Digestibilidade das proteínas do soro do leite mediante ensaio in vitro

Pós-graduação em Alimentos e Nutrição - FCFAR

Composição química, digestibilidade e produção de gases in vitro de cultivares de Brachiaria manejados em diferentes ofertas de forragem

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Composição química, digestibilidade e produção de gases in vitro de três espécies forrageiras tropicais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Silagens de milho inoculadas microbiologicamente em diferentes estádios de maturidade: perdas fermentativas, composição bromatológica e digestibilidade in vitro

Objetivou-se com este estudo avaliar as perdas fermentativas, composição bromatológica e digestibilidade in vitro da matéria orgânica de silagens de milho produzidas em diferentes estádios de maturidade, inoculadas microbiologicamente. Aplicaram-se dois inoculantes comerciais nas silagens produzidas nos estádios SLL, 1/3 LL, 1/2 LL, 2/3 LL e CN, permanecendo ainda um tratamento sem inoculação (silagem controle), configurando um esquema fatorial 3x5. A inoculação com BAL resultou em menores perdas fermentativas (P=0,0348), ao passo que silagens produzidas com plantas mais secas também apresentam menores perdas de MS (P<0,01). A inoculação das silagens resultou em maiores concentrações de PB nas silagens produzidas nos estádios SLL, 2/3 LL e CN (P=0,0033). O uso do inoculante Maize All® resultou em menor concentração de FDN (P=0,0140) no estádio CN e acréscimo dos coeficientes de DIVMO quando as plantas foram colhidas com 2/3 LL e CN (P=0,0006). As perdas fermentativas diminuem devido à utilização dos inoculantes bacterianos e também em silagens produzidas com plantas mais secas. A aplicação de bactérias ácido-láticas (inoculante Maize All®) em silagens de milho produzidas com plantas em estádio de maturidade mais avançado melhora a composição química e digestibilidade in vitro.

Composição química e digestibilidade in vitro da massa seca de cana-de-açúcar acrescida de ureia em diferentes tempos de estocagem

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative in vitro evaluation of forage legumes (prosopis, acacia, atriplex, and leucaena) on ruminal fermentation and methanogenesis

Two experiments in vitro were conducted to evaluate four Egyptian forage legume browses, i.e., leaves of prosopis (Prosopis juliflora), acacia (Acacia saligna), atriplex (A triplex halimus), and leucaena (Leucaena leucocephala), in comparison with Tifton (Cynodon sp.) grass hay for their gas production, methanogenic potential, and ruminal fermentation using a semi-automatic system for gas production (first experiment) and for ruminal and post ruminal protein degradability (second experiment). Acacia and leucaena showed pronounced methane inhibition compared with Tifton, while prosopis and leucaena decreased the acetate:propionate ratio (P<0.01). Acacia and leucaena presented a lower (P<0.01) ruminal NH3-N concentration associated with the decreasing (P<0.01) ruminal protein degradability. Leucaena, however, showed higher (P<0.01) intestinal protein digestibility than acacia. This study suggests that the potential methanogenic properties of leguminous browses may be related not only to tannin content, but also to other factors.

Effects of Aspergillus spp. exogenous fibrolytic enzymes on in vitro fermentation of tropical forages

BACKGROUND: Cellulose and hemicellulose are quantitatively the most important structural carbohydrates present in ruminant diets. Rumen micro-organisms produce enzymes that catalyse their hydrolysis, but the complex network formed by structural carbohydrates and lignin reduces their digestibility and restricts efficient utilisation of feeds by ruminants. This study aimed to produce two enzymatic extracts, apply them in ruminant diets to determine the best levels for ruminal digestibility and evaluate their effects on in vitro digestibility. RESULTS: In experiment 1 a two-stage in vitro technique was used to examine the effects of different enzymatic levels of Aspergillus japonicus and Aspergillus terricola on tropical forages. Enzyme addition had minor effects on corn silage at the highest enzymatic level. In experiment 2 an in vitro gas production (GP) technique was applied to determine apparent in vitro organic matter digestibility and metabolisable energy. The addition of enzymes in GP showed interesting results. Good data were obtained using sugar cane and Tifton-85 hay supplemented with extracts of A. japonicus and A. terricola respectively. CONCLUSION: Overall, the study suggests that addition of crude extracts containing exogenous fibrolytic enzymes to ruminant diets enhances the effective utilisation of ruminant feedstuffs such as forages. Copyright (c) 2012 Society of Chemical Industry

Chemical characterization and in vitro biological activity of four tropical legumes, Styzolobium aterrimum L., Styzolobium deeringianum, Leucaena leucocephala, and Mimosa caesalpiniaefolia, as compared with a tropical grass, Cynodon spp. for the use in ruminant diets

Leucaena leucocephala (LEU) and three under-utilized tanniferous legumes, Styzolobium aterrimum L. (STA), Styzolobium deeringianum (STD), and Mimosa caesalpiniaefolia Benth (MIC) were chemically characterized and the biological activity of tannins was evaluated using in vitro simulated ruminal fermentation through tannin-binding polyethylene glycol (PEG) and compared with a non-tanniferous tropical grass hay, Cynodon spp. (CYN). The Hohenheim gas test was used and gas production (GP) was recorded at 4, 8, 12, 24, 32, 48, 56, 72, 80, and 96 h incubation with and without PEG. Kinetic parameters were estimated by an exponential model. STA, STD, and LEU contained higher (P < 0.05) crude protein than MIC, which had greater neutral detergent fibre and acid detergent fibre. Total phenols, total tannins, and condensed tannins (CT) were consistently the highest in MIC. Gas production was the lowest from MIC (P < 0.05) and the highest in LEU and STA. MIC + PEG largely reduced (P < 0.05) the lag phase and the fractional rate of fermentation and increased potential GP. Kinetic parameters of STA + PEG and LEU + PEG were not affected. LEU + PEG produced greater gas increment (P < 0.05) than STD + PEG, although both legumes had the same CT. All legumes except MIC were more extensively degraded than CYN. However, fermentation of the legumes was differently affected by the presence and proportions of CT, indigestible fibre or both.

Efecto de la sustitución de N no proteico por proteína de soja sobre la producción de metano in vitro

Incubations were carried out with batch cultures to study the effects of different nitrogen (N) sources on in vitro fermentation by ruminal micro-organisms of two substrates of variable fermentation rate. The substrates were composed by starch and cellulose in proportions of 75:25 (starch) or 25:75 (cellulose). Three treatments were made by replacing ammonia-N (NH4Cl) with purified soyabean protein (SP) at levels of 0 (NNP), 50% (S50) and 100% (S100) of total N. Compared with NNP, S50 and S100 treatments increased CH4 production by 51.0 and 50.6% for starch and by 7.7 and 29.7% for cellulose substrates, respectively. The increases in volatile fatty acids (VFA) production were 4.4 and 6.3% for starch and 33.1 and 58.9% for cellulose substrates, respectively. These results indicate that the influence of N source on CH4 and VFA production are influenced by the characteristics of the incubated substrate.

Fermentación in vitro de pepsina/pancreatina con inóculos de conejos

The in vitro gas production of pepsin/pancreatin used in the determination of in vitro digestibility was evaluated using different inocula from rabbits (ileal, caecal and soft faeces from rabbits). In experiment 1 were used 3 different ileal and caecal inocula obtained each one from the combination of the digesta of 3 different 70 d old rabbits.

Design of Polyamine-Grafted Starches for Nucleotide Analogue Delivery: In Vitro Evaluation of the Anticancer Activity

International audience

Evaluation of polycaprolactone scaffold degradation for 6 months in vitro and in vivo

The use of polycaprolactone (PCL) as a biomaterial, especially in the fields of drug delivery and tissue engineering, has enjoyed significant growth. Understanding how such a device or scaffold eventually degrades in vivo is paramount as the defect site regenerates and remodels. Degradation studies of three-dimensional PCL and PCL-based composite scaffolds were conducted in vitro (in phosphate buffered saline) and in vivo (rabbit model). Results up to 6 months are reported. All samples recorded virtually no molecular weight changes after 6 months, with a maximum mass loss of only about 7% from the PCL-composite scaffolds degraded in vivo, and a minimum of 1% from PCL scaffolds. Overall, crystallinity increased slightly because of the effects of polymer recrystallization. This was also a contributory factor for the observed stiffness increment in some of the samples, while only the PCL-composite scaffold registered a decrease. Histological examination of the in vivo samples revealed good biocompatibility, with no adverse host tissue reactions up to 6 months. Preliminary results of medical-grade PCL scaffolds, which were implanted for 2 years in a critical-sized rabbit calvarial defect site, are also reported here and support our scaffold design goal for gradual and late molecular weight decreases combined with excellent long-term biocompatibility and bone regeneration. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 90A: 906-919, 2009