Resumo
Na maioria dos estudos de digestibilidade de aminoácidos em suínos usam-se animais de peso igual ou superior a 20 kg, isso se deve a menor dificuldade na implantação de cânulas íleo-cecais e a melhor recuperação pós-cirúrgica na fase do crescimento. No entanto, avaliar ingredientes com leitões mais jovens torna-se importante, visto que há limitações fisiológicas do trato gastrointestinal nesse período que podem afetar o seu desenvolvimento. Assim, 175 leitões desmamados, divididos em 7 ensaios experimentais com 25 animais cada, foram usados para determinar o balanço de nutrientes e da energia, a digestibilidade ileal aparente (AID) e estandardizada (SID) dos aminoácidos (AA) de sete ingredientes usualmente utilizados em dietas de leitões, com ou sem suplementação de multi-carboidrase (MC) e fitase (F). Os leitões foram desmamados aos 23 dias de idade e alojados em gaiolas para estudo de digestibilidade e metabolismo, permanecendo no experimento até os 45 dias de idade. Adaptação, coleta total de fezes e urina ocorreram do 10º ao 20º dia do período experimental e as amostragens do conteúdo ileal se deu ao abate, no 22º dia (45 dias de idade). Foi utilizado o delineamento experimental inteiramente casualisado com 4 tratamentos e cinco repetições. O leitão foi considerado como unidade experimental. As dietas experimentais consistiram de ingrediente teste sem enzimas e combinado a MC, F ou MC + F. Dois tipos de dieta referência foram usados como base para os cálculos do balanço nutricional e os coeficientes de digestibilidades aparente e estandardizada dos aminoácidos. Óxido de cromo (0,3%) foi usado como marcador indigestível nas avaliações dos aminoácidos. A enzima MC apresentava 10% de galactomananase, 10% de xilanase, 10% de ß-glucanase, 60% de cevada maltada e 10% de -galactosidase. A F era proveniente da fermentação de Saccharomyces cerevisiae com atividade de 10.000 FTU/g. Os ingredientes testados foram: farelo de arroz integral, soja integral micronizada, farelo de trigo, quirera de arroz, sorgo, milho e farinha de soja texturizada. Os resultados indicaram efeitos da combinação ingrediente e enzima exógena e as evidencias se deram de acordo com as características bromatológicas de cada um.
Most of the studies, involving AA digestibility in pigs are used animals with 20 kg minimal weight or higher than. This is due difficulty to implant a simple T-cannula on distal ileum of younger pigs, besides a better post-surgical recovery in growing phase. However, ingredient evaluations with young pigs become important because there are physiological limitations in gastrointestinal tract that may affect its performance. Thus, 175 weaned pigs, divided into seven experimental trials with 25 animals each, were used to determine the nutrients and energy balance, the apparent (AID) and standardized (SID) ileal digestibility of amino acids (AA) from seven ingredients usually used in pig diets, with or without multi-carbohydrase (MC) and phytase (Phy) supplementation. Weaned piglets at 23 d old were housed in cages to studies digestibility and metabolism, remaining in the experiment until 45 d of age. Pig adaptation to feces and urine collection was 10 to 20 d experimental period and ileal content sampling at slaughter at 22 d (45 d old). A completely randomized experimental design was used with 4 treatments and 5 replicates. The pig was considered as an experimental unit. The experimental diets consisted of test ingredient as the sole source of protein with or without MC, Phy or MC+Phy. Two kind of reference diet were used to calculate the nutrient balance or AID and SID of AA. Titanium dioxide (0.3%) was used as indigestible marker. The MC enzyme had: galactomannanase, 10%; xylanase, 10%; beta-glucanase, 10%; malted barley, 60% and -galactosidase, 10%. The Phy was obtained from the Saccharomyces cerevisiae fermentation with 10,000 FTU/g activity. The ingredients used were: rice bran, micronized full fat soybean meal, wheat bran, broken rice, sorghum, corn and texturized soybean meal. The results indicated effects from ingredients and enzymes combinations and the evidences occurred according to bromatological characteristics of each one.
Resumo
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.
Resumo
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.
Resumo
Existe uma série de evidências que os pintos de corte na fase pré-inicial têm seu sistema digestório ainda imaturo, implicando em menor capacidade de aproveitamento dos alimentos. Em função desse fato, ingredientes de maior digestibilidade seriam recomendados para proporcionar um desenvolvimento adequado do organismo. Com isso, o objetivo do presente trabalho foi determinar a energia metabolizável aparente corrigida pelo balanço de nitrogênio (EMAn) de ingredientes como fontes de carboidrato e proteína para frangos de corte na fase pré- inicial, bem como avaliar a utilização destes ingredientes sobre o desenvolvimento inicial de órgãos do trato gastrintestinal, desempenho e características da carcaça das aves. Os ingredientes avaliados foram: milho (MI), amido de milho (AMI), amido de mandioca (AMA), glicose (GLI), lactose (LAC) e sacarose (SAC), como fontes de carboidrato; e farelo de soja (FS), soja integral micronizada (SIM), isolado protéico de soja (IS), ovo em pó (OP), plasma sanguíneo (PS), farelo de glúten de milho (GM) e levedura seca (LS), como fontes de proteína. Para a determinação da EMAn foram desenvolvidos vários ensaios de metabolismo utilizando-se o método de coleta total de excretas. Para a avaliação do desempenho, desenvolvimento do trato gastrintestinal e características da carcaça foram conduzidos diversos experimentos, em gaiolas e em piso de galpão experimental, com a inclusão dos ingredientes nas dietas. Os valores de EMAn para a fase pré- inicial das fontes de carboidrato foram: 3.213; 3.269; 3.690; 3.427; 1.225 e 3.524 kcal/kg para MI, AMI, AMA, GLI, LAC e SAC, respectivamente. Para as fontes protéicas a EMAn foi: 2.085; 4.068; 2.110; 5.095; 3.831; 3.374 e 2.037 kcal/kg para FS, SIM, IS, OP, PS, GM e LS, respectivamente. Para as aves criadas em gaiolas pode-se dizer que o desenvolvimento do trato gastrintestinal, de maneira geral, não foi influenciado pelas diferentes fontes de carboidrato, mas o consumo de ração das aves foi aumentado pelo fornecimento de carboidrato de maior disponibilidade na dieta préinicial, contribuindo para um aumento no peso vivo das aves. As diferentes fontes de proteína afetaram o desenvolvimento dos órgãos, mas esse efeito não foi suficiente para explicar as variações no desempenho das aves. A adição de diferentes fontes de proteína e carboidrato, bem como suas misturas, em dietas pré- iniciais de frangos de corte criados sob piso de galpão experimental, promoveram alterações no desempenho e no desenvolvimento do intestino delgado das aves até o sétimo dia de idade, entretanto as diferenças de desempenho não foram mantidas nas fases subseqüentes, contribuindo para que as características da carcaça e composição da carne de perna não apresentassem diferenças no momento do abate
There are some evidences in the literature that newly hatched chicks have the digestive system still immature, what result in a small capacity to metabolize feed ingredients. So, more digestible ingredients could be recommended to allow an adequate development of the body. Herewith, the objective of this work was to determine the Ncorrected apparent metabolizable energy (EMAn) of carbohydrate and protein sources for newly hatched chicks, and to evaluate the utilization of these ingredients on the early development of gastrointestinal tract organs, performance and carcass characteristics of birds. The ingredients evaluated were: corn (MI), corn starch (AMI), cassava starch (AMA), glucose (GLI), lactose (LAC) and sucrose (SAC), as carbohydrates sources, and soybean meal (FS), micronized full fat soybean (SIM), isolated soy protein (IS), dried whole eggs (OP), blood plasma (PS), corn gluten meal (GM) and dried sugar cane yeast (LS), as protein sources. Several metabolism trials were conducted to determine the EMAn, using the total excreta collection method. To evaluate the performance, gastrointestinal tract development and carcass characteristics, experiments were conducted, in cages and floor pens, using diets containing those ingredients. The EMAn of the carbohydrate sources determined for chicks in the first week were: 3,213; 3,269; 3,690; 3,427; 1,225 and 3,524 kcal/kg for MI, AMI, AMA, GLI, LAC and SAC, respectively. The EMAn for protein sources were: 2,085; 4,068; 2,110; 5,095; 3,831; 3,374 and 2,037 kcal/kg for FS, SIM, IS, OP, PS, GM and LS, respectively. For the birds reared in cages, the results showed, in general, that the different carbohydrate sources did not affect the gastrointestinal tract development, but the feed consumption of the birds was improved by the more available carbohydrate sources in the newly hatched chicks diets, contributing to a higher liveweight of the birds. Otherwise, the different protein sources affected the gastrointestinal tract development, but these effects did not explain the changes on broiler performance. The addition of different protein and carbohydrate sources, and their mixtures, in the diets of newly hatched chicks reared in the floor pens resulted in differences on performance and on small intestine development of the birds until seven days of age, but these differences were not maintained on the following phases, contributing to a similar carcass characteristics and similar chemical composition of the whole leg meat at slaughter time