Foram avaliados descarte de resíduos químicos em análises dos teores de fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA), utilizando métodos convencional (Van Soest) e alternativos de análises. A recuperação da acetona promoveu ganhos tanto econômico como ambiental, observando-se taxa de recuperação de 84,12%. A precisão das análises não foi observada na maioria das determinações com reutilização de resíduos químicos, em todos os métodos analíticos testados, apesar de promover redução no custo, no tempo investido no preparo das soluções e no descarte de resíduos químicos.

The disposal of chemical waste and the precision of analyses of the neutral (NDF) and acid (ADF) detergent fiber contents were evaluated utilizing conventional (Van Soest) and alternative methods of analyses. The recovery of acetone promoted both economic and environmental gains, with a recovery rate of 84.12%. The precision of the analyses was not observed in most of the determinations with reutilization of chemical waste in all the analytical methods tested, in spite of promoting decrease in cost, time invested in the preparation of solutions and the disposal of chemical waste.

Objetivou-se com este trabalho avaliar a produção fecal por meio do indicador interno, fibra em detergente neutro indigestível (FDNi), e externos, cromo complexado com ácido etilenodiaminotetracético (Cr-EDTA ) e o cloreto de itérbio (YbCl3), além de estimar o fluxo duodenal da matéria seca e os coeficientes de digestibilidades aparentes total, ruminal e pós-ruminal, de diferentes nutrientes. Foram utilizadas oito novilhas mestiças Holandês/Zebu, distribuídas em duplo quadrado latino 4 x 4. Os indicadores Cr-EDTA, YbCl3 e o FDNi não estimaram produção fecal de forma eficiente (p < 0,05), obtendo resultado de 1,64; 1,71 e 2,71 kg dia-1, respectivamente, quando comparado à coleta total de fezes, que obteve resultado de 1,39 kg dia-1. Os valores estimados de fluxo de matéria seca, tanto para a metodologia de único, quanto para de duplo indicador, podem ser considerados biologicamente aceitáveis. Contudo, o valor obtido pela associação Cr-EDTA/YbCl3, utilizada na forma de duplo indicador, foi o mais confiável, pela melhor recuperação dos indicadores externos (Cr-EDTA e YbCl3), que obtiveram médias de 89 e 85%, respectivamente, em comparação ao interno (FDNi), que obteve média 67%. Os coeficientes de digestibilidade ruminal e pós ruminal, estimados pela associação Cr-EDTA/YbCl3, foram considerados melhores, em consequência do valor de fluxo de matéria seca estimado por esta associação.

This study evaluated fecal excretion by means of the internal indicator indigestible neutral detergent fiber (iNDF) and external indicators such as chromium complexed with ethylenediaminetetraacetic acid (Cr-EDTA) and ytterbium chloride (YbCl3), in addition to estimating the duodenal flow of dry matter and the total, ruminal and post-ruminal apparent digestibility coefficients. Eight crossbred Holstein x Zebu heifers were distributed into a 4 x 4 Latin square. Indicators Cr-EDTA, YbCl3and iNDF did not efficiently estimate the fecal production (p < 0.05), with results of 1.64, 1.71 and 2.71 kg day-1, respectively, compared with the total feces collection, which resulted in 1.39 kg day-1. The estimated values of dry matter flow, both for the methodologies of single and double indicator, can be considered biologically acceptable. However, the value obtained by the Cr-EDTA/YbCl3 association, used as a double indicator, was the most reliable, due to better recovery of the external indicators (Cr-EDTA and YbCl3), which have had averages of 89 and 85%, respectively, in comparison with the internal one (iNDF), which averaged 67%. The ruminal and post-ruminal digestibility coefficients, estimated by the Cr-EDTA/YbCl3 association, were considered the best indicators owing the dry matter flow estimated by this association.

The present study was conducted to determine the body composition and the mineral requirements for growth of wool and hair lambs. A total of 34 castrated lambs with an initial body weight (BW) of 19.9±0.8 kg were used; 17 of these lambs were of the genotype Ideal × Ile de France and 17 were Santa Inês. Ten lambs (5 of each genotype) were slaughtered at the beginning of the experiment to establish their initial body composition. The remaining lambs were assigned to one of three diets (40% roughage and 60% concentrate, 60% roughage and 40% concentrate, or 80% roughage and 20% concentrate) in a 2 × 3 factorial arrangement of treatments. All of the diets were provided ad libitum. When the group under 40% roughage and 60% concentrate reached 35 kg BW, all of the animals were slaughtered. Linear regressions were used to determine the relationship between the shrunk BW and the empty body weight (EBW) for each genotype. These equations were compared and revealed differences between the genotypes. The allometric equations were calculated using the relationship between the amount of minerals and the EBW. The equations of a given mineral for each genotype were compared to verify if they were statistically different. The equations for calcium, phosphorus, magnesium and sodium differed between genotypes. The same equations were used to estimate the major body mineral composition per kilogram of EBW. The net requirement for gain of the fleece-free Ideal × Ile de France lambs ranged from 7.77 to 6.80 g Ca, 4.54 to 4.14 g P, 0.30 to 0.27 g Mg, 1.18 to 1.07 g K and 0.84 to 0.76 g Na per kg BW gain, and the requirements of the Santa Inês animals ranged from 9.57 to 8.37 g Ca, 5.39 to 4.91 g P, 0.36 to 0.33 g Mg, 1.18 to 1.07 g K and 0.90 to 0.81 g Na per kg BW gain for the lambs weighting 20 to 35 kg. Santa Inês lambs showed higher requirements for Ca, P, Mg and Na.

O objetivo do trabalho foi comparar os valores de fibra em detergente neutro (FDN) e os de fibra em detergente ácido (FDA) obtidos com o equipamento ANKOM e pelo método convencional (Van Soest). No primeiro ensaio foram analisados cinco materiais diferentes (cana-de-açúcar, capim-braquiária, silagem de milho, polpa cítrica e fezes bovina) e testados quatro tipos de saquinhos para filtragem de amostra. O delineamento experimental foi em blocos casualizados, em um fatorial 5x4 (cinco materiais diferentes e quatro tipos de saquinhos de filtragem), com três repetições. As médias obtidas foram comparadas àquelas obtidas com método convencional. No segundo ensaio procurou-se avaliar o efeito da quantidade de amostra por saquinho (0,5; 0,8 e 1,0 g) sobre os teores de FDN e FDA em três tipos de alimentos, utilizando o ANKOM. Neste ensaio, o delineamento experimental foi em blocos casualizados em esquema fatorial 3x3 (três alimentos x três quantidades), com três repetições. Os tipos de saquinhos de filtragem utilizados não influenciaram os teores de FDN nos diferentes alimentos, com exceção das fezes, cujos saquinhos de náilon resultaram em concentrações de FDN inferiores. Não houve diferença entre os valores de FDN e FDA, obtidos pelo equipamento ANKOM ou pelo convencional, para os alimentos estudados, com exceção da polpa cítrica, cujo valor médio de FDA pelo ANKOM foi inferior àquele obtido pelo método convencional. A quantidade não exerceu efeito sobre a concentração de FDN dos alimentos analisados no equipamento ANKOM.

The ANKOM filter bag system was compared with the conventional filtration system (Van Soest) to determine acid detergent fiber (ADF) and neutral detergent fiber (NDF) in different materials. In the first experiment five feeds (sugar cane, Marandu grass - Brachiaria brizantha cv. Marandu, corn silage, citrus pulp and cattle feces) and four types of filter bags were compared. A completely randomized block design in a factorial scheme (5x4), with three replications, was used. The means obtained by the ANKOM system were compared with those obtained by the conventional filtration procedure. The sample amount effect (0.5; 0.8; 1.0 g) in each filter bag on ADF and NDF contents was studied in the second experiment, using three feeds and the ANKOM system. In this experiment, a completely randomized blocks design, in a factorial scheme (three feeds x three amount feed) and three replications, was used. The types of filter bag did not affect the NDF content of the different feeds, except for feces, which bags showed smaller NDF contents. There were no statistical differences among NDF or ADF values determined either by the ANKOM or by the conventional filtration procedures for most of the feeds used, except citrus pulp, which had lower ANKOM- ADF values than the conventional procedure. The sample amount did not affect the NDF of the feed determined by the ANKOM System.