• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1521-1530
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• 2009

A metabolic study was conducted with four ruminally-cannulated lactating goats (Saanen, 29 weeks lactation, 65${\pm}$5 kg) in a 4${\times}$4 Latin square design with 4 dietary treatments. The goats were fed a basal mixed diet consisting of 80% concentrate and 20% chopped rye grass hay (DM basis, CON). The goats were also fed the CON diet supplemented with soybean oil at a 5% level of the concentrate (SO), the SO diet supplemented with 0.5% of sodium bicarbonate (SO-B) or the SO-B diet supplemented with 30 ppm monensin (SO-BM). The goats were housed in individual pen and the study was conducted for 8 weeks. An increased molar proportion of propionate (C3) was observed at 1 h (p<0.003) and 6 h (p<0.029) post-feeding from all the supplemented diets. Calculated methane emission was markedly decreased prior to morning feeding (p<0.01), and at 1 h (p<0.05) and 6 h post-feeding (p<0.05) in goats fed the supplemented diets. All the supplements increased (p<0.0001) cis9, trans11-CLA content in rumen fluid. Concentrations of both cis9, trans11-CLA (p<0.0001) and trans10, cis12-CLA (p<0.026) were also increased in the milk fat of lactating goats fed the supplemented diets. The SO-B and SO-BM diets further increased CLA content in goat milk compared to the SO diet. All supplements increased unsaturated (UFA, p<0.002), monounsaturated (MUFA, p<0.002) and polyunsaturated fatty acids (p<0.014) and reduced SFA to UFA ratio (p<0.023). The concentration of MUFA was even greater (p<0.002) for SO-BM than for the SO-B diet. In conclusion, feeding soybean oil (5% of concentrate) to lactating goats was a useful way to improve milk fat and to improve fatty acid profile in the milk by increasing potentially healthy fatty acids such as CLA. Supplementation of sodium bicarbonate or sodium bicarbonate with monensin to the soybean oil-based diet increased CLA content further in goat milk. Supplementation of soybean oil may be an effective method to reduce methane emission in lactating goats.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.306-314
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• 2003

Bio-hydrogenation of $C_{18}$-unsaturated fatty acids released from the hydrolysis of dietary lipids in the rumen, in general, occurs rapidly but the range of hydrogenation is quite large, depending on the degree of unsaturation of fatty acids, the configuration of unsaturated fatty acids, microbial type and the experimental condition. Conjugated linoleic acid (CLA) is incompletely hydrogenated products by rumen microorganisms in ruminant animals. It has been shown to have numerous potential benefits for human health and the richest dietary sources of CLA are bovine milk and milk products. The cis-9, trans-11 is the predominant CLA isomer in bovine products and other isomers can be formed with double bonds in positions 8/10, 10/12, or 11/13. The term CLA refers to this whole group of 18 carbon conjugated fatty acids. Alpha-linolenic acid goes through a similar bio-hydrogenation process producing trans-11 $C_{18:1}$ and $C_{18:0}$, but may not appear to produce CLA as an intermediate. Although the CLA has been mostly derived from the dietary $C_{18:2}$ alternative pathway may be existed due to the extreme microbial diversity in the reticulo-rumen. Regardless of the origin of CLA, manipulation of the bio-hydrogenation process remains the key to increasing CLA in milk and beef by dietary means, by increasing rumen production of CLA. Although the effect of oil supplementation on changes in fatty acid composition in milk seems to be clear its effect on beef is still controversial. Thus further studies are required to enrich the CLA in beef under various dietary and feeding conditions.

• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.253-259
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• 2003

Conjugated linoleic acid (CLA) is a class of positional, geometric conjugated dienoic isomers of linoleic acid (LA). CLA activates the immune system, protects against tumorigenesis, and reduces the incidence of atherosclerosis. Trans-10, cis-12 CLA has specific effects on lipid metabolism, it has been shown to reduce body fat gain and regulates some adipocyte secreted proteins in vivo and in vitro. Here we report that a CLA mixture affects cytokine secretion from rat primary adipocytes. Rat primary adipocytes were treated with 1 mM, 100 $\mu$M, 1 $\mu$M or 100 nM CLA mixture doses; and leptin, tumor necrosis factor alpha (TNF a ), interleukin-6 (IL-6) and glycerol levels in the medium were measured. Leptin secretion was lower, TNF $\alpha$ secretion higher and IL-6 secretion did not change in response to the CLA mixture. Leptin and TNF $\alpha$ secretions did not change with CLA mixture treatment in a dose-dependent manner. In addition, the CLA mixture did not appear to enhance lipolysis in rat primary adipocytes. In conclusion, our study demonstrates that the decrease in leptin and increase in TNF $\alpha$ secretion in adipocytes treated with CLA mixture may be due to the apoptotic effect and to a reduction in peroxisome proliferator-activated receptor gamma (PPAR ${\gamma}$ ) ligands.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1417-1423
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• 2007

The present study was conducted to investigate the supplementation effects of $C_{18:2}$ rich-soybean oil or $C_{18:3}$ rich-perilla oil (7% of total diet, DM basis) for 12 weeks on plasma metabolites, fatty acid profile, in vitro lipogenesis, and activities of LPL and FAS in adipose tissue of sheep. The treatments were basal diet (Control), $C_{18:2}$ rich-soybean oil supplemented diet (SO-D) and $C_{18:3}$ rich-perilla oil supplemented diet (PO-D). All the sheep were fed the diets consisting of roughage to concentrate in the ratio of 40:60 (DM basis). Oil supplemented diets (SO-D and PO-D) slightly increased contents of triglyceride (TG) and total cholesterol (TC), proportions of both cis-9 trans-11 and trans-10 cis-12 CLA and TVA, but lowered (p<0.01) those of $C_{18:0}$ compared to the control diet. No differences were observed in the contents of TG and TC and proportions of fatty acids in plasma between supplemented oils. Oil supplemented diets slightly increased the proportions of cis-9 trans-11 and trans-10 cis-12 types of CLA in subcutaneous adipose tissue of sheep compared to the control diet. The rate of lipogenesis with acetate was higher (p<0.01) for intermuscular- and subcutaneous adipose tissues than that for intramuscular adipose tissue, while that with glucose did not differ among fat locations in sheep fed SO-D. No differences were observed in the rate of lipogenesis between substrates in all fat locations. The rates of lipogenesis with glucose increased only in the intermuscular- (p<0.01) and subcutaneous adipose tissue (p<0.005) compared to those with acetate. The rates of lipogenesis with acetate were the highest in the intermuscular and intramuscular adipose tissue of the sheep fed PO-D. Oil supplemented diets slightly increased the rate of lipogenesis with glucose for all fat locations. Supplementation of oils to the diet numerically increased the fatty acid synthase activity but did not affect the lipoprotein lipase activity in subcutaneous adipose tissue.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.739-747
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• 2018

The low solubility and high-cost recovery of Propionibacterium acnes polyunsaturated fatty acid isomerase (PAI) are key problems in the bioproduction of high value-added conjugated linoleic acid (CLA). To improve the solubility of recombinant PAI, six chaperone proteins were coexpressed with PAI. Introduction of GroELS proteins dramatically improved the PAI solubility from 29% to 97%, with increased activity by 57.8%. Combined expression of DnaKJ-GrpE and GroELS proteins increased the activity by 11.9%. In contrast, coexpression of DnaKJ-GrpE proteins significantly reduced the activity by 57.4%. Plasmids pTf16 harboring the tig gene and pG-Tf2 containing the tig and groEL-groES genes had no visible impact on PAI expression. The lytic protein E was then introduced into the recombinant Escherichia coli to develop a cell autolysis system. A 35% activity of total intracellular PAI was released from the cytoplasm by suspending the lysed cells in distilled water. The PAI recovery was further improved to 81% by optimizing the release conditions. The lipase from Rhizopus oryzae was also expressed in E. coli, with an extracellular activity of 110.9 U/ml. By using the free PAI and lipase as catalysts, a joint system was established for producing CLA from sunflower oil. Under the optimized conditions, the maximum titer of t-10,c-12-CLA reached 9.4 g/l. This work provides an effective and low-cost strategy to improve the solubility and recovery of the recombinant intracellular PAI for further large-scale production of CLA.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.444-449
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• 2006

This study investigated the effects of dietary supplementation of cheese byproduct on performance, egg quality and fatty acid profile of egg yolk lipids from laying hens. One hundred five 30-wk-old White leghorn laying hens were randomly distributed into five groups of twenty one hens each and maintained in individual laying cages for 4 weeks. The hens were assigned to five treatments that consisted of corn-soybean meal based diets containing 0, 1, 3, 5 or 10% of cheese byproduct. Feed intake and rate of egg production of hens were not significantly different across the treatments during the whole experiment (p>0.05). Similarly, egg yolk cholesterol level, egg weight, Haugh's unit, eggshell thickness, color, and strength were not significantly different across the treatments (p>0.05). The amount of C16:0 in egg yolk was not significantly different across the treatments, but that of C18:0 decreased with increased cheese byproduct (p<0.01). Monounsaturated fatty acid (C16:1 and C18:1) content in egg yolk was similar across the treatments. Total CLA and cis-9, trans-11 CLA content increased linearly with increased cheese byproduct (p<0.001), while trans-10, cis-12 CLA amount was not significantly different across the treatments (p>0.05). Total saturated fatty acid (SFA) in the egg yolk was decreased as the level of cheese byproduct including CLA increased (p<0.01). However, the amount of unsaturated fatty acids (UFA) such as monounsaturated fatty acids (MUFA), n-3 polyunsaturated fatty acids (PUFA), n-6 PUFA, and total PUFAs in the egg yolk were not significantly different across the treatments (p>0.05). Therefore, the present results showed that cheese byproduct beneficially improved the fatty acid composition of concern to human health in the egg yolk without adverse effects on egg quality.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.819-826
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• 2009

An in vitro study was conducted to investigate the effect of malate or fumarate on fermentation characteristics, and production of conjugated linoleic acid (CLA) and methane ($CH_4$) by rumen microbes when incubated with linolenic acid (${\alpha}-C_{18:3}$). Sixty milligrams of ${\alpha}-C_{18:3}$ alone (LNA), or ${\alpha}-C_{18:3}$ with 24 mM malic acid (M-LNA) or ${\alpha}-C_{18:3}$ with 24 mM fumaric acid (F-LNA) were added to the 150 ml culture solution consisting of 75 ml strained rumen fluid and 75ml McDougall's artificial saliva. Culture solution for incubation was also made without malate, fumarate and ${\alpha}-C_{18:3}$ (Control). Two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were also added to the culture solution of each treatment. In vitro incubation was made anaerobically in a shaking incubator up to 12 h at $39^{\circ}C$. Supplementation of malate (M-LNA) or fumarate (F-LNA) increased pH at 6 h (p<0.01) and 12 h (p<0.001) incubation times compared to control and linolenic acid (LNA) treatments. Both malate and fumarate did not influence the ammonia-N concentration. Concentration of total VFA in culture solution was higher for M-LNA and F-LNA supplementation than for control and LNA treatments from 6 h (p<0.040) to 12 h (p<0.027) incubation times, but was not different between malate and fumarate for all incubation times. Molar proportion of $C_3$ was increased by F-LNA and M-LNA supplementation from 6 h (p<0.0001) to 12 h (p<0.004) incubation times compared to control and LNA treatments. No differences in $C_{3}$ proportion, however, were observed between M-LNA and F-LNA treatments. Accumulated total gas production for 12h incubation was increased (p<0.0002) by M-LNA or F-LNA compared to control or LNA treatment. Accumulated $CH_4$ production for 12 h incubation, however, was greatly reduced (p<0.0002) by supplementing malate or fumarate compared to the control, and its production from M-LNA or F-LNA treatment was smaller than that from LNA treatment. Methane production from LNA, M-LNA or F-LNA treatment was steadily lower (p<0.01 - p<0.001) from 3 h incubation time than that from the control, and was also lower for M-LNA or F-LNA treatment at incubation times of 6 h (p<0.01) and 9 h (p<0.001) than for LNA treatment. Methane production from LNA, however, was reduced (p<0.01 - p<0.001) from 3 h to 9 h incubation times compared to the control. Both malate and fumarate increased concentration of trans11-$C_{18:1}$ from 3 h to 12 h incubation (p<0.01), cis9,trans11-CLA up to 6 h incubation (p<0.01 - p<0.01), trans10,cis12-CLA at 3 h (p<0.05) and 12 h (p<0.01), and total CLA for all incubation times (p<0.05) compared to corresponding values for the ${\alpha}-C_{18:3}$ supplemented treatment (LNA). In conclusion, malate and fumarate rechanneled the metabolic $H_2 pathway to production of propionate and CLA, and depressed the process of biohydrogenation and methane generation. Linolenic acid alone would also be one of the optimistic alternatives to suppress the $CH_4$ generation.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.951-959
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• 2014

The objective of this study was to determine the effects of linseed oil or whole linseed supplementation on performance and milk fatty acid composition of lactating dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The treatments consisted of basal ration (53:47; forage:concentrate ratio, on a dry matter [DM] basis, respectively) supplemented with 300 g/d of palm oil as a positive control diet (PO), or supplemented with 300 g/d of linseed oil (LSO), or supplemented with 688 g/d of top-dressed whole linseed (WLS). All cows were received ad libitum grass silage and individually fed according to the treatments. The experiment lasted for 10 weeks including the first 2 weeks as the adjustment period, followed by 8 weeks of measurement period. The results showed that LSO and WLS supplementation had no effects on total dry matter intake, milk yield, milk composition, and live weight change; however, the animals fed WLS had higher crude protein (CP) intake than those fed PO and LSO (p<0.05). To compare with the control diet, dairy cow's diets supplemented with LSO and WLS significantly increased milk concentrations of cis-9,trans-11-conjugated linoleic acid (CLA) (p<0.05) and n-3 fatty acids (FA) (p<0.01), particularly, cis-9,12,15-C18:3, C20:5n-3 and C22:6n-3. Supplementing LSO and WLS induced a reduction of medium chain FA, especially, C12:0-C16:0 FA (p<0.05) while increasing the concentration of milk unsaturated fatty acids (UFA) (p<0.05). Milk FA proportions of n-3 FA remarkably increased whereas the ratio of n-6 to n-3 decreased in the cows supplemented with WLS as compared with those fed the control diet and LSO (p<0.01). In conclusion, supplementing dairy cows' diet based on grass silage with WLS had no effect on milk yield and milk composition; however, trans-9-C18:1, cis-9,trans-11-CLA, n-3 FA and UFA were increased while saturated FA were decreased by WLS supplementation. Therefore, it is recommended that the addition 300 g/d of oil from whole linseed should be used to lactating dairy cows' diets.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1115-1120
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• 2002

The effects of seed-associated or free linseed oil on fermentation characteristics and long-chain unsaturated fatty acids composition, especially the formation of conjugated linoleic acid (CLA) and octadecenoic acid (trans-11 $C_{18:1}$, $t-C_{18:1}$) by mixed ruminal bacteria were examined in vitro. Concentrate (1% of culture solution, w/v, as-fed basis) with ground linseed (0.6% of culture solution, w/v, DM basis) or linseed oil as absorbed onto ground alfalfa hay was added to 600 ml mixed solution consisting of strained rumen fluid and artificial saliva at the ratio of 1:1 in a glass culture jar. The culture jar was covered with a glass lid with stirrer, and placed into a water-bath ($39^{\circ}C$) and incubated anaerobically up to 24 h. Seed-associated or free linseed oil did not significantly affect the pH and ammonia concentration in the culture solution. Molar percent of acetate tended to increase while that of propionate decreased with the addition of free oil treatment throughout the incubation. Differences in bacterial number were relatively small, regardless of the form of supplements. Decreasing trends in the compositions of linoleic acid ($C_{18:2}$) and linolenic acid ($C_{18:3}$) but increasing trends of stearic acid ($C_{18:0}$), $t-C_{18:1}$ and CLA compositions were found from culture contents up to 12h incubation when incubated with both ground linseed and linseed oil. The compositions of $C_{18:0}$, $C_{18:2}$ and $C_{18:3}$ were greater but those of oleic acid ($C_{18:1}$), $t-C_{18:1}$ and CLA were smaller in a culture solution containing ground linseed than those containing linseed oil. The ratio of $t-C_{18:1}$ to CLA was lower in the culture solutions containing linseed oil up to 12h incubations as compared to those containing ground linseed.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.244-251
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• 1996

Molecular weight and partial amino acid sequence of the cis, 9-cis, 12-octadecadienoate isomerase(linoleate isomerase) of Butyrivibrio fibrisovens A-38 were determined. Linoleate isomerase was isolated from the bac-teria cultured anaerobically and purified by ultracentrifugation in conjunction with Sepharose 6B column chro-matography, Phenyl sepharose 4B column chromatography and fast performance liquid chromatography (EPLC). The isomerase was single polypeptide with 19KD of molecular weight, when determined by SDS-PAGE. Fourteen amino acids sequence of N-terminal of the linoleate isomerase was N-GEIDKYPRIIKQQ determined by Edman method.