Effects of dietary coconut oil on fatty acid oxidation capacity of the liver, the heart and skeletal muscles in the preruminant calf

Abstract

The oxidative capacity of the liver, the heart and skeletal muscles for fatty acids were investigated in preruminant calves fed for 19 d on a milk-replacer containing either coconut oil (CO, rich in 12:0) or tallow (rich in 16:0 and 18:1). Weights of the total body and tissues did not differ significantly between the two groups of animals but plasma glucose and insulin concentrations were lower in the CO group. Feeding on the CO diet induced an 18-fold increase in the hepatic concentration of triacylglycerols. Rates of total and peroxisomal oxidation of [1-14C]laurate, [1-14C]palmitate and [1-14C]oleate were measured in fresh tissue homogenates. Higher rates of total oxidation in liver homogenate and of peroxisomal oxidation in liver, heart and rectus abdominis muscle homogenates were observed with laurate used as substrate. Furthermore, the relative contribution of peroxisomes to total oxidation was 1·9-fold higher in the liver and in the heart with laurate than with oleate or palmitate. Finally, the peroxisomal oxidation rate of oleate was 1·5-fold higher in the hearts of calves fed on the CO diet. Whatever the tissue, citrate synthase (CS, EC 4.1.3.7) and cytochrome c oxidase (COX, EC 1.9.3.1) activities were similar between the two groups of calves but the COX : CS activity ratio was lower in the liver of the CO group. In conclusion, laurate is better catabolized by peroxisomes than long-chain fatty acids, especially in the liver. Elongation of lauric acid after partial oxidation might explain the hepatic triacylglycerol accumulation in calves fed on the CO diet.

Effects of body condition score at parturition and postpartum supplemental fat on metabolite and hormone concentrations of beef cows and their suckling calves1

“…However, concentrations of serum glucose were greater (P = 0.004) in calves nursing lipidsupplemented cows than control-fed cows. Piot et al (1999) also reported greater circulating glucose concentrations in preruminant calves supplemented with tallow (high in long-chain fatty acids) in a milk replacer. Total milk fat output was not different in the current study due to lipid supplementation (Lake et al, 2005); therefore, metabolic adaptation resulting in increased circulating glucose concentrations is likely attributed to increased long-chain fatty acid content of milk from lipid-supplemented cows (Lake et al, 2004).…”

Jersey calf performance in response to high-protein, high-fat liquid feeds with varied fatty acid profiles: Blood metabolites and liver gene expression

“…An increase in the amount of lipid infiltration would have most likely indicated that the calf's hepatocytes had reduced FA oxidation or increased incorporation of FA into TG in excess of what was being exported to peripheral tissues. Coconut oil included in CMR as the sole source of fat has been shown to increase the amount of TG present in the liver of Holstein-Friesian calves when fed for 19 d; TG content of wet liver weight was determined to be 4.1% compared with 0.2% for those not fed CO (Piot et al, 1999). Piot et al (1999) showed that CO fed at high levels can increase lipid infiltration in the liver.…”

“…Coconut oil included in CMR as the sole source of fat has been shown to increase the amount of TG present in the liver of Holstein-Friesian calves when fed for 19 d; TG content of wet liver weight was determined to be 4.1% compared with 0.2% for those not fed CO (Piot et al, 1999). Piot et al (1999) showed that CO fed at high levels can increase lipid infiltration in the liver. However, even at the highest level of CO inclusion in this trial (40% of total fat), no increase in liver lipid infiltration was seen.…”

“…Coconut oil has been formulated into CMR and used in prior experiments (Jenkins et al, 1985;Piot et al, 1999;Graulet et al, 2000;Mills et al, 2010), but not in CMR for Jersey calves. Mills et al (2010) found evidence of fatty liver development when preweaned Holstein calves were fed a CMR (28% CP, 23% fat; DM basis) containing CO with a total FA profile of 32% medium-chain triglycerides (TG).…”

Irvingia gabonensis fat: nutritional properties and effect of increasing amounts on the growth and lipid metabolism of young rats wistar sp

“…However, the mechanism by which the lauric acid influences the increase of the triglycerides still unknown. In addition and base on previous work of Piot [38], the elongation of lauric acid after its partial oxidization can explain the possible accumulation of the triglycerides in the serum. An eventual inhibitory effect of lauric acid on hepatic triglyceride secretion via the VLDL pathway could also be responsible for TG accumulation [39].…”