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In this experiment sunflower oil, soybean oil and fish oil were incubated in rumen-fistulated adult ewes (n = 5) to study conjugated linoleic acid (CLA) production in the rumen. The individual oils were incubated in nylon bags in the rumen on perlite carrier (40% oil, 60% carrier) over a period of 2, 4, 6, 8, 10 and 12 h for all treatments. During the incubation of each oil primarily the formation of the cis-9, trans-11 isomer of CLA could be observed. Both sunflower and soybean oils showed similar changes in the rumen. After the incubation of these two vegetable oils the proportion of linoleic acid decreased significantly as the duration of incubation increased in the rumen. These changes were accompanied by a significant increase in the amount of cis-9, trans-11 CLA. However, in the case of sunflower oil the rate of formation of the cis-9, trans-11 CLA isomer was significantly higher after the different incubation times as compared to soybean oil. Much lower amounts of CLA were formed when fish oil was incubated in the rumen. The level of cis-9, trans-11 isomer produced during these treatments was 10% less than the amount obtained with the other two oils of vegetable origin. Besides the cis-9, trans-11isomer, trans-10, cis-12 CLA could also be detected during the incubation of the different oils in the rumen. However, the level of this isomer was low and did not show consistent differences among the treatments. The results of this experiment indicate that the fatty acid composition of the oils and the duration of incubation collectively determine the amount of CLA produced in the first compartment of the forestomach of ruminants.
An experiment was performed to study the effect of different vegetable oils containing high proportions of PUFA (5% soybean oil, SBO; and sunflower oil, SFO; respectively, in the DM of concentrate) or grass silage (150 g DM/d/animal, GSL) on the level of conjugated linoleic acid (CLA) isomers and other C18 fatty acids in muscle and adipose tissues of growing lambs. Control animals were fed on the same diet as SBO or SFO groups; however, instead of vegetable oils hydrogenated palm oil containing low level of PUFA was applied. In both muscle and adipose samples tested c-9, t-11 C18:2 showed the highest levels among the CLA isomers, however, t-10, c-12 CLA could also be measured in lower proportions. Considering vegetable oil supplementations, only SBO resulted in a significantly higher level of c-9, t-11 CLA in the triceps brachii muscle as compared to the control. Such a difference could not be detected in either the gracilis muscle or in the adipose tissue samples. However, lambs fed on the GSL diet had significantly higher c-9, t-11 CLA levels in both the triceps and gracilis muscles and lower proportion of t-10, c-12 CLA in the adipose than those fed on the control, SBO and SFO diets, respectively. Concerning C18 fatty acids other than CLA, SFO lambs showed significantly higher proportions of C18:1n-9 than those of control animals in both muscles and perirenal fat tested. However, level of C18:0 in the adipose tissue of GSL lambs was significantly lower than that of the animals fed both control or vegetable oil supplemented diets. Results of this experiments show that different dietary fatty acid sources have various potential to increase CLA contents in the meat of lambs. In addition to vegetable oils rich in PUFA, grass silage may be good dietary source for nutritional manipulation of the fatty acid composition of lamb meat.
Chañar (Geoffroea decorticans- Fabaceae) is a tree from South America that is normally infected with galls originated by insects. One of its parasites is Allodiplosis crassa (Cecidomyiidae, Diptera) which produces globular galls with sticky prolongations. Since this plant has medicinal uses in Argentina, its infestation could alter the quality of the plant drug. The surface of insect-induced galls usually contains defensive features such as trichomes, increased hardness and an increase in the content of polyphenolic compounds. The objective of this research is to assess the structural and histochemical features of the gall and to compare the content of polyphenolic metabolites in the gall, in the healthy leaf and in lignified stems of G. decorticans. The methanolic extract from the galls showed the highest amount of polyphenolic and proanthocyanidins and the lowest amount of hydroxycinnamic derivatives and flavonoids compared to the methanolic extract of the leaves. The photographs taken from the external surface of the gall showed that some prolongations have heads. The histochemical analysis showed that the prolongations have a high amount of proanthocyanidins and flavonoids; and that the heads are reactive to Sudan III. These phytochemical and histological characteristics may have a defensive role against harmful fungi and parasites that attack the larvae of the A. crassa. The results of this study show the presence of defensive features in an insect-induced gall of a medicinal plant with potential implications in the pharmacological activity of this species. This is the first report of a histochemical and phytochemical study in G. corticans galls.
The purpose of the present study was to investigate the effect of experimental T-2 toxin load (2.35 mg/kg of feed) and vitamin E supply in the drinking water (10.5 mg/bird/day) on vitamin E levels of the blood plasma and liver in broiler chickens in a 14-day experiment. It was found that T-2 toxin load did not influence vitamin E content of the blood plasma except at day 3 after the toxin load when a moderate increase was detected in plasma vitamin E. No significant changes were found in vitamin E content of the liver. The simultaneous use of high-dose vitamin E supplementation and T-2 toxin load caused a significantly higher plasma vitamin E content but the changes were less expressed in the group subjected to T-2 toxin load. Vitamin E supply also resulted in a marked and significant increase in vitamin E concentrations of the liver on days 3 and 7 even in the T-2 loaded group, but this concentration significantly decreased thereafter. The results show that T-2 contamination of the diet has an adverse effect on the utilisation of vitamin E in broiler chickens.
The influence of fish oil (highly unsaturated) and beef tallow (highly saturated) with vitamin E (100 IU/kg) supplementation on the antioxidant status of broiler chicken cockerels was investigated. Chicks were fed a control diet with no added fat, 40 g/kg each of fish oil and beef tallow diets, respectively, from 11 to 42 days of age. Tocopherol concentration and the rate of lipid peroxidation, thiobarbituric acid reactive substance (TBARS) in liver, fatty acid composition of the liver lipids, blood serum total antioxidant status (TAS), and reduced glutathione (GSH) content were determined. Vitamin E supplementation of the diet increased liver ?-tocopherol content in chicks regardless of the type of dietary fat. Fish oil diet resulted in higher liver TBARS value while beef tallow diet showed lower values compared to the control diet. Vitamin E supplementation reduced liver TBARS as well as serum GSH, and raised serum TAS for all diets. Serum GSH was the same for vitamin E supplemented diets regardless of the fat supplement. Fish oil diets resulted in a significant increase in hepatic lipid n-3 PUFA content. A significant positive correlation was found between liver TBARS and n-3 PUFA content. No relationships were established, however, between liver TBARS and n-6 PUFA or saturated fatty acids. The results suggest that feeding oils rich in n-3 PUFA increases tissue concentration of these fatty acids, consequently increasing tissue lipid peroxidation and reducing the antioxidative status of broiler chickens. Supplementing high levels of vitamin E with such oils may increase tissue oxidative stability. Serum TAS or GSH may be used as a measure of antioxidative status in chickens.
In the past years several methods have been developed for the determination of the proportion of the nitrogen-containing substances of microbial origin passed from the rumen into the abomasum or the small intestine. Recently, on examining the D-amino acid content of foodstuffs, particularly milk and milk products, it has been observed that, in addition to D-Ala, D- glutamic acid (D-Glu) and D-aspartic acid (D-Asp) can also be detected in similar quantities, primarily in products which have links with bacterial activity. This gave rise to the idea of examining the diaminopimelic acid (DAPA), D-Glu and D-Asp content of bacteria extracted from the rumen of cattle and that of chyme from the same cattle, in order to determine the type of relation existing among these three components, and to establish whether D-Asp and D-Glu can be used in the estimation of protein of bacterial origin. On determination of the DAPA, D-Asp and D-Glu content by means of amino acid analyser and high performance liquid chromatography of duodenal chyme from five growing bulls and of ruminal bacteria from the same bulls, the following values were established. For chyme (and, in brackets, for ruminal bacteria) r value calculated by means of linear regression was 0.78 (0.76) between DAPA and D-Asp, and 0.70 (0.81) between DAPA and D-Glu. The r values between the crude protein content of ruminal bacteria and the markers examined were found to be the following: DAPA, 0.74; D-Asp, 0.73; D- Glu, 0.61. In the model experiment performed for the re-obtaining of values for protein of bacterial origin the theoretical values were determined on the basis of D-Asp and D-Glu and values approximately 10% higher than the theoretical value on the basis of DAPA. It is therefore recommended that in addition to DAPA these other two amino acids be included among the bacterial protein markers.
