212 research outputs found

    Quantitative analysis of ruminal bacterial populations involved in lipid metabolism in dairy cows fed different vegetable oils

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    Vegetable oils are used to increase energy density of dairy cow diets, although they can provoke changes in rumen bacteria populations and have repercussions on the biohydrogenation process. The aim of this study was to evaluate the effect of two sources of dietary lipids: soybean oil (SO, an unsaturated source) and hydrogenated palm oil (HPO, a saturated source) on bacterial populations and the fatty acid profile of ruminal digesta. Three non-lactating Holstein cows fitted with ruminal cannulae were used in a 3x3 Latin square design with three periods consisting of 21 days. Dietary treatments consisted of a basal diet (Control, no fat supplement) and the basal diet supplemented with SO (2.7% of dry matter (DM)) or HPO (2.7% of DM). Ruminal digesta pH, NH3-N and volatile fatty acids were not affected by dietary treatments. Compared with control and HPO, total bacteria measured as copies of 16S ribosomal DNA/ml by quantitative PCR was decreased (P < 0.05) by SO. Fibrobacter succinogenes, Butyrivibrio proteoclasticus and Anaerovibrio lipolytica loads were not affected by dietary treatments. In contrast, compared with control, load of Prevotella bryantii was increased (P < 0.05) with HPO diet. Compared with control and SO, HPO decreased (P < 0.05) C18:2 cis n-6 in ruminal digesta. Contents of C15:0 iso, C18:11 trans-11 and C18:2 cis-9, trans-11 were increased (P < 0.05) in ruminal digesta by SO compared with control and HPO. In conclusion, supplementation of SO or HPO do not affect ruminal fermentation parameters, whereas HPO can increase load of ruminal P. bryantii. Also, results observed in our targeted bacteria may have depended on the saturation degree of dietary oils

    Toward assessing the role of dietary fatty acids in lamb's neurological and cognitive development

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    Understanding and measuring sheep cognition and behavior can provide us with measures to safeguard the welfare of these animals in production systems. Optimal neurological and cognitive development of lambs is important to equip individuals with the ability to better cope with environmental stressors. However, this development can be affected by nutrition with a special role from long-chain fatty acid supply from the dam to the fetus or in lamb's early life. Neurological development in lambs takes place primarily during the first two trimesters of gestation. Through late fetal and early postnatal life, the lamb brain has a high level of cholesterol synthesis. This rate declines rapidly at weaning and remains low throughout adulthood. The main polyunsaturated fatty acids (PUFA) in the brain are ω-6 arachidonic acid and ω-3 docosahexaenoic acid (DHA), which are elements of plasma membranes' phospholipids in neuronal cells. DHA is essential for keeping membrane integrity and is vital for normal development of the central nervous system (CNS), and its insufficiency can damage cerebral functions and the development of cognitive capacities. In sheep, there is evidence that supplying PUFA during gestation or after birth may be beneficial to lamb productive performance and expression of species-specific behaviors. The objective of this perspective is to discuss concepts of ruminant behavior and nutrition and reflect on future research directions that could help to improve our knowledge on how dietary fatty acids (FA) relate to optimal neurological and cognitive development in sheep

    Estudio comparativo del perfil de ácidos grasos de quesos de oveja comerciales

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    The present study was carried out to characterize the FA profile of sheep cheese marketed in Chile. Fifty-eight cheeses were collected from supermarkets of 5 different Chilean cities including 34 sheep cheeses, 7 from goat’s milk, 11 from cow’s milk, 4 from a mixture of sheep, goat and cow’s milk and 2 from a mixture of sheep and cow’s milk. Compared to the cow and goat cheese (3.4 and 2.5 g·100g−1), the sheep cheese (3.8 g·100g−1) contained higher contents of C18:1t. The saturated and polyunsatured FA contents were greater in goat cheese than in sheep and cow cheese. The n6/n3 ratio was greater in goat (6.1) cheese than in sheep and cow cheese (3.8 and 5.2). The atherogenicity index was unaffected by cheese type, however, the thrombogenic index was lower in sheep cheese (2.8) than in goat and cow cheese (3.1 and 2.9). The n6/n3 ratio and thrombogenic index were lower in Chilean sheep cheese than in those imported from Europe. The fatty acid profile of cheese can be used to differentiate animal species from which the cheese is made and to some extent the geographical origin that may give some insight as to animal feed and production management.Este estudio fue llevado a cabo para caracterizar el perfil de AG de quesos de oveja que se comercializan en Chile. Cincuenta y ocho quesos fueron recogidos de supermercados de 5 ciudades de Chile de los cuales 34 fueron de oveja, 7 de cabra, 11 de vaca, 4 de mezcla de leche de oveja, cabra y vaca y 2 de mezcla de leche de oveja y vaca. Comparado con quesos de vaca y cabra (3.4 y 2.5 g·100g−1), los quesos de oveja (3.8 g·100g−1) presentaron mayor contenido de C18:1t. Los AG saturados y poliinsaturados tuvieron concentraciones más altas en los quesos de cabra que en los quesos de oveja y vaca. La relación n6/n3 fue más alta en quesos de cabra (6.1) que en quesos de oveja y vaca (3.8 y 5.2). El índice aterogénico no fue afectado por el tipo de queso, sin embargo, el índice trombogénico fue menor en quesos de oveja (2.8) que en quesos de cabra y vaca (3.8 y 5.2). La relación n6/n3 y el índice trombogénico fueron menores en quesos chilenos que en quesos importados de Europa. El perfil de AG de quesos puede ser usado para diferenciar entre especies animales de las cuales proviene el queso y hasta cierto grado, el origen geográfico, ofreciendo indicios sobre el tipo de alimento y sistema productivo animal del cual provienen los quesos

    Efecto de la inclusión de aceite de oliva lampante en la dieta de ovejas sobre el perfil de ácidos grasos de leche y queso

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    The objective of this experiment was to evaluate the effect of a dietary supplementation of lampant olive oil on the fatty aid profiles of the milk and cheese of ewes. Nine lactating ewes were used in a 3 × 3 Latin square design. Dietary treatments were supplemented with 0 (control; T0), 36 (T1) and 88 (T2) g of lampante olive oil/kg of dry matter intake (DM). DM, milk yield and milk composition (fat and protein) were not affected by dietary treatments. Oleic and vaccenic acids gradually increased (P < 0.05) and the saturated FA and atherogenicity index decreased (P < 0.05) in milk and cheese as the concentration of lampante olive oil was increased in dietary rations. Overall, the supplementation of lampante olive oil in the diets of lactating ewes increased monounsaturated FA and decreased saturated FA concentrations in milk and cheese, thus improving their quality from the human health standpoint.El objetivo de este estudio fue evaluar el efecto de la inclusión de aceite de oliva lampante en la dieta de ovejas sobre el perfil de ácidos grasos de leche y queso. Nueve ovejas fueron utilizadas en un diseño de CuadradoLatino 3 × 3. Las dietas fueron suplementadas con 0 (control; T0), 36 (T1) y 88 (T2) g de aceite de oliva lampante por kg de materia seca de alimento. La ingesta, la producción de leche y la composición de leche (grasa y proteína) no se vieron afectados por los tratamientos. Los ácidos oleico y vaccénico incrementaron (P < 0.05) gradualmente mientras que los ácidos grasos saturados y el índice aterogénico disminuyeron (P < 0.05) en leche y queso a medida que la inclusión de aceite de oliva lampante se incrementó en la dieta. En conclusión, la inclusión de aceite de oliva lampante en dietas de ovejas lactantes aumenta la concentración de ácidos grasos monoinsaturados y disminuye la de los saturados en leche y queso con posibles efectos benéficos sobre la salud humana
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