Contaminação proteica sobre os teores de lignina Klason em gramíneas e leguminosas tropicais

The objective of this work was to evaluate the extent of protein contamination on Klason lignin (KL) in tropical grasses and legumes, and to propose an equation to estimate the protein‑free content of Klason lignin (KLp). Five grass (30 samples) and 12 legume species (31 samples) were evaluated. Legumes had higher KL contents. Protein contamination was significant in both grasses and legumes, but greater in legume samples. The model to predict KLp was based on KL and crude protein (CP) contents, as follows: KLp = 0.8807KL ‑ 0.0938KL x D ‑ 0.00338CP (R2=0.935), in which D=0, for grasses, and D=1 for legumes.O objetivo deste trabalho foi avaliar a extensão da contaminação proteica sobre a lignina Klason (LK) em gramíneas e leguminosas tropicais, e propor uma equação para estimar o conteúdo livre de proteína da lignina Klason (LKp). Foram avaliadas cinco espécies de gramíneas (30 amostras) e 12 de leguminosas (31 amostras). As leguminosas apresentaram maiores teores de LK. A contaminação proteica foi significativa em gramíneas e leguminosas, mas maior em amostras de leguminosas. O modelo para estimar LKp foi baseado nos conteúdos de LK e de proteína bruta (PB), da seguinte forma: LKp = 0,8807LK ‑ 0,0938LK x D ‑ 0,00338PB (R2=0,935), em que D=0, para gramíneas, e D=1 para leguminosas

Variations in laboratory procedures to evaluate the neutral detergent fiber and ether extract contents in animal feeds and ruminant feces

A presente dissertação foi baseada em dois artigos científicos. No primeiro artigo, objetivou-se comparar as estimativas do teor de fibra insolúvel em detergente neutro (FDN) obtidas pelo método oficial Association of Official Analytical Chemists (AOAC; método 2002.04) e por métodos modificados baseados no uso de ambientes pressurizados ou com a utilização direta de α-amilase termoestável industrial em amostras de forragens, alimentos concentrados e fezes de ruminantes. As variações estudadas foram: aplicação do método AOAC 2002.04 substituindo-se o equipamento de refluxo por autoclave ou por extrator Ankom220® e sacos filtrantes F57; e aplicação do método AOAC 2002.04 substituindo-se os procedimentos de padronização e utilização da solução de α-amilase por adição única de 250 μL de solução industrial de Termamyl 2X previamente ao aquecimento da solução de detergente neutro. Foram avaliadas 39 amostras de fezes de animais ruminantes, 37 amostras de forragem e 30 amostras de concentrados. Os valores obtidos por cada variação foram comparados aos valores obtidos pelo método AOAC 2002.04 por intermédio do ajustamento de equação de regressão linear simples. Considerando-se amostras fecais e de forragens, as variações baseadas no uso de autoclave e na modificação da utilização de α-amilase propiciaram resultados similares (P>0,05) aos obtidos com o método AOAC 2002.04. Resultados superestimados (P0,05) dos diferentes recipientes. Foi observada interação significativa (P0,05). O teor de clorofila nos resíduos não foi afetado pelo método de extração em amostras fecais, mas foi menor utilizando-se o método AOCS (P0,05) de proteína e minerais no material após extração. Os resultados indicam que o método AOCS produz maiores estimativas de concentração de EE possivelmente por propiciar maior extração de material não graxo.This thesis consists of two different scientific articles. The first one aimed to compare the estimates of the neutral detergent fiber content (NDF) obtained by the official method of the Association of Official Analytical Chemists (AOAC, method 2002.04) and by modified methods based on the use of pressurized environments or by direct using of industrial thermo stable α-amylase in forage, concentrate feed and ruminant feces samples. The modified methods were: application of AOAC method 2002.04 replacing the refluxing equipment by an autoclave or the Ankom220® fiber analyzer with F57 filter bags, and application of AOAC method 2002.04 replacing the standardized procedures and using α- amylase solution by single addition of 250 μL of a industrial Termamyl 2X solution prior to heating the solution of neutral detergent. Thirty nine ruminants feces samples, 37 forage samples and 30 samples of concentrates were evaluated. The values obtained for each modified method were compared to the values obtained by the AOAC 2002.04 method through the adjustment of a simple linear regression equation. Considering only forage and fecal samples, variations methods based on the use of autoclave and the modified use of α- amylase provided similar values (P>0.05) to those obtained with the AOAC method 2002.04. Overestimated NDF contents (P0.05) was observed in any experiment. A significant interaction (P0.05) using the different containers. The chlorophyll content in the residual material was not affected by extraction method in fecal samples (P>0.05), but it was lower using the AOCS method (P0.05) in the material after ether extraction. The results indicate that the AOCS method produces greater estimates of EE contents, possibly by providing greater extraction of non-fatty material.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Protein contamination on Klason lignin contents in tropical grasses and legumes

The objective of this work was to evaluate the extent of protein contamination on Klason lignin (KL) in tropical grasses and legumes, and to propose an equation to estimate the protein-free content of Klason lignin (KLp). Five grass (30 samples) and 12 legume species (31 samples) were evaluated. Legumes had higher KL contents. Protein contamination was significant in both grasses and legumes, but greater in legume samples. The model to predict KLp was based on KL and crude protein (CP) contents, as follows: KLp = 0.8807KL - 0.0938KL x D - 0.00338CP (R2=0.935), in which D=0, for grasses, and D=1 for legumes

Intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage and supplemented with nitrogen and different levels of starch

Effects of nitrogen supplementation associated with different levels of starch on voluntary intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage (Brachiaria decumbens hay, 7.4% crude protein, CP) were evaluated using ruminal and abomasal cannulated steers.Five European×Zebu young bulls (186 kg body weight, BW) were distributed according to a 5×5 Latin square. The following treatments were evaluated: control, supplementation with 300 g CP/d (0:1), supplementation with 300 g starch/d and 300 g CP/d (1:1), supplementation with 600 g starch/d and 300 g CP/d (2:1), and supplementation with 900 g starch/d and 300 g CP/d (3:1). A mixture of nitrogenous compounds provided 1/3 from true protein (casein) and 2/3 from non-protein nitrogen (mixture of urea and ammonium sulphate, 9:1) was used as the nitrogen supplement. In order to supply energy a unique source of corn starch was used.Supplements increased (p0.05) forage intake. There was a cubic effect (p0.05) neutral detergent fibre corrected for ash and protein (NDFap) digestibility. There was a positive linear effect (p0.05) by the amount of supplemental starch. Ruminal ammonia nitrogen concentrations were higher (p<0.05) in supplemented animals, however, a negative linear effect (p<0.05) of amount of starch was observed. Supplements increased (p<0.05) the nitrogen balance (NB) and efficiency of nitrogen utilization. These effects were attributed to increased body anabolism, supported by higher (p<0.05) serum concentration of insulin-like growth factor 1. Increasing the amount of starch tended (p<0.06) to linearly increase the NB. In spite of this, there was a highest NB value for the 2:1 starch:CP ratio amongst the treatments with supplementation.Nitrogen supplementation in cattle fed low-quality tropical forage increases nitrogen retention in the animal’s body. An additional supply of starch increases nitrogen retention by increasing energy availability for both rumen and animal metabolism

Performance and carcass characteristics of young cattle fed with soybean meal treated with tannins

This study aimed to evaluate the effects of replacement of soybean meal (SBM) with soybean meal treated with tannin (SBMT) on the intake, digestibility, performance and characteristics of the carcasses of young cattle fed a high-concentrate diet. Forty- two Nellore bulls with body weight of 244.5 ± 4.99 kg were used. Diets had the inclusion of 7.5% SBM, with a proportion of that SBM (0, 33, 66 or 100%) replaced for SBMT; and other treatment (SBMT + urea) just with 2.5% of SBM which was treated with tannins. Seven animals were randomly selected and slaughtered, and the remaining animals were distributed on treatments and remained for 112 days. After, all animals were slaughtered. There was a linear decline in dry matter intake (P = 0.026) when SBM was replaced with SBMT. No decrease in carcass weight (P > 0.05) was observed. The efficiency of carcass weight gain showed a quadratic function effect (P = 0.049). There were changes in carcass gain composition when SBMT was added (P < 0.05), with an increase in muscle and reduction in fat deposition. The use of SBMT in place of SBM causes changes in body gain composition in animals and reduces DM intake by the animals, achieving a better feed conversion efficiency