The aim of this study was to compare performance and carcass characteristics of broilers fed diets with different Dietary Electrolyte balances (DEB) during the summer season. A total of 1,280 one-day-old Ross sexed chicks were distributed in 32 experimental units according to a randomized block design in a 4x2 factorial arrangement (4 levels and 2 sexes) and 4 replicates per treatment (40 birds per replicate). Feed program consisted of 3 phases (1-21, 22-42, 43-49 days of age). Experimental diets were formulated based on corn and soybean meal and adjusted to 210, 250, 290 and 330 mEq/kg of Na + K -Cl through the addition of sodium carbonate, potassium carbonate and ammonium chloride. Weekly measurements of body weight gain and feed intake were done, and at 49 days, birds were slaughtered to evaluate the dressing percentage and parts yield. Weight gain during the starter phase increased linearly (p<0.01) as DEB increased. Different DEB levels did not affect feed intake or mortality. Carcass characteristics were not affected by treatments. Dietary electrolytic balance influenced weight gain and feed gain ratio from 1 to 21 days, and best results were observed when diets contained 290 and 330 mEq/kg.

Two assays were conducted to evaluate nutritive value of canola meal (CM) fed to broiler chicks without or with a multi-carbohydrase (MC) preparation (700 U α-galactosidase, 2,200 U galactomannanase, 30,000 U xylanase, and 22,000 U β-glucanase per kg of diet) and phytase (Phy, 500 FTU per kg of diet). Assay 1 determined apparent total tract digestibility (ATTD) of nutrients and metabolizable energy (AME) by the difference method. Assay 2 determined apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids by the index method. Two reference diets (RD) - an 85% corn based and a 5% casein-cornstarch diet fortified with vitamins and minerals - were made for assays 1 and 2, respectively. For each assay, the test diets were made by mixing RD and CM 7:3 wt/wt basis and fed without or with MC or Phy or combination. A total of 245 day-old male broilers (Cobb 500) was allocated to 5 treatments to give 7 replicates (7 birds/cage). The birds were fed a commercial diet from day zero to 10 followed by assay 1 fed from d 11 to 18 and assay 2 fed from d 19 to 21. Excreta samples were collected on d 15 to18, and all birds were slaughtered on d 21 for ileal digesta. There was an interaction (P < 0.05) between MC and Phy on ATTD of DM, N, and P. There was no interaction (P > 0.05) between MC and Phy on AMEn; however, MC and Phy individually improved AMEn retention. Enzymes interacted (P < 0.05) on SID of Arg, His, Leu, Met, Thr, Ala, Asp, Gln, and Gly. In this context, feeding a combination of MC and Phy resulted in higher (P < 0.05) SID of Arg, His, Met, and Thr relative to single activity or control. Both enzymes improved (P < 0.05) SID of Lys independently. The combination of carbohydrase and Phy may be an effective strategy to improve amino acid utilization in CM for poultry.

RESUMO -Em dois ensaios experimentais, avaliaram-se níveis de lisina digestível (0,90; 1,00; 1,10; 1,20 e 1,40%) combinados a zinco quelado (43 e 253 ppm) para frangos de corte machos. Os períodos considerados foram: 1 a 11 dias de idade (desempenho) e 1 a 7 dias de idade (balanço de nitrogênio). O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 5 × 2. No ensaio de desempenho, utilizaram-se 7 repetições e 15 aves por unidade experimental e, no ensaio de digestibilidade, 6 repetições e 6 aves por unidade experimental. As dietas continham 2.960 de EM/kg e 21% de proteína bruta. Na fase de 1 a 11 dias de idade, não houve efeito de interação lisina digestível × zinco quelado no desempenho, mas verificou-se efeito quadrático dos níveis de lisina digestível sobre o peso final, o ganho de peso e o ganho de peso relativo e efeito linear crescente no consumo de ração. A conversão alimentar não diferiu com as variações dos níveis de lisina digestível e zinco na dieta. Nas condições de avaliação do desempenho, o nível ótimo de lisina digestível para frangos de corte machos mantidos em piso de concreto é de 1,19%. Na fase de 1 a 7 dias de idade, não houve influência da relação entre níveis de lisina digestível e zinco quelado no balanço de nitrogênio. A retenção de nitrogênio aumentou de forma linear crescente com o aumento da concentração de lisina digestível na dieta, o que está de acordo com o aumento linear do ganho de peso e da eficiência alimentar. A exigência de lisina digestível para frangos de corte machos de 1 a 7 dias de idade é igual ou superior a 1,40%.Palavras-chave: aminoácidos, deposição de nutrientes, micronutrientes, nutrição Digestible lysine and zinc chelate to male broiler: Performance in the preinitial phase and nitrogen retention ABSTRACT -Two experiments were carried out to evaluate different levels of digestible lysine (0.90; 1.00; 1.10; 1.20; e 1.40%) combined with zinc chelate (43 and 253 ppm) to male broiler. The considered periods were: initial phase -performance(1 to 11 days old) and nitrogen retention (1 to 7 days old). A randomized block experimental design in a 5 × 2 factorial arrangement was used. In performance assay, 7 replications and 15 birds per experimental unit was used. In the digestibility essay, 6 replications 6 birds for experimental unit were used. The diets contained 2.960 kcal/kg ME and 21.0% crude protein.In the initial phase, there was no digestible lysine × zinc chelate interaction on performance study, however a quadratic effect of digestible lysine on final weight, weight gain, relative weight gain and crescent linear effect in feed intake was observed.In feed: gain ratio did not differ with digestible lysine level and zinc chelate in the diet. In the performance, the better digestible lysine level for broiler raised in concrete floor is 1.19%. From 1 at 7 days old, there was no influence of the combinations of digestible lysine and zinc chelate on nitrogen balance. The nitrogen retention linearly increased as digestible lysine increased in...

Organic acids are used as feed additives to promote growth of weaned piglets since they prevent the occurrence of diarrhea. Thus, performance and digestibility assays were conducted and economic viability of diets was evaluated. In the performance assays, 64 hybrid piglets weaned with a mean weight of 5.87±0.31kg were divided in a randomized block design consisting of 4 treatments, 8 repetitions and 2 piglets per experimental unit (1 castrated male and 1 female). In the digestibility assay, 24 castrated male hybrid piglets with a mean weight of 8.21±0.79kg were individually assigned to 4 treatments and 6 repetitions. The treatments in the two assays were as follows: control, basal diet without addition of an acidifier; blend: inclusion of 0.5% of a mixture of organic acids; butyrate: inclusion of 0.1% of sodium butyrate; blend+butyrate: inclusion of 0.5% of a mixture of organic acids and 0.1% sodium butyrate. There was no effect (P>0.05) of the acidifiers on animal performance during the period studied. Organic acids exerted no effect (P>0.05) on the apparent digestibility coefficients of nutrients. Diets supplemented with sodium butyrate had an economic advantage for the period of 10-24 days. No episode of diarrhea was observed. This study demonstrated no effect of acidifier feed additives as growth promoters in complex diets for weaned piglets.Keywords: acidifiers, additives, digestibility, performance, pigs RESUMO Ácidos orgânicos são utilizados como aditivos promotores de desempenho em leitões, pois podem prevenir a ocorrência de diarreias. Para tanto, foram conduzidos ensaios de desempenho, digestibilidade, e foi avaliada a viabilidade econômica das dietas. No desempenho, foram utilizados 64 leitões híbridos desmamados, com peso médio de 5,87±0,31kg, distribuídos em um delineamento em blocos ao acaso, com quatro tratamentos, oito repetições e dois leitões por unidade experimental (sendo um macho castrado e uma fêmea

Protein sources from cereals are used in broiler diets, usually in order to reduce feeding costs. However, their efficient use in poultry diets is limited by the level of fiber whose compounds are resistant to digestion in the small intestine; due to this sugars are not digested by endogenous poultry enzymes. The aim of this study was to determine the effect of multi-carbohydrase (MC) and phytase (Phy) on the total retention of nutrients, retention of apparent metabolizable energy corrected for nitrogen (AMEN) (trial 1) and apparent and standardized ileal digestibility of amino acids (trial 2) of rice bran (RB). A total of 245-day-old male broilers (Cobb 500) was distributed at 21-day-old in a completely randomized design in a 2 × 2 + 1 (0 and 200 mg/kg MC; 0 and 50 mg/kg Phy, and basal diet – BD) factorial arrangement of treatments, to give seven replicates and seven birds per replicate. The BD based on corn (trial 1) and cornstarch and casein (trial 2) was used only to determine the coefficients of retention of nutrients and energy, and coefficients of digestibility of amino acids of the RB. The test diets were made by mixing BD and RB 7 : 3 wt/wt basis. There was interaction (P<0.05) between MC × Phy for DM, nitrogen and AMEN, retention and no interaction (P>0.05) for ash, calcium, phosphorous and NDF was observed. Enzymes interacted (P<0.05) on standardized ileal digestibility of arginine, histidine, leucine, methionine, phenylalanine, threonine, valine, aspartic acid, glutamic acid, proline and serine. Dietary combination of MC and Phy resulted in higher (P<0.05) standardized digestibility of arginine, histidine, methionine and threonine relative to single enzyme supplementation or control diet without enzymes. Enzyme isolated inclusions in the diets improved (P<0.05) standardized digestibility of methionine. The supplementation of carbohydrases and Phy in RB will improve the nitrogen, energy and amino acids utilization for broiler chickens.

RESUMO -A pesquisa foi conduzida para avaliar o fluxo biológico do P em suínos, na fase de crescimento, alimentados com dietas à base de milho, farelo de soja, farelo de arroz desengordurado e óleo de soja, isentas de P inorgânico e suplementadas com níveis crescentes de fitase (253, 759, 1.265 e 1.748 UF/kg de dieta), e destacar o melhor nível de utilização da enzima, usando modelos matemáticos. O modelo utilizado foi determinístico e compartimental, em que o trato gastrintestinal (C 1 ), o plasma C 2 , os ossos (C 3 ) e os tecidos moles (ossos, coração, figado, rins e músculos), estudados em conjunto (C 4 ), representaram os compartimentos. Foram utilizados dados de metabolismo e cinética do P nos tecidos, obtidos pela técnica de diluição isotópica. Os parâmetros estimados foram: absorção, retenção, P endógeno que retorna ao trato gastrintestinal, P dietético absorvido, incorporação, reabsorção, balanço de P, P proveniente do osso, dos tecidos moles e do total absorvido que retorna ao trato gastrintestinal. O modelo biomatemático utilizado mostrou-se eficiente em explicar o fluxo do fósforo no organismo de suínos em crescimento. A fitase interferiu no fluxo biológico do P do compartimento C 1 para o C 3 e no refluxo dos compartimentos C 3 e C 4 para o C 1 . O nível 759 UF/kg de ração disponibilizou mais eficientemente o fósforo orgânico para o metabolismo dos suínos.Palavras-chave: absorção, cinética, modelos matemáticos, perdas endógenas, radiofósforo Biological P Flow on Metabolism of Pigs Fed Diets Containg PhytaseABSTRACT -The study was conducted to evaluate the biological flow of P in pigs fed diets based on corn, soybean meal, defatted rice bran (DRB) and soybean oil, with increasing phytase levels (253, 759, 1265 and 1748 PU/kg of diet), using mathematics models. The model was deterministic and compartimental, in which the gastrintestinal tract (GIT) (C 1 ), the plasma C 2 , the bones (C 3 ) and the soft tissues (liver, heart, kidney and muscle) (C 4 ) represented the compartments. Metabolism data and kinetics of P in tissues were used in the model, obtained by the isotopic dilution technique. The parameters used were: absorption, retention, endogenous P that return to the gastrintestinal tract (GIT), dietary absorbed P, accretion, reabsorption, balance of P in bone and soft tissues and P from total absorbed that returned the GIT. The biomathematical model used is adequate to explain the P flow in growing pig. The phytase enzyme interfere in biological flow of P from compartment C 1 to C 3 and with the output flow of P from compartment C 3 and C 4 to C 1. The level of 759 PU of phytase in diet of growing pig availability more efficientily the organic phosphorus for the pigs metabolism.Key Words: absorption, endogenous losses, kinetics, mathematic model, radiophosphorus R. Bras. Zootec., v.33, n.6, p.2066-2075, 2004 (Supl. 2) 1 Parte da tese de Doutorado do primeiro autor apresentada ao CENA/USP -Piracicaba, SP, como um dos requisitos para a obtenção do título de Doutor em ciência. IntroduçãoOs animais ...

Quarenta e oito leitões híbridos comerciais, machos castrados e fêmeas, com 5,5 ± 0,21 kg foram distribuídos em blocos ao acaso, com quatro tratamentos e seis repetições, para determinar a melhor concentração de lisina até os 11,9 ± 0,35 kg (fase inicial-1) e os efeitos subseqüentes até os 19,0 kg (fase inicial-2). A composição química das frações corporais e a deposição de tecido muscular na carcaça e no corpo vazio foram determinadas. As concentrações de lisina total utilizadas na primeira fase pós-desmame foram 1,16 a 1,46%. Não foi observado efeito na composição química do sangue e das vísceras, caracterizando a independência das concentrações de lisina. As respostas para acúmulo protéico e água da carcaça e do corpo vazio foram ascendentes com o aumento de lisina, caracterizando a maior eficiência na utilização e direcionamento do nutriente para a síntese protéica da musculatura esquelética. Na segunda fase, não foram observados efeitos, mas os animais que, anteriormente, receberam menores níveis de lisina tenderam acumular mais proteína e água na carcaça e no corpo vazio. Possivelmente, encontrando-se em déficit de lisina, fisiologicamente tolerável, a nova dieta supriu parte da demanda anterior, porém pode não ter atendido à demanda para síntese protéica dos animais que se encontravam em maior ascensão de síntese e acúmulo protéico na fase inicial-1. As respostas favoráveis ao aumento da concentração de lisina na dieta de leitões entre 5,5 e 11,9 kg de peso vivo recomendam novos estudos utilizando níveis de lisina superiores aos empregados, combinados com maiores níveis de energia metabolizável, a fim de estabelecer a eficiência máxima de deposição protéica. Estudos nas fases subseqüentes devem complementar informações de melhor aporte nutricional para o suíno.

The objective of this study was to evaluate the effects of autolyzed yeast on performance, cecal microbiota, and leukogram of weaned piglets. A total of 96 piglets of commercial line weaned at 21-day-old were used. The experimental design was a randomized block design with four treatments (diets containing 0.0%, 0.3%, 0.6%, and 0.9% autolyzed yeast), eight replicates, and three animals per pen in order to evaluate daily weight gain, daily feed intake, and feed conversion in periods of 0 to 15, 0 to 26, and 0 to 36 days. Quadratic effects of autolyzed yeast inclusion were observed on the feed conversion from 0 to 15 days, on daily weight gain from 0 to 15 days, 0 to 26 days and, 0 to 36 days, indicating an autolyzed yeast optimal inclusion level between 0.4% and 0.5%. No effect from autolyzed yeast addition was observed on piglet daily feed intake, cecal microbiota, and leukogram; however, i.m. application of E. coli lipopolysaccharide reduced the values of total leukocytes and their fractions (neutrophils, eosinophils, lymphocytes, monocytes, and rods). Therefore, autolyzed yeast when provided at levels between 0.4% and 0.5% improved weaned piglets' performance.