The effect of dietary conjugated linoleic acid on the levels of lipids, cholesterol and iodothyronines in the blood of pigs

Abstract

The aim of the investigation was to study the effect of dietary conjugated linoleic acid (CLA) on the concentrations of lipids, fatty acids and iodothyronines: thyroxine (T 4 ), triiodothyronine (T 3 ), reverse-triiodothyronine (rT 3 ), free T 4 (FT 4 ) and free T 3 (FT 3 ) in blood plasma of pigs. The experiment was carried out on 50 fatteners (average liveweight 50 kg) divided into 5 groups (5 gilts and 5 barrows per group). The pigs were fed a basal diet supplemented with 0, 0.5, 1, 1.5 and 2% of CLA isomers. Blood samples were collected from fatteners weighing 105 kg. Supplementation of the diet with CLA did not significantly affect lipid parameters in blood plasma. In comparison with gilts, a significantly higher concentration of triglycerides in barrows was found. In CLA-fed pigs, significant changes in the plasma fatty acid profile were noticed. The higher doses of CLA caused a significant increase in CLA and saturated fatty acids (SFA) with a concomitant decrease in monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids in blood plasma. Moreover, dietary CLA decreased the ∆9 desaturase index in a dose-dependent manner, probably as a result of Journal of Animal and Feed Sciences, 16, 2007, 193-204 8 Corresponding author: e-mail: rzsechma@cyf-kr.edu.pl DIETARY CLA ON LIPIDS AND IODOTHYRONINES IN PIGSthe inhibitory effect of CLA on stearoyl-CoA activity.Only the lowest dose of CLA (0.5%) increased T 4 and T 3 concentrations in blood plasma of fatteners by 64 and 27%, respectively. There were no significant changes in rT 3 , FT 4 and FT 3 in the plasma of CLA-treated pigs. The results obtained indicate that dietary CLA influenced the fatty acid profile in blood plasma of fatteners without affecting basic lipid parameters. The increase in T 4 and T 3 concentrations in the blood of CLAtreated pigs suggests that low doses of CLA may stimulate the function of the pituitary-thyroid axis and/or deiodinase activity. On the other hand, the absence of changes in FT 4 and FT 3 indicates that CLA treatment does not affect thyroid hormone homeostasis in blood.

Analysis of variability of plasma leptin and lipids concentration in relations to glycolytic potential, intramuscular fat and meat quality in P76 pigs

“…Total cholesterol level in blood plasma in pigs obtained in this experiment was higher than results of Sechman et al (2007) and Yu et al (2007). As was discussed by Sechman et al (2007) the plasma lipoprotein profi le in pigs varies according to not only feed components but also sex and race.…”

“…As was discussed by Sechman et al (2007) the plasma lipoprotein profi le in pigs varies according to not only feed components but also sex and race. HDL fractions was lower and LDL was higher in comparison to results obtained by Scheman et al (2007).…”

ToF‐SIMS spectrometry to observe fatty acid profiles of breast tissues in broiler chicken subjected to varied vegetable oil diet

“…Stearic acid is one of those fatty acids that plays an important role in development of the tenderness and juiciness of meat. 31 Woodet al's research 10 indicates that there is a positive correlation between the meat taste and its SFA content and a negative correlation with unsaturated acids. In the presented work, in the case of measurements made for stearic acid (m/z 283.26) and arachidonic (m/z 311.30), analogous relations were observed.…”

“…Therefore, for the reasons mentioned above, it is recommended to limit the consumption of this fat. Stearic acid is one of those fatty acids that plays an important role in development of the tenderness and juiciness of meat . Woodet al's research indicates that there is a positive correlation between the meat taste and its SFA content and a negative correlation with unsaturated acids.…”

Dietary conjugated linoleic acid (CLA) has comparable effects to ractopamine on the growth performance, meat quality and fatty acid profiles of loin muscles of finishing pigs under commercial husbandry

“…Thus, these discrepancies in response to CLA may be related to the age/weight of the animal, genetic factors, the level of supplementation, differences in response to the different isomers or proportion of isomers used in supplementation of diets or the duration of supplementation with CLA administration during the study (Fern andez-F ıgares et al 2008;Schiavon et al 2010). We hypothesised that the difference found in response by sex and the level of CLA 0.5% could be due to an increase in hormone thyroid T3 in barrows, reported by Sechman et al (2007). This hormone was increased in the blood of barrows, but not gilts, fed a diet supplemented with CLA 0.5%, but no effect was found with CLA 1.0%, which may be related to the higher metabolic rate in barrows according to Danfort and Burguer (1989).…”