Kinetics of transit and degradation of the fiber from guinea grass silages enriched with waste from soybean pre-cleaning

The objective was to study the kinetics of transit and degradation of the fiber from guinea grass and the waste from soybean pre-cleaning (WSPC), ensiled with different proportions of mass (0, 100, 150, and 200 g WSPC/kg total mass). Four crossbred (Gyr × Holstein), fistulated cattle with an average body mass of 400±50 kg were organized in a 4 × 4 Latin square experimental design. The fiber utilized in the study of the transit kinetics was stained with chromium mordant, whereas the in situ technique was adopted for the degradation kinetics. The level of inclusion of WSPC only affected the true digestibility and the mean retention time. The addition of waste from soybean pre-cleaning to the silage of guinea grass is beneficial, in terms of kinetics of digestion and passage, at up to levels close to 100 g/kg, because after this quantity the fiber digestion and passage in and through the reticulo-rumen are impaired and there may be alterations in the ruminal environment that will affect the use of silage by animals

Application of a nonlinear optimization tool to balance diets with constant metabolizability

AbstractThe goals of this study were to evaluate the ability of a nonlinear optimization tool to provide solutions for maintaining consistent qualities of diets irrespective of the plane of nutrition (L) and to evaluate the effect of the plane of nutrition on intake and digestibility of dry matter (DM), organic matter (OM), crude protein (CP), crude fat (CF), non fibrous carbohydrates (NFC), neutral detergent fiber (NDF), and metabolizability (qm) of diets using sheep as a generalized experimental model. Eight wethers were randomly assigned to two balanced four-treatment Latin squares conducted simultaneously with four diets providing nutritional levels that were multiples of maintenance levels (ME=Mm; 1.5Mm; 2Mm; and 2.5Mm, where ME is the metabolizable energy intake, and Mm is the metabolizable energy intake for maintenance). The ME, Mm, metabolizable protein (MP) and NDF of the diet were subjected to nonlinear constraints; the model was considered a general nonlinear programming problem and solved using Microsoft Excel Solver® with Newton's method of resolution. The intake of nutrients, digestible nutrients, digestible energy (DE) and the amounts of feces and urine produced daily were measured and analyzed statistically by fitting a linear mixed model. The corrected metabolizability (qm') and plane of nutrition (Lc) were obtained on the basis of the digestible, urinary, and simulated methane losses. The trends of some variables were reanalyzed by regressing observed values against Lc. All measured variables were affected by L. The intakes of DM and OM increased in an asymptotic fashion as Lc increased, whereas the intake of NDF increased linearly as Lc increased. At levels immediately below maintenance, observed values were approximately constant. Digestible amounts of OM, DE, CF, and CP consumed increased linearly at levels above maintenance, whereas the digestible amounts of total carbohydrates, neutral detergent solubles, and ashes increased in an asymptotic fashion. Under conditions of controlled feeding, the nonlinear optimization tool yielded dietary solutions with a nearly constant metabolizability in which the rate of increase in crude protein, digestible crude protein, and digestible energy intakes remained constant as the plane of nutrition increased

L. as a Potential High Quality Forage Legume

Samples of Clitoria ternatea L. (Cunhã) were harvested at 35, 50, 70, and 90 d after a uniformity harvest in a field study designed as a completely randomized design with a total of 18 experimental plots. The dry matter yield of the whole plant was separated quantitatively into leaves, stems, and pods at each harvesting age. Chemical analyses and in vitro gas production kinetics were performed to assess the quality of the plant parts. Yields, chemical composition, and estimates of gas production parameters were analyzed by fitting a mixed statistical model with two types of covariance structures as follows: variance components and an unrestricted structure with heterogeneous variances. Fast and slow gas yielding pools were detected for both leaves and stems, but only a single pool was detected for pods. The homoscedasticity assumption was more likely for all variables, except for some parameters of the gas production kinetics of leaves and stems. There was no presence of typical pods at 35 and 50 d. In the leaves, the fibrous fractions were affected, whereas the non-fibrous fractions were unaffected by the harvesting age. The harvesting age affected the majority of the chemical constituents and gas kinetic parameters related to the stems. The leaves of this legume were the least affected part by the aging process

Produção e composição química de Brachiaria decumbens cv. Basilisk em sistema silvipastoril sob diferentes espaçamentos com Eucalyptus urophylla s.t. Blake

A Digital Object Identifier (DOI) disponibilizada pela revista não corresponde.O objetivo deste estudo foi avaliar o efeito do espaçamento de plantio do eucalipto em sistema silvipastoril sobre a produção e composição química da Brachiaria decumbens. Foram utilizados quatro tratamentos, referentes aos três espaçamentos de plantio do eucalipto (3x2, 6x4 e 10x4 m), mais o tratamento controle (ausência de árvores). O delineamento experimental utilizado foi em blocos completos casualizados, com quatro tratamentos, quatro blocos e duas repetições por bloco, e análise dos dados foi realizada como medidas repetidas no tempo. Constataram-se efeitos significativos de tratamento para a massa de forragem (MF) e taxa de acúmulo de massa seca (TAMS). Para a relação folha/colmo (F/C), porcentagem de proteína bruta (PB), porcentagem de fibra em detergente neutro (FDN) e porcentagem de matéria mineral (MM) não foram observados efeitos de espaçamento de plantio do eucalipto. Em conclusão, verificou-se que os espaçamentos de plantio afeta tanto a produção quanto a composição química da braquiária avaliadas até os 24 meses de crescimento do Eucalyptus urophylla cultivado em sistema silvipastoril.The objective of this study was to evaluate the effect of spacing on eucalyptus in silvopastoral system under production and chemical composition of Brachiaria decumbens. Four treatments were used, which were related to the three spaces planting of eucalyptus (3x2, 6x4 and 10x4m) plus the control treatment (no tree). The experimental design was randomized complete block with four treatments, four blocks and two repetitions per block, and the analysis was made by repeated measurements. It was found effects of treatment on the forage mass yielding and dry matter accumulation rate (DMAR). There were no effect of planting spacing either or leaf/stem ratio or CP percentage, NDF percentage and mineral percentage. Planting spacing of Eucalyptus urophylla affects both production and chemical composition of Brachiaria evaluated up to the 24 months