This research examined the quantitative effects of dietary conjugated linoleic acid (CLA) on juvenile cobia Rachycentron canadum with a mean initial weight of 10g and fed for 8 weeks. Four experimental diets that contained 16% crude lipid and 0%, 0.5%, 1.0% or 2.0% CLA were compared. At the end of the growth trial there was no significant differences in growth parameters. With increased CLA supplement, the body lipid content tended to reduce and protein content was significantly decreased. Increased dietary CLA caused significantly decreased hepatic FAS activity. Hepatic ME activity was decreased significantly in 0.5%, 0.75% and 1% CLA treatment, while no significant effect was detected on hepatic G6PDH activity. Total lipid contents of the liver and visceral fatty depot were significant decreased in 0.5%, 0.75% and 1% CLA treatment. There was a significant decrease in lipid content in the ventral muscle when CLA was supplemented at 0.75%, 1% and 2%. Fish fed 0.5% CLA had a lower adipocyte density in dorsal muscle, while fish fed 2% CLA treatment had a larger size of adipocytes in the liver and dorsal muscle. Gene expression of PPAR-£\ and PPAR-£^ showed no definite trend. Significant deposition of CLA was found in the liver, ventral muscle, dorsal muscle and visceral fatty depot of the cobia. The deposition ratio of cis-9, trans-11 CLA was slightly higher than that of trans-10, cis-12 CLA. Dietary CLA also affected the deposition of other fatty acids. Increased dietary inclusion of CLA significantly increased the total percentages of saturated fatty acids (SFA) but significantly decreased polyunsaturated fatty acids (PUFA). However DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) contents of the visceral fatty depot were significantly increased. In terms of immune response, dietary CLA had no effect on respiratory burst activities of head kidney phagocytes. Serum of fish fed 0.5% CLA had significantly increased lysozyme activities. In conclusion, dietary CLA affected the metabolism of lipid and fatty acid composition of cobia juveniles, and enhanced slightly immune responses. As CLA can deposit in the tissues of cobia, production of CLA-containing fish as a functional food is thus possible in cobia through dietary manipulation. An supplemental rate of 0.5% CLA is the optimal concentration considering fish nutrition and cost effectiveness.

No description available.

The effects of diet on milk fatty acid profile, including conjugated linoleic acid (CLA) have been well documented, however, there is limited information on the interaction of diet with genetics. The objective of this research was to determine the effect of single nucleotide polymorphisms (SNP) in the stearoyl CoA desaturase (SCD) gene on the ability to produce CLA in dairy cows fed low and high fat diets. The secondary objective was to determine the effect of a SNP in fatty acid synthase (FASN) on milk yield and composition. There was no effect of SCD genotype on CLA concentration, however there was an effect of SCD genotype on the ratio of C14:1/C14:0 which tended to be associated with CLA concentration when animals were fed a high fat diet. The FASN genotype affected milk yield, while composition remained constant. / Animal Science

There is an increasing body of evidence that conjugated linoleic acid (c9t11 CLA) suppresses chemically induced tumor development in cell cultures and animal models. Ruminant-derived foods make a major contribution to total fat consumption and are the main source of c9t11 CLA in the human diet. In light of the potential benefits to long-term human health, there has been increased interest in enhancing the concentrations of potentially beneficial fatty acids (FA) in milk and meat. Factors affecting c9t11CLA production and secretion into milk fat have been extensively studied the last 10 years and a large pool of knowledge has accumulated. However, little information is currently available about the effects of feeding c9t11 CLA- stimulating diets on rumen microbial ecology, particularly, bacterial species believed to be involved in the biohydrogenation (BH) process. The main objective of this study was to evaluate the effect of lipid source on the DNA concentrations of selected ruminal bacteria. Four continuous culture fermenters were used in 4 x 4 Latin square design with four periods of 10 d each. Treatment diets were fed (45 g/d DM basis) in three equal portions during the day. The diets were 1) control diet (50% alfalfa pellets, 50% concentrate, CON), 2) CON plus saturated fat (rumofat; SAT), 3) CON plus soybean oil (SBO), and 4) CON plus fish oil (FO). Lipid supplements were added at 3% of diet DM. Lipid supplements had no effect on feed digestibility, total VFA and acetate concentrations or fermenter pH. Propionate concentration was higher with the FO diet in comparison with the other treatment diets. Butyrate concentration was similar between the SBO and FO diets and both were lower than the levels for the CON and SAT diets. The concentration of VA in effluents increased with SBO and FO diets and was highest with SBO diet. The concentrations of C18:0 in effluents were lowest for the FO diet compared with the other treatment diets. The concentrations of c9t11 CLA in effluents were similar between SBO and FO diets and both were higher than levels for the CON and SAT diets. Concentrations of DNA for total bacteria, A. lipolytica, C. proteoclasticum and S. dextrinosolvens were similar for all diets. The concentrations of B. fibrisolvens (69.1 pg/45ng total DNA) and R. albus (1.96 pg/45ng total DNA) were least with the FO diet but were similar among the other treatment diets (SAT-104.2; 5.4, SBO-121.2; 5.71, and CON-126.3; 5.17 pg/45ng total DNA). S. ruminantium DNA concentration was highest with the FO diet and was least with the SAT diet (177.5, 54.9, 75.5, and 691.1 pg/20ng total DNA for treatment diets 1 to 4, respectively). In conclusion, SBO had no effect on bacterial DNA concentrations tested in this study and the inhibitory effects of FO on BH may be due in part to its influence on B. fibrisolvens, R. albus and S. ruminantium.

No description available.

Seventeen wk old male obese Zucker rats were given 0.4% (w/w) conjugated linoleic acid (CLA) isomers for 8 wk to determine effects of specific isomers on multiple eicosanoids in obesity. Liquid-chromatography-mass spectrometry analysis showed that compared to controls, those given t10,c12 CLA had increased liver leukotriene B4 levels, while immunoblotting revealed that rats given either t10,c12 or c9,t11 CLA had lower liver cyclooxygenase-2. In kidney, compared to c9,t11 CLA or controls, t10,c12 CLA increased cyclooxygenase-1, 6-keto-prostaglandin F2α and thromboxane B2 and inhibited the in vitro production of 13-hydroxyoctadecadienoic acid and 5-, 8-, 12- and 15-hydroxyeicosatetraenoic acid. In lean compared to fa/fa rats, endogenous levels and in vitro production of liver and kidney 9- and 13-hydroxyoctadecadienoic acid were elevated. Previous investigations on these tissues revealed that t10,c12 CLA reduced hepatic steatosis, but increased renal damage. How these changes in eicosanoids in response to t10,c12 CLA relate to the previous findings remains to be elucidated.

Seventeen wk old male obese Zucker rats were given 0.4% (w/w) conjugated linoleic acid (CLA) isomers for 8 wk to determine effects of specific isomers on multiple eicosanoids in obesity. Liquid-chromatography-mass spectrometry analysis showed that compared to controls, those given t10,c12 CLA had increased liver leukotriene B4 levels, while immunoblotting revealed that rats given either t10,c12 or c9,t11 CLA had lower liver cyclooxygenase-2. In kidney, compared to c9,t11 CLA or controls, t10,c12 CLA increased cyclooxygenase-1, 6-keto-prostaglandin F2α and thromboxane B2 and inhibited the in vitro production of 13-hydroxyoctadecadienoic acid and 5-, 8-, 12- and 15-hydroxyeicosatetraenoic acid. In lean compared to fa/fa rats, endogenous levels and in vitro production of liver and kidney 9- and 13-hydroxyoctadecadienoic acid were elevated. Previous investigations on these tissues revealed that t10,c12 CLA reduced hepatic steatosis, but increased renal damage. How these changes in eicosanoids in response to t10,c12 CLA relate to the previous findings remains to be elucidated.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T12:21:30Z No. of bitstreams: 2 amelia_katiane_almeida.pdf: 1222604 bytes, checksum: 425b7619f4dc4922de71736b30ce9457 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T12:21:49Z (GMT) No. of bitstreams: 2 amelia_katiane_almeida.pdf: 1222604 bytes, checksum: 425b7619f4dc4922de71736b30ce9457 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-10-26T12:21:49Z (GMT). No. of bitstreams: 2 amelia_katiane_almeida.pdf: 1222604 bytes, checksum: 425b7619f4dc4922de71736b30ce9457 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2010 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / O experimento foi realizado na Fazenda Experimental do Moura, Curvelo-MG, no Setor de Ovinos da FCA da Universidade Federal dos Vales do Jequitinhonha e Mucuri. Foram utilizados 24 cordeiros, machos inteiros, da ra?a Santa In?s, recebendo dieta ad libitum com duas propor??es de volumoso (30 e 70 %), sem fonte de lip?dios ou com a inclus?o dela (gordura protegida ou gr?o de soja), abatidos com peso m?dio de 37,3 ? 1,53 kg. Objetivou-se determinar o consumo volunt?rio de nutrientes, o desempenho de cordeiros, as caracter?sticas de suas carca?as e o perfil de ?cidos graxos da gordura intramuscular do lombo desses animais. Os animais com dietas com 30% de volumoso apresentaram melhores desempenhos no que diz respeito ? efici?ncia alimentar, convers?o alimentar, ganho de peso e tempo no confinamento (m?dias de 18,9%; 5,38; 191g; 110 dias; respectivamente) comparados aos animais que receberam 70% de volumoso, que apresentaram m?dias de 9,1%; 11,97; 100g; 222 dias, para os par?metros supracitados, respectivamente. Os animais com dietas com 30% de volumoso apresentaram pesos e rendimentos de carca?a fria (16,43 kg e 46,48%) superiores aos indiv?duos alimentados com 70% de volumoso (15,27 kg e 43,17%). Apesar de as dietas n?o terem efeito na maioria dos cortes, o efeito sobre o pernil destaca a import?ncia da dieta sobre esse corte nobre, que apresentou m?dias de 2,15 kg e 1,99 kg para dietas com 30 e 70% de volumoso, respectivamente. A propor??o de 70% de volumoso na dieta de cordeiros em termina??o proporcionou aumento de 19,5% na quantidade de ?cidos graxos poli-insaturados (PUFAs), mas houve diminui??o de 49,6% dos ?cidos linol?icos conjugados (CLA) no m?sculo Longissimus. O uso de gordura protegida, na forma de sab?es de c?lcio, como fonte de lip?dios na dieta, ? mais eficiente que o gr?o de soja mo?do, proporcionando maiores concentra??es de PUFAs e CLA, sendo que a propor??o de volumoso na dieta pode alterar as propor??es desses ?cidos graxos na carne de cordeiro. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT The experiment was conducted in a farm in Moura, Curvelo-MG, in the lamb area of Universidade Federal dos Vales do Jequitinhonha e Mucuri. 24 lambs of Santa In?s race were used under a diet ad libitum with two roughage (30 and 70 %), with or without fat source. They were slaughtered at about 37.3 ? 0.74 kg. The aim of this study was to determine nutrient intake, lambs performance, carcass traits, and the fatty acid profile of their loin intramuscular fat. Animals under 30% roughage diet showed higher alimentary efficience, feed conversion, weigh gain and confinement time (average: 18.9%; 5.38; 191g; 110 days; respectively). Animals under 30% roughage diet showed weigh and cold carcass (16.43 kg and 46.48%) superior to the ones under 70% roughage diet (15.27 kg and 43.17%). Besides diets did not affect most of the cuts, its effect on ham in emphasized by the averages 2.15 kg and 1.99 kg to 30 and 70% of roughage, respectively. 70% roughage diet to finishing lamb provided an increase of 19.5% on poliinsatured fatty acids (PUFAs). But there was a decrease of 49.6% of conjugated linoleic acids (CLA) on Long?ssimus, muscles. Using protected fatty, under calcium soap form, as fat source is more efficient than soy grain, providing higher PUFAs and CLA. Roughage on diet can upset proportions of fatty acid on lamb meat.

Conjugated linoleic acid (CLA) reduces adipose mass in several species. Studies were conducted to determine: 1) the effect of dietary trans10,cis12-CLA on growth, tissue fatty acid profile, mRNA expression for stearoyl-CoA desaturase (SCD) in adipose and liver, and mRNA expression for fatty acid synthase (FAS) in adipose of mice, 2) the effect of a dietary combination of trans-vaccenic acid (TVA) and trans10,cis12-CLA on delta9- desaturation, and 3) the effect of cis9,trans11-CLA, trans10,cis12-CLA, and carnitine palmitoyltransferase-1 (CPT-1) inhibitors on expression of mRNA for CPT-1 and fatty acid profile in mouse hepatocytes (AML-12) and human hepatoma cells (HepG2). In the first study, male or female mice were fed diets containing 0, 0.15%, or 0.30% trans10,cis12-CLA for 6 wk. Epididymal adipose weights (males) and inguinal adipose weights (females) decreased by 81% and 52%, respectively, in response to 0.30% trans10,cis12-CLA. Dry carcass weights decreased from 4.75 g for the control to 3.62 g for mice fed 0.30% trans10,cis12-CLA and the decrease was due to a reduction in ether extract. Liver weights increased linearly from 0.55 g (control) to 0.65 g (0.30% trans10,cis12-CLA). Dietary trans10,cis12-CLA (0.30%) reduced FAS and SCD mRNA in adipose by 60 and 30 % respectively, compared with the control, suggesting reduced lipogenesis and desaturation might be primary factors responsible for reducing body fat. In the second study, adult male or female mice were fed diets containing 0.40% TVA in combination with 0, 0.15, or 0.30% trans10,cis12-CLA for 10 d. Both TVA and trans10,cis12-CLA were incorporated into plasma, liver, adipose, muscle, and bone lipids proportional to their concentrations in the diets. Desaturation ratios were not affected in adipose, liver, and bone. However, ratios of 16:0 to 16:1 and 18:0 to 18:1 increased from 0.81 to 0.86 and 0.15 to 0.19 respectively, in response to dietary trans10,cis12-CLA (0.30%), suggesting inhibition of delta9 desaturation in muscle. In the third study, AML-12 or HepG2 cells were incubated with control media or media containing 15 uM etomoxir (ETM), 30 uM ETM, 15 uM hemipalmitoylcarnitinium (HPC), 30 uM HPC, 100 uM cis9,trans11-CLA, or 100 uM trans10,cis12-CLA for 24 h. Half the cells were harvested for analysis of fatty acids, mRNA for CPT-1, and cholesterol after 24 h. The remaining cells were incubated for an additional 24 h in control medium. Incorporation (% of total fatty acids) of trans10,cis12-CLA was greater than cis9,trans11-CLA in AML-12 (34 vs 23.6) and HepG2 (28 vs 18) cells. Cells incubated with trans10,cis12-CLA had higher ratios of 16:0 to 16:1, 18:0 to 18:1, and 18:2n6 to 20:4n-6, suggesting inhibition of delta9, delta5 , and delta6 desaturation. Cis9,trans11-CLA also reduced ratio of 18:2n-6 to 20:4n-6 in both cell lines. Trans10,cis12-CLA increased mRNA for CPT-1 in both cell lines compared with the control, suggesting enhanced oxidation of fatty acids. In addition, trans10,cis12-CLA caused a 4-fold and 5-fold increase in free cholesterol content of AML-12 and HepG2 cells, respectively. Overall, results demonstrated that trans10,cis12-CLA modulated lipid metabolism in tissues in vivo and altered fatty acid metabolism, cholesterol synthesis, and CPT-1 mRNA in hepatic cell lines in vitro. / Ph. D.

This comprehensive review critically evaluates whether supposed health benefits propounded upon human consumption of conjugated linoleic acids (CLAs) are clinically proven or not. With a general introduction on the chemistry of CLA, major clinical evidences pertaining to intervention strategies, body composition, cardio-vascular health, immunity, asthma, cancer and diabetes are evaluated. Supposed adverse effects such as oxidative stress, insulin resistance, irritation of intestinal tract and milk fat depression are also examined. It seems that no consistent result was observed even in similar studies conducted at different laboratories, this may be due to variations in age, gender, racial and geographical disparities, coupled with type and dose of CLA supplemented. Thus, supposed promising results reported in mechanistic and pre-clinical studies cannot be extrapolated with humans, mainly due to the lack of inconsistency in analyses, prolonged intervention studies, follow-up studies and international co-ordination of concerted studies. Briefly, clinical evidences accumulated thus far show that CLA is not eliciting significantly promising and consistent health effects so as to uphold it as neither a functional nor a medical food.