Telma Teresinha Berchielli

Avaliação de indicadores internos em ensaios de digestibilidade

The digestibilities of dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), gross energy (GE) and total digestible nutrients (TDN) were determined by using four internal markers (acid detergent fiber - ADF and lignin and acid insoluble ash - AIA). The three first markers were submitted to in vitro disappearance for three and six days and the results were compared with data determined by total feces collection. The nutrient digestibility estimated by NDF, ADF and lignin incubated during six days did not differ from that using total feces collection, while the markers incubated during three days and AIA subestimated the digestibility of nutrients, due to their lower recovery.

Comparação de marcadores para estimativas de produção fecal e de fluxo de digesta em bovinos

In order to estimate fecal production and digesta flow of cattle, three assays were carried out using indigestible NDF and ADF as internal markers, applying in vitro and in situ incubation procedures, as well as chromium oxide as an external marker. The experiment was a randomized block design in a factorial arrangement. Indigestible NDF and ADF contents exhibited high variation despite the methodology employed (in vitro or in situ). These results indicate that, eventually, 144-h incubation time does not reproduce the indigestible total fraction. The estimates of fecal production and duodenal digesta flow, calculated in function of the marker used, presented a variable behavior according to the roughage, which implies its effect on the marker concentration. Regarding important criteria involved in their determination, these internal markers can be used as predictors of the evaluated parameters.

Metano entérico de bovinos leiteiros em condições tropicais brasileiras

The objective of this work was to quantify methane (CH4) emission using the sulfur hexafluoride (SF6) tracer technique, by dairy cattle on pasture in Brazilian tropical field conditions. Measurements were performed in the rainy season, with Holstein and Holstein x Zebu crossbred, from lactating and dry cows and heifers grazing fertilized Tobiata grass, and heifers grazing unfertilized Brachiaria grass. Methane and SF6 concentrations were determined by gas chromatograph. Methane emissions by lactating cows varied from 13.8 to 16.8 g/hour, by dry cows from 11.6 to 12.3 g/hour, by heifers grazing fertilized grass was 9.5 g/hour and by heifers grazing unfertilized grass varied from 7.6 to 8.3 g/hour or 66 to 72 kg/head/year. Methane emission per digestive dry matter intake (DMDI) varied from 42 to 69 g/kg DMDI for lactating cows, 46 to 56 g/kg for dry cows, 45 to 58 g/kg for heifers grazing fertilized grass and 58 to 62 g/kg for heifers in unfertilized grass pasture. The CH4 emission measured on dairy cattle feeding tropical grasses was higher than that observed for temperate climate conditions.

Characterization of condensed tannins from native legumes of the Brazilian northeastern semi-arid

Despite the possible influence of tannins on the nutritional value of the forages from Caatinga vegetation, there are few studies that evaluated their tannin concentration. This study was conducted to characterize condensed tannins present in the legumes species Mimosa hostilis (Jurema Preta), Mimosa caesalpinifolia (Sabia) and Bauhinia cheilantha (Mororo), at three stages of their phenological cycle. The concentration of soluble tannin (ST), bound tannin (BT) and total tannin (TT) were determined using the butanol-HCL method; astringency was by the radial diffusion method, and the monomeric composition of purified tannins by a high-performance liquid chromatograph with delphinidin, cyanidin and pelargonidin as standards. Concentration and astringency of purified condensed tannins, as well as their monomeric composition varied between species, and in some cases among phenological cycles. The values observed were always above the limits considered beneficial for ruminal digestion (i.e. 5%). Jurema Preta presented the highest values (30.98% TT and 22% astringency at full growth stage), and Mororo the lowest (10.38% TT and 14% astringency during fructification). Jurema Preta presented a mean relationship prodelfinidin (PD): procyanidin (PC) of 97:3, which did not vary during the phenological cycle, showing the high astringent capacity of these tannins. Sabia presented a relationship of 90:20 during full growth and flowering stages, decreasing to 40:50 at fructification. In Mororo the PD:PC relationship was more equilibrated, around 40:50 during full growth and flowering stages, decreasing to 35:60 During fructification. Propelargonidin was not detected or was present at low concentration in the three species.

Composição química, fracionamento de carboidratos e proteínas e digestibilidade in vitro de forrageiras tropicais em diferentes idades de corte

Objetivou-se avaliar o valor nutritivo de tres especies forrageiras tropicais: capim-tanzânia (Panicum maximum Jacq.), capim-marandu (Brachiaria brizantha) e capim-tifton 85 (Cynodon spp), em duas epocas do ano (janeiro-marco e abril-junho) e em tres idades de rebrota (28, 35 e 42 dias), por meio da composicao quimica, do fracionamento de proteinas e carboidratos e da digestibilidade in vitro da materia seca (DIVMS) e da materia orgânica (DIVMO). O capim-marandu destacou-se no periodo de janeiro-marco, com menores conteudos de parede celular e fracao B2 dos carboidratos e maiores valores de proteina bruta, fracao A + B1, DIVMS e DIVMO, em comparacao aos capins tanzânia e tifton 85, independentemente da idade de corte. O aumento da concentracao de parede celular em detrimento ao conteudo celular com o avanco da maturidade das plantas foi evidente no capim-marandu no periodo de janeiro-marco, quando foram observados maior valor da fracao B2, maior conteudo de fibra em detergente neutro (FDN) e menor concentracao da fracao carboidratos nao-fibrosos. No periodo de abril-junho, a composicao em parede celular nao apresentou diferencas evidentes com aumento da idade, devido as condicoes ambientais observadas. O capim-tanzânia apresenta, de modo geral, baixos valores de parede celular e altos valores de carboidratos nao-fibrosos, DIVMS e DIVMO nesse periodo, seguido pelos capins marandu e tifton 85, respectivamente.

Fatty acid profile, carcass and meat quality traits of young Nellore bulls fed crude glycerin replacing energy sources in the concentrate.

Carcass and meat quality traits of 60 Nellore young bulls fed diets without crude glycerin (CG); with CG replacing corn (CGc; 10% of dry matter - DM) in the concentrate; and with CG replacing soybean hull (CGsh; 10% of DM) in the concentrate were evaluated. Diets were evaluated at two concentrate levels (CLs). The CL did not affect cold carcass weight (CCW; P=0.6074), cold carcass dressing (CCD; P=0.9636), rib fat thickness (RFT; P=0.8696) and longissimus muscle area (LMA; P=0.7524). Animals fed diets with CGc or CGsh showed meat with greater deposition of monounsaturated fatty acid (MUFA; P=0.0022) and CLA (18:2 cis-9, trans-11) contents (P=0.0001) than animals fed diets without CG. The inclusion of 10% of CG in diets CGc or CGsh does not affect the carcass and meat quality traits; however, it increases the MUFA and CLA contents in beef, although these changes are very small in nutritional terms.

Estimativas de Consumo do Capim-Elefante (Pennisetum purpureum Schum), Fornecido Picado para Vacas Lactantes Utilizando a Técnica do Óxido Crômico

O consumo de materia seca (CMS) de vacas mesticas Holandes-Zebu, fistuladas no rumen, em lactacao, foi medido pela diferenca de peso do alimento oferecido e das sobras e estimado com auxilio do oxido cromico (Cr2O3) pela producao fecal (PF) e indigestibilidade do alimento. O delineamento experimental foi em tres quadrados latinos (3x3) e os tratamentos consistiram de capim-elefante cortado nas idades de 30, 45 e 60 dias. A digestibilidade in vitro da materia seca (DIVMS) foi determinada nas amostras do capim-elefante e estimada a partir do consumo medido diretamente e pela producao fecal obtida com o Cr2O3. A producao fecal foi tambem calculada (PFc) a partir dos valores do consumo (direto) e da DIVMS e foi estimada pela relacao do indicador administrado/indicador excretado. Foram observadas diferencas entre os CMS obtidos nas tres idades de corte do capim-elefante pelos dois metodos avaliados. Os CMS medios obtidos pelo metodo direto foram de 8,00; 10,00 e 11,02 kg/vaca/dia, respectivamente, para o capim cortado com 30, 45 e 60 dias. Os CMS estimados com auxilio do Cr2O3 foram de 9,00; 11,10 e 12,00 kg/vaca/dia, para os mesmos tratamentos. As estimativas de consumo utilizando o Cr2O3 foram superestimadas em 9,25% em relacao aos resultados obtidos pelo metodo direto.

Avaliação da queima e da adição de milho desintegrado com palha e sabugo na ensilagem de cana-de-açúcar

This research aimed to evaluate the effects of burning and the use of dry additive on the sugar cane silage fermentative pattern. Six treatments were tested: natural or burned sugarcane, associated to three supplementation levels: 0, 50 or 100 g/kg of dehydrated corn grain, cob, and straw (CGCS) based on forage fresh mater. The following response variables were determined in the forage: DM, CP, acid detergent insoluble nitrogen (ADIN), NDF, ADF, cellulose, hemicellulose and lignin concentrations. Considering the fermentative traits, soluble carbohydrate levels, buffering capacity, pH, ammonia nitrogen and ethanol levels were measured. The CGCS inclusion increased DM concentration and slightly reduced ethanol and N-NH3 levels in silages, but did not affect pH or yeast growth. Burning reduced DM and N-NH3 concentration, as well as increased ethanol levels and yeast growth. Ethanol production in sugarcane silage was not controlled by using dry additive or burning.

Produção Fecal e Fluxo Duodenal de Matéria Seca e Matéria Orgânica Estimados por Meio de Indicadores

This research was conducted to compare the internal markers: indigestible neutral detergent fiber and acid detergent fiber, obtained after 144 h of in vitro (ivNDF, ivADF) and in situ (isNDF, isADF) rumen incubations; and the chromium oxide (Cr2O3) as external marker. The fecal output of dry matter and organic matter and the duodenal flow of crossbred steers, castrated and canulated in the rumen and in the duodenum. The steers were and fed with corn silage or the cassava hulls + citrus pulp, the cassava meal + citrus pulp, and sugar cane + citrus pulp, silages. The animals were adapted to diets during 11 days following 8 days for sampling. The dry matter and the organic matter duodenal flow estimated using the fecal output calculated by the ivADF. It was used a 4x4 Latin Square design with Split-splots. The fecal output results, expressed in live weight percentage, showed that the ivADF (0.88%), isADF (0.85%) and Cr2O3 (0.99 %) supplied biological consistent values and they could be used in spite of the significant differences among them. The internal markers did not show differences among them for the estimation of dry matter duodenal flow with an average of 3.29 kg/day. The chromium oxide overestimated the DM duodenal flow (4.95 kg/day). The organic matter duodenal flow estimates, there were no difference among the markers with an average of 2.73 kg/day.

Desempenho de bovinos de corte mantidos em pastagem de capim-marandu submetidos a diferentes estratégias de suplementação no período das águas e da seca

The objective of this study was to evaluate weight gain of beef steers grazing Brachiaria brizantha cv. Marandu and receiving one out of three different supplementation strategies during the rainy season of 2003 and the dry and rainy seasons of 2004. Twenty-four crossbreed steers averaging 230 kg of initial body weight were assigned to one of the following supplementation strategies: daily supplementation (DS), supplementation in alternated days (AD), or supplementation from Monday to Friday (MF) in a completely randomized design (8 replicates/treatment). Animals were individually weighted with no fasting every 28 days. There were no differences in weight gain among the different supplementation strategies averaging 0.76, 0.74, and 0.71 kg/day during the rainy season of 2003; 0.61, 0.62, and 0.57 kg/day during the dry season of 2004; and 0.57, 0.54, and 0.51 kg/day during the rainy season of 2004, respectively, for DS, AD and MF treatments. It can be concluded that reducing supplementation frequency may decrease feeding and labor costs with no negative impact on animal performance.