e contabilizada a mortalidade. Posteriormente, as ninfas foram abatidas e realizada a análise da sua composição corporal. Foi possível verificar no fim do ensaio que as ninfas, apesar de ingerirem maior quantidade de alimento no grupo D40, obtiveram um melhor desempenho, tanto no peso final como comprimento final, nos grupos D20 e D30, apresentando diferenças não significativas (P > 0,05) entre eles. Este facto pode ser justificado devido à uma particularidade por parte das baratas de formar ácido úrico durante a digestão de conteúdos azotados, que é acumulado na sua gordura corporal e pode posteriormente ser convertido outra vez em proteína em casos de adversidade. Este ácido, quando acumulado em grandes quantidades acaba por ser tóxico, e sendo a dieta do grupo D40 uma dieta com elevado teor em proteína, consequentemente a sua acumulação nas ninfas foi maior que nos outros grupos. Conclui-se então, que os valores ideais de proteína para o crescimento das ninfas de Blaptica dubia no nosso ensaio situaram-se entre 20 a 30%.
Due to a raise on the population, one of the challenges faced by the man is to ensure enough resources for the future. With the shortage that has been observed in protein sources, consequently the prices that have been practiced are increasingly high. Being the protein an extreme important component in the animal nutrition, this reflected on the search for new and sustainable alternatives sources. Stand out so insects, their reproductive facility and, considered a high nutritional value source. The Blaptica dubia cockroaches became popular among the reptile breeders due to their high protein value and low fat content, calcium:phosphorus relation and breeding advantages related to cricket (Acheta domesticus), which is currently the insect with the highest utilization rate as animal feed. The experimental relied on the evaluation of the differents diet compositions, namely, the protein level effect (20, 30 and 40%) in practical diets on the Blaptica dubia nymphs growing, with the goal of determine an optimal inclusion level. During the experimental, three experimental diets were used (D20, D30 and D40) with protein levels around 22, 33 and 42%, respectively. Nine homogeneous groups of twenty nymphs were formed with individual average weight 0.12 ± 0.03g and average length 14 ± 0.09mm, constituting three experimental units for treatment. The diets were randomly distributed for the nine groups, ad libitum, being made the feed intake registration each two days. The experimental took one-hundred and twenty days, with monthly group weighing and mortality accounted. Posteriorly, the nymphs were slaughtered and analyzed for body composition.At the end, it was possible to verify that the nymphs, in spite of the highest feed intake rate was from the D40 group, obtained better performance, either on the final weight as the final length, in the D20 and D30 groups, with no significant differences (P > 0,05) among them. This fact can be justified due to the cockroaches’ particularity of form uric acid during the nitrogen contents digestion, which is accumulated in their fat body and can be again converted as protein in misfortune times. This acid, when accumulated in high ammounts turns out to be toxic, and being the group D40 diet the one with high protein content, consequentlythe accumulation by the nymphs was higher than the other groups. It then concluded, the ideal protein values for Blaptica dubia nymph growing in our experimental stood between 20 to 30%.
Due to a raise on the population, one of the challenges faced by the man is to ensure enough resources for the future. With the shortage that has been observed in protein sources, consequently the prices that have been practiced are increasingly high. Being the protein an extreme important component in the animal nutrition, this reflected on the search for new and sustainable alternatives sources. Stand out so insects, their reproductive facility and, considered a high nutritional value source. The Blaptica dubia cockroaches became popular among the reptile breeders due to their high protein value and low fat content, calcium:phosphorus relation and breeding advantages related to cricket (Acheta domesticus), which is currently the insect with the highest utilization rate as animal feed. The experimental relied on the evaluation of the differents diet compositions, namely, the protein level effect (20, 30 and 40%) in practical diets on the Blaptica dubia nymphs growing, with the goal of determine an optimal inclusion level. During the experimental, three experimental diets were used (D20, D30 and D40) with protein levels around 22, 33 and 42%, respectively. Nine homogeneous groups of twenty nymphs were formed with individual average weight 0.12 ± 0.03g and average length 14 ± 0.09mm, constituting three experimental units for treatment. The diets were randomly distributed for the nine groups, ad libitum, being made the feed intake registration each two days. The experimental took one-hundred and twenty days, with monthly group weighing and mortality accounted. Posteriorly, the nymphs were slaughtered and analyzed for body composition.At the end, it was possible to verify that the nymphs, in spite of the highest feed intake rate was from the D40 group, obtained better performance, either on the final weight as the final length, in the D20 and D30 groups, with no significant differences (P > 0,05) among them. This fact can be justified due to the cockroaches’ particularity of form uric acid during the nitrogen contents digestion, which is accumulated in their fat body and can be again converted as protein in misfortune times. This acid, when accumulated in high ammounts turns out to be toxic, and being the group D40 diet the one with high protein content, consequentlythe accumulation by the nymphs was higher than the other groups. It then concluded, the ideal protein values for Blaptica dubia nymph growing in our experimental stood between 20 to 30%.
Descrição
Dissertação de Mestrado em Engenharia Zootécnica
Palavras-chave
Blattaria , Dieta , Qualidade da proteína , Ninfa , Crescimento , Composição aproximada