Einfluß von Futterfetten auf die Qualität tierischer Veredlungsprodukte

Effects of Feed Fats on Quality of Animal Product At the same level of energy supply intake of fats/oils do not lead to a higher fat deposition in the carcass. Additionally, fats are carrier of fat soluble vitamins A, D, E, K and improve their absorption from the intestinal tract. The fatty acid profile of fat deposited in the organism, as for example in egg yolk is influenced by the intake of fatty acids provided by feed. This especially concerns linoleic- and linolenic acid as well as lauric- and myristic acid, High contents of polyunsaturated fatty acids negatively influence oxidative stability as well as consistency of body fat and therefore quality of animal products. An improved oxidation protection can be carried out by supplementation of antioxidants. Medium-chain, saturated fatty acids reveal positive effects on both criteria.     

Effect of soy oil supplementation and protein level in laying hen diets on praecaecal nutrient digestibility,performance, reproductive performance,fatty acid composition of yolk fat,and on other egg quality parameters

An experiment was carried out with laying hens in the age of 22—45 weeks to examine the effects of added soy oil (0%, 3.5%, 7%, 10.5%, and 14%) and dietary protein level (13.2% and 16.3%) on laying and reproductive performance, fatty acid composition of yolk fat, and other egg quality parameters. Moreover, digestibility of nutrients and of energy was determined by using a marker technique. Laying intensity and feed intake were not influenced by dietary treatments whereas egg weight and daily egg mass production were significantly improved by soy oil addition in a non‐linear related manner. The feed conversion ratio reached a minimum at soy oil proportions between 3.5% and 10.5%. Reproductive performance in terms of fertilized eggs, hatchability, and mortality of chicks was not affected by dietary treatments. The increase of egg weights due to soy oil addition was accompanied by a simultaneous increase in the proportion of albumen and a decrease of yolk and shell percentage. Palmitic acid (C16:0) and oleic acid (C18:1) proportions in yolk fat decreased as soy oil addition was increased whereas the proportions of linoleic acid (C18:2 n‐6), linolenic acid (C18:3 n‐3), and docosahexaenoic acid (C22:6 n‐3) were increased at the same time. Praecaecal digestibility of crude fat and fatty acids of the diets were non‐linearly improved by soy oil addition. Digestibility of crude protein and amino acids were not affected by either protein content of the diet or by soy oil supplementation. In conclusion, a decrease in dietary protein content from 16.3% to 13.2% did not negatively influence performance of hens and egg quality under the experimental conditions applied. Soy oil addition improved egg quality.     

Effect of browning reaction products of phospholipids on autoxidation of methyl linoleate

Methyl linoleate was allowed to autoxidize in bulk phase at 50 C in the presence of either synthetic phospholipids consisting of saturated fatty acids or egg yolk phospholipids to estimate the effect of base group and fatty acid moiety of phospholipids on oil autoxidation. Dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylethanolamine (DPPE) exhibited poor antioxidant activity at 50 C and showed no synergistic effect with α-tocopherol. The addition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of egg yolk accelerated the oxidation of methyl linoleate. However, egg yolk PC and PE collected at various stages of heating at 180 C inhibited hydroperoxide formation at the initial stage of oxidation. This effect could be attributed to the browning products formed during heating reaction. Thus, browning color products formed from unsaturated phospholipids at high temperatures may influence oil stability, although the base group of phospholipids did not exert any significant effect.     

Encapsulation of Long-Chain n-3 Polyunsaturated Fatty Acids Using Egg Yolk

Egg yolk is well known for its excellent emulsifying property. In this article, egg yolk was used as the encapsulating matrix to prevent the oxidation of n-3 long-chain polyunsaturated fatty acids from fish oil. A 2 × 2 × 5 complete block design with three replications was used. Two levels of fish oil (1% and 5%) and two levels of esterification type (triglycerides or ethyl esters) of eicosapentaenoic/docosahexaenoic fatty acids were used. Time was considered a fixed factor with five levels. Emulsions were prepared by homogenization and stored for up to 4 weeks at 4–6 °C, with weekly sampling. Emulsions were analyzed for particle size and distribution, encapsulation efficiency, and surface oil. The oxidative stability of the emulsions was evaluated before and after cooking at 150–170 °C for 75 s. The addition of triglycerides resulted in a larger average particle size (234 ± 12.4 nm). All emulsions achieved 100% encapsulation efficiency and showed no significant change in the surface oil concentration during storage. After 4 weeks of storage, the concentration of eicosapentaenoic + docosahexaenoic fatty acids in nonencapsulated fish oil triglycerides and ethyl esters decreased by 20.32% and 14.74%, respectively, while the emulsions showed no significant differences. In addition, no peroxide or propanal formation was detected in raw emulsions over the storage period. Propanal formation was negligible in cooked samples, and the peroxide value showed no differences between the egg yolk control and the emulsions. Therefore, egg yolk was observed to be an efficient encapsulating food matrix that protects n-3 polyunsaturated fatty acids against oxidation and degradation.     

Einfluß gestaffelter Rapssaatanteile im Legehennenfutter auf das Fettsäurenmuster des Eifettes unter besonderer Berücksichtigung der polyungesättigten Fettsäuren

Influence of Graded Levels of Rape Seed in Laying Hen Diets on the Fatty Acid Composition of the Yolk Fat with Special Consideration of the Polyunsaturated Fatty Acids Technical treated rape seed was evaluated as feed ingredient for laying hens and the influence of rape oil on the fatty acid composition of the egg yolks was also investigated. Rape seed levels of 7.5%, 15% and 22.5% were fed both to brown and white laying hens (Lohmann Brown, LB, and Lohmann Selected Leghorn, LSL, resp.). A depression in performance was recorded only with the highest rape inclusion level for the parameters feed conversion (LB-hens) and daily egg production (LSL-hens). The fatty acid composition of the egg yolk was influenced in a dose-response related manner. The percentage of the saturated fatty acids decreased with increasing levels of rape seed whereas the mono-unsaturated fatty acids and the n-6 polyunsaturated fatty acids were hardly influenced. The level of the polyunsaturated n-3 fatty acids was characterized by a strong dose-dependent increase. In addition, long chained polyunsaturated fatty acids of the n-3 family - not present in rape oil - were detected in the yolks.     

Influence of a modified fatty acid profile of egg yolk fat on technological properties of hen's eggs

A feeding experiment with brown layers was carried out to find effects of graded levels of rapeseed (without, 15% and 30%) in layer diets on the fatty acid composition of egg yolk and related functional properties of such modified eggs. A considerable increase of the content of essential n-3 fatty acids in egg yolk fat was noticed by including graded levels of rapeseed in layer diets. The destruction force of a gel prepared from whole egg was improved by the highest rapeseed level (30%) and emulsifying capacity by medium inclusion of rapeseed in layer diets (15%). The thermal stability of an emulsion prepared from whole egg was not influenced by rape feeding. Viscosity of mayonnaise prepared from egg yolk and whole egg yolk was decreased by increased rapeseed levels in the diets. In tendency, organoleptic evaluation of sponge cake prepared from whole egg revealed better results for the control group. The baking height of sponge cake was improved by rapeseed inclusion in layer diets. It may be assumed that all these changes caused by rapeseed feeding are closely related to the mentioned changes in the fatty acid profile.     

Über trans-Lipoide: Die Lipoide des Hühnerei-Dotters

Trans Lipids: The Egg Yolk Lipids of the Hen The feeding of hens with a trans-containing edible fat resulted in an increase in the trans fatty acids of the egg yolk lipids to the extent of 10%, which completely disappeared within 14 days after stopping the trans-containing feed. The fatty acids in the triglyceride fractions contained in each case more trans unsaturated fatty acids than those in the corresponding phosphatide fractions. The gas chromatographic analysis of the fatty acid methyl esters showed that the triglycerides contained more oleic acid than the phosphatide fatty acids whereas stearic as well as polyunsaturated components were concentrated predominently in the phosphatides. The analysis of the fatty acid methyl esters from triglyceride and phosphatide fractions after feeding of trans-containing fat showed distinct changes in both the groups, thus for example a reduction of oleic acid in the neutral fat analogous to that in the total lipids as against its increase in phosphatides. The amount of linoleic acid in the phosphatide fatty acids increased while it remained constant in triglyceride fatty acids.     

Egg Yolk as Means for Providing Essential and Beneficial Fatty Acids

The new American Dietary Guidelines now recommend optimizing the types of fat consumed instead of reducing or eliminating fat from the diet. Chicken eggs are a means to deliver essential and beneficial human dietary fatty acids (FA), and can be staple component of healthy eating behavior. Additionally, polyunsaturated fatty acids can be increased in the avian egg yolk by simply incorporating selected lipid sources into the avian diet. Poultry feed rich in omega‐3 FA (omega‐3) has allowed commercialization of enriched eggs containing up to 600 mg of omega‐3. Conjugated linoleic acid (CLA) has also been used in the research setting to enrich eggs to provide a portion of the 3–4 g CLA day^?1 needed to promote weight loss to combat obesity. However, Americans consume only 50% of the omega‐3 recommended adequate intake, and average CLA consumption is under 600 mg day^?1. While a variety of foods are naturally rich in omega‐3, conventional sources of CLA are limited to bovine milk and meat, which do not provide enough CLA to produce clinical effects in a balanced diet. Since eggs and egg‐based products are common in the Western diet, eggs enriched with both omega‐3 and CLA using dietary additions to poultry feed may promote consumption of the recommended levels of these FA. This article reviews the design of poultry eggs with enhanced lipid profiles through dietary intervention, and discusses the future direction of enriched egg research.     

Hen egg yolk and white contain high amounts of lysophosphatidic acids, growth factor-like lipids: Distinct Molecular species compositions

Hen egg yolk and white were found to contain high amounts of lysophosphatidic acid (acyl LPA) in addition to small amounts of lysoplasmanic acid (alkyl LPA). The levels of acyl LPA in hen egg yolk (44.23 nmol/g tissue) and while (8.81 nmol/g tissue) were on the same order as or higher than the levels of acyl LPA known to be required to elicit biological responses in various animal tissues. Noticeably, there is a marked difference between the fatty acid composition of egg yolk acyl LPA and of egg white acyl LPA; egg yolk acyl LPA predominantly contains saturated fatty acids as the acyl moiety, whereas egg white acyl LPA primarily contains polyunsaturated fatty acids. We found that the level of acyl LPA, especially polyun-saturated fatty acid-containing acyl LPA, in egg white was augmented markedly during the incubation at 37°C, while there was no change in egg yolk. We confirmed that egg white contains both the substrate, i.e., polyunsaturated fatty acid-containing lysophosphatidylcholine (LPC), and the enzyme activity catalyzing the hydrolysis of polyunsaturated fatty acid-containing LPC to the corresponding acyl LPA. Egg yolk LPA and egg white LPA may play separate physiological roles in the development, differentiation, and growth of embryos.     

Dietary modifications of animal fats: status and future perspectives

The purpose of modifying animal fats is to produce high quality products, which meet the dietary recommendations for a reduced intake of fat in the human diet, notably that of certain saturated fatty acids and cholesterol, and an increased intake of mono- (MUFA) and polyunsaturated fatty acids (PUFA) in order to minimize the risk for obesity, cancer, cardiovascular, and other life-style diseases. The body fat of farm animals is partly synthesized from dietary carbohydrates, partly from dietary fatty acids. In monogastric animals, preruminants and poultry PUFAs are readily absorbed and deposited in the edible parts of the body and incorporated into egg yolk lipids. In ruminants, however, PUFAs are hydrogenated to mainly saturated fatty acids by the rumen microorganisms with some formation of MUFAs, trans-, odd-, branched chain, and conjugated fatty acids. The latter fatty acids are absorbed, deposited in adipose and muscle tissue and incorporated into milk lipids, unless dietary PUFAs are protected against hydrogenation. Thus, it is relatively easy to change the fatty acid composition of pork, poultry meat, lamb, and veal, whereas beef and milk can only be enriched significantly with PUFAs by manipulation. Products enriched with PUFAs are, however, prone to oxidation, and enrichment with antioxidants, notably with dietary vitamin E, is necessary in order to prevent the risk of oxidative damage.     

Transfer of Lauric and Myristic Acid from Black Soldier Fly Larval Lipids to Egg Yolk Lipids of Hens Is Low

Implementing insects, such as the black soldier fly larvae (BSFL), as animal feed commonly includes the previous removal of substantial amounts of fat. This fat may represent an as yet underutilized energy source for livestock. However, transfer of lauric and myristic acid, prevalent in BSFL fat and undesired in human nutrition, into animal-source foods like eggs may limit its implementation. To quantify this, a laying hen experiment was performed comprising five different diets (10 hens/diet). These were a control diet with soybean oil and meal and a second diet with soybean oil but with partially defatted BSFL meal as protein source. The other three diets were based on different combinations of partially defatted BSFL meal and fat obtained by two different production methods. Lauric acid made up half of the BSFL fat from both origins. Both BSFL fats also contained substantial amounts of myristic and palmitic acid. However, in the insect-based diets, the net transfer from diet to egg yolk was less than 1% for lauric acid, whereas the net transfer for myristic and palmitic acid was about 30% and 100%, respectively. The net transfer did not vary between BSFL originating from production on different larval feeding substrates. The results illustrate that hens are able to metabolize or elongate very large proportions of ingested lauric acid and myristic acid, which are predominant in the BSFL lipids (together accounting for as much as 37 mol%), such that they collectively account for less than 3.5 mol% of egg yolk fatty acids.     

Incorporation of dietary linoleic and conjugated linoleic acids and related effects on eggs of laying hens

In the present study, laying hens received 29 g per kg diet of a preparation containing either 70% linoleic acid (LA) or approximately the same amount of conjugated linoleic acid (CLA) in the control and experimental treatments, respectively. The CLA preparation consisted predominantly of cis-9,trans-11 and trans-10,cis-12 fatty acid isomers as free fatty acids in a ratio of 1∶1. The diets were fed for 8 wk to determine the effect of dietary CLA on quality characteristics of eggs. In addition, the fatty acid composition of liver and heart was analyzed. Performance parameters (egg weight, feed efficiency) were not significantly affected by feeding the diets supplemented with CLA. The overall amount of CLA that was incorporated into yolk was 7.95 g CLA/100 g total fatty acids, or approximately 400 mg CLA/egg. The transfer efficiency of the cis-9,trans-11 isomer was higher than that of the trans-10,cis-12 isomer; however, the transfer rate of CLA isomers into yolk and tissues was significantly lower than that of linoleic acid. Dietary CLA increased the concentration of saturated fatty acids in yolk and tissues at the expense of monounsaturated fatty acids. The proportions of myristic, palmitic, and stearic acids in yolk lipids were also changed by dietary CLA. Additionally, long-chain polyunsaturated fatty acids (arachidonic acid and docosahexaenoic acid) were decreased without changing the balance of the n−6/n−3 ratio in egg yolk. The inclusion of CLA in layer diets altered the shape of the yolk and various egg parameters (albumen height, foam index, and yolk index). The results of this study indicate that CLA induces various changes in lipid and fatty acid metabolism of laying hens and affects quality characteristics of eggs.     

Lipid composition and peroxide levels of mucosal cells in the rat large intestine in relation to dietary fat

To examine whether dietary fat alters membrane lipid composition and peroxidation of polyunsaturated fatty acids in “non-proliferative” and “proliferative” cells in the large intestine, Sprague-Dawley rats were fed diets providing a polyunsaturated-to-saturated fatty acid ratio of 1.2 or 0.3 at a high or low level of fat intake for a 25-day period. Cell populations were isolated and the effect of dietary fat on membrane polyunsaturated fatty acid content and peroxide levels was determined. Neither fat level nor fatty acid composition of diet influenced total cholesterol, total phospholipids, and percentage of phospholipid classes in membrane phospholipids. Feeding the high fat and/or high polyunsaturated-to-saturated fatty acid ratio diet increased polyunsaturated fatty acid content of mucosal cell phospholipids. Increase in polyunsaturated fatty acid content was paralleled by a decrease in the monounsaturated fatty acid content of mucosal cell phospholipids. Membrane content of total saturated fatty acids was not significantly affected by diet. Variation in phospholipid fatty acid composition between “non-proliferative” and ”proliferative” cells was observed. Lipid peroxide levels in mucosal cell lipid fractions were altered by dietary fat treatment. Animals fed high fat diets, compared to groups fed low fat diets, exhibited higher membrane peroxide levels when results are expressed as nmol/mg protein. Higher peroxide levels were observed in mucosal cells for rats fed high polyunsaturated-to-saturated fatty acid ratio diets when results were expressed per nmol of phospholipid. It is concluded that changes in fat level and fatty acid composition of the diet alters the mucosal cell membrane lipid composition in the rat large intestine and influences susceptibility of mucosal cell lipid to peroxidation. Further research is required to delineate which dietary factors—fat level, polyunsaturated-to-saturated fatty acid ratio, or both—have a primary influence on the degree of lipid peroxidation.     

The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract.     

Verwendung von Futterfetten in der Tierernährung sowie ihr Einfluß auf die Qualität der Schlachtkörper

Use of Feed Fats for Animal Nutrition and their Influence on the Quality of the Slaughtered Bodies For about 40 years fats have become an important feed component in rations of agricultural working animals. An increase of fat use in compound feed up to forty times was noted in the period from 1955 to 1984. But still today there are signs of uncertainty concerning quality assessment and selection of fats for feeding the various working animals. Today the quality of feed fats can be determined by analysis methods which enable a relatively quick assessment. Unfortunately there is no official control so that at last the compound feed factories have to fulfil this task. As fats have in comparison to carbohydrates an energy value which is 2.3 times higher, the energy amount of the compound feed increases by their addition. Thus the improved genetic ability of putting on weight of the working animals can completely be made use of. A greater fattiness of slaughtered bodies is not caused by fat addition in balanced rations. Because of their variety of different fatty acids and above all by their differences in the consistency and oxidation stability fats are of great influence on the performance of the animals and their slaughtered body quality. Depending on the content of polyenic acids and their oxidation degree lower increases of weight and damages in the organism are possible. High amounts of multiple unsaturated fatty acids cause a worse fat consistency in the slaughtered body and the from that produced products. Furthermore the suitability for storage declines by the lacking stability of the polymeres. Higher additions of vitamin E, Selenium or also of technical antioxidants show positive effects.     

Omega‐3 long‐chain polyunsaturated fatty acid enriched eggs by microalgal supplementation

The health promoting effects of omega‐3 polyunsaturated fatty acids (n‐3 PUFA) are mainly ascribed to the n‐3 long chain (LC)‐PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, their intake is mostly below the recommended daily intake. A possible way to raise their average intake is to enrich food products with n‐3 LC‐PUFA. Addition of autotrophic microalgae to the diet of the laying hens can increase the level of these fatty acids in the egg yolk. Moreover, depending on the microalgal species, other nutritionally interesting algal carotenoids can also be transferred to the egg yolk. As a consequence egg yolk colour changes may occur. A survey conducted among 511 people showed that they will buy n‐3 PUFA enriched products, such as enriched eggs, and are even prepared to pay more for these products. However, the change of the yolk colour must be taken into account, since consumer' acceptability decreases when a deeply red yolk colour is obtained.     

Einfluß der Einarbeitung von Futterfetten auf den Gehalt an Vitaminen in vitaminiertem Futter

Influence of Processing of Feed Fats on the Content of Vitamins in Vitaminized Feed The use of minor feed oils or unsuitable processing of feed oils into laying-hens feed meal or broiler pellets may lead to a decrease of the content to added lipophile vitamins. Thus the colour of the egg yolk, the laying capacity and the fattening performance can be influenced. In this paper the influence of addition of feed oils at different storage time with or without antioxidans stabilisation in poultry feed on the concentration of the vitamins A, E and D₃ directly after blending and after storage are discussed. Further the applied analytical methods for determination of the above mentioned vitamins are discussed.     

Einlagerungen und Austausch von Linolsäure im Körperfett von Broilern bei zeitlich begrenzter Aufnahme verschiedener Öle und Fette

Deposition and Exchange of Linoleic Acid in Depot Fat of Broilers During the Uptake of Various Oils and Fats for Limited Periods The fat quality of slaughtered broiler bodies is mainly determined by two parameters, on the one hand by the viscosity, whose decrease leads to increased losses in body fat during the slaughtering process, on the other hand by the oxidation stability, whose deterioration makes the slaughtered body not eatable. Both parameters are determined by the share of polyen acids, above all of linoleic acid, in vegetable oils. As the fatty acid pattern of the body fat depends in a high degree on the feed fat and broiler rations contain 8–10% fat, the composition of the additional fat is of significant importance. A feed fat with high contents of long chained, saturated fatty acids causes, however, a smaller utilization for chicken in the first 3–5 weeks of life. Both demands, a sufficient viscosity or oxidation stability and a good utilization, lead to the reflection to feed first a high unsaturated vegetable oil and to change during the further fattening period to an animal fat. A corresponding test was carried out with 156 male broilers. Group 1 got throughout the feeding time sunflower oil, group 6 got lard, the other groups underwent a change in feed from sunflower oil to lard, each shifted for one week. During the weekly slaughters abdominal fat was removed for the investigation of fatty acid pattern and iodine value. Feed uptake, increase in weight and feed utilization showed no significant differences. The content of linoleic acid amounted on the 43th day of life in group 1 to 59%, in group 6 to 14%. In the groups with weekly changes the following data were found: group 2: 31.6% (22nd day of life), 19.3% (28th day of life), 17.8% (36th day of life), 16.6% (43rd day of life); group 3: 35.0% (28th day of life), 25.3% (36th day of life), 21.1% (43rd day of life); group 4: 39.4% (36th day of life), 28.7% (43rd day of life); group 5: 42.7% linoleic acid (43rd day of life). After the change to the ration with lard the share of linoleic acid in the abdominal fat diminished significantly. This decrease was the more lower, the later the change in feed took place. The low content of linoleic acid in group 6 was not achieved by any other test group. The determination of the iodine value led to corresponding results.     

Three Hen Strains Fed Photoisomerized <Emphasis Type="Italic">trans,trans</Emphasis> CLA-Rich Soy Oil Exhibit Different Yolk Accumulation Rates and Source-Specific Isomer Deposition

Most CLA chicken feeding trials used cis,trans (c,t) and trans,cis (t,c) CLA isomers to produce CLA‐rich eggs, while reports of trans,trans (t,t) CLA enrichment in egg yolks are limited. The CLA yolk fatty acid profile changes and the 10–12 days of feeding needed for maximum CLA are well documented, but there is no information describing CLA accumulation during initial feed administration. In addition, no information on CLA accumulation rates in different hen strains is available. The aim of this study was to determine a mathematical model that described yolk CLA accumulation and depletion in three hen strains by using t,t CLA‐rich soybean oil produced by photoisomerization. Diets of 30‐week Leghorns, broilers, and jungle fowl were supplemented with 15 % CLA‐rich soy oil for 16 days, and eggs were collected for 32 days. Yolk fatty acid profiles were measured by GC‐FID. CLA accumulation and depletion was modeled by both quadratic and piecewise regression analysis. A strong quadratic model was proposed, but it was not as effective as piecewise regression in describing CLA accumulation and depletion. Broiler hen eggs contained the greatest concentration of CLA at 3.2 mol/100 g egg yolk, then jungle fowl at 2.9 mol CLA, and Leghorns at 2.3 mol CLA. The t,t CLA isomer levels remained at 55 % of total yolk CLA during CLA feeding. However, t‐10,c‐12 (t,c) CLA concentration increased slightly during CLA accumulation and was significantly greater than c‐9,t‐11 CLA. Jungle fowl had the smallest increase in yolk saturated fat with CLA yolk accumulation.     

Zusammenhänge zwischen Fettoxidation und Antioxidantienzulagen im Mischfutter

Relations Between Fat Oxidation and Antioxidative Additives in Mixed Feeding Stuff Storage experiments with various mixtures of feeding stuffs were carried out. The influence of single factors on fat stability in test mixtures should be tested. The type of fat (refined soya bean oil, free fatty acids from soya bean oil raffination) fat content (3, 6, 9%), antioxidants (BHA, TBHQ), amount of anti oxidants (0 - 50 - 100 - 150 mg/kg feeding stuff), storage temperature (4, 14, 24°C) and storage period (6 - 12 - 24 weeks) were varied. The peroxide value (POZ) and the remaining amounts of antioxidants were used as parameters for the determination of the fat oxidation. The test results showed a some what enlarged stability of the fatty acids of soya bean oil raffination compared with refined soya bean oil in presence of anti oxidants. The stabilising effect of TBHQ was higher than that of BHA, but the consumption of antioxidants was lower with BHA than with TBHQ. With increasing amounts of antioxidants the stability of the fat was enlarged. The stability was lowered with rising storage temperature. Increasing storage period gives rise to a considerable increase in oxidation.