Tierische Fette in der Tierernährung

Animal Fats in Animal Nutrition Intensive feeding of several types of farm animals is unthinkable without the use of fats in feed formulations. Animal fats are, however, considered inferior to plant oils with respect to quality and energy utilization. In the practical application, only mixed fat formulations are used. Therefore, there is little chance that the absorption of fat from the gastro-intestinal tract is inhibited by the presence of relatively high proportions of saturated C₁₆ and C₁₈ fatty acids. Large proportions of fat are used in feeds for broilers and calves. Moreover, from nutritional viewpoint, the fat content of feeds for swine and laying hen could be increased, if technical devices for restricted feeding are used, which prevent excessive intake of energy. A higher content of fat in ruminant feed is also to be recommended. Since in monogastric animals the consistency of fatty tissues is influenced by unsaturated fatty acids of dietary fat, the use of animal fats having low content of unsaturated fatty acids is favorable for the quality of slaughtered products.     

Trans-Fettsäuren in Lebensmitteln

Trans Fatty Acids in Foods The fatty acid compositions of the fat in 196 german food samples were analyzed with emphasis on trans components by gas liquid chromatograghy. The range of trans fatty acids (weight percent of methyl esters) in several foods was: margarines 0.6 - 23.5%, shortenings 0.1 - 31.8%, french fried potatoes 508 - 32.8%, cakes and cookies 0 - 15.5%, candies and frostings 0.2 - 15.7%, Crisps and other snacks 0.1 - 20.2%, animal and dairy fats from ruminants. 1.5 - 10.6%, other meat products animals and sausages less than 1%. Teh composition of trans fatty acids differed between hydrogenated fats and ruminant fats. Food processing (except hydrogenation) did not substantially alter the fatty acid composition. The daily intake of trans fatty acids in Germany was estimated by the National Consumption Assay. women consumed 3.4 g/day and men 4.1 g/day. Hydrogenated fats and ruminant fats contributed to the consumption nearly equally. Trans fatty acids influence the plasma lipoprotein levels similarly to saturated fatty acids. The trans fatty acids appear mostly as monounsaturated fatty acids in food composition tables. It seems necessary to distinguish between cis and trans isomers.     

Zur Ernährungsphysiologie der Schlachttierfette

Nutritional Properties of Animal Fats Dietary fat plays two roles, as a carrier of energy, and, in the form of essential fatty acids, as an indispensable component of food. Animal fats can meet both requirements. Since fats are greatly accepted by the people due to their taste, the fat consumption by the entire population has been very high. High fat consumption are believed to have resulted in increased level of cholesterol and premature occurrence of coronary diseases. Increase in the incidence of deaths by coronary diseases has drawn attention to the nutritional properties of dietary fats, which affect the level of cholesterol. It has been established that saturated fatty acids in foods raise the level of serum cholesterol, whereas polyunsaturated fatty acids lower it. However, with diets of relatively low fat content the ratio of saturated to polyunsaturated fatty acids is not so significant with regard to level of serum cholesterol as with high-fat diets.     

Fettsäurenaufnahme des Menschen und Möglichkeiten der Beeinflussung durch die Tierernährung

Fatty acid intake of men and possibilities to influence the intake by animal nutrition. About 70% of total fat intake (≈ 100 g per person per day) are from fat of animal origin in Germany. Animal nutrition may influence fat content and fatty acid pattern in animal products. This paper summarizes the influence of feeding on fatty acid pattern of meat (pork, beef, poultry, rabbit, fish), milk and eggs. Fatty acid intake is demonstrated under consideration of fat intake of men and variation of fatty acid pattern of various fats of animal origin. Daily fat intake of men amounted to 43 g saturated, 37 g monoen and 13 g polyen fatty acids. It may vary between 38 and 46 g saturated, 33 and 45 g monoen and 11 and 17 g polyen fatty acids if variation of fatty acid pattern of animal fats is considered. By combination of lower fat intake and changed fatty acid pattern of animal products fatty acid intake may be changed to more monoen and polyen fatty acids.     

Fettsäure-Spektren wichtiger Nahrungsfette

Fatty Acid Composition of Important Dietary Fats The recommendations issued by the German Nutrition Association (DGE) include both total fat quantities and the distribution of fatty acids in daily food intake. It is recommended that fats should account for 30% of the daily energy intake, comprising 10% each of saturated, mono-unsaturated and polyunsaturated fatty acids. An increasing number of scientific studies are quoted according to which the chain lengths of saturated fatty acids and the stereoisomers of unsaturated fatty acids play a part in raising the blood cholesterol level. Examples are given of both vegetable oils and fats and a animal and “hidden” fats. Recommendations from DGE for fat intake and fatty acid composition in fat in Germany are not reached yet. The fat intake has to be reduced.     

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.     

Veränderungen der Fette unter Fritierbedingungen und deren analytische Erfassung Beurteilung des Gebrauchswertes und Analytik von Fritierfetten I

Alterations in Fats Under Frying Conditions and Their Analytical Detection: Evaluation of the Quality of Frying Fats and Their Analysis The quality of a frying fat at a certain stage of use depends on its composition, its freshness, and the frying conditions. The frying stability, i. e. the length of time a fat can be heated in the fryer till the content of petroleum ether insoluble oxidized fatty acids reaches a level of 1%, is proportional to the degree of saturation of the fat, and inversely proportional to its specific surface in the fryer and its reversion period. Frying stability can be increased considerably by excluding atmospheric oxygen. Thus, under suitable frying conditions even highly unsaturated fats, such as peanut oil, sunflower oil, and soybean oil, can be used without an increase in the content of oxidized fatty acids above a permitted level. In the choice of fats one should prefer those having lower UV-absorbance and higher SWIFT stability. In order to define the degree of oxidation of used frying fats, it is recommended to determine the content of oxidized fatty acids according to DGF-Standard Method C-III 3 (68). Moreover, acid value, smoke point and UV-absorbance provide valuable information regarding the degree of oxidative changes. A rather loose relationship exists between the saponification colour number and the content of oxidized fatty acids.     

Aspekte bei der Hydrierung von Fetten und Fettsäuren

Aspects of Hydrogenation of Fats and Fatty Acids Hydrogenation of fat products is of great significance, both for human and animal nutrition as well as for technical purposes. In the area of nutrition, adequate food for the increasing world population is unthinkable without utilization of all fat resources, that can be made available as food fats only after catalytic hydrogenation. In the area of technical use, a similar development is observed owing to shortage of mineral oils. Thus, fatty alcohols derived from vegetable oils and waxes can already compete in price with fully synthetic fatty alcohols derived from mineral oils. In the past 70 years of hydrogenation of fats till the present time, catalysts based on nickel have been most commonly used. In addition, small proportions of catalysts based on copper and noble metals have also been used. Homogenous catalysts have been used very recently. The present communication deals primarily with the hydrogenation of neutral fats and fatty acids using nickel catalysts. The aspects of selectivity and isomerization in the partial hydrogenation of neutral fats are discussed. In the hydrogenation of fatty acids and their derivatives, emphasis is laid on other factors, such as activity, poisoning and acid resistance of the catalyst. These factors are discussed.     

Die Zusammensetzung tierischer Organ- und Depotfette in Abhängigkeit von der Fütterung III: Gas-chromatographische Analyse von Kälberfetten nach definierter Fütterung

The Composition of Animal Organ and Depot Fats in Relation to Feed III: Gas-chromatographic Analysis of Fats from Calves after Definite Feed Within the scope of the feeding experiments, which had been carried out for explaining the accumulation of trans fatty acids in animal organs, we studied the composition of mixed fatty acids of heart, kidney and liver as well as that of the corresponding depot fats with the help of gas-chromatography. The fatty acid composition of the separated neutral fat and phosphatide fractions of the organ fats are discussed.     

Content and distribution oftrans-18:1 acids in ruminant milk and meat fats. Their importance in european diets and their effect on human milk

Thetrans-18:1 acid content and distribution in fats from ewe and goat milk, beef meat and tallow were determined by a combination of capillary gas-liquid chromatography and argentation thin-layer chromatography of fatty acid isopropyl esters. Thetrans isomers account for 4.5 ± 1.1% of total fatty acids in ewe milk fat (seven samples) and 2.7±0.9% in goat milk fat (eight samples). In both species, as in cow, the main isomer is vaccenic (trans-11 18:1) acid. The distribution profile oftrans-18:1 acids is similar among the three species. The contribution of ewe and goat milk fat to the daily intake oftrans-18:1 acids was estimated for people from southern countries of the European Economic Community (EEC): France, Italy, Greece, Spain, and Portugal. It is practically negligible for most of these countries, but in Greece, ewe and goat milk fat contributeca. 45% of the daily consumption oftrans-18:1 acids from all dairy products (0.63 g/person/day for a total of 1.34 g/person/day). Thetrans-18:1 acid contents of beef meat fat (ten retail cuts, lean part) and tallow (two samples) are 2.0 ± 0.9% and 4.6%, respectively, of total fatty acids (animals slaughtered in winter). Here too, the main isomer is vaccenic acid. Othertrans isomers have a distribution pattern similar to that of milk fat. Beef meat fat contributes less than one-tenth of milk fat to thetrans-18:1 acid consumed. The daily per capita intake oftrans-18:1 acids from ruminant fats is 1.3–1.8 g for people from most countries of the EEC, Spain and Portugal being exceptions (ca. 0.8 g/person/day). In France, the respective contributions of ruminant fats and margarines to the daily consumption oftrans-18:1 acids are 1.7 and 1.1 g/person/day (60 and 40% of total, respectively). These proportions, based on consumption data, were confirmed by the analysis of fat from milk of French women (ten subjects). The mean content oftrans-18:1 acids in human milk is 2.0 ± 0.6%, with vaccenic acid being the major isomer. Based on the relative levels of thetrans-16 18:1 isomer, we could confirm that milk fat is responsible for the major part of the daily intake oftrans-18:1 acids by French people. The daily individual intake oftrans-18:1 isomers from both ruminant fats and margarines for the twelve EEC countries varies from 1.5 g in Spain to 5.8 g in Denmark, showing a well-marked gradient from the southwest to the northeast of the EEC.     

Spurennachweis von mehrfach verzweigten Fettsäuren in Fetten

Detection of Traces of Polybranched Fatty Acids in Fats A method for the detection and quantitative determination of saturated polybranched fatty acids in animal and vegetable fats is described. The method is based on gas-chromatographic determination of polybranched fatty acid methyl esters in the methyl esters which do not form urea adducts. The following amounts of polybranched fatty acids were determined in animal fats: whale oil 15 000 ppm., fish oil 6000 ppm., butter fat 4000 ppm., beef tallow 2000 ppm. and lard 110 ppm. In different vegetable oils and fats upto 200 ppm. of polybranched fatty acids were found. Not only the difference in total content of polybranched fatty acids but also differences in their percentage composition and retention volumes in gas-chromatograms were found. This method therefore offers the possibility of identification of some of the animal fats.     

Fats in the diet

Fats are important constituents of the human diet since on the one hand, they contribute to the caloric density of the diet, and on the other, they serve as vehicles of essential nutrients such as linoleic and alpha-linolenic acids, as well as fat-soluble vitamins. The existence of human populations subsisting on diets with values as low as 10% or more than 50% of the calories represented by fats, has been documented, demonstrating the great adaptability of man to a wide availability of this type of food. Nevertheless, extensive epidemiological and experimental research in relation to a frequent degenerative diseases of man, arteriosclerosis, have consistently demonstrated that the proportion of saturated fats in the diet has a positive correlation with the frequency of these alterations. Mortality and fat availability in Latin America is consistent with these results. In consequence, and taking into consideration the present level of fat availability in the Region, we propose that no more than 25% of the caloric requirement should be covered by fats. Additionally, this amount of fat should have equal proportions of saturated, monounsaturated and polyunsaturated fatty acids. Cholesterol, which is contained in animal fats, is not a necessary nutrient for humans, so that no minimum consumption needs to be established. Daily ingestion of cholesterol should be restrained to no more than 100 mg/1,000 calories. Introduction of new fatty foods for human consumption should be preceded by a thorough investigation of the metabolic consequences.     

Lipoide tierischer Organ- und Depotfette in Abhängigkeit von der Fütterung I: trans-Fettsäuren in Kälber- und Schweinefetten

Dietary Fat and the trans-Unsaturated Fatty Acids in Bovine and Porcine Tissues of Heart, Liver and Kidney and Depot Fats from different Localities within the same Animal The content of trans-unsaturated fatty acids in lipids of heart, liver and kidney and depot fats from different localities within the same animal (visceral, pericardial, perinephric, extrahepatic, subcutaneous and/or back fat and fat attached to ribs) of calves and pigs, fed a basal diet without trans-unsaturated fatty acids or fed a hardened fat diet, was determined by IR-spectrography. The lipids of heart, kidney and liver were separated by Silica Gel G column chromatography in cholesterol ester, neutral lipids and phospholipid fractions. The trans-unsaturated fatty acids of each were determined.     

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.     

Fatty acid profile of high consumption foods by school population of the region Metropolitan of Chile, including trans fatty acid content

The Chilean school population has shown remarkable changes in their eating habits, incorporating high fat content foods to their diet, which could explain the current high obesity rates. A great proportion of these foods uses industrial fats whit high content of saturated fatty acids (SFA) and potentially contains trans fatty acids (TFA) as a result of partial oil hydrogenation or as a natural form in ruminant animals fat. The purpose of this investigation was to determine fatty acid profile, including trans fatty acids, from food consumed by the Metropolitan Region school population. A food consumption survey was applied to 203 Metropolitan Region of Chile school-children, which consisted of questions about food consumption frequency and consumer preferences. Based on the results, ten types of food products were selected. Fat content, fatty acids profile, including trans fatty acid, were determinate by GLC according to the UNE 5509 Norm. Each analysis was carried out in duplicate and three samplings were performed. It was found that a great percentage of the analyzed foods showed low TFA content (<1%). However, some of them presented remarkable saturated fatty acids content, generating a PUFA/SFA ratio with poor fat nutritional quality. The low TFA concentration found in the food may be explained by a decrease in the use of hydrogenated fats, following PAHO/WHO recommendation, which are being applied in Chile.     

Untersuchung von in Haushalten benutzten Fritürefetten

Investigation of Frying Fats Used in Households Each of three fat mixtures with increasing content of polyunsaturated fatty acids were employed for frying in 140 households. The used fats were tested for free fatty acids (ffa), smoke point, foam value, iodine colour value, oxidized fatty acids insoluble in petroleum ether. Additionally, the unpolar dimeric fatty acids and the viscosity were determined in one series of experiments. It was concluded by statistical analysis that the fats in the household were subjected to very little stress. No direct relationship could be derived between the analytical data and the content of polyunsaturated fatty acids.     

Die Zusammensetzung tierischer Organ- und Depotfette in Abhängigkeit von der Fütterung II Gas-chromatographische Analyse der Fettsäuren von Kälber- und Rinderfetten

The Composition of Lipids of Animal Organ and Depot Fats in Relation to Feed II: Gas-chromatographic Analysis of Fatty Acids of Calves and Cattle Fats In the milk as well as in the fats of calves and cattle 81 fatty acids were found. The composition of fatty acids of the depot and organ fats of cattle — in winter with stall-feeding and in summer with pasture-feeding — were compared with the winter and summer milk fats. The differences between the fats from the same parts of calves and cattle are discussed.     

Einsatzmöglichkeiten von Fetten in der Ernährung landwirtschaftlicher Nutztiere

Application Feasibilities of Fats in the Nutrition of Agricultural Cattle The main application feasibilities of fats for animal nutrition are for monogastric cattle - poultry and pigs - as well as for calves. For ruminants, especially for milk cows, feeding of higher amounts of fat is more restricted because of the particularity of their digestion (pregastric fermentation). In case of fat additions rations have to be balanced concerning their content of protein or essential amino acids and other structural nutriants and effective agents with respect to the higher energy concentration. The effect of feeding fats on fat composition of the final product has to be observed. Using qualitatively unobjectionable fats fat additions of 3–5% for young pigs and 4–6% far fatted pigs are recommended. The corresponding recommendations for poultry are 2–4% for laying hens and 7–9% for broilers. For milk cows an encroachment on pregastric fermentation by higher fat additions can be expect ed. The maximum fat amount is about 800–1000 g per day. Using so called “protected” fat (stabilization by formalin) 1000 g per day should not be exceeded, either.     

Qualitative und quantitative Untersuchung der freien Fettsäuren in Depotfetten und fetthaltigen Erzeugnissen

Qualitative and Quantitative Investigation of Free Fatty Acids in Depot Fats and Fat-Containing Products The free fatty acids (FFA) in the fat of dry sausages were adsorbed on aluminia. After elution the methylesters of the fatty acids were separated on Reoplex (400). The composition of fatty acids released from fats showed distinct differences to the composition of a fat after saponification. Myristic, palmitoleic and linoleic acid had increased in the amount expressed as percentage of fatty acids while the percentage of stearic and possibly palmitic acid had decreased in concentration. The volatile fatty acids (<14 C) increased in the fat of dry sausages, too.     

Die Verdauung von Speisefetten mit Pankreaslipasen und ihre Beeinflussung durch das Fettsäuremuster

The Influence of Fatty Acids in Triglycerides on the Digestion of Dietary Fats by Pancreatic Lipase The digestion of dietary fats by pancreatic lipase was studied in in-vitro-experiments. We tested the following fats: coconut, butterfat, cocoabutter, lard and oil of corn germ. The breakdown of triglycerides was followed up by monitoring the free fatty acids and glycerol. Additionally we analyzed the fatty acid distribution by gas-liquid chromatography of triglycerides, 1,2-diglycerides and 2-monoglycerides. Fatty acids with a chain length from C₁₀C₂₀ were determined by gas chromatography. Short chain fatty acids were not regarded separately. As pancreatic lipase has a positional specificity for the 1- and 3-position of a triglyceride there is information on the distribution of fatty acids in fats and of their digestion by such experiments. For the resorption of the fatty acids it may be of a certain importance in which position it is esterified in the fat when it is hydrolysed in gut. The hydrolysis of fats used in these experiments was quite different. This can be explained by the fatty acid distribution, the chain length and by a varying rate of emulsification of fats in an aqueous phase.