The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how ... more The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how these are affected by different conditions during confinement in a mixed system (MS:grazing + total mixed ration:TMR) is not known. The aim of this study was to compare the FAs of the milk and cheese from MS in a compost-bedded pack barns (CB-GRZ) versus an outdoor soil-bedded pen (OD-GRZ) during confinement, and with a confinement system (100%TMR) in a compost-bedded pack barns (CB-TMR). Individual milk samples (n = 12 cows/group), cheese, and pooled milk (MilkP) samples were collected. The saturated FA percentages in the milk and the omega 6/omega 3 ratio in the MilkP and cheese were greater for the CB-TMR (p < 0.0001), while the unsaturated and monounsaturated FA percentages in the milk were lower for the CB-TMR than the MS (p < 0.001). The milk n-3, C18:3, and conjugated linoleic acid percentages were lower for the CB-TMR than the MS (p < 0.001). The milk n-3 and C18:3 were ...
Journal of Animal Physiology and Animal Nutrition, 2017
Milk fatty acid (FA) profiles were determined in Holstein cows (n = 27) fed total mixed rations (... more Milk fatty acid (FA) profiles were determined in Holstein cows (n = 27) fed total mixed rations (TMR) ad libitum (G0) or diet composed by TMR (50% dry matter [DM] offered) plus grazing of pasture with 6 hr of access time to paddock in one session (G1) or 9 hr in two sessions (G2) at 45 days in milk (DIM). Moreover, milk FA was determined at 65 DIM when G0 cows turned out to G1 diet without adaptation period (Post-G0), G1 remained as controls. Milk FA was quantified using gas chromatography and mass spectrometry. Preformed FA at 45 DIM was greater (+27%) for G2 than G0 cows (p < .05). Stearic acid (C18:0) was 30% greater for G2 cows (p < .05). De novo FA was lowest for G2 cows (p < .05). Conjugated linoleic acid (CLA) did not differ (p < .12), while vaccenic acid (C18:1trans) was twofold greater for grazing treatments (p < .01).
The rice crop is one of the most developed agricultural activities in Uruguay, having become the ... more The rice crop is one of the most developed agricultural activities in Uruguay, having become the third item of export. Although the main product of the rice chain is the elaborated rice, in the recent years several industries have begun to produce co-products of rice: crude rice oil and refined oil, rice flour and cookies. The production of crude oil begins with ground, peeled and polished rice grain. This product can be used in animal nourishment or in oil extraction. Refinement from the crude rice oil takes the same steps than any other vegetable oil. As any other vegetable oil, rice oil is very prone to oxidation, this is due to the high percentage of polyinsaturated acids, despite the vitamin E content and its role of antioxidant. Therefore, sometimes additional stabilization is needed. The main purpose of this work is to characterize the Uruguayan Rice Oils by determining the following parameters: profile of fatty acids, alpha tocopherol, Iodine Index, Refraction Index, Saponification Index, Unsaponifiable Matter and Density at 20oC. The Norm used as reference was the American Oil Chemistry Society. In this condition the statistical analysis performed shows that there is not a model that could explain the variability of the studied factors nor reduce the number of factors that must be taken into consideration. The Kolmogorov-Smirnov test, performed according to Lillieford correction to verify normality, showed that distribution of fluctuations that correspond to the three most abundant fatty acids studied (16:0, 18:1 and 18:2) can be considered as normal. The obtained values for the insaturated fatty acids were from15.6 to18.2 for 16:0, from 42.1 to 43.8 for 18:1 and from 34.8 to 37.4 for 18:2. These results obtained were correlated with the high values of the Iodine Index: 100.6 - 101.8. Results of vitamin E expressed as alpha tocopherol are between 7 and 35 mg/100g, but in 75% of the cases the results oscillated between 18 and 26 mg/100g. As the study of the residuals does not show evidence of lack of linear fit, we do not discard such adjust in this instance. Therefore it is possible that, introducing a substantially larger quantity of samples than the ones performed in the present preliminary study, could enable to find an appropriate and relatively simple model, which could explain the linear fit.
This study is aimed at comparing the milk fatty acid profile (FAP) of cows that changed from a mi... more This study is aimed at comparing the milk fatty acid profile (FAP) of cows that changed from a mixed system (MS) of double grazing plus total mixed ration (TMR) to a total confinement system (TCS, 100% TMR) with cows that changed to another MS with one overnight grazing plus TMR and compare with cows that were kept unchanged in TCS. The diet change was made in the second month of lactation. The milk samples were collected at one (M1-spring) and three months of lactation (M3-summer). Three treatments are as follows (each n = 10): confined cows fed with TMR throughout the period (GTMR), cows that changed from MS with double grazing plus TMR in M1 to TCS in M3 (GCHD), and cows that changed from a MS with double grazing plus TMR in M1 to a MS with overnight grazing plus TMR in M3 (GTMR+P). Unlike GTMR+P, GCHD improved milk production after change (increased 14% from M1 to M3), but milk FAP was impaired. In M3, conjugated linoleic acid (C18 : 2-CLA) in GTMR and GCHD was lower than GTMR+P...
La proteccion de los microorganismos mediante microencapsulacion se desarrolla en forma creciente... more La proteccion de los microorganismos mediante microencapsulacion se desarrolla en forma creciente, donde es importante encontrar un soporte adecuado que sea biocompatible y estable en el tiempo. En este trabajo se estudiaron tres sistemas de encapsulacion de una levadura "Kluyveromyces marxianus" con el fin de poder obtener un sistema estable que permita fermentaciones en sustratos con presencia de inhibidores como derivados de lignina y subproductos de hemicelulosa. La fermentacion alcoholica con Kluyveromyces libre presenta una disminucion en el rendimiento del 50 y 75% cuando se trabaja con inhibidores fenolicos y de xilano, respectivamente. Kluyveromyces encapsulado en alginato presenta una disminucion del rendimiento de la produccion de alcohol del 50 y 60%, respectivamente, mientras que encapsulado en quitosano la disminucion del rendimiento es del 25 y 30%, respectivamente. La encapsulacion en PVA presenta una disminucion del rendimiento del 20 y 10%, respectivamente. Todos los sistemas permitieron desarrollar el crecimiento y fermentar azucares a altas temperaturas, siendo la encapsulacion en PVA la mas adecuada probablemente por el tamano pequeno de las particulas, que aumenta la superficie de accion. Consideramos que es un buen sistema de fermentacion para procesos que utilizan lignocelulosicos como materia prima obteniendo buena proteccion y aumentando los rendimientos productivos.
Journal of Animal Physiology and Animal Nutrition, 2012
The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving ... more The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (-30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ-casein was greater, and β-casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ-casein fraction was affected by BCS at -30 days as PL showed a higher concentration than PH. The de novo (4:0-15:1) and mixed-origin fatty acids (16:0-16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High-BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n-6 and n-3 fatty acids in milk fat than low-BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre-calving period (BCS at -30 days) in cows under grazing conditions.
In this study the effect of vacuum frying (VF) and traditional frying (TF) on oil degradation, fa... more In this study the effect of vacuum frying (VF) and traditional frying (TF) on oil degradation, fatty acid composition and alpha-tocopherol content was investigated. Two different refined sunflower oils were used: sunflower oil with high oleic acid content (HOSO) and sunflower oil with synthetic antioxidant (tertiary-butylhydroquinone) (TBHQ-SO). Oil degradation was monitored by measuring the free acidity (FFA), peroxide (PV), p-anisidine (p-AV),) total polar compounds (TPC) and oxidative stability (OE). Oils samples were taken every 4h of frying during 10 consecutive days. Values of FFA, p-AV, TPC using TBHQ-SO with traditional frying were (0.201, 207.0, 25.0) significantly higher than the obtained values with vacuum frying (0.073, 25.8, 11.2). The same parameters by using HOSO were (0.327, 82.0, 21.9) with traditional frying and (0.099, 33.3, 6.4) with vacuum frying. The EO was 2.44 and 7.95 with TBHQ-SO traditional and vacuum frying respectively, and with for HOSO 0.65 and 2.67, respectively. The polyunsaturated fatty acids percentage decreased in all treatments except in TBHQ-SOv. The alpha-tocopherol content decreased in all treatments at different rates. At the end of the frying processes the percentages of alpha-tocopherol reduction were TBHQ-SOv (4.90%), TBHQ-SOt (53.62%), HOSOv (96.87%), HOSOt (99.76%).
The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how ... more The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how these are affected by different conditions during confinement in a mixed system (MS:grazing + total mixed ration:TMR) is not known. The aim of this study was to compare the FAs of the milk and cheese from MS in a compost-bedded pack barns (CB-GRZ) versus an outdoor soil-bedded pen (OD-GRZ) during confinement, and with a confinement system (100%TMR) in a compost-bedded pack barns (CB-TMR). Individual milk samples (n = 12 cows/group), cheese, and pooled milk (MilkP) samples were collected. The saturated FA percentages in the milk and the omega 6/omega 3 ratio in the MilkP and cheese were greater for the CB-TMR (p < 0.0001), while the unsaturated and monounsaturated FA percentages in the milk were lower for the CB-TMR than the MS (p < 0.001). The milk n-3, C18:3, and conjugated linoleic acid percentages were lower for the CB-TMR than the MS (p < 0.001). The milk n-3 and C18:3 were ...
Journal of Animal Physiology and Animal Nutrition, 2017
Milk fatty acid (FA) profiles were determined in Holstein cows (n = 27) fed total mixed rations (... more Milk fatty acid (FA) profiles were determined in Holstein cows (n = 27) fed total mixed rations (TMR) ad libitum (G0) or diet composed by TMR (50% dry matter [DM] offered) plus grazing of pasture with 6 hr of access time to paddock in one session (G1) or 9 hr in two sessions (G2) at 45 days in milk (DIM). Moreover, milk FA was determined at 65 DIM when G0 cows turned out to G1 diet without adaptation period (Post-G0), G1 remained as controls. Milk FA was quantified using gas chromatography and mass spectrometry. Preformed FA at 45 DIM was greater (+27%) for G2 than G0 cows (p < .05). Stearic acid (C18:0) was 30% greater for G2 cows (p < .05). De novo FA was lowest for G2 cows (p < .05). Conjugated linoleic acid (CLA) did not differ (p < .12), while vaccenic acid (C18:1trans) was twofold greater for grazing treatments (p < .01).
The rice crop is one of the most developed agricultural activities in Uruguay, having become the ... more The rice crop is one of the most developed agricultural activities in Uruguay, having become the third item of export. Although the main product of the rice chain is the elaborated rice, in the recent years several industries have begun to produce co-products of rice: crude rice oil and refined oil, rice flour and cookies. The production of crude oil begins with ground, peeled and polished rice grain. This product can be used in animal nourishment or in oil extraction. Refinement from the crude rice oil takes the same steps than any other vegetable oil. As any other vegetable oil, rice oil is very prone to oxidation, this is due to the high percentage of polyinsaturated acids, despite the vitamin E content and its role of antioxidant. Therefore, sometimes additional stabilization is needed. The main purpose of this work is to characterize the Uruguayan Rice Oils by determining the following parameters: profile of fatty acids, alpha tocopherol, Iodine Index, Refraction Index, Saponification Index, Unsaponifiable Matter and Density at 20oC. The Norm used as reference was the American Oil Chemistry Society. In this condition the statistical analysis performed shows that there is not a model that could explain the variability of the studied factors nor reduce the number of factors that must be taken into consideration. The Kolmogorov-Smirnov test, performed according to Lillieford correction to verify normality, showed that distribution of fluctuations that correspond to the three most abundant fatty acids studied (16:0, 18:1 and 18:2) can be considered as normal. The obtained values for the insaturated fatty acids were from15.6 to18.2 for 16:0, from 42.1 to 43.8 for 18:1 and from 34.8 to 37.4 for 18:2. These results obtained were correlated with the high values of the Iodine Index: 100.6 - 101.8. Results of vitamin E expressed as alpha tocopherol are between 7 and 35 mg/100g, but in 75% of the cases the results oscillated between 18 and 26 mg/100g. As the study of the residuals does not show evidence of lack of linear fit, we do not discard such adjust in this instance. Therefore it is possible that, introducing a substantially larger quantity of samples than the ones performed in the present preliminary study, could enable to find an appropriate and relatively simple model, which could explain the linear fit.
This study is aimed at comparing the milk fatty acid profile (FAP) of cows that changed from a mi... more This study is aimed at comparing the milk fatty acid profile (FAP) of cows that changed from a mixed system (MS) of double grazing plus total mixed ration (TMR) to a total confinement system (TCS, 100% TMR) with cows that changed to another MS with one overnight grazing plus TMR and compare with cows that were kept unchanged in TCS. The diet change was made in the second month of lactation. The milk samples were collected at one (M1-spring) and three months of lactation (M3-summer). Three treatments are as follows (each n = 10): confined cows fed with TMR throughout the period (GTMR), cows that changed from MS with double grazing plus TMR in M1 to TCS in M3 (GCHD), and cows that changed from a MS with double grazing plus TMR in M1 to a MS with overnight grazing plus TMR in M3 (GTMR+P). Unlike GTMR+P, GCHD improved milk production after change (increased 14% from M1 to M3), but milk FAP was impaired. In M3, conjugated linoleic acid (C18 : 2-CLA) in GTMR and GCHD was lower than GTMR+P...
La proteccion de los microorganismos mediante microencapsulacion se desarrolla en forma creciente... more La proteccion de los microorganismos mediante microencapsulacion se desarrolla en forma creciente, donde es importante encontrar un soporte adecuado que sea biocompatible y estable en el tiempo. En este trabajo se estudiaron tres sistemas de encapsulacion de una levadura "Kluyveromyces marxianus" con el fin de poder obtener un sistema estable que permita fermentaciones en sustratos con presencia de inhibidores como derivados de lignina y subproductos de hemicelulosa. La fermentacion alcoholica con Kluyveromyces libre presenta una disminucion en el rendimiento del 50 y 75% cuando se trabaja con inhibidores fenolicos y de xilano, respectivamente. Kluyveromyces encapsulado en alginato presenta una disminucion del rendimiento de la produccion de alcohol del 50 y 60%, respectivamente, mientras que encapsulado en quitosano la disminucion del rendimiento es del 25 y 30%, respectivamente. La encapsulacion en PVA presenta una disminucion del rendimiento del 20 y 10%, respectivamente. Todos los sistemas permitieron desarrollar el crecimiento y fermentar azucares a altas temperaturas, siendo la encapsulacion en PVA la mas adecuada probablemente por el tamano pequeno de las particulas, que aumenta la superficie de accion. Consideramos que es un buen sistema de fermentacion para procesos que utilizan lignocelulosicos como materia prima obteniendo buena proteccion y aumentando los rendimientos productivos.
Journal of Animal Physiology and Animal Nutrition, 2012
The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving ... more The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (-30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ-casein was greater, and β-casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ-casein fraction was affected by BCS at -30 days as PL showed a higher concentration than PH. The de novo (4:0-15:1) and mixed-origin fatty acids (16:0-16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High-BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n-6 and n-3 fatty acids in milk fat than low-BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre-calving period (BCS at -30 days) in cows under grazing conditions.
In this study the effect of vacuum frying (VF) and traditional frying (TF) on oil degradation, fa... more In this study the effect of vacuum frying (VF) and traditional frying (TF) on oil degradation, fatty acid composition and alpha-tocopherol content was investigated. Two different refined sunflower oils were used: sunflower oil with high oleic acid content (HOSO) and sunflower oil with synthetic antioxidant (tertiary-butylhydroquinone) (TBHQ-SO). Oil degradation was monitored by measuring the free acidity (FFA), peroxide (PV), p-anisidine (p-AV),) total polar compounds (TPC) and oxidative stability (OE). Oils samples were taken every 4h of frying during 10 consecutive days. Values of FFA, p-AV, TPC using TBHQ-SO with traditional frying were (0.201, 207.0, 25.0) significantly higher than the obtained values with vacuum frying (0.073, 25.8, 11.2). The same parameters by using HOSO were (0.327, 82.0, 21.9) with traditional frying and (0.099, 33.3, 6.4) with vacuum frying. The EO was 2.44 and 7.95 with TBHQ-SO traditional and vacuum frying respectively, and with for HOSO 0.65 and 2.67, respectively. The polyunsaturated fatty acids percentage decreased in all treatments except in TBHQ-SOv. The alpha-tocopherol content decreased in all treatments at different rates. At the end of the frying processes the percentages of alpha-tocopherol reduction were TBHQ-SOv (4.90%), TBHQ-SOt (53.62%), HOSOv (96.87%), HOSOt (99.76%).
Uploads
Papers by Laura Olazabal