1,602 research outputs found

    Ruminal fermentation and degradation, kinetic flow of the digesta and milk fatty acid composition of cows fed chopped elephantgrass supplemented with soybean oil.

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    Abstract The aim of this study was to evaluate the ruminal parameters of fermentation and degradation, kinetic flow of rumen digesta, and milk fatty acid composition of cows fed 52% chopped elephantgrass-based diets containing 0.0% (control), 1.5%, 3.0% and 4.5% soybean oil (SO) on a dry matter (DM) basis. Four rumen-cannulated Holstein x Gyr dairy cows with an average milk production of 15.6 ± 3.0 kg day-1 and 90 ± 25 days in milk were allocated in a 4 x 4 Latin square design. The results were analyzed by mixed models. Significant differences were declared at P&#8804;0.05, and P-values from 0.05 < P &#8804; 0.10 were considered as a trend. The inclusion of SO in the diet had no effect on the ruminal pH or total volatile fatty acid concentration, but there was a quadratic effect on the ruminal ammonia nitrogen content and a trend for a linear reduction (P=0.07) in the molar proportion of rumen acetate. Linear reductions were also observed in the DM and neutral detergent fiber (NDF) effective degradabilities of elephantgrass forage, but the fluid and particulate passage rates in the rumen and the DM and NDF intakes were unchanged by SO inclusion in the diet. Milk production, protein and lactose contents and yields were unaltered by dietary SO levels. There were linear reductions in the milk fat and total solids contents, but there was no effect of dietary treatments on their yields. The inclusion of soybean oil in the diet of Holstein x Gyr cows fed chopped elephantgrass improved the nutritional quality of milk fat as a result of increased contents of oleic, rumenic and vaccenic acids, which are beneficial to human health, and a concomitant reduction in hypercholesterolemic saturated fatty acids such as lauric, myristic and palmitic acids

    Estimativa do Nível de Infecção por Babesia bigemina Utilizando a qPCR em Bovinos de Corte de Diferentes Grupos Genéticos.

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    O objetivo deste trabalho foi padronizar um protocolo de quantificação que possibilitasse estimar o nĂ­vel de infecção por de Babesia bigemina em bovinos de corte de trĂȘs grupos genĂ©ticos e faixas etĂĄrias diferentes. Foram colhidas amostras de sangue de 149 animais, criados em regiĂ”es endĂȘmicas para as babesioses. ApĂłs a extração do DNA, foi realizada a tĂ©cnica de qPCR em todos os indivĂ­duos. A curva padrĂŁo foi elaborada a partir da purificação e quantificação dos produtos de PCR. A anĂĄlise estatĂ­stica foi realizada com os dados transformados por logaritmos, empregando-se o programa computacional Statistical Analysis System v.9.1 (SAS). A metodologia empregada nĂŁo permitiu estimar o nĂ­vel de infecção na raça Nelore, entretanto, para animais Angus e cruzados, foram observadas diferenças significativas (P<0,05) em nĂ­vel de infecção entre grupos genĂ©ticos e categorias etĂĄrias estudadas

    Short-term changes in plasma and milk fatty acid profiles in cows fed chopped elephant grass-based diets containing two types of sunflower oil associated with two methods of concentrate feeding.

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    This study was carried out in a randomized block design in a 2 x 2 factorial arrangement with the aim of evaluating the short-term changes in the plasma and milk fatty acid (FA) profiles of Holstein x Gyr cows (444±84 kg; 75±31 days in milk; 15.4±4.8 kg day-1 of milk) fed 600 g kg-1 DM chopped elephant grass-based diets supplemented with 45 g kg-1 DM sunflower oil (SO) for 21 days. Two types of SO were evaluated: high oleic/low linoleic acid (HO) and medium oleic/medium linoleic acid (MO). The concentrates containing SO were supplied separately from forage twice a day (TAD) or as part of a total mixed ration (TMR). Temporal changes were analyzed by mixed models (P < 0.05) using six, four and seven repeated measures over time for FA intake and the plasma and milk FA compositions, respectively. There was higher oleic acid intake in HO SO-fed cows, while higher linoleic and &#945;-linolenic acid intake were observed in MO SO-fed cows. TAD-fed cows had a higher plasma vaccenic acid content than TMR-fed cows, while MO SO-fed cows had higher plasma vaccenic and rumenic acid contents than HO SO-fed cows. As a function of day, there were linear increases in oleic and linoleic acid intake; plasma contents of oleic, vaccenic and linoleic acids; and the milk fat content of linoleic acid, while quadratic effects were adjusted for the milk fat contents of palmitic, oleic, vaccenic and rumenic acids. In comparison with TMR-fed cows, the milk fat of TAD-fed cows produced between days 13 and 17 showed an FA profile that was more nutritionally desirable for human health, with lower contents of hypercholesterolemic FAs and higher contents of oleic, rumenic and vaccenic acids. Between days 15 and 16, the vaccenic and rumenic acid contents in the milk fat of MO SO-fed cows were 81% higher than those obtained from HO SO-fed cows, which on the 14th day had a 14% higher oleic acid content in milk fat. Lower milk fat levels of hypercholesterolemic FAs were produced between days 13 and 14 by cows fed both types of SO.Suplemento

    Taxa de passagem ruminal e digestibilidade aparente de nutrientes em vacas alimentadas com dois tipos de Ăłleo de girassol e dois modos de fornecimento do concentrado em dietas Ă  base de capim-elefante.

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    Milk fatty acid composition in Holstein x Gyr dairy cows fed chopped elephantgrass-based diets containing two types of sunflower oil associated with two methods of concentrate feeding.

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    Two experiments were carried out in a 2 x 2 factorial arrangement with the objective of evaluating two methods of concentrate feeding for Holstein x Gyr cows fed 600 g kg-1 chopped elephantgrass-based diets supplemented at 45 g kg-1 DM with two types of sunflower oil (SO). The types of SO differed in the levels of oleic and linoleic fatty acids (FAs): high oleic/low linoleic acid ? HO (73 and 10 g 100 g-1 FA, respectively) and medium oleic/medium linoleic acid ? MO (43 and 34 g 100 g-1 FA, respectively). The concentrates containing HO SO or MO SO were supplied separately from the forage twice a day after the two milkings (TAD) or as part of a total mixed ration (TMR). In Experiment 1, a 4 x 4 Latin square design was used to evaluate the ruminal fermentation and degradation parameters in four rumen-cannulated cows (430±39 kg; 79±20 days in milk; 16.4±3.1 kg day-1 of milk). In Experiment 2, a randomized block design was used to evaluate the nutrient intake, plasma contents of metabolites and FAs, milk yield and composition, and FA profile of milk fat in 32 cows (444±84 kg; 75±31 days in milk; 15.4±4.8 kg day-1 of milk). The results were analyzed by mixed models (P < 0.05). The TMR diets promoted higher nutrient intake and rumen fermentation (higher ammonia N, acetate, propionate and total volatile FA contents) without affecting milk, fat, protein and lactose yields. TAD-fed cows presented higher feed efficiency and produced milk fat with a more nutritionally desirable FA composition, with higher vaccenic and rumenic acid contents and lower trans-10 C18:1 and palmitic acid contents. The DM intake, parameters of rumen fermentation and milk, fat, protein and lactose yields were similar for the HO SO and MO SO diets. The most nutritionally positive characteristics for human health in the milk fat of HO SO-fed cows were the higher eicosapentaenoic (+34%) and oleic acid (+11%) contents and lower palmitic acid content (-10%). Higher contents of vaccenic (+71%) and rumenic (+74%) acids and lower trans-10 C18:1 (-10%), elaidic (-32%), lauric (-14%) and myristic (-11%) acid contents were the most positive aspects of the milk fat of MO SO-fed cows. Considering the magnitudes of the differences in the levels of these FAs, it is concluded that the milk fat of cows fed MO SO showed a healthier milk FA profile

    Desenvolvimento do hibrido triplo BRS 3101.

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