Tower Rapeseed Research Articles

COMPARISON OF TOWER RAPESEED MEAL AND SOYBEAN MEAL AS SOURCES OF PROTEIN IN PELLETED CALF STARTER RATIONS

Forty Holstein calves (20 male, 20 female) were used in an experiment to compare Tower rapeseed meal (RSM) with soybean meal (SBM) as the sole or partial source of supplemental protein in calf starter rations. Four pelleted calf starter rations were fed to calves on a free choice basis from 2 days until 12 wk of age. Calves were weaned from a limited milk feeding program at 5 wk of age. Rations were 16% crude protein formulations with supplemental protein from (1) SBM, (2) 50% SBM + 50% RSM and (3) RSM or (4) a 14% crude protein formulation with RSM as the supplemental protein. A 50/50 isonitrogenous combination of SBM + RSM (ration (2) or complete substitution of SBM by RSM (ration 3) resulted in feed intake, daily gain and feed/gain ratios similar to those in calves fed rations containing SBM (ration 1) as the protein source. The 16% crude protein rations were similar in the preweaning and postweaning periods and with respect to overall performance. Calves fed the 14% crude protein ration with RSM exhibited similar feed intakes and daily gains but required more feed per unit gain than calves fed the 16% rations containing SBM, RSM and SBM + RSM. Tower RSM can provide 100% of the supplementary protein or up to 17.3% of calf starter rations without resulting in impaired calf performance.

Influence of Low Glucosinolate (cv. Tower) Rapeseed Meal on the Eating Quality of Broiler Chickens. II. Subjective Evaluation by a Consumer Panel

The eating quality of eight-week-old White Mountain X Hubbard broiler chickens fed four commercial-type rations was evaluated by 146 consumer households. The rations were: a soybean meal control ration (SBM), a 20% Tower rapeseed meal ration (RSM), a soybean meal ration with 5% herring meal, .1% DL methionine, and .05% choline chloride (SBMHM), and a 20% Tower rapeseed meal ration with 5% herring meal, 1% DL methionine, and .05% choline chloride (RSMHM). Participants received four coded frozen half-chickens (one representing each ration treatment) and were instructed to cook each defrosted chicken half. Consumer panelists scored the odor, flavor, and overall acceptability of the chickens and then ranked the chickens in order of preference. Generally chickens fed the RSM ration received scores that were similar to those of comparable samples from chickens fed the SMB ration. The odor intensity of chicken representing the RSM treatment was rated lower (P<.05) than that of SMB chickens. Chickens raised on the RSMHM diet also received palatability scores which were similar to those for chickens fed the control ration or the ration containing 20% Tower rapeseed meal. Chickens fed the SBMHM ration received significantly lower odor intenstiy and flavor (intensity and like/dislike) scores than chickens fed the SBM ration. These findings suggest that the eating qualtiy of chickens was not affected by the inclusion of 20% Tower rapeseed meal in the rations. Inclusion of 5% herring meal along with supplemental methionine and choline in the SMB ration resulted in chickens with slightly lower eating quality scores, but the meat was judged to be acceptable in eating quality.

Influence of Low Glucosinolate (cv. Tower) Rapeseed Meal on the Eating Quality of Broiler Chickens. I. Subjective Evaluation by a Trained Test Panel and Objective Measurements

White Mountain X Hubbard broiler chickens were fed one of four rations: a soybean meal control ration (SBM); a 20% Tower rapeseed meal ration (RSM); a soybean meal ration with 5% herring meal, .1% DL methionine, and .05% choline chloride (SBMHM); or, a 20% Tower rapeseed meal ration with 5% herring meal, .1 % DL methionine, and .05% choline chloride (RSMHM). At eight weeks of age, chickens from each ration treatment were killed, eviscerated, and frozen for later evaluation. Cooked light and dark meat and broth samples were evaluated subjectively. Objective measurements were also made.Results obtained indicated that inclusion of 20% Tower rapeseed meal in the ration (RSM ration) did not affect the eating quality of the cooked chicken meat. However, broth prepared from chickens fed the RSM ration was rated significantly more rancid in odor, less chickeny in flavor, and lower in overall acceptance than comparable scores for broth from chickens fed the SBM ration.Inclusion of 5% herring meal along with DL methionine and choline chloride in rations for chickens resulted in significantly lower odor and overall acceptance scores in light meat, while dark meat received less chickeny, slightly fishy odor and flavor scores as well as lower acceptability scores than comparable samples fed the control diet. Generally odor, flavor, and acceptability scores for broths representing the RSMHM treatment differed significantly from comparable scores for SBM ration broths.Light and dark meat samples from chickens fed the SBMHM diet were generally similar to those samples from chickens fed the RSMHM ration. However, judges rated the flavor of dark meat from chickens fed the SBMHM ration significantly lower than that of RSMHM dark meat. Broths prepared from chickens raised on the SBMHM ration differed significantly from SBM ration broths. There were no significant differences in tenderness (taste panel data and Warner Bratzler shear) and juiciness (panel scores and water holding capacity) of light meat attributable to ration.These studies provide evidence that feeding a ration containing 20% Tower rapeseed meal (RSM ration) to broiler chickens does not affect the eating quality of the meat. The addition of 5% herring meal along with a high level of methyl groups to rations for broilers (RSMHM and SBMHM rations) may decrease the palatability of the resulting cooked chicken.

A COMPARISON OF SOYBEAN MEAL AND TOWER RAPESEED MEAL AS SUPPLEMENTS TO CORN IN DIETS OF GROWING-FINISHING AND HEAVY WEIGHT PIGS

Ninety-six Yorkshire barrows and gilts were used in each of two experiments conducted in the spring-summer (exp. 1), and fall-winter (exp. 2) months, respectively, to evaluate 15% Tower rapeseed meal (RSM) as a partial replacement for soybean meal (SBM) on an isonitrogenous basis in corn-based diets for pigs from 23 to 91 kg body weight. At 91 kg, half the number of pigs in each dietary group were slaughtered. Then, three levels of protein (12, 14 and 16%) in both corn-SBM and corn-SBM-RSM diets were fed to the remaining pigs in each group up to a final body weight of 125 kg. The energy level in the RSM diets was not adjusted to equal that in the SBM diets. In the 23- to 91-kg gain period, average daily gain (ADG) (P &lt; 0.01) and backfat (P &lt; 0.05) were lower in the RSM-fed pigs compared to SBM-fed pigs only in exp. 2. From 91 to 125 kg body weight, ADG (P &lt; 0.05), feed intake (P &lt; 0.01) and backfat (P &lt; 0.01) were lower for RSM-fed pigs only in exp. 2. The heavy weight pigs fed RSM diets had a lower (P &lt; 0.01) dressing percentage than SBM fed pigs in exp. 1. Reduction of dietary protein from the 16% fed up to 91 kg body weight to either 14 or 12% in the 91- to 125-kg gain period did not affect performance.

The Nutritional Value of Tower and Candle Rapeseed Meals for Turkey Broilers Housed under Different Lighting Conditions

A total of 1200 poults were housed in a split plot arrangment to evaluate four different dietary treatments and three light treatments. Pre-starter and starter diets contained 0 or 10% Tower rapeseed meal (RSM), Candle RSM, combination of Tower and Candle RSM (50:50), and 0 or 20% of these RSM treatments, respectively. Grower, developer, and finisher diets contained 0 or 30% of these RSM treatments, respectively. The light treatments tested were continuous (23L:1D), intermittent (4L:2D), and total darkness. Tower and Candle RSM, singularly or in combination, when included in turkey diets resulted in significantly lower mortality, higher live weights, improved feed conversion, higher percentage Grade A carcasses, and improved monetary returns. There were no significant differences observed for any of these traits for turkeys raised under continuous or intermittent lighting or total darkness. There was, however, some indication that the turkeys tended to perform better under intermittent lighting. No light X diet interaction was observed for any of the traits measured indicating that the turkeys responded in a similar manner regardless of the diet or light treatment.

USE OF TOWER RAPESEED SOAPSTOCKS IN BROILER DIETS

In terms of growth rate and feed intake:body weight gain, the feeding value of soapstocks derived from Tower rapeseed was shown to be comparable to that of tallow and an animal-vegetable blend fat. The above results were ascertained from regression analysis relating these production parameters to the inclusion level of fat, with the latter maximized at 6 and 9%, respectively, in two separate trials.

Cardiopathogenicity of soybean oil and tower rapeseed oil triglycerides when fed to male rats.

The triglycerides of soybean oil were purified by molecular distillation and those of Tower rapeseed oil by molecular distillation and adsorption chromatography. The original oils and the purified triglycerides were incorporated in semisynthetic diets at 20% by weight and fed for 16 weeks to weanling male Sprague-Dawley rats to compare the nutritional and pathological effects of the oils and their triglyceride fractions on rats. The study was carried out at two independent laboratories. No significant differences were observed between the results of the two establishments. The incidence of myocardial lesions was significantly higher in rats fed Tower rapeseed oil than in those fed soybean oil. Purification of the triglycerides by molecular distillation and adsorption chromatography appeared to have no major effect on the incidence of myocardial lesions. This supports our previous findings that the cardiopathogenicity appeared to have no major effect on the incidence of myocardial lesions. This supports our previous findings that the cardiopathogenicity of the test oils to rats resides in the triglycerides of these oils.

Beneficial Effect of Zinc Supplementation on Reproduction in Rats Fed Rapeseed Protein Concentrate

Three groups of 33 90-day-old female Sprague-Dawley rats were fed, ad libitum, the following diets for 2 weeks before breeding. Diet 1 (D1) contained 20% protein from casein, diet 2 (D2) had the same level of protein from Tower rapeseed (Brassica napus) protein concontrate (RPC) and diet 3 (D3) was the same as D2 with a zinc supplement (70 mg/l) in the drinking water. From each group 6 animals were killed before breeding and 5-9 animals were killed at 1 and 2 weeks of gestation and post-partum. From each rat, blood, thyroids, liver and femur were collected for the determination of zinc, copper, iron, manganese, calcium and magnesium. As a measure of the reproductive performance, body weight, number of pups in the uterus or delivered live or dead, and gestations days before parturition were recorded. The pups were examined for obvious deformities and also analysed for the above mineral elements by atomic absorption spectroscopy. In group D2, levels of zinc in maternal serum, liver, femur and in the pups were significantly lower than the comparable levels in the other two groups. The zinc supplemented RPC-fed group did not show the anorexia experienced by the unsupplemented group and there was neither a significant difference between reproductive performances of groups D1 and D3 nor was there any significant difference between the zinc levels determined. It was concluded that the toxic symptoms caused by RPC feeding was attributable to zinc deficiency probably caused by the high phytate level in the RPC.

UTILIZATION OF DIETARY TOWER RAPESEED PRODUCTS BY GROWING TURKEYS

Four replicate groups of 22 male large white day-old poults were assigned to each of eight dietary treatments. These consisted of a corn–soybean meal control diet and isocaloric, isonitrogenous diets containing either 25% Target, high-glucosinolate, rapeseed meal (RSM), 25% Tower, low-glucosinolate RSM derived from two sources or 21.5% whole autoclaved Tower rapeseed plus three other treatments where 10% of oil derived from either soybean, Tower rapeseed or Target rapeseed was added. Dietary specifications were changed with age of bird. Weight gain and feed intake were recorded to 112 days of age. Target RSM resulted in a significant depression in weight gain and feed intake. Compared to the corn–soybean control, 25% Tower RSM and whole autoclaved Tower rapeseed, which supplied most of the dietary fat, had no effect on turkey performance. There was an indication that poults to 56 days of age were not able to fully utilize whole rapeseed. Performance of turkeys fed Tower rapeseed oil or soybean oil was similar, while Target oil significantly depressed weight gain. A perotic-type condition was observed in poults to 28 days of age when fed diets containing Target RSM. The condition was not observed in poults fed the other diets. It is concluded that both the oil and meal resulting from the processing of Tower rapeseed are superior in nutritional value to those obtained from Target rapeseed, and that these products may be included in turkey diets from day-of-age up to 10% for the oil and 25% for the meal, without adversely affecting performance.

EFFECTS OF TOWER AND 1821 RAPESEED MEALS AND TOWER GUMS ON MILK YIELD, MILK COMPOSITION AND BLOOD PARAMETERS OF LACTATING DAIRY COWS

The effects of 1821 and Tower rapeseed meals (RSM) and Tower gums on feed intake, milk yield and composition, iodine and thiocyanate (SCN) content of milk and selected blood parameters were studied in two Lucas switch-back trials with lactating Holstein cows. Experimental treatments consisted of the sources of supplemental protein in the grain mixtures. In the first trial, Tower RSM at 26% and 1821 at 20 and 30% were compared to soybean meal (SBM) in grain mixtures balanced for protein and fiber content. Milk yield of cows receiving 30% 1821 RSM was greater than that of the control group (P &lt; 0.05). There were no other treatment effects on feed intake, milk yield, fat, protein and solids not fat content of milk or plasma thyroxine levels (P &gt; 0.05). Both Tower and 1821 RSM increased SCN and reduced iodine content of milk (P &lt; 0.05). In the second trial, Tower RSM containing 0, 4 and 8% Tower rapeseed gums were compared to the SBM control. There were no treatment effects on feed intake, milk yield and composition (P &gt; 0.05). Rapeseed meal decreased milk iodine content, increased milk SCN content (P &lt; 0.01), and red blood cell concentration but decreased white blood cell concentration (P &lt; 0.10). No effect on hemoglobin and packed cell volume was observed. There were no effects of level of gums on any of the above parameters.

THE EFFECTS OF LEVELS OF ISOLATION, OR VARIETAL DIFFERENCES IN, HIGH FIBRE HULL FRACTION OF LOW GLUCOSINOLATE RAPESEED MEALS ON RAT OR PIG PERFORMANCE

Forty-eight crossbred pigs of average initial weight 21 kg were fed 10% Tower rapeseed meal (RSM) and 10% Candle RSM as partial replacements for soybean meal (SBM). Diets were formulated to be isocaloric. Pigs fed the SBM diet consumed less feed, gained significantly (P &lt; 0.01) faster and were more efficient at converting feed to gain than those fed the RSM diets. Performance of pigs fed Candle RSM was not significantly different to that obtained with Tower RSM. In a second experiment, dehulled Tower RSM and Tower RSM hulls were mixed in amounts to produce RSM with crude fibre levels of 6.8, 10.8, 13.5 and 15.8%. The simulated RSM and Tower and Candle RSM were used to completely replace SBM in the diets of weanling (75 g) Sprague-Dawley rats. Rats fed SBM had significantly (P &lt; 0.05) higher average daily gain (ADG) than those fed Tower or Candle RSM, or diets containing the rapeseed meats. There was no significant (P &lt; 0.05) difference in ADG, feed intake or feed to gain ratio of rats fed either Tower or Candle RSM. Feed intake, feed to gain ratio and fecal volatile fatty acid concentrations increased while average daily gain decreased with increasing level of hulls in simulated RSM diets. There was no significant difference (P &lt; 0.05) in thyroid weight between rats fed SBM, Tower RSM or Candle RSM.

Low Erucic Acid, Low Glucosinolate Rapeseed Meal, with and without Added Gums in the Layer Diet

White Leghorn pullets of two strains were fed 20% of Tower rapeseed meal in the laying diet for one year. The rapeseed meal was manufactured with and without addition of 2% of either Tower or Midas gums. Control birds were fed a soybean meal diet. Each diet was fed to 1018 birds of two commercial lines. Rate of production during a one-year period was similar on all diets. Gums were without effect on any aspect of production. Overall mortality in the experiment was 11.7%, or 6.5% when neoplasms were excluded. There was a strain difference in the rate of mortality which was not due to any single cause. The birds fed the rapeseed meal with Midas gums had the highest mortality. The incidence of haemorrhagic lesions in various tissues was significantly affected by diet, being lowest in the birds fed the soybean meal diet and highest in the birds fed the rapeseed meal with added Midas gums.

Influence of steam pelleting on the feeding value of Tower and Candle rapeseed products for broiler chickens

Male broiler chickens were offered diets containing up to 30% Tower rapeseed meal, with these diets being prepared in mash or steam pelleted (crumble) form. In 4 experiments, birds receiving a maize and soya bean meal control diet showed a significant improvement in weight gain when crumbles, rather than mash diets, were used. With isocaloric, isonitrogenous diets containing rapeseed meal, no such improvement in growth rate was observed. Steam pelleting exerted no consistent effect on feed conversion. There was no significant difference in the growth rate of birds receiving mash diets irrespective of composition, while for crumbled diets, birds consuming the maize and soya bean control diet were heavier than comparable rapeseed-fed birds, with this difference being significant in 2 experiments. By adding fat, necessary to maintain rapeseed diets isocaloric, after the pelleting process, it was shown that fat per se was not responsible for failure to elicit a growth response with pelleted rapeseed meal diets. The response to pelleting was similar with diets prepared in an experimental pelleting machine at the university or by a commercial feed mill. Reduction in amino acid availability, in particular of arginine, is tentatively discussed in relation to the non-improved growth rate observed with pelleted diets containing rapeseed meal. Improvement in growth rate with pelleted vs. mash diets containing whole, raw rapeseeds is interpreted as a response to the heat treatment involved with the pelleting process.

The nutritive value of Tower rapeseed meal for swine

Two experiments involving 144 Yorkshire × Lacombe gilts, with an average initial weight of 20 kg, were conducted. In Experiment 1 the gilts were allotted to a control diet containing soya bean meal (SBM) or to diets in which either 50% or all of the supplementary protein was provided by Tower rapeseed meal (RSM). In the second experiment the two diets had either SBM or Tower RSM as the supplementary protein source. In a third diet Tower RSM was supplemented with sufficient lysine to equal the calculated available lysine level of the SBM control diet. In Experiment 1, gilts given the SBM diet grew from 20 to 60 kg significantly faster ( P<0.01), and had better feed conversion efficiency ( P<0.01), than those given the RSM diets. A 50% replacement of SBM by Tower RSM gave intermediate results. Partial or total replacement of SBM by Tower did not significantly affect the growth rate or feed conversion efficiency of the gilts when growing from 60 to 100 kg liveweight. Serum triiodothyronine (T3) and thyroxine (T4) concentrations of the gilts at 100 kg were lower in pigs fed on the RSM diets but the differences were not significant. In the second experiment, total replacement of SBM by Tower RSM, with or without the addition of lysine, significantly ( P<0.001) reduced growth rate and feed conversion efficiency during the growing period (20–60 kg) but did not significantly affect performance during the finishing period (60–90 kg). Serum T3 concentration was not significantly affected by the addition of Tower RSM to the diet but T4 concentrations were significantly reduced ( P<0.01). None of the carcass parameters studied were significantly affected by the addition of Tower RSM to the diets.

A COMPARISON OF CANDLE AND TOWER RAPESEED MEALS IN LAMB, SHEEP AND BEEF STEER RATIONS

The meal from Candle, a new strain of rapeseed that is low in erucic acid, glucosinolates and fiber was compared with the meal from Tower rapeseed that is low in erucic acid and glucosinolates. Sheep were fed equal quantities of chopped timothy hay and one of the test rapeseed meals. The digestibility coefficients of the diets containing Candle rapeseed meal with respect to dry matter, nitrogen, organic matter, energy, acid detergent fiber and neutral detergent fiber were significantly greater than those for diets containing Tower rapeseed meal. Lambs were fed a creep ration containing barley or corn and up to 32% rapeseed meal. While there were no differences in lamb growth rates before weaning, those consuming Candle rapeseed meal in the creep rations after weaning tended to grow faster and with greater feed efficiency (kg DM/kg gain; Mcal gross energy/kg gain) than did those receiving Tower rapeseed meal and the corresponding grain. These differences were not statistically significant. Corn silage, barley and Tower or Candle rapeseed meals were fed to growing beef steers in rations formulated to produce weight gains of 0.5, 0.75, or 1.0 kg/day. Those animals receiving Candle rapeseed meal tended to have poorer feed efficiencies at the low rate of gain and better feed efficiencies at the intermediate and high rates of gain although differences in growth were not significant. It was concluded from those experiments that Candle rapeseed meal was as good as, if not better than, Tower rapeseed meal in ruminant rations.

METABOLIZABLE ENERGY CONTENT OF TOWER AND CANDLE RAPESEEDS AND RAPESEED MEALS DETERMINED IN TWO LABORATORIES

True metabolizable energy (TME) of soybean meal and rapeseed products was determined in two laboratories by feeding the ingredients singly or mixed with a basal diet. Apparent metabolizable energy (AME) was also determined on the same samples and the values compared with TME. TME results between the two laboratories agreed well for the soybean meal and rapeseed meals obtained either by feeding the ingredients alone or with the assay diet, but with whole rapeseeds there was wide disagreement. This was due to poor and variable utilization of the whole seeds by birds in the two laboratories. AME values for the whole rapeseeds were considerably lower than expected, but the values for the rapeseed meals were as anticipated. Grinding significantly (P &lt; 0.01) increased the AME of Tower and Candle rapeseed and the TME of Candle rapeseed. Tower and Candle rapeseed meals did not differ significantly in TME or AME; nor were there differences in the ground seed of the two cultivars.

PERFORMANCE OF EGG-STRAIN BIRDS DURING THEIR COMMERCIAL LIFE CYCLE WHEN CONTINUOUSLY FED DIETS CONTAINING TOWER RAPESEED GUMS

In response to queries regarding the long-term effect of utilizing rapeseed gums in poultry diets, an experiment was initiated in which this product was continuously fed throughout the life cycle of the laying hen. Treatments consisted of: (1) soybean meal control, (2) 15% Tower rapeseed meal (3) 15% Tower rapeseed containing 1.5% of rape gums (4) soybean meal containing 1.5% of rape gums, and (5) soybean meal containing 1.5% of soy gums. The meals containing gums were manufactured in Western Canada. The diets were offered to one commercial White Leghorn and University strains of White Leghorns and Rhode Island Red, with conventional dietary specifications used in relation to age of bird. Gums had no persistent effect on feed intake or body weight of pullets from day of age to 20 wk. During this period mortality was low and not influenced by diet. In a subsequent laying period of 308 days, these same dietary treatments had no significant effect on egg production, while breed differences influenced all parameters measured. The addition of gums to rapeseed meal caused a reduction in egg size for a commercial strain of White Leghorns while the converse was true for a Guelph strain of White Leghorns. This apparent dichotomy may have been related to differences in feed intake. Diet had no influence on fertility or hatchability or on the performance of subsequent offspring when these were fed diets comparable to those of their dams. It is concluded that no toxic effects in terms of productive performance accrue from the use of up to 15% Tower rapeseed meal which contains 1.5% rapeseed gums, when fed throughout the commercial life cycle of egg strain birds and their offspring. Performance data also indicate that the addition of such gums to soybean meal offers an alternative means of their disposal.

EVALUATION OF LOW ERUCIC ACID RAPESEED OIL FED TO MONKEYS: BODY AND ORGAN WEIGHTS, ELECTROCARDIOGRAM AND BLOOD ANALYSIS

Male and female cynomolgus monkeys (Macaca fascicularis), equally divided as to sex, were fed diets which contained 20% by weight of either soybean oil or Brassica napus cv. Tower rapeseed oil, low in erucic acid (0.2%), for up to 24 wk. The monkeys ate well and grew normally, except for four monkeys which lost nominal amounts of weight. There were no significant differences between any of the groups in the relative weights of heart, liver and thyroid. Feeding diets which contained Tower rapeseed oil, however, resulted in increased adrenal weights in females and decreased kidney weights in males. The electrocardiograms in all monkeys appeared normal. The hematological studies failed to suggest that feeding either oil had any adverse effect on blood coagulation. Clinical chemical results revealed no serum enzyme changes suggestive of myocardial necrosis.

EVALUATION OF LOW ERUCIC ACID RAPESEED OIL FED TO MONKEYS: CARDIAC LIPIDS, HISTOCHEMISTRY AND PATHOLOGY

Male and female cynomolgus monkeys (Macaca fascicularis), equally divided as to sex, were fed, up to 24 wk, diets which contained 20% by weight of either soybean oil or Brassica napus cv. Tower rapeseed oil which contained 0.2% erucic acid. Long-chain monoenes appeared to accumulate in the cardiac lipids of both sexes fed Tower rapeseed oil. Histochemical studies suggested no myocardial damage associated with the feeding of either diet. Histopathological examination of the hearts of monkeys fed the two diets showed that only two male monkeys fed soybean oil for 24 wk had myocardial lesions, and these were multiple small foci of mononuclear cells. The results indicate that Tower rapeseed oil is indistinguishable from soybean oil in its nutritional and pathological properties.

The effect of dietary erucic acid on cardiac triglycerides and free fatty acid levels in rats.

AbstractMale Sprague‐Dawley rats, 3 weeks of age, were fed semisynthetic diets containing test oils at 20% by weight for 3 days, 1 week, and 16 weeks. The test oils contained up to 22.3% erucic acid. Growth retardation was evident in rats fed rapeseed oil high in erucic acid, and soybean oil and Tower rapeseed oil diets containing about 5% erucic acid. Cardiac triglyceride accumulation was found in rats fed diets containing about 5% erucic acid but not in rats fed Tower rapeseed oil which contains 0.2% of this acid. The cardiac free fatty acid levels were low, 50–100 μg/g of wet heart tissue, and were not affected by feeding diets containing about 5% erucic acid. Feeding a diet containing a high erucic acid rapeseed oil did result in higher free fatty acid levels but only at 3 days and 1 week; the level at 16 weeks was similar to the other oils. The fatty acid analysis of cardiac triglycerides and free fatty acids showed high percentages of erucic acid at 3 days and 1 week; at 16 weeks these levels had declined significantly. The results indicate that the accumulated erucic and eicosenoic acids, at 3 days and 1 week, accounted for the increase in cardiac free fatty acids when rats were fed the high erucic acid rapeseed oil. There appears to be no evidence that the early cardiac triglyceride or free fatty acid accumulation is related to the formation of the long term myocardial lesions.