[Show abstract][Hide abstract] ABSTRACT: Antecedentes: la composición de ácidos grasos de la leche ha tomado gran importancia para los consumidores a causa de la relación positiva que se ha encontrado entre algunos ácidos grasos y la salud humana. En los últimos años, el contenido y composición de ácidos grasos en las diferentes fracciones de los lípidos de la leche también ha tomado importancia debido a las posibles implicaciones tecnológicas y sensoriales que se han reportado. Objetivo: el objetivo del presente estudio fue evaluar los cambios en la proporción de lípidos neutros (triglicéridos) y lípidos polares (fosfolípidos) y alteraciones de la composición de ácidos grasos e isómeros del Ácido Linoléico Conjugado (CLA) del total de lípidos de la leche como resultado de la suplementación dietaria con diferentes suplementos lipídicos. Métodos: 18 vacas Holstein Alemán de primera lactancia fueron asignadas a tres tratamientos dietarios durante 10 semanas, así: grasa de palma fraccionada y estable al rumen, aceite de lino más alga, y aceite de girasol más alga. Resultados: la suplementación con ácidos grasos poliinsaturados incrementó la proporción de fosfolípidos y disminuyó la de triglicéridos en la grasa de la leche comparado con grasa de palma fraccionada y estable al rumen. Los ácidos grasos poliinsaturados de cadena larga fueron preferencialmente depositados en los fosfolípidos. El efecto de la dieta fue más pronunciado en los triglicéridos que en los fosfolípidos. Las dietas suplementadas con aceite vegetal y alga indujeron a menores proporciones de ácidos grasos saturados y mayores proporciones de ácidos grasos insaturados en los triglicéridos. Conclusiones: la suplementación con aceite de lino más alga generó los mejores resultados respecto a la composición de ácidos grasos relacionados con la salud humana. El aceite de girasol más alga causó una acumulación de isomeros CLAtrans-10,cis-12, CLAtrans-7,cis-9, CLAtrans- 7,trans-9 y CLAtrans-10,trans-12 y disminuyó CLAtrans-9,trans-11 en la grasa total de la leche mientras que el aceite de lino más alga incrementó CLAtrans-12,trans-14, CLAtrans-11,trans-13, y CLAtrans-11,cis-13 comparado con la grasa de palma fraccionada y estable al rumen.
Revista Colombiana de Ciencias Pecuarias 06/2013; 26(2):79-89. · 0.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The effect of a 10-week supplementation with polyunsaturated fatty acids [via sunflower oil/DHA-rich algae (SUNA) or linseed oil/DHA-rich algae (LINA) enriched diets] versus saturated fatty acids (SAT) of lactating German Holstein dairy cows in mid-lactation on expression patterns of lipid metabolism-associated genes and gene products in hepatic, longissimus muscle and subcutaneous/perirenal/omental adipose tissue was assessed. Most pronounced transcriptomic responses to dietary PUFA were obtained in hepatic [down-regulated ACACA (FC = 0.83, SUNA; FC = 0.86, LINA), FADS1 (FC = 0.60, SUNA; FC = 0.72, LINA), FADS2 (FC = 0.64, SUNA; FC = 0.79, LINA), FASN (FC = 0.64, SUNA; FC = 0.72, LINA), SCD (FC = 0.37, SUNA; FC = 0.47, LINA) and SREBF1 (FC = 0.79, SUNA, LINA) expression] and omental adipose [up-regulated ACACA (FC = 1.58, SUNA; FC = 1.22, LINA), ADFP (FC = 1.33, SUNA; FC = 1.32, LINA), CEBPA (FC = 1.75, SUNA; FC = 1.40, LINA), FASN (FC = 1.57, SUNA; FC = 1.21, LINA), LPL (FC = 1.50, SUNA; FC = 1.20, LINA), PPARG (FC = 1.36, SUNA; FC = 1.12, LINA), SCD (FC = 1.41, SUNA; FC = 1.17, LINA) and SREBF1 (FC = 1.56, SUNA; FC = 1.18, LINA) expression] tissue. Interestingly, gene/gene product associations were comparatively low in hepatic and omental adipose tissue compared with longissimus muscle, perirenal adipose and subcutaneous adipose tissue, indicating matches only in regard to minor concentrations of SCD product 18:1c9, FADS1 product 20:4n-6 and FADS2 product 18:3n-6 in hepatic tissue, and higher concentrations of ACACA and FASN gene products 12:0 and 14:0 and SCD product 18:2c9,t11 in omental adipose tissue. Whereas all analyzed tissues accumulated dietary PUFA and their ruminally generated biohydrogenation products, tissue-divergent preferences for certain fatty acids were identified. This descriptive study reports tissue-divergent effects of dietary PUFA and outlines the significance of a PUFA intervention with regard to dairy cows' nutritional management.
[Show abstract][Hide abstract] ABSTRACT: The main aim of the present study was to examine the effects of long-term supplementing diets with saturated or unprotected polyunsaturated fatty acids from two different plant oils rich in either n-3 or n-6 fatty acids (FAs) plus docosahexaenoic acid (DHA)-rich algae on mammary gene expression and milk fat composition in lactating dairy cows. Gene expression was determined from mammary tissue and milk epithelial cells. Eighteen primiparous German Holstein dairy cows in mid-lactation were randomly assigned into three dietary treatments that consist of silage-based diets supplemented with rumen-stable fractionated palm fat (SAT; 3.1% of the basal diet dry matter, DM), or a mixture of linseed oil (2.7% of the basal diet DM) plus DHA-rich algae (LINA; 0.4% of the basal diet DM) or a mixture of sunflower oil (2.7% of the basal diet DM) plus DHA-rich algae (SUNA; 0.4% of the basal diet DM), for a period of 10 weeks. At the end of the experimental period, the cows were slaughtered and mammary tissues were collected to study the gene expression of lipogenic enzymes. During the last week, the milk yield and composition were determined, and milk was collected for FA measurements and the isolation of milk purified mammary epithelial cells (MECs). Supplementation with plant oils and DHA-rich algae resulted in milk fat depression (MFD; yield and percentage). The secretion of de novo FAs in the milk was reduced, whereas the secretion of trans-10,cis-12-CLA and DHA were increased. These changes in FA secretions were associated in mammary tissue with a joint down-regulation of mammary lipogenic enzyme gene expression (stearoyl-CoA desaturase, SCD1; FA synthase, FASN) and expression of the regulatory element binding transcription factor (SREBF1), whereas no effect was observed on lipoprotein lipase (LPL) and glycerol-3-phosphate acyltransferase 1, mitochondrial (GPAM). A positive relationship between mammary SCD1 and SREBF1 mRNA abundances was observed, suggesting a similar regulation for these genes. Such data on mammary gene expression in lactating cows presenting MFD contribute to strengthen the molecular mechanisms that govern milk fat synthesis in the mammary glands. In purified MEC, the dietary treatments had no effect on gene expressions. Differences between mammary tissue and milk purified MEC gene expression were attributed to the effect of lipid supplements on the number of milk purified MEC and its RNA quality, which are determinant factors for the analysis of gene expression using milk cells.
[Show abstract][Hide abstract] ABSTRACT: Organic waste from markets represents about 10-20% of the total waste of a city. A large proportion comes from the overproduction of fruit and vegetables, turning them into potential pollutant. The nutritional value found for fruit and vegetable waste (FV) from a marketplace, in a previous work, showed that this product might be considered as a potential alternative for animal feeding. This study evaluated the use of FV as feedstuff for diets of lactating Holstein cows with an emphasis on milk yield and quality. FV was included in 0, 6, 8, 12, and 18% of the concentrate. A 4 x 4 Latin squares model was used to analyze data (4 animal groups, 4 periods of evaluation, and 4 treatments). No statistical differences in milk yield per kilogram of eaten concentrate or concentrate intake were recorded between groups fed FV and the control group. There was a significant effect of the treatment on cis-9,trans-11 CLA and α-linolenic acid content in milk. These results showed that FV can be used as a dietary ingredient for high-yield lactating cows without detriment in the milk yield and with improvement in the milk quality. FV could be included at proportions of between 6% and 18% in the concentrate, as long as the animal's dietary requirements are covered. The main impact of these results is the alternative generated for the improvement of the environment.
[Show abstract][Hide abstract] ABSTRACT: There are different sources for the generation of solid waste, and marketplaces are considered one of them. Fruit and vegetable waste (FV) from a marketplace in Colombia was quantitatively and nutritionally characterized to contribute to its use in bovine feeding and to contribute minimizing its environmental impact. The evaluation was carried out 7 days per week during 4 periods of the year. FV was grouped by cluster analysis using SAS(®) 2006. FV was composed of 43% fruit, 30% vegetables and 27% stems, leaves, leaf wrappers, corncobs, roots, refuse and others. FV was defined in four main groups. On average, FV contained 10% crude protein (CP), 36.6% neutral detergent fiber (NDF), 29.6% acid detergent fiber (ADF), 87.8% ruminal degradability at 24 h, 3657 kcal/kg, 0.59% calcium (Ca(+2)), and 0.21% phosphorous (P). There were no statistical differences between days or between periods of evaluation (p > 0.05) for CP or for Ca(+2). As for NDF and ADF, there were statistically significant differences between periods but not between days. The microbiological parameters only increased when the humidity was up to 12%. FV represents a potential feedstuff for bovine feeding, and its recycling could avoid the discharge of a large amount of waste to landfills, which would minimize its environmental impact.
[Show abstract][Hide abstract] ABSTRACT: The present study investigated the effect of three different dietary fats [saturated fat (SAT) (3.1% TMR DM); linseed oil (LINA) (2.7% TMR DM) or sunflower oil (SUNA) (2.7% TMR DM) added with docosahexaenoic acid rich algae (0.4% TMR DM)] on SREBP-1 protein expression in mammary gland tissue of German Holstein cows (n=18) in the context of milk yield, milk fat content and milk fatty acid composition. Prerequisite for this investigation was the development of a Western blot methodology adapted for bovine mammary gland tissue using two different primary antibodies to specifically detect and differentiate between precursor (pSREBP-1, 125kDa) and transcriptionally active SREBP-1 (mSREBP-1, 68kDa).Upon a ten-week feeding intervention, significantly reduced milk fat contents, total saturated fatty acid amounts and single saturated fatty acid concentrations (C10:0, C12:0, C14:0, C16:0) were obtained in LINA and SUNA group, whereas milk yields did not substantially differ between feeding groups. The assumption that the effects of plant oil/DHA rich algae supplementation on milk fat composition were mediated by shifted SREBP-1 protein expression were only confirmed in regard to slightly reduced protein expression levels of pSREBP-1 in SUNA group tissue samples (P=0.087), whereas similar protein expression levels of transcriptionally active mSREBP-1 were found in SAT, LINA and SUNA group.
[Show abstract][Hide abstract] ABSTRACT: This study was conducted to evaluate if supplementing bypass fat to cows under silvopastoral systems, increases the concentration of unsaturated fatty acids in milk, thus improving the saturated/ unsaturated ratio without a negative effect on total milk yield in fat or protein. Two concentrations of two different sources of bypass fat were evaluated for 40 days, each in a group of 24 multiparous Lucerna (Colombian breed) cows. A cross-over design of 8 Latin squares 3 x 3 was used. The variables submitted to analysis were body condition, daily milk production and milk composition. Body condition, milk yield and milk quality were not different but there was a significant decrease in the amount of saturated fatty acid in both experiments while the unsaturated fat increased significantly in experiment 1 and remained stable in experiment 2. Results, such as these have as far as we know, not been reported previously and they provide an approach for the improvement of milk as a "functional food".
Tropical Animal Health and Production 05/2008; 40(3):209-16. · 1.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It was estimated the effect of rumen protected fat during the suckling period (7 months with the permanent presence of the calf), in 30 Angus/Zebu (AxZ) and 18 Zebu (Z) first calving cows. Mothers body weight and body condition (BC) were recorded. The weight of calves was also analyzed. Supplementation finished at weaning. The cows and the calves grazed on brachiaria (mixture of Brachiaria decumbens y Brachiaria humidicola) with amounts of dry green matter (DGM) varying from 1587 kg DGM/ha during the rainy period (August to November) to 175 kg DGM/ha in the transition and the dry period (December to April). The data corresponding to each genetic group were analyzed independently using a mixed model with repeated measurement data. Supplemented Z cows (n=12) as well as their controls (Z cows not receiving bypass fat) lost weight all along the seven months suckling but maintained a better BC up to the fourth month after parturition (p