Tallow Group Research Articles

Macronutrient Selection in Rats: Effect of Fat Type and Level

The effect of type and level of dietary fat on subsequent diet selection was examined in young Sprague-Dawley rats. Isoenergetic, isonitrogenous diets composed of corn oil or tallow (commercial grade), each at 5 or 34%, were fed to rats for 2 wk, and their preference for diets covarying in carbohydrate and protein was subsequently tested. When compared to either of the corn oil groups or the 5% tallow group, rats previously fed the high tallow diet selected more protein and less carbohydrate. Subsequent experiments testing the effects of 5, 20 or 34% tallow indicated that this preference for protein was induced by exposure to the tallow diets for only 18 h. In addition, the 34% tallow group selected more protein than did rats fed 5 or 20% tallow. Tests of diet selection with 5 or 34% corn oil, tallow or hydrogenated coconut oil indicated that rats fed 34% tallow ate significantly more protein than the 34% corn oil group. Furthermore, animals fed a 34% pure, additive-free tallow diet exhibited a preference for protein. These studies suggest that the type and level of dietary fat interact to influence dietary selection.

Composition and structure of triacylglycerol of muscle lipids from laying hen as influenced by dietary fats.

The effects of dietary fats (soybean oil, coconut oil, lard and beef tallow) on the changes in composition and structure of triacylglycerol (TG) in muscle lipids of laying hens were studied. The fatty acid composition found in muscle total lipids from each dietary treatment group reflected the composition of fats added to the rations. The TG from thigh and breast muscle were subjected to stereospecific analysis. Generally, C16:0, C16:1, and C18:0 were preferentially esterified at positions sn-1 and sn-3. C18:1 tends to linked to position sn-3 more than other positions, and C18:2 was predominated in position sn-2 of muscle TG. TG species were resolved on the basis of carbon number by high temperature gas-liquid chromatography. The muscle lipids from soybean oil, lard and tallow groups commonly comprised the TG of C50, C52 and C54 as the major TG components, and those from coconut oil group contained many medium chain length TG as C34-C48 components in addition to C50-C54. The TG was separated into simpler molcular species according to the degree of unsaturation by argentation thin-layer chromatography (AgNO3-TLC). The lipids from soybean oil group contained less S2M and SM2 and more of M2D, SD2, MD2, SMT and D3 species than the other groups, while the lipids from coconut oil group had the highest level of S3 and S2M species among the dietary groups. The experimentally determined values of TG species were compared with the values predicted assuming a 1-random, 2-random, 3-random arrangement of fatty acids in intact TG. The agreement was considerably good for muscle TG from lard and tallow groups, but some discrepancies were observed for TG from soybean oil and coconut oil groups. This suggests that in laying hen there is preferential synthesis of some TG species influenced by ingested dietary fatty acids.

Effects of dietary fats on triacylglycerol composition and structure of egg yolk lipids.

Effects of dietary soybean oil, coconut oil, lard and beef tallow on the changes in triacylglycerol (TG) composition and structure in egg yolk lipids of laying hens were studied. Generally, the fatty acid composition of egg yolk TG reflected partially that of the dietary fats fed to hens, though, the short chain saturated fatty acids (C8:0, C10:0) were not availably utilized for the egg yolk lipid formation. Egg yolk TG from hens fed soybean oil, lard and beef tallow was commonly composed of C50, C52 and C54 species as main TG components. More TG species of C44-C50 were contained in egg yolk of coconut oil group than in that of the other diet groups, while, C52 and C54 components were less in coconut oil group. Egg yolk lipid of soybean oil group contained less amounts of TG comprising monoenoic acids and more of TG comprising dienoic acid than the other groups. Lipid of coconut oil group contained the most amount of S2M and the least of U3 among the experimented diet groups. Lipids from lard and tallow group comparatively resembled each other in distribution pattern of TG species. In egg yolk TG from every dietary group, saturated fatty acids were preferentially esterified at position 1 of TG, on the contrary, position 2 comprised predominantly unsaturated fatty acids. Position 3 was largely occupied by C18:1 accompanied with C16:1. This species specificity of positional distribution of fatty acids in hen's egg TG was not changed regardless of variation of dietary fats fed to hens.

Effect of tallow and choline chloride addition to the diet of sows milk composition, milk yield and preweaning pig performance.

Four trials were conducted with a total of 188 crossbred sows to determine the effect of feeding diets supplemented with tallow (0 or 8%) and choline chloride (220 or 770 mg/kg diet) prior to parturition and during lactation on preweaning pig performance. On d 100 of gestation, sows were allotted to four factorially arranged dietary treatments: 0% tallow-220 mg/kg choline chloride, 0% tallow-770 mg/kg choline chloride, 8% tallow-220 mg/kg choline chloride, 8% tallow-770 mg/kg choline chloride. Diets without tallow were fed at the rate of 1.82 kg/d with an additional .18 kg/d of cornstarch, whereas sows receiving diets supplemented with tallow were fed 1.82 kg/d. Daily metabolizable energy intake was constant for all diets (approximately 6,240 kcal). Following parturition, the diets were fed ad libitum for a 21-d lactation period. Pig survival to 21 d, in relation to the number of pigs born alive/litter, did not differ significantly between litters from sows receiving tallow (94.0%) and litters from sows receiving the control diet (92.5%). Although not significantly different, there was a trend toward slightly heavier pigs (6.35 vs 6.11 kg) and litters (53.97 vs 51.94 kg) after the 21-d lactation period in the groups nursing sows receiving tallow-supplemented diets. Litter performance was not improved by the addition of choline to sows' diets. A second study was conducted to measure the effect of energy source on milk yield and composition. Twelve crossbred sows was allotted to two dietary treatments (0 and 8% tallow), each supplemented with 770 mg choline chloride/kg of diet. The composition of colostrum and milk was determined on d 0, 9 and 18, and milk yield was measured on d 12 and 19. Throughout the lactation period, sows fed the tallow supplemented diet produced higher concentrations of total milk solids (22.15%, P less than .10) and fat (14.9%, P less than .01) than the control group (21.37 and 12.0%, respectively). Milk protein content, averaged over the lactation period, was lower (P less than .10) for sows receiving tallow (8.60 vs 9.22%); however, the depression appeared to be related to the colostrum samples, because values for the two treatment groups were similar on d 9 and 18. The mean milk yield was 9.44 kg/d for sows receiving tallow and 8.72 kg/d for those fed the control diet. Therefore, not only did sows in the tallow group produce a greater concentration of milk solids and fat, but the total quantity of the milk constituents available to the offspring was increased.

INFLUENCE OF PROPIONIC ACID ON THE CHOLESTEROL METABOLISM OF PIGS FED HYPERCHOLESTEROLEMIC DIETS

Sixty-four crossbred pigs averaging 24 kg liveweight were used to study the effects of dietary propionic acid (PA) on plasma and tissue cholesterol concentrations of pigs fed hypercholesterolemic diets for 10 wk. Four diets, based on barley, wheat and soybean meal, consisting of a control diet and a diet containing 10% tallow, both fed with and without the addition of 5% PA were used in this study. Addition of PA to the control diet decreased feed intake (ADF) by 16%, decreased average daily gain (ADG) by 8% and improved feed conversion efficiency (FCE) by 8%. Addition of tallow to the control diet resulted in a 15% reduction in ADF, a 3% improvement in ADG and an 18% improvement in FCE. When both tallow and PA were present, ADF was depressed 26%, ADG decreased 5% and FCE improved 23%. The addition of tallow significantly increased the levels of total plasma cholesterol while the addition of PA significantly decreased the plasma cholesterol levels in comparison with the control diet and prevented the increase noted in the tallow group. Addition of PA to the control diet significantly increased the cholesterol content of backfat and significantly reduced the cholesterol content of the kidneys. Addition of PA to the tallow diet significantly reduced the cholesterol content of kidneys, but did not significantly affect the cholesterol content of backfat. It is suggested that the increased cholesterol content of backfat in pigs fed diets containing PA reflects a reduced transport of cholesterol from peripheral tissues to the liver for excretion in the bile.

Effect of maternal dietary energy source on glucose homeostasis, liver glycogen and carcass lipid in the neonatal pig.

Two experiments were conducted to determine the effects of supplementary dietary energy (carbohydrate versus fat) fed to sows during late gestation on energy storage and glucose homeostasis in neonatal pigs. In the first experiment, 28 crossbred sows received one of two dietary treatments that were initiated on day 100 of gestation. The control group was fed daily 1.82 kg of a corn-soybean meal-based diet plus an additional .18 kg of cornstarch. Their counterparts were fed 1.82 kg of a corn-soybean meal diet containing 8% bleachable fancy tallow. The effect of maternal dietary energy source during late gestation on glucose homeostasis was evaluated by fasting pigs from birth (t0), whereas the gestation-lactation effect was evaluated by fasting pigs after they had nursed the sow for 24 hr (t24). Pigs on the tallow treatment responded differently to the t0 fast, as determined by the patterns of plasma glucose (treatment x time, P less than .05) and free fatty acids (treatment x time, P less than .10). The tallow group maintained a slightly higher glucose concentration during the initial 24 hr, after which no difference was observed. Control pigs reached a peak free fatty acid (FFA) concentration by 12 hr, whereas the tallow group reached a maximum by 24 hr, which corresponded with declining glucose concentration. Pigs on the t24 tallow treatment maintained a slightly higher plasma glucose concentration during the initial 24 hr of fasting (12 hr - 68.3 vs 63.2 mg/100 ml; 24 hr - 67.1 vs 56.3 mg/100 ml); however, no significant treatment effect or treatment x time interaction was observed. Pigs on the tallow treatment maintained a higher, although not significantly different, plasma FFA concentration during the fast (144 mueq/liter) than pigs in the control group (126 mueq/liter). In the second experiment, progeny of 12 sows were sacrificed immediately after birth. The respective carcass lipid (percentage) and liver glycogen (milligrams/gram) concentrations for pigs from sows fed the control and tallow diets were 1.48, 229.1 vs 1.50, 234.9. The liver glycogen to body weight ratio (milligrams:gram) was 7.1 and 7.8 for the control and tallow groups, respectively.

Dietary enrichment with the polyunsaturated fatty acid eicosapentaenoic acid prevents proteinuria and prolongs survival in NZB x NZW F1 mice.

Prostaglandins and related compounds are active mediators of inflammation, but data concerning their role in the pathogenesis of the glomerulonephritis of New Zealand Black x New Zealand White (NZB x NZW) F1 mice are conflicting. Dietary eicosapentaenoic acid (EPA, C20:5), a fatty acid analogue of arachidonic acid (C20:4), has been shown to impair platelet aggregation in humans, apparently through inhibition of the synthesis of prostaglandins and thromboxanes from arachidonic acid. We report here the effects of a diet high in EPA on the development of renal disease and survival in female NZB x NZW F1 mice. Animals from 4--5 wk of age were fed diets containing 25% lipid, supplied either as beef tallow or menhaden oil, with fatty acid analysis of less than 0.05 and 14.4% EPA, respectively. In the first experiment, by 13.5 mo of age, mice on the beef tallow diet had all (9/9) developed proteinuria and the majority (6/9) had died, with renal histologic examination revealing severe glomerulonephritis. In contrast, none of 10 menhaden oil-fed animals had developed proteinuria, and all were alive at this time (P less than 0.005 for both proteinuria and survival). In a second experiment using 50 mice in each dietary group, 56% of the beef tallow group vs. none of the menhaden oil group had developed proteinuria at 9 mo of age (P less than 0.005). Native DNA binding at 6 mo of age was 23.9 +/- 14.7 vs. 10.1 +/- 9.7% in the beef and menhaden oil groups, respectively (P less than 0.01). Weights were similar in all groups, and there was no evidence of essential fatty acid deficiency in any group. These results demonstrate that a diet high in EPA protects NZB x NZW F1 mice from the development of glomerulonephritis.

The Influence of Dietary Inositol on Glyceride Composition and Synthesis in Livers of Rats Fed Different Fats

The effect of inositol supplementation on the composition and biosynthesis of glycerides in the livers of rats fed diets containing fats with differing fatty acid composition was investigated. The dietary fats employed in these studies included corn oil, Tower rapeseed oil (RSO), partially hydrogenated soybean oil (SBO), and tallow. No significant influence of inositol on hepatic triglyceride levels was found in animals fed corn oil and SBO whereas inositol deficiency caused a two-and four-fold elevation in triglyceride concentrations in the RSO and tallow groups, respectively. The level of total fatty acids in phospholipid (mg/g liver) was slightly decreased in all fat groups and included a notable decrease in the concentration of monoenoic (18:1) and dienoic (18:2) acids in the RSO and tallow groups. Dietary inositol had a minor effect on the weight % of individual fatty acids in hepatic triglycerides. Inositol-deficient animals showed an increased rate of glyceride synthesis from glycerol-3-phosphate (glycerol-3-P) regardless of the type of fat that was fed. The results indicate that triglyceride accumulation in liver under conditions of inositol deficiency is not only produced with highly saturated fats since the most unsaturated of all the fats tested, Tower RSO, also gave the syndrome. The results further suggested that the accumulation of hepatic lipid due to the feeding of inositol-deficient diets likely arises from their effect on specific metabolic site(s) other than the conversion of glycerol-3-P into lipid.

Influence of dietary fat on bile acid secretion of rats after portal injection of 3H-cholesterol and (4-14C) cholesteryl esters.

AbstractLabeled cholesterol and its esters were injected via the portal vein into bile duct‐cannulated rats, subsequent to a 7 week regimen of either 5% safflower oil or 5% beef tallow in a hypercholesterolemic diet. Analysis of bile collected over a 6 hr period from the safflower group showed 8.6% higher output of bile acids, 13.6% higher conversion of3H‐cholesterol to bile acids and 40% higher conversion of [4‐14C]cholesteryl oleate to bile acids than bile collected from the tallow group. During the 1st hr conversion of both oleyl and linoleyl esters of14C‐cholesterol to bile acids was much slower than conversion of the free3H‐cholesterol to bile acids, thus eliminating these esters as preferred substrate for bile acid formation. However at 6 hr two‐thirds of the injected14C of oleyl ester was recovered in the liver, and about half of this was in the form of free cholesterol. Thus cholesterol ester hydrolase, though inhibited by dietary cholesterol, evidently did not impose limitations on formation of free cholesterol for subsequent oxidation reactions. Specific radioactivities were of doubtful significance because of uncertainities as to “active” pool size. The data suggest that dietary linoleate exerts its hypocholesterolemic effect in some manner other than ester formation and that its point of action involves stimulation of cholesterol oxidation to bile acids.

Acetoacetate metabolism of rats fed high fat or restricted calorie diets

Ethyl-(14)C-acetoacetate was used to trace oxidation and metabolism of acetoacetate when rats were fed a high fat diet (80% of total calories from beef tallow or corn oil, carbohydrate free), a high carbohydrate diet (2% corn oil) or a high carbohydrate diet with restriction of calories to one half of ad lib. consumption for two weeks. The rate of expiration of(14)CO(2) in all groups of animals did not differ significantly and was not related to plasma concentration of acetoacetate. The high fat diets slightly enhanced the oxidation of acetoacetate to(14)CO(2) over a 3 hr period compared to other diets. Incorporation of acetoacetate into fatty acids did not differ significantly among groups. Rats fed the high carbohydrate diet ad lib. incorporated into liver cholesterol more acetoacetate than did any other group, but dietary unsaturated fat resulted in greater incorporation of acetoacetate into cholesterol than saturated fat. High calorie and high beef tallow groups were ketonemic but the low concentration of plasma acetoacetate in rats fed a high corn oil diet indicates that unsaturated fatty acids are not ketogenic. The data show that utilization of acetoacetate is not significantly reduced in a ketonemic condition and support the premise that overproduction of ketone bodies is the cause of ketonemia. Rats appeared to be normal during the two-week period when no carbohydrate was included in the diet.

INFLUENCE OF DIETARY SATURATED AND UNSATURATED FATS ON BLOOD COAGULATION IN MINIATURE PIGS.

SummaryMiniature pigs maintained for one year on diets containing 15% of either beef tallow or safflower oil did not exhibit lipemia in the fasting state, yet the clotting time was much shorter in the tallow group than in the safflower group. The clotting time was shortened 3 hours after ingestion of either fat, but the effect produced by the saturated fat was much more pronounced than that produced by the unsaturated fat. The recalcified plasma clotting time was also a satisfactory measure of the increase in coagulability brought about by dietary fats, and served to detect differences in coagulability brought about by saturated and unsaturated fats.