Effect of the addition of ß-mannanase on the performance, metabolizable energy, amino acid digestibility coefficients, and immune functions of broilers fed different nutritional levels.

Three experiments were conducted to evaluate the effect of ß-mannanase BM: supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels : NL : were formulated to meet the nutritional requirements of broilers : NL1 : ; reductions of 100 kcal metabolizable energy : NL2 : ; 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain : BWG : and increased (P < 0.05) feed conversion : FCR : for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance, energy values, and TIDc levels of amino acids and immune response of broilers.

Digestibilidade do cálcio de ingredientes para suínos, avaliada por meio de dois métodos / Calcium digestibility from feedstuffs for pigs evaluated using two methods

Determinaram-se os coeficientes de digestibilidade aparente e verdadeira do cálcio (Ca) de ingredientes para suínos por meio de dois métodos. Foram utilizados 60 suínos machos castrados, alojados em gaiolas de metabolismo e distribuídos em delineamento experimental inteiramente ao acaso, em arranjo fatorial 2 x 10 (métodos x tratamentos) e seis repetições por tratamento. Os tratamentos consistiram em oito alimentos, uma ração basal (0,072% de Ca total) e uma ração com baixo teor de Ca (0,018%). Os coeficientes de digestibilidade aparente e verdadeira do Ca foram avaliados utilizando-se simultaneamente dois métodos: coleta total de fezes e coleta de fezes com indicador fecal (cinza ácida insolúvel - CAI). Os coeficientes de digestibilidade verdadeira do Ca, obtidos pelo método de coleta total e pelo método de indicador fecal, foram, respectivamente: calcário calcítico 1, 84,80 e 87,33%; calcário calcítico 2, 84,19 e 86,32%; fosfato bicálcico, 79,36 e 84,55%; fosfato monobicálcico, 83,83 e 85,81%; calcário dolomítico, 85,65 e 87,39%; farinha de carne e ossos (40% PB), 70,00 e 68,64%; farinha de carne e ossos (50% PB), 66,92 e 68,03%; farinha de vísceras, 73,40 e 73,95%, lactato de Ca, 95,10 e 97,33%. Não houve diferença significativa (P>0,05) entre os métodos avaliados coleta total (80,14%) e indicador fecal (82,15%)...

The coefficients of apparent and true digestibility of calcium (Ca) of eight feedstuffs for pigs were determined. A total of 60 barrows were housed in metabolism cages and distributed in a completely randomized design in a factorial 2 X 10 (treatments X methods) and 6 replicates per treatment. Treatments consisted of eight feedstuffs, a basal diet (0.072% Ca) and a diet with low Ca content (0.018%). The coefficients of apparent and true digestibility of Ca were determined using two methods simultaneously: total fecal collection and fecal marker (Acid Insoluble Ash - AIA). The true digestibility coefficients of Ca, obtained by the total fecal collection and the fecal marker methods were respectively: Limestone 1, 84.80 and 87.33%; Limestone 2, 84.19% and 86.32; Dicalcium Phosphate, 79.36 and 84.55%; Monodicalcium Phosphate, 83.83 and 85.81%, Dolomitic Limestone, 87.39% and 85.65; Meat and Bone Meal (40% CP), 70.00 and 68,64%; Meat and Bone Meal (50% CP), 66.92% and 68.03; Poultry by Product Meal, 73.40 and 73.95%, Calcium Lactate, 95.10 and 97.33%. There was no significant difference (P>0.05) between the total fecal collection (80.14%) and fecal marker (82.15%) with the methods evaluated...

Efeito da adição de agentes tróficos na dieta de leitões desmamados sobre a estrutura e ultraestrutura do intestino delgado e sobre o desempenho / The effect of the addition of trofic agents in weaned piglet diets over the structure and ultra-structure of small intestine and over performance

Foram estudados os efeitos da glutamina, dos ácidos graxos poli-insaturados e da parede celular de levedura (PCL) sobre a estrutura e ultraestrutura do intestino delgado e o desempenho de leitões. Foram utilizados 45 leitões, desmamados aos 21 dias de idade, para testar os seguintes tratamentos: T1 - dieta basal; T2 - dieta basal + 1 por cento de glutamina; T3 - dieta basal + 0,2 por cento de PCL; T4 - dieta basal + 5 por cento de óleo de peixe. Nos dias sete e 14 pós-desmame, foram abatidos cinco leitões de cada tratamento. Os aditivos testados não alteraram a altura e a densidade dos vilos nem a profundidade das criptas do intestino delgado. Foi observado efeito de idade, mostrando redução na altura e na densidade dos vilos e na profundidade das criptas após o desmame. No duodeno e jejuno, foram observados maiores valores de relação vilo:cripta, que aumentaram com a idade pós-desmame. Ocorreram redução da altura dos microvilos do duodeno aos sete dias e aumento da largura dos microvilos do jejuno aos 14 dias pós-desmame. A área de superfície apical dos enterócitos não foi alterada pelos fatores estudados. Os aditivos estudados não foram eficientes em prevenir a atrofia da mucosa intestinal do jejuno, ao não interferir na sua ultraestrutura. Os aditivos incluídos na dieta não influenciaram o desempenho dos leitões no pós-desmame.

The effects of glutamine, poliunsatured fatty acids and cellular wall of yeast (CWY) under the structure and ultra structure of the small gut and the performance of the piglets were studied. Forty five piglets weaned at 21 days were used to test the following treatments: T1 - basal diet; T2 - basal diet + 1 percent of glutamine; T3 - basal diet + 0,2 percent of CWY; T4 - basal diet + 5 percent of fish oil. At seven and 14 post weaning days, five piglets of each treatment were slaughtered. The height, density of villus and depth of small gut crypts were not altered by the inclusion of additives. The effect of age was observed, showing a reduction in the height and density of villus and depth of crypts after weaning. In duodenum and jejunum higher values were observed in the relation villus:crypt, which increased with the post wean age. There was a decrease in the height of microvillus of the duodenum at 7 days and an increase of the width of the microvillus of jejunum at 14 days after wean. The area of the apical surface of the enterocytes was not altered by the studied factors. The studied additives were not efficient to prevent the atrophy of the intestinal mucosa of the jejunum, since they did not interfere on its ultra structure. Piglet performance was not affected by the additives included in the diet.