Corn Oil Feeding Research Articles

399 Effect of feeding palm oil products on finishing cattle performance, carcass characteristics, and methane production

Abstract The objectives of this experiment were to evaluate feeding palm oil products on feedlot cattle performance and methane production. Steers (n = 320; 380 ± 14.5 kg) were allocated to 40 pens in a randomized block design and assigned to 1 of 5 treatments consisting of different sources of supplemental fat: 1) No Oil; negative control containing 0.0% supplemental fat, 2) Corn Oil; positive control containing 4.0% supplemental corn oil, 3) Whole Palm; 4.0% supplemental whole palm oil, 4) Olein; 4.0% supplemental palm olein oil, or 5) Stearin; 4.0% supplemental palm stearin oil. Cattle consuming Corn Oil, Olein and Stearin all had greater (P = 0.04) final body weight (BW) and hot carcass weight (HCW) than cattle consuming no oil but were not different (P > 0.11) from each other or from Whole Palm, which was intermediate. Dry matter intake (DMI) of cattle consuming No Oil, Whole Palm and Stearin oil was not different from each other; however, cattle fed Corn Oil had greater intake than Whole Palm (P = 0.03). Corn Oil, Olein, and Stearin all had greater average daily gain (ADG) than cattle consuming No Oil (P = 0.04) but were not different (P > 0.12) from Whole Palm. Adding fat improved feed efficiency (gain to feed; G:F) as all diets including added fat had greater (P < 0.01) G:F than No Oil. Marbling scores were greater (P = 0.01) for Olein and Stearin than Corn and Whole Palm. There were no differences in backfat, ribeye area or liver abscess rate among any treatments (P > 0.74). Gas emissions were evaluated for only the No Oil and Whole Palm treatments. Total methane and methane produced per pound of dry matter intake was less for cattle consuming Whole Palm than No Oil by 14.8% (P < 0.04) while cattle were in the methane chamber. Methane produced per kilogram of ADG for Whole Palm was also reduced (P < 0.01) by 21.4% compared with No Oil. The results of this study indicate feeding palm oil products as a source of supplemental fat in finishing diets increases final BW, ADG, and HCW compared with feeding no supplemental fat, but had minimal impact on DMI resulting in an improvement in G:F. Adding supplemental fat reduced methane emissions in cattle when feeding Whole Palm compared with No Oil. The value of palm oil products in feedlot finishing diets is comparable with feeding corn oil.

Influence of grain type and fat source on performance, nutrient utilization, and gut properties in broilers fed pelleted diets

The influence of grain type and fat source on the performance, coefficient of apparent ileal digestibility (CAID), and intestinal characteristics in broiler starters fed pelleted diets were studied. The experiment included 8 treatments arranged as a 2 × 4 factorial with 2 grains (wheat and corn) and 4 fat sources (soybean oil, fish oil, tallow, and palm oil). In all fat sources, corn-fed birds had a higher weight gain than those fed wheat-based diets. However, improvement in the weight gain of birds fed wheat-based diets supplemented with tallow resulted in a significant (P < 0.001) interaction between grain type and fat source. Inclusion of wheat and tallow increased feed intake compared to corn and other fat sources, respectively. Pellets made from wheat were harder (P < 0.01) than those based on corn. Broilers fed corn-based diets, had higher CAID of fat, Ca, and phosphorus (P < 0.01) than those fed wheat-based diets. Soybean oil inclusion, also increased (P < 0.01) fat digestibility compared to other fat sources. An interaction occurred between grain type and fat source where pellets made from corn and soybean oil had higher protein digestibility compared to the other treatments (P < 0.01). Feeding wheat-based diets increased pH of gizzard and proventriculus compared to corn-based diets (P < 0.01). Highest viscosity value was observed in wheat-diets supplemented with fish oil, and palm oil (P < 0.01). The pancrease, gizzard and cecum were heavier in corn-based fed birds compared to those fed wheat-based diets (P < 0.01). A significant interaction between grain type and fat source was noted for Lactobacillus spp. and the total anaerobic bacteria population in the cecum. Overall, the effect of grain type on weight gain, CIAD of protein and cecal microbiota differed depending on the fat sources. Feeding corn and soybean oil resulted in better gut development and growth performance in broilers fed pelleted diets.

Feeding Corn Oil in a Nanoemulsified Form Alters the Unsaturated Fatty Acids in the Milk of Zaraibi Dairy Goats.

Simple SummaryIncreasing the polyunsaturated fatty acid content of ruminant milk represents a much needed step to increase the functional properties of the milk. However, boosting milk fatty acids through feeding strategies has remained a significant challenge for years; it requires new solutions to deliver unsaturated fatty acids in a much safer form for rumen microorganisms than the traditional supplemented raw oil form. The goal is to target less biohydrogenation, which results in less saturated fatty acid accumulation in the rumen and milk. In the present study, the ultrasonic nanoemulsification of corn oil was introduced as a replacement for the raw form of oil supplementation; it was used at 3% of the offered feed dry matter in a trial on dairy goats. The new form of corn oil supplementation was more effective than the raw form of corn oil in increasing milk productivity and fat percentage and preserving a more significant proportion of polyunsaturated fatty acids in the milk of dairy goats. Conversely, the raw form of corn oil resulted in milk fat depression and lower total solid content in addition to milk with higher proportions of saturated fatty acid.Oil in water nanoemulsion represents a new and unstudied form of oil supplementation to the ruminant diet; that is why the aim was to evaluate the potential of nanoemulsified corn oil in dairy goats’ diets on milk productivity and fatty acid proportion. Twenty-four lactating Zaraibi goats in early lactation were randomly allocated to the following treatments: control—a basal diet without any supplementation, CO—the control diet + corn oil supplied at 3% on a dry matter basis (DM), NCO—the control diet + nanoemulsified corn oil provided at 3% on a DM basis. A completely randomized design that lasted 30 days (25 days of adaptation + 5 days of sampling) was used with eight goats in each treatment. The control diet consisted of 50% concentrate and 50% Egyptian berseem clover. The NCO increased the milk production, fat percentage, and yield compared to the CO and the control. The proportions of oleic, linoleic, and linolenic acids were higher in the NCO compared to the control and CO. The NCO had less effect on the biohydrogenation intermediates’ profile than the CO; noticeably, higher proportions of unsaturated fatty acid (UFA) were associated with the NCO. In conclusion, the NCO increased milk production and decreased the transformation rate of UFA to saturated fatty acids in the biohydrogenation environment.

EFFECT OF DIETARY CORN OIL ON PRODUCTIVE PERFORMANCE, YOLK FATTY ACIDS CONTENT AND REPRODUCTIVE ASPECTS OF SAUDI LOCAL STRAIN LAYERS

The study aimed to investigate the effect of feeding corn oil as a rich source of linoleic fatty acid on productive performance, yolk fatty acid pattern, hatchability, and progeny growth of Hager 2 Saudi local strains. This study used 140 layers and 20 males at 31 week of age for 12 weeks experimental period. The hens were allocated into four treatments. The treated groups were fed four isocaloric corn-soy basal diets supplemented with 3% palm oil (T1, control), 2% palm +1% corn oil (T2), 1% palm+2% corn oil (T3) or 3% corn oil (T4). The main results indicated to insignificant increase in egg production % due to adding different levels of corn oil into diets while average egg weight was not affected by treatments. Daily feed intake slightly increased due to feeding dietary corn oil and feed efficiency ratios were similar. Egg yolk % increased significantly and yellowish yolk color was less due to adding 3% corn oil into diet. Both of egg albumen % and eggshell % was not affected by treatments. Plasma total cholesterol was reduced by feeding dietary corn oil which did not affect plasma triglycerides. Egg yolk cholesterol and triglycerides decreased significantly due to adding 3% corn oil only into laying hen diet. There were increments in total saturated fatty acids (SFA) ratio inherent with reduction in monounsaturated fatty acids (MUFA). Polyunsaturated fatty acid (PUFA) increased obviously due to treatments. Hatchability of chicks fed 3% corn oil diet was lower than other treated groups while fertility was not affected. Day-old progeny weights were significantly similar and parallel to the average egg weights. It can be concluded that, enriched high linoleic fatty acid into diets can increase average egg weights without any effect on reproductive aspects, fertility, hatchability, or weights of hatched chicks.

Evaluation of methane production manipulated by level of intake in growing cattle and corn oil in finishing cattle.

Growing crossbred steers [n = 80, initial body weight (BW) = 274 kg, SD = 21] were used to evaluate the effect of ad libitum and limit-fed intakes on methane (CH4) production. Two treatments with four pens per treatment (10 steers per pen) were evaluated in a randomized block designed experiment, with BW as a blocking factor. Treatments included feeding the same diet at ad libitum intake or limit fed at 75% of ad libitum intakes. Diet consisted of 45% alfalfa, 30% sorghum silage, 22% modified distillers grains plus solubles, and supplement at 3% on a dry matter (DM) basis. This trial was followed by a finishing trial (n = 80; initial BW = 369 kg; SD = 25) to evaluate the effects of dietary corn oil on CH4 production. Two treatments with four pens per treatment (10 steers per pen) were used in a randomized complete block designed experiment. Cattle were rerandomized and blocked by BW within the previous treatment. Treatments consisted of a control diet (CON) containing 66% corn, 15% wet distillers grains plus solubles, 15% corn silage, and 4% supplement (DM basis). Corn oil treatment (OIL) displaced 3% corn by adding corn oil. Methane was collected in two pen-scale chambers by collecting air samples continuously from pens by rotating every 6 min with an ambient sample taken between pen measurements. Steers fed ad libitum had greater DM intake (DMI) by design and greater average daily gain (ADG; P < 0.01) compared to limit-fed cattle; however, feed efficiency was not different between treatments (P = 0.40). Cattle fed ad libitum produced 156 g/d of CH4, which was greater (P < 0.01) than limit-fed cattle (126 g per steer daily). In the finishing trial, BW, gains, and carcass traits were not impacted by treatment (P ≥ 0.14). Feed efficiency (P = 0.02) improved because intakes decreased (P = 0.02) by feeding OIL compared to CON. Daily CH4 production was less (P = 0.03) for OIL-fed cattle (115 g per steer daily) compared to CON-fed cattle (132 g per steer daily). Methane was reduced (P < 0.01) by 17% for OIL-fed cattle compared to CON-fed cattle when expressed as grams of CH4 per kilogram of ADG. Feeding corn oil at 3% of diet DM reduced enteric CH4 production (grams per day) by 15%, which was only partially explained by a 3% decrease in DMI. Overall, a decrease in CH4 was observed when intake is limited in growing cattle and when corn oil is added in finishing diets.

Impact of dietary oils and fats on lipid peroxidation in liver and blood of albino rats

ObjectiveTo investigate the effects of different dietary fat and oils (differing in their degree of saturation and unsaturation) on lipid peroxidation in liver and blood of rats. MethodsThe study was conducted on 50 albino rats that were randomly divided into 5 groups of 10 animals. The groups were fed on dietary butter (Group I), margarine (Group II), olive oil (Group III), sunflower oil (Group IV) and corn oil (Group V) for 7 weeks. After 12 h of diet removal, livers were excised and blood was collected to measure malondialdehyde (MDA) levels in the supernatant of liver homogenate and in blood. Blood superoxide dismutase activity (SOD), glutathione peroxidase activity (GPx), serum vitamin E and total antioxidant capacity (TAC) levels were also measured to determine the effects of fats and oils on lipid peroxidation. ResultsThe results indicated that no significant differences were observed in SOD activity, vitamin E and TAC levels between the five groups. However, there was significant decrease of GPx activity in groups IV and V when compared with other groups. The results indicated that feeding corn oil caused significant increases in liver and blood MDA levels as compared with other oils and fats. There were positive correlations between SOD and GPx, vitamin E and TAC as well as between GPx and TAC (r: 0.743; P<0.001) and between blood MDA and liver MDA (r: 0.897; P<0.001). The results showed also negative correlations between blood MDA on one hand and SOD, GPx, vitamin E and TAC on the other hand. ConclusionsThe results demonstrated that feeding oils rich in polyunsaturated fatty acids (PUFA) increases lipid peroxidation significantly and may raise the susceptibility of tissues to free radical oxidative damage.

Down-regulation of vascular HMGB1 and RAGE expression by n-3 polyunsaturated fatty acids is accompanied by amelioration of chronic vasculopathy of small bowel allografts

Chronic allograft rejection, which is manifested as chronic allograft vasculopathy (CAV), continues to refrain the long-term success of small bowel transplantation (SBTx). The pathway mediated by the receptor for advanced glycation end products (RAGE) and its ligand, high mobility group box-1 (HMGB1), may contribute to the pathogenesis of CAV, given that they were involved in the process of allograft rejection. n-3 polyunsaturated fatty acids (PUFAs), which have been discovered to attenuate CAV, may have potential impacts on this pathway. The present study investigated whether n-3 PUFAs attenuated CAV via the regulation of the HMGB1-RAGE pathway in a chronic rejection model of rat SBTx. We revealed that the expression of HMGB1 and RAGE was increased in CAV-bearing vessels as well as endothelial cells isolated from these vessels. Oral administration of fish oil with high levels of n-3 PUFAs following SBTx significantly reduced the HMGB1 and RAGE expression, which coincided with the amelioration of CAV. In contrast, feeding of corn oil that contained low levels of n-3 PUFAs had no favorable effects on CAV development and failed to decrease the HMGB1 and RAGE expression. These results indicate that protective effects of n-3 PUFAs on allograft vessels exist via down-regulation of the HMGB1-RAGE pathway.

Effects of dietary broccoli fibre and corn oil on serum lipids, faecal bile acid excretion and hepatic gene expression in rats

To determine the effects of broccoli fibre and corn oil on lipid metabolism, male Sprague–Dawley rats were fed diets containing high (30%) or low (5%) corn oil, in combination with either 7.5% broccoli fibre or cellulose, for 4months. High corn oil groups had significantly lower serum cholesterol and triglycerides than had low corn oil groups (p<0.001). Broccoli fibre also lowered serum cholesterol and triglyceride levels compared to cellulose fibre. Faecal bile acid concentrations were higher in high corn oil-fed rats than in low corn oil-fed rats, with broccoli fibre inclusion in high corn oil diets resulting in higher faecal bile acid concentrations. Regardless of corn oil level, broccoli fibre supplementation in the diet resulted in an increase (p=0.018) in hepatic cytochrome P450, family 7A1 (CYP7A1) expression. High corn oil feeding resulted in reduced expression of fatty acid synthase (FAS) and increased expression of carnitine palmitoyl transferase 1a (CPT1a) and 3-hydroxy-3-methyl-coenzyme A reductase (HMGCR) (p<0.05). Our findings suggest that high dietary corn oil and broccoli fibre have beneficial effects on lipid metabolism. Corn oil lipid-lowering effects may be due to alteration of hepatic expression of genes involved in lipid synthesis and increased rate of cholesterol catabolism to bile acids. Broccoli fibre may also act via its physical properties to reduce enterohepatic bile acid recycling and intestinal lipid absorption, and increase luminal binding of bile acids, resulting in increased faecal bile acid excretion.

Effects of dietary corn oil and vitamin E supplementation on fatty acid profiles and expression of acetyl CoA carboxylase and stearoyl‐CoA desaturase gene in Hu sheep

This study was conducted to assess the effects of dietary corn oil and vitamin E supplementation on fatty acid (FA) profiles and abundances of acetyl-CoA carboxylase (ACC) and Delta(9) stearoyl-CoA desaturase (SCD) mRNA of Hu sheep. Animals were allocated to three dietary treatments: basal and supplemented with 3% corn oil (CNO), or CNO plus 500 mg/kg vitamin E (COE). The experiment lasted for 10 weeks. No differences were observed in growth performance and carcass qualities among the three treatments (P > 0.05). Feeding CNO and COE diets increased polyunsaturated FAs including cis 9 trans 11 conjugated linoleic acid, and decreased saturated FA in longissimus muscle (P < 0.05). The mRNA abundances of ACC and SCD as detected by real-time PCR were reduced (P < 0.05) in liver and subcutaneous fat by supplementary oil, while the SCD mRNA level in longissimus muscle was also reduced (P < 0.05). Inclusion of vitamin E did not have further effects on mRNA abundances of these two enzymes. It is suggested that dietary corn oil supplementation may reduce FA biosynthesis and influence FA profiles in Hu sheep through decreased expression of both ACC and SCD genes.

Enhanced fat consumption potentiates acrylamide-induced oxidative stress in epididymis and epididymal sperm and effect spermatogenesis in mice

Acrylamide (ACR) and high contents of fat could be found co-existent in many foods processed by high temperature, such as deep-frying and roasting. This study investigated the effect of enhanced fat consumption on deficits of spermatogenesis induced by ACR, and explored potential mechanisms of oxidative damage involved in this pathology in mice. Results show that enhanced feeding of corn oil and pork fat on mice potentiated the decreases of spermatogonia along with mature sperms after treatment of ACR, and that spermatozoa quality is significantly reduced as a result of enhanced feeding of corn oil and pork fat on mice treated with ACR. Moreover, enhanced consumption of corn oil and pork fat potentiated the up-regulation of malondialdehyde (MDA) level in epididymal sperm and cauda epididymides, also up-regulated level of Protein carbonyls (PCOs) in cauda epididymides, of mice after treatment of ACR. Last, enhanced consumption of corn oil and pork fat potentiated the reduced activity of superoxide dismutases (SOD) in epididymal sperm, corpus, and cauda epididymides, also reduced activity of glutathione peroxidase (GPx) in cauda epididymides, of mice treated with ACR. These data suggest that enhanced feeding of corn oil and pork fat on mice potentiates ACR-induced oxidative stress in the epididymis and epididymal sperm and a subsequent effect on spermatogenesis.

Dietary Fat Feeding Alters Lipid Peroxidation in Surfactant-like Particles Secreted by Rat Small Intestine.

BackgroundLong-term feeding of fish oil (n-3) and corn oil (n-6) markedly enhances levels of lipid peroxidation within isolated rat enterocytes. The effect is 10-fold greater at the villus tip than in the crypt region, correlating with the distribution of deleterious oxidative systems (glutathione reductase) in the tip and beneficial systems (superoxide dismutase) at the base of the villus. Because of this vertical gradient of peroxidation, the process was thought to play a role in apoptosis of enterocytes at the villus tip. Surfactant-like particles (SLPs) are membranes secreted by the enterocyte and a component of these membranes is directed to the intestinal surface overlying villus tips. One suggested role for SLPs has been to protect the mucosal surface from the harsh luminal conditions that might enhance apoptotic loss of enterocytes. The hypothesis to be tested was whether SLP lipids, like those in enterocytes, were also peroxidized, although they were external to the cellular processes that seem to oxidize enterocyte lipids, or whether SLP were immune to these biological processes. Feeding with groundnut oil (n-9) was compared with fish oil (n-3) and corn oil (predominantly n-6) to determine whether oils with various lipid composition would affect peroxidation in both SLP and enterocytes.MethodsAfter an overnight fast, Wistar rats were fed 2 mL of dietary oil by gavage. Five hours later SLPs and underlying microvillus membranes (MVM) were isolated and analyzed for generation of thiobarbituric acid reactive substances (TBARS) and for hydrolase activities, at baseline and after addition of an Fe+2/ascorbate system to induce peroxidation.ResultsIn vitro lipid peroxidation using the Fe2+/ascorbate system produced greater peroxidation than in MVM. Intestinal alkaline phosphatase (IAP), sucrase and lactase activities were decreased in SLPs, but were unaltered in MVM except for IAP. The activities of maltase, trehalase, Leucine aminopeptidase and γ–glutamyltranspeptidase, were unaffected both in SLPs and MVM under these conditions.ConclusionsSLPs are more susceptible to oxidative damage than are the underlying MVMs. This may reflect results of a hostile luminal environment. It is not clear whether SLPs are acting as a lipid ‘sink’ to protect the MVM from greater oxidation, or are providing an initial stimulus for apoptosis of villus tip enterocytes, or both.

Effects of Supplemented Diacylglycerol Rich in Docosahexaenoic Acid on Serum Triacylglycerol in a Diet-Induced Hyperlipidemic Model of Rats Are Essentially Equivalent to Those of Triacylglycerol Rich in Docosahexaenoic Acid

Effects of supplemented docosahexaenoic acid (DHA), given as diacylglycerol (DG) rich in DHA (DHA-DG), triacylglycerol (TG) rich in DHA (DHA-TG) or fish oil concentrate (DHA-70), on the serum concentration of TG and its bioavailability in the rats with diet-induced hyperlipidemia were studied. Hypertriglyceridemia was induced by feeding male Wistar rats a semi-purified diet that contained 5% corn oil and 50% sucrose by weight. In addition to the feeding of dietary corn oil, the rats received DHA intragastrically at a dose of 500 mg/kg body weight once a day for 28 d and the control rats were given olive oil. The serum concentration of TG in the rats that received DHA-DG was significantly lower than in the control rats. However, there were no significant differences in diet intake, energy intake, body weight gain, visceral fat mass or fecal excretion of total fatty acids among the four groups. The amounts of DHA excreted into the feces of the three groups of rats that received DHA were approximately 0.4% of the DHA administered. The extent of the decreases induced by DHA-DG in the serum level of TG was almost the same as those induced by DHA-TG and DHA-70. The administration of DHA, regardless of the differences in molecular structure, did not affect the hepatic contents of TG or phospholipid. The administration of DHA-DG considerably increased the proportions of DHA and eicosapentaenoic acid (EPA) while decreasing the proportion of arachidonic acid in hepatic lipids, and as a result in the lipids in serum and erythrocytes, to the same extents as did DHA-TG and DHA-70. These results suggest that the hypotriglyceridemic effects and bioavailability of DHA when supplemented in the form of DG are essentially equivalent to those of DHA-TG and DHA-70.

The parsing of food reward

what is it that is habit-forming about food? Sweet foods and fatty foods are habit-forming and sweet-fatty foods perhaps more than doubly so. Many kitchen and industrial experiments have gone into the determination of the amounts of sugar and butter to optimize the palatability of a given meal or

Sham feeding corn oil increases accumbens dopamine in the rat

Both real and sham feeding of sucrose increase dopamine (DA) overflow in the nucleus accumbens (NAc). Fat is another constituent of foods that is inherently preferred by humans and rodents. We examined the affect of sham feeding corn oil in rats that were food and water deprived overnight. Rats were implanted with guide cannulas aimed at the NAc, as well as gastric fistulas. On alternate days, they were trained to sham lick 100% corn oil or distilled water (dH2O) for 20 min in the morning. Twenty-minute microdialysis samples were taken before, during, and after sham licking. DA and monoamines were analyzed by reverse-phase HPLC with coulometric detection. The results show that DA release in the NAc was significantly increased during sham licking of corn oil compared with the prior baseline (157.5+/-18.8%, n=12). During sham licking of dH2O, DA release in the NAc was not changed (93.0+/-4.0%, n=15). This experiment demonstrates that sham feeding of corn oil releases accumbens DA in a manner similar to ingestion of sucrose. Although both stimuli may have an olfactory component, sucrose is a gustatory, and 100% corn oil appears to be a trigeminal stimulus. Thus these data support the hypothesis that different sensory modalities produce reward using the same or closely related substrates in the forebrain.

In vitro rumen fermentation and in vivo bloat dynamics of steers grazing winter wheat to corn oil supplementation

The influence of corn oil on in vitro ruminal gas production, bloat potential and weight gain of steers was investigated. Overall objectives were to: (1) quantify in vitro, the effect of sources of rumen fluid, levels of corn oil supplementation on rate of gas production, foam height and foam strength and (2) quantify the influence of corn oil on in vivo rumen fluid bio-film production, bloat potential and weight gain of steers grazing wheat pasture. In Experiment 1, in vitro gas production was measured from 0 to 6 h rumen incubation periods. In vitro rumen foam production and foam strength were measured. In Experiment 2, rumen cannulated steers ( n = 18; 330 ± 22 kg) were randomly allocated to one of three treatments (0, 7.5 and 15.0 g corn oil of kg dry matter intake (DMI) steer −1 per day). Samples of rumen contents were taken at day −30, 0, 20 and 30 for analysis of rumen microbial protein fractions, rumen microbial DNA concentration and ethanol precipitable polysaccharide slime (referred to as bio-film). Bloat was visually scored (from 0 to 3) 5 days a week. In Experiment 1, mineral oil was used as a non-nutritive surfactant to serve as a non-nutritive negative control. In vitro rate of gas production was greater (P<0.01) for mineral oil than for corn oil addition to Bermuda grass rumen fluid in Experiment 1. Wheat forage rumen fluid exhibited no response to addition of either oil. Changing the sources of rumen fluid from Bermuda grass hay to wheat forage increased (P<0.01) the rate of gas and potential gas production. As microbial DNA mass in the source of rumen fluid increased, the rate of gas and potential gas production increased. Addition of either mineral oil or corn oil decreased (P<0.01) foam height and foam strength. In Experiment 2, daily feeding corn oil to steers grazing wheat forage had no effect on animal weight gain. Mean bloat scores and steer bloat day, however, were lower (P<0.01) for corn oil addition than for control. Bio-film complexes in clarified rumen fluid increased (P<0.01) at 15.0 g corn oil over control. It is concluded that addition of corn oil reduced bloat by reducing foam production and foam strength in the rumen. There was no nutritive benefit detected in terms of increased live weight gain with either dose level of corn oil.

Effect of Increasing Oil from Distillers Grains or Corn Oil on Lactation Performance

The objective of this study was to evaluate production response and more specifically percentage and yield of fat in milk from dairy cows fed distillers grains with added solubles (DGS). It was hypothesized that the oil present in DGS would decrease milk fat yield. Four dietary treatments consisted of dried DGS replacing soybean meal and soybean hulls. The DGS inclusion rates as a percentage of dry matter (DM) were 0, 5, 10, and 15% DGS. To determine the role of oil in DGS, a fifth diet similar to 0% DGS with added corn oil (OIL) was included. Twenty multiparous Holsteins were assigned to a replicated, 5×5 Latin Square design with periods of 21 d. Diets were formulated to have similar crude protein and neutral detergent fiber (NDF) concentration. Feeding OIL or 15% DGS resulted in similar production of milk, milk protein, and milk fat. Increasing dietary DGS linearly increased milk production and milk true protein yield. Adding corn oil increased milk yield and, although milk true protein yield also tended to increase with oil, milk true protein concentration decreased. The addition of DGS or OIL did not significantly change fat yield from 0% DGS; however, fat concentration in milk was significantly decreased by DGS due to increased fluid milk production. In diets containing approximately 28% NDF, cottonseed, blood and fish meal, feeding DGS to bring total dietary fatty acids to 5% of diet DM increased milk and milk protein yield without decreasing milk fat yield. Reduced proportions of shorter chain fatty acids and increased proportions of longer chain fatty acids in milk as dietary fatty acid content increased suggests that de novo fatty acid synthesis in the mammary gland was inhibited but this was offset by increased secretion of long-chain fatty acids, presumably absorbed from the diet. Therefore, our hypothesis that feeding corn oil either as DGS or as pure corn oil would decrease milk fat yield was not correct.

Fish Oil Decreases Oxidative DNA Damage by EnhancingApoptosis in Rat Colon

: To determine if dietary fish oil protects against colon cancer by decreasing oxidative DNA damage at the initiation stage of colon tumorigenesis, oxidative DNA damage, proliferation, and apoptosis were assessed by colonic crypt cell position using quantitative immunohistochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG), Ki-67, and TUNEL assay, respectively. Sixty rats were provided one of two diets (corn oil or fish oil) and dextran sodium sulfate (DSS, an inducer of oxidative DNA damage) treatments (no DSS, 3% DSS, or DSS withdrawal). Fish oil feeding resulted in lower 8-OHdG levels (P = 0.038), higher levels of apoptosis (P = 0.035), and a lower cell proliferative index (P = 0.05) compared with corn oil feeding. In the top third of the crypt, fish oil caused an incremental stimulation of apoptosis with increased DNA damage (P = 0.043), whereas there was no such relationship with corn oil. Because polyps and tumors develop from DNA damage that leads to loss of growth and death control, the significant difference in fish oil vs. corn oil on these variables may account, in part, for the observed protective effect of fish oil against oxidatively induced colon cancer.

Dietary (n-3) Fatty Acids from Menhaden Fish Oil Alter Plasma Fatty Acids and Leukotriene B Synthesis in Healthy Horses

The study objective was to determine the effect of feeding corn oil or fish oil to horses on plasma fatty acid profiles and leukotriene B (LTB) synthesis by stimulated peripheral blood neutrophils. Two groups of horses (n = 5) were randomly assigned to diets supplemented with either 3.0% (by weight) corn oil or fish oil for a period of 14 weeks. The ratio of (n-6) to (n-3) fatty acids in oil supplements was 68.1:1 for corn oil and 0.12:1 for fish oil. Production of LTB4 and LTB, by peripheral blood neutrophils stimulated with calcium ionophore A23187 and plasma cholesterol, triacylglycerol, and alpha-tocopherol concentrations were measured. At 12 weeks, horses fed fish oil had increased plasma concentrations of eicosapentaenoic acid (27-fold; 8.5 versus 0.3 g/100 g fatty acids; P < .0001), docosahexaenoic acid (34-fold; 5.1 versus 0.1 g/100 g fatty acids; P < .0001), and arachidonic acid (8.3-fold; 4.1 versus 0.5 g/100 g fatty acids; P < .0001) compared with horses fed corn oil. Neutrophils from horses fed fish oil produced 78-fold (P = .01) more LTB5 and 9.5-fold (P = .003) more LTB4 compared with predietary levels, and 17.6-fold (P = .01) and 3.3-fold (P = .02), respectively, more than horses fed corn oil, and the ratio of LTB5 to LTB4 concentrations was 4.0-fold (P = .002) higher in horses fed fish oil. This study suggests that dietary polyunsaturated fatty acids modulate the leukotriene inflammatory response of horses. If the ratio of LTB5 to LTB4 concentrations is important in determining how inflammatory processes are mediated, then fish oil supplementation may have value in treatment of equine inflammatory diseases.

Rat enterocytes secrete SLPs containing alkaline phosphatase and cubilin in response to corn oil feeding.

Surfactant-like particles (SLP) are unilamellar secreted membranes associated with the process of lipid absorption and isolated previously only from the apical surface of enterocytes. In this paper, the intracellular membrane has been isolated from corn oil-fed animals, identified by its content of the marker protein intestinal alkaline phosphatase (IAP). Another brush-border protein, cubilin, and its anchoring protein megalin have been identified as components of extracellular SLP, but only cubilin is present to any extent in intracellular SLP. During fat absorption, IAP is modestly enriched in intracellular SLP, but full-length cubilin (migrating at 210 kDa in fat-fed mucosal fractions) falls by one-half, although fragments of cubilin are abundant in the intracellular SLP. Both IAP and cubilin colocalize to the same cells during corn oil absorption and colocalize around lipid droplets. This localization is more intense during feeding of corn oil with Pluronic L-81, a detergent that allows uptake of fatty acids and monoglycerides from the lumen, but blocks chylomicron secretion. Confocal microscopy confirms the colocalization of IAP and the ligand for cubilin, intrinsic factor. Possible roles for cubilin in intracellular SLP include facilitating movement of the lipid droplet through the cell and binding to the basolateral membrane before reverse endocytosis.

EFFECT OF FRESH AND HEATED CORN OIL FEEDING ON LIPID METABOLISM IN RATS

EFFECT OF FRESH AND HEATED CORN OIL FEEDING ON LIPID METABOLISM IN RATS