Dietary Oil Sources Research Articles

Tailoring of a cardioprotective muscle fatty acid composition of Atlantic salmon ( Salmo salar) fed vegetable oils

A feeding experiment was performed to investigate the possibility of feeding vegetable oils to Atlantic salmon, followed by a wash-out period to maintain salmon fillet as a product highly beneficial for human health, due to the high levels of VLC n−3 PUFA and high n−3/ n−6 ratio. Six groups of Atlantic salmon, initial weight 142 ± 1 g, were fed increasing dietary inclusion of rapeseed oil (RO) in a regression design and one group was fed a 50% olive oil (OO)/50% capelin oil (FO) diet for 42 weeks, followed by 25 weeks, of wash-out, when all groups were fed 100% FO. Muscle gross composition, lipid class and fatty acid composition and astaxanthin were measured at the start and after 22 and 42 weeks of feeding. Fillet fatty acid composition was analysed at the start and throughout the wash-out period of 25 weeks and 1788 day degrees. Growth, total lipid, astaxanthin content, and lipid class composition were not affected by dietary oil source. Muscle and fillet fatty acid composition were highly affected by dietary fatty acid composition. Through the wash-out period, the VLC n−3 PUFAs EPA and DHA was restored already after 1300 day degrees, whereas the wash-out of 18:2 n−6, 18:1 n−9 and 18:3 n−3 was a slower process, requiring a minimum 1788 day degrees for reaching 100% FO levels. For reducing n−6 fatty acids and increasing VLC n−3 PUFA, a period of feeding with 100% FO was sufficient for the groups fed 25% RO, 50% RO and 50% OO prior to wash-out. Considering the recommended n−3/ n−6 ratio and VLC n−3 PUFA intake for human consumption, fillets from fish fed 100% FO, 25% RO, 50% RO and 50% OO prior to wash-out, followed by 1788 day degrees of 100% FO diet, can be considered beneficial for human health promotion.

Flesh quality of raw and smoked fillets of Atlantic salmon as influenced by dietary oil sources and frozen storage

The aim of this study was to evaluate the effects of dietary oil source and frozen storage on flesh quality characteristics of Atlantic salmon. Four diets containing either 100% of Peruvian fish oil (PO), capelin oil (CO), soybean oil (SO) or low-erucic acid rapeseed oil (RO) as supplemental oil were fed to triplicate groups of salmon for 135 days. After slaughter, half of the fish were smoked while the rest were analysed when raw. For smoked and raw fish, the left fillet was analysed as fresh fillet while the right fillet was frozen and stored at −20 °C for two or four months before analyses. Fish fed SO and PO diets had firmer texture than fish fed RO diet. Liquid holding capacity (LHC) and colour evaluation were influenced by dietary oil source. Colour of fish fed fish oil-diets had significantly higher colour than fish fed vegetable oil-diets. Frozen storage decreased the firmness of raw fillets and the LHC of raw and smoked fillets. Colour evaluation was affected by frozen storage by increasing L *, a * and b * values whereas muscle carotenoid concentrations slightly decreased. Lipid oxidation was more pronounced in fish fed high levels of n-3 fatty acids and increased with frozen storage.

Effect of oils sources on blood lipid parameters of commercial laying hens

The experiment was carried out to verify if total cholesterol, HDL-cholesterol and triacylglicerol plasma levels are affected when laying hens are fed rations containing different dietary oil sources. One hundred sixty 50 week-old hens, assigned to four treatments with five replicates using 8 hens per replicate were used. The experimental period was of 84 days divided in 3 cycles of 28 days each. In the last day of each cycle, blood samples of 2 hens per replicate were randomly choose and blood samples were collected. On the other hand, blood was also collected at 7 am, 11 am and 3 pm aiming to study the daily changes of these lipids. Blood lipid parameters were not affected by different dietary oil sources (p > 0.05); however, HDL-cholesterol did change during the day, giving evidence that this lipid is indeed involved in the egg yolk formation.

Dietary lipids and temperature interact to influence tissue fatty acid compositions of Atlantic salmon,Salmo salarL., parr

Fatty acid compositions of both the polar phospholipids (PLs) and the non-polar neutral lipids (NLs) in fish tissues are influenced by dietary fatty acids, and tissue fatty acid compositions also change during thermal acclimation. The interaction between these factors in governing fatty acid compositions has been little studied, even though this may have importance when fish are reared in cold water. An experiment was conducted to investigate the effects of temperature (2 vs. 8°C), dietary oil source (fish oil vs. vegetable oils) and feed fat content (21% vs. 34% fat) on tissue fatty acid compositions of Atlantic salmon parr. The fish were held in fresh water under a 12 h light:12 h dark photoperiod until they doubled in body mass (from ca. 19 to 38 g, which took ca. 2 months at 8°C and ca. 6 months at 2°C), and then the muscle, viscera and carcass PLs and NLs were analysed for fatty acid composition. The ratios of unsaturated to saturated fatty acids (UFA:SFA), and the unsaturation indices (UIs, the number of unsaturated bonds per 100 fatty acid molecules) were calculated for each lipid class (PL, NL) within each tissue (muscle, viscera and carcass). Both dietary fatty acids and temperature influenced the compositions of the tissue lipids, with the dietary effects being most pronounced. The fatty acid composition of the feed oils was strongly reflected in the NLs of all three tissues, and also had a significant influence on the fatty acid profiles of the PLs. The effects of temperature were more marked in the PLs than in the NLs. Exposure to the lower temperature resulted in PLs with higher UFA:SFAs, and this is interpreted as a thermal acclimation response that would contribute to the maintenance of membrane fluidity. The PLs of fish given vegetable oils had higher UFA:SFAs than those of salmon provided with feeds containing fish oil, implying that the cell membranes of the former may have had greater fluidity. By contrast, the PLs of salmon fed with fish oil had higher concentrations of n-3 highly unsaturated fatty acids, and higher UIs, which may have made them more prone to peroxidative damage. This raises the intriguing possibility that the feeding of vegetable oils may have produced fish that were better able to withstand exposure to low temperature as a result of improved membrane fluidity (implied from the higher UFA:SFAs in these fish), while having membrane PLs that were less susceptible to oxidative damage (implied from the lower UIs).

Early in vivo cytokine genes expression in chickens after challenge with Salmonella typhimurium lipopolysaccharide and modulation by dietary n−3 polyunsaturated fatty acids

We studied the effects of Salmonella typhimurium lipopolysaccharide (LPS) on in vivo cytokine mRNA levels in chickens, and investigated whether these levels could be altered by different nutrients. Two hundred and forty chicks were assigned in a 2×4 factorial design of treatments. Factors were intravenous injection with S. typhimurium LPS, or saline (control), and four dietary fat sources: corn oil (CO), linseed oil (LO), menhaden oil and beef tallow (BT). Two hours after injection birds were killed and their spleens removed for RNA extraction. Quantitative real-time RT-PCR assays for mRNA of chicken IFN-γ, IL-6, IL-8, IL-15, IL-18 and 28S rRNA were used to obtain the in vivo splenic cytokine profiles. Expression levels of IL-6, IL-8, IL-18 and IFN-γ mRNA increased, but IL-15 mRNA decreased 2 h after challenge with LPS compared with saline controls. In saline-injected control chickens, the dietary oil source did not affect the splenic mRNA level of any cytokine. In LPS challenged chickens IFN-γ mRNA was significantly higher in the chickens fed the fish oil enriched diet compared with the LO, CO and BT enriched diets. The present data imply that avian IL-15 has, at least partially, a different function compared to its mammalian counterpart, and in addition, chicken innate immune responses might be affected differently by n−3 PUFA compared to mammals.

Effect of high-oil corn or added corn oil on ruminal biohydrogenation of fatty acids and conjugated linoleic acid formation in beef steers fed finishing diets.

Three Angus steers (410 kg) cannulated in the proximal duodenum were used in a replicated 3 x 3 Latin square to evaluate the effects of dietary lipid level and oil source on ruminal biohydrogenation and conjugated linoleic acid (CLA) outflow. Dietary treatments included: 1) typical corn (TC; 79.2% typical corn), 2) high-oil corn (HOC; 79.2% high-oil corn), and 3) the TC diet with corn oil added to supply an amount of lipid equal to the HOC diet (OIL; 76.9% TC + 2.4% corn oil). Duodenal samples were collected for 4 d following 10-d diet adaptation periods. Data were analyzed with animal, square, period, and treatment in the model and planned, nonorthogonal contrasts were used to test the effects of dietary lipid content (TC vs HOC and OIL) and oil source (HOC vs OIL) on ruminal biohydrogenation. Intake and duodenal flow of total long-chain fatty acids were increased (P < 0.05) by over 63% for diets containing more lipid regardless of oil source. Apparent ruminal dry matter and long chain fatty acid digestibilities were not altered (P > 0.05) by dietary lipid level or oil source. Ruminal biohydrogenation of total and individual 18-carbon unsaturated fatty acids was greater (P < 0.05) for diets with higher lipid content. Biohydrogenation of oleic acid was greater (P < 0.05) for HOC than OIL, but biohydrogenation of linoleic acid was lower (P < 0.05) for HOC than OIL. Duodenal flows of palmitic, stearic, oleic, linoleic, and arachidic acids were more than 30% greater (P < 0.05) for diets containing more lipid. Flow of all trans-octadecenoic acids was greater (P < 0.05) for diets containing more lipid. Corn oil addition increased (P < 0.05) the flow of trans-10 octadecenoic acid and the trans-10, cis-12 isomer of CLA by threefold compared to feeding high-oil corn. Feeding high-oil corn or adding corn oil to typical corn rations increased intake, biohydrogenation, and duodenal flow of unsaturated long-chain fatty acids. Compared with high-oil corn diets, addition of corn oil increased duodenal flow of trans-10, trans-12 and cis-12 isomers of octadecenoic acid and the trans-10, cis-12 isomer of CLA. The amount of cis-9, trans-11 isomer of conjugated linoleic acid flowing to the duodenum was less than 260 mg/d, a value over 20 times lower than flow of trans-11 vaccenic acid indicating the importance of tissue desaturation for enhanced conjugated linoleic acid content of beef.

Serum and liver lipids in rats fed diets containing corn oil, cottonseed oil, or a mixture of corn and cottonseed oils.

Previous research has demonstrated that the total replacement of corn oil (CO) with cottonseed oil (CSO) in the diets of growing male rats results in a lowering of the total cholesterol (TC) concentration in the serum. It is not, however, known if a partial replacement of dietary CO with CSO would be sufficient to lower TC levels, nor is the effect of replacing dietary CO with CSO on other indices of cholesterol status (e.g., the levels of high-density lipoprotein cholesterol [HDL-C], non-HDL-C [i.e., very-low and low-density lipoprotein-cholesterol], or the TC/HDL-C ratio). Growing male rats were fed diets having CO, CSO, or a CO/CSO (1:1, w/w) oil mixture (OM) as the source of dietary oil (diet groups CO, CSO, and OM, respectively). There were no differences between CO and OM groups for TC, HDL-C, non-HDL-C, or the TC/HDL-C ratio. However, TC was significantly lower (p < or = 0.05) for the CSO group than the CO group (2.85 vs. 3.23 mmol/l, or 110 vs. 125 mg/dl, respectively) as was HDL-C (1.83 vs. 2.13 mmol/l, or 71 vs. 82 mg/dl, respectively), but there were no differences between these groups for non-HDL-C or the TC/HDL-C ratio. Diet had no effect on serum triglycerides (TGs) or on total liver content of either cholesterol or TGs. Thus, partial (50%) replacement of CO with CSO was without effect on any of these serum indices of cholesterol status, but total replacement resulted in lower TC and HDL-C, without affecting non-HDL-C or the TC/HDL-C ratio. Because, relative to CO, CSO has higher levels of saturated fatty acids but lower levels of monounsaturated and polyunsaturated fatty acids, the cholesterol-lowering effect of CSO appears to be unrelated to its fatty acid composition, and may be caused by a component of its nonsaponifiable fraction.

The effect of different dietary oil sources on dairy cow performance and the level of C14:0 and C16:0 fatty acids in milk fat

AbstractHuman nutritionists have identified that dietary myristic and palmitic fatty acids are major risk factors in cardiovascular disease. Bovine milk fat is particularly rich in these fatty acids as they can be produced de novo in the mammary gland from by-products of fibre fermentation in the rumen. However, increased dietary levels of C18 fatty acids has been shown to reduce the concentration of myristic and palmitic acids in milk fat. Supplying dietary oil from whole oilseeds treated with xylose, may reduce rumen biohydrogenation of polyunsaturated fatty acids and further decrease the saturated fatty acid content of milk. In this study, the effect of feeding whole ground soya beans, whole ground soya beans treated with xylose and whole ground rape seed on dairy cow performance and milk composition was investigated. All three oilseeds reduced dry matter intakes and milk protein concentration. Both the xylose treated whole ground soya beans and the whole ground rape seed increased milk yield, but the whole rape reduced milk fat content. Levels of linoleic acid in milk fat increased when whole soya was fed, whereas oleic acid concentration was highest when whole rape was included in the diet. Concentrations of myristic and palmitic acids in milk fat were lower when any whole ground oilseed was fed, but the reduction was greatest with whole ground rape which reduced the myristic plus palmitic acid content of milk fat to 25 g/100 g fatty acid, compared with 47 g/100 g milk fatty acid in the milk from cows fed a standard low oil diet. These results suggest that feeding specific sources of dietary oil can dramatically reduce levels of myristic and palmitic acids in milk fat, and that different oilseeds have different effects on milk fat concentration.

Deposition of astaxanthin in fillets of Atlantic salmon ( Salmo salar) fed diets with herring, capelin, sandeel, or Peruvian high PUFA oils

To elucidate whether absorption and deposition of dietary astaxanthin are influenced by the use of different dietary fish oils having different melting points and fatty acid profiles, triplicate groups of individually labeled Atlantic salmon (initial average weight 569 g) were reared in 2 m 2 tanks, supplied with saltwater. The fish were fed four different experimental diets coated with either herring oil, capelin oil, sandeel oil, or a Peruvian oil high in polyunsaturated fatty acids. Salmon fed diets containing Peruvian high PUFA oil had significantly higher (13%) fillet carotenoid content than salmon fed herring oil ( P<0.05). Astaxanthin retention was significantly higher ( P<0.05) in salmon fed capelin and Peruvian high PUFA oil than in the two other groups. The effects of dietary oil supplements on carotenoid deposition were rather small and require verification. Redness of fillets and blood plasma astaxanthin levels did not differ among treatments. Liver weights, body weights, as well as specific growth rates, and feed conversion ratios were unaffected by dietary oil source. Significant ( P<0.05) positive linear relationships were found between final fillet idoxanthin concentration and total saturated fatty acids in supplement oils, astaxanthin and total monounsaturated fatty acids, and redness and total n−3 fatty acids, whereas the relationships between redness and total monounsaturated fatty acids and astaxanthin and total n−3 fatty acids were negative.

N−3 and n−6 fatty acid enrichment by dietary fish oil and phospholipid sources in brain cortical areas and nonneural tissues of formula‐fed piglets

Sufficient availability of both n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFA) is required for optimal structural and functional development in infancy. The question has been raised as to whether infant formulae would benefit from enrichment with 20 and 22 carbon fatty acids. To address this issue, we determined the effect of fish oil and phospholipid (LCPUFA) sources on the fatty acid composition of brain cortical areas and nonneural tissues of newborn piglets fed artificially for 2 wk. They were fed sow milk, a control formula, or the formula enriched with n-3 fatty acids from a low-20:5n-3 fish oil added at a high or a low concentration, or the formula enriched with n-3 and n-6 fatty acids from either egg yolk- or pig brain-phospholipids. Both the fish oil- and the phospholipid-enriched formula produced significantly higher plasma phospholipid 22:6n-3 concentrations than did the control formula. The 22:6n-3 levels in the brain, hepatic, and intestinal phospholipids were significantly correlated with plasma values, whereas cardiac 22:6n-3 content appeared to follow a saturable dose-response. Feeding sow milk resulted in a much higher 20:4n-6 content in nonneural tissues than did feeding formula. Supplementation with egg phospholipid increased the 20:4n-6 content in the heart, red blood cells, plasma, and intestine in comparison to the control formula, while pig brain phospholipids exerted this effect in the heart only. The addition of 4.5% fish oil in the formula was associated with a decline in 20:4n-6 in the cortex, cerebellum, heart, liver, and plasma phospholipids, whereas using this source at 1.5% limited the decline to the cerebellum, liver, and plasma. Whatever the dietary treatment, the phosphatidylethanolamine 20:4n-6 level was 10-20% higher in the brain temporal lobe than in the parietal, frontal, and occipital lobes in the temporal lobe by administering the formula enriched with egg or brain phospholipids. In conclusion, feeding egg phospholipids to neonatal pigs increased both the 22:6n-3 content in the brain and the 20:4n-6 content in the temporal lobe cortex. This source also increased the 22:6n-3 levels in nonneural tissues with only minor alterations of 20:4n-6. These data support the notion that infant formulae should be supplemented with both 22:6n-3 and 20:4n-6 rather than with 22:6n-3 alone.

Effect of dietary energy level and oil source on broiler performance and response to an inflammatory challenge

Broiler chicks were fed one of five diets from 3 d of age: a low energy diet containing 7% cellulose (ME 2,714 kcal/kg), or high energy diets containing approximately 7% of either tallow, corn oil, safflower oil, or fish oil (each 3,302 kcal/kg). Half of the chicks were injected intra-abdominally with Salmonella typhimurium lipopolysaccharide (LPS) on Day 11, sephadex on Day 13, and Freund's complete adjuvant on Day 15; samples were collected on Day 16. The uninjected chicks served as controls. In a second experiment, 3-d-old chicks were fed one of eight isocaloric diets containing tallow as the sole supplemental fat source, or tallow plus either 2% corn oil, 1, 1.5, or 2% fish oil, or fish meal at an amount to provide 1, 1.5 or 2% supplemental oil. Half of the chicks were injected intra-abdominally with S. typhimurium LPS on Days 10, 12 and 14; the uninjected chicks served as controls. Samples were taken on Day 15. In Experiment 1, the cellulose diet decreased performance to 10 d of age relative to the other diets, whereas immunogen injection decreased weight gain and feed efficiency and increased indices of inflammation among all dietary groups. Fish oil at approximately 7% of the diet did not improve weight gain. Fish oil diets improved weight gain and feed efficiency in Experiment 2 relative to the other diets, in spite of minimal effects on indices of inflammation. Injection of LPS decreased performance and increased inflammation across dietary treatment, although the second LPS injection was less potent in altering performance responses and inflammation compared to the first injection, indicating that repeated injections of LPS amy cause the chicks to become refractory to that stimulus. The fish meal diets resulted in poorer performance than similar levels of lipid provided as fish oil. Lower levels of dietary fish oil were more efficacious in improving broiler performance than higher levels, and fish oil provided from fish meal was not as efficacious as oil per se, possibly due to nonlipid components of the meal.

Fish Oil Source Differentially Affects Rat Immune Cell α-Tocopherol Concentration , , ,

We have previously reported that both the source of dietary fish oil and the chemical form of vitamin E supplied in the diet affect the vitamin E status of immune cells in rats. The purpose of this study was to investigate further the effect of fish oil source on immune cell vitamin E status using free α-tocopherol (α-T) at the AIN recommended level as the sole source of vitamin E. Sixty weanling female rats were fed semipurified, high fat (20 g/100 g) diets containing either tocopherol-stripped lard (LRD), menhaden fish oil (MFO), sardine fish oil (SRD) or cod liver oil (CLO) as the primary lipid source. Endogenous α-T concentration was measured and equalized to 150 mg/kg oil by addition of free RRR-α-T to each lipid source, allowing for a final concentration of α-T in the mixed diet of 30 mg/kg. An additional group of rats was fed LRD without supplemental vitamin E (LRD−) as a negative control. After feeding experimental diets for 5 or 10 wk, tissues were collected for α-T analysis by HPLC. After 5 wk, plasma and liver α-T (μmol α-T/g lipid) were significantly lower in SRD- and CLO-fed rats compared with LRD-fed rats. At 10 wk, only plasma α-T in CLO-fed rats remained significantly depressed. Plasma and liver α-T concentrations (μmol α-T/g lipid) were not significantly lower in MFO-fed rats than LRD-fed rats at either time point. Compared with LRD, feeding MFO to rats for 5 or 10 wk resulted in significantly greater α-T content of immune cells. In similar fashion, SRD-fed rats, compared with LRD-fed rats, also had significantly greater α-T content in splenocytes at both time points and greater thymocyte α-T at 10 wk. In all instances, the α-T status of rats fed CLO was indistinguishable from that of rats fed the vitamin E–free diet (LRD−). These data further demonstrate the complexity of the relationship between vitamin E status and dietary (n-3) polyunsaturated fatty acids (PUFA).

Tissue fatty acid deposition is influenced by an interaction of dietary oil source and energy intake level in rats

To investigate the net tissue fatty acid deposition in response to graded levels of energy restriction and modification of diet fatty acid composition, rats were randomly assigned into four dietary groups and fed for 10 weeks diets containing 40% as energy of either fish, safflower, or olive oil, or beef tallow, consumed ad libitum or energy restricted to 85% or 68% of ad libitum intake by reducing diet carbohydrate content. An additional eight rats were killed before the diet regimen, to provide baseline data from which fatty acid deposition rates were calculated. Body weight, and heart, liver and fat mass gains were decreased with energy restriction ( P<0.001). Olive oil feeding resulted in higher body weight gain ( P < 0.03) than tallow feeding, whereas fish oil feeding was associated with highest ( P < 0.007) liver weight and lowest ( P < 0.03) fat mass gains. Energy deficit-related differences in the deposition of stearic, linoleic, arachidonic, and docosahexaenoic acids in heart and palmitic and docosahexaenoic acids in liver were dependent on the dietary oil consumed ( P < 0.03). Similarly, interactive effects of restricted food intake and dietary oil type were found in the gain of palmitic, stearic, oleic, and linoleic acids in adipose tissue ( P < 0.01) when expressed in relation to the amount of each fatty acid consumed. These data suggest that energy intake level can influence the deposition pattern, as well as oxidation rate, of tissue fatty acids as a function of tissue type, fatty acid structure, and dietary fatty acid composition.

Light and nitrogen deficiency effects on the growth and composition ofPhaeodactylum tricornutum

The marine microalgaePhaeodactylum tricornutum, with a high lipid content constituting 20–60% of its dry weight under controlled growth conditions (1), has recently come into focus as a potentially rich source of dietary marine vegetable oil. In particular, this species has a characteristic high content of eicosapentenoic acid (EPA), which has potential benefits in human nutrition, since it cannot be synthesized in vivo in the human body. Some factors that could alter the biochemical composition ofPhaeodactylum tricornutum in favor of lipid production have been examinated in this study.

Effect of feeding high-oleic-acid peanuts to growing-finishing swine on resulting carcass fatty acid profile and on carcass and meat quality characteristics.

A high-oleic-acid peanut breeding line was used in a study designed to determine the effects of feeding swine diets containing elevated levels of monounsaturated fatty acids as a means to increase the level of monounsaturates and total unsaturates in the resulting carcass fat. Forty-eight pigs were allotted to four treatments that consisted of corn-soybean meal diets that contained 1) high-oleic peanuts (HOP), 2) regular commercial peanuts (RP), or 3) canola oil (CO), each added at a dietary level to provide 10% added fat/oil, and 4) a control diet with no added fat/oil. The oil of HOP averaged 75% oleic acid vs 60% for CO and 53% for RP. The pigs were fed the experimental diets from 33 to 102 kg BW, after which all pigs were slaughtered. All three dietary oil sources resulted in increases (P < .01) of monounsaturates in the backfat; the HOP diet resulted in the greatest increase (32% greater than control). Both CO and RP increased (P < .01) the level of polyunsaturates by nearly twofold; HOP resulted in a small decrease. Total unsaturates increased (P < .01) by 24, 24, and 27% for HOP, RP, and CO treatments, respectively, over that obtained from the control treatment. Carcass fat was softer/oilier (P < .05) from pigs fed CO and RP diets, but not from those fed HOP diets, compared with carcass fat of pigs fed the control diet. Dietary fat/oil source had no effect (P > .05) on other carcass compositional traits and various meat quality attributes.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of initial postweaning diet and supplemental coconut oil or soybean oil for weanling swine.

Two experiments involving a total of 581 crossbred pigs weaned at 23 +/- 2 d of age evaluated 1) the efficacy of two diets that contained milk products during the initial 14 d postweaning and 2) the effect of coconut oil or soybean oil additions to swine starter diets. In Exp. 1, postweaning performance responses of pigs fed a control corn-soybean meal-dried whey (C-SBM-DW) diet without added fat were compared with those of pigs consuming diets that contained 3, 6, or 9% levels of coconut oil or degummed soybean oil. The results demonstrated no beneficial weight gain, feed intake, or gain-to-feed ratio response during the initial 14 d postweaning to either dietary oil source. From 15 to 35 d, gains increased to the 6% added fat level, but there was no effect on feed intake when the gain-to-feed ratio was improved to the 9% fat level. In Exp. 2, two diets containing milk products were fed during the initial 14-d postweaning period. The first diet contained corn, soybean meal, dried whey, dried skim milk, and fishmeal (high nutrient dense diet, HNDD), and the second was a C-SBM diet with 25% dried whey. During the period from 15 to 35 d, diets contained no added fat or a 6% level of coconut oil, soybean oil, or the 1:1 combination of each at 3%. The results demonstrated that for the postweaning period from 0 to 14 d pigs fed the HNDD had higher gains (P less than .01), feed intakes (P less than .01), and gain-to-feed ratios (P less than .01) than pigs fed the C-SBM-DW diet.(ABSTRACT TRUNCATED AT 250 WORDS)

The relation of growth performance to dietary oil source in African giant rat (Cricetomys gambianus Waterhouse).

An experiment is described in which palm-oil, groundnut oil, cottonseed oil and soybean oil were each fed as a 5% dietary supplement to the African giant rat (AGR). 4 AGR were fed each diet from 6-12 weeks of age. The groundnut oil-based diet supported the best liveweight gain of 4.23 g/day, while AGR fed the cottonseed oil diet lost an average weight of 1.42 g/day during the 6-week study. The efficiency of feed utilization was similar for AGR fed on palm-oil and soybean oil diets, but this was significantly (P less than 0.05) better than the 3.24 g feed/g gain obtained for AGR fed on groundnut oil diet. There was an abnormally low feed intake by AGR fed the cottonseed oil diet, and this probably resulted in their poorest performance. In terms of feed conversion efficiency, the results suggest that either palm-oil or soybean oil can be used in the diet of AGR. This observation is not in line with the practice whereby groundnut oil was used in the diet of albino rat.

Taxonomy of the genusGlycine, domestication and uses of soybeans

The genusGlycine has had a stormy taxonomic history. Recent studies of herbarium specimens and cytological and morphological analyses of living collections, coupled with chemotaxonomic investigations, have made it necessary to revise the genus. In the first part of this paper the current taxonomic status of the genusGlycine is reviewed. The soybean was domesticated in China. It is unfortunate that the literature concerned with the antiquity and historical development of the soybean is obscured by legends and myths. In the second section of the paper, the archeological, historical, agricultural and botanical literature is summarized in order to present all the known evidence as to when, where and by whom the soybean was domesticated. The soybean is the world’s premier source of dietary vegetable oil and is nutritionally an excellent and inexpensive source of protein for use either as human food or animal feed. In addition, the soybean has numerous industrial uses. In the last section of this paper the traditional uses of fermented and nonfermented soybeans in the East as well as the high-technology-developed uses of soybeans in the West are summarized.

A NEW DRY DIET WITH ALTERNATIVE OIL SOURCES FOR PACIFIC SALMON

ABSTRACTA dry diet utilizing two oil sources that are less expensive and easier to obtain than marine fish oils was developed and found acceptable to salmon.Chinook salmon fry (initial wt = 0.5 g) were fed the dry diet with either cod liver oil, linseed oil, or a linseed oil‐tallow mixture as the dietary oil source. A commercial moist pellet and a commercial dry pellet were also fed. Growth and feed conversions were monitored throughout the 12‐week experiment and the proximate composition of the fish were determined at the end of the experiment along with the fatty acid compositions of the diets and total body lipids of the fish.Fish fed the experimental dry diets were significantly larger than those on the moist pellets. The commercial dry pellet was discontinued after six weeks due to poor growth. Among groups of fish fed the dry diet, those given the formulation containing cod liver oil were slightly heavier than those receiving either the linseed oil or linseed oil plus tallow formulations. Feed conversion was similar among fish fed the experimental dry diets and lower than the feed conversion of fish given the moist pellets.Fish receiving the moist pellets had less carcass fat and more carcass protein than did fish on the experimental dry diets. The difference reflected the level of protein in the diets. The fatty acid composition of the total body lipids varied with the fatty acid composition of the diets.