Marginal efficiencies of long chain-polyunsaturated fatty acid use by barramundi (Lates calcarifer) when fed diets with varying blends of fish oil and poultry fat

Abstract

An experiment was conducted with barramundi (Lates calcarifer) juveniles to examine the marginal efficiency of utilisation of long chain-polyunsaturated fatty acids (LC-PUFA). A series of five diets with blends of fish (anchovy) oil and poultry fat (F100:P0, F60:P40, F30:P70, F15:P85, F0:P100) were fed to 208 ± 4.1 g fish over a 12-week period. The replacement of fish oil with poultry fat had no impact on growth performance (average final weight of 548.3 ± 10.2 g) or feed conversion (mean = 1.14 ± 0.02). Analysis of the whole body composition showed that the fatty acid profile reflected that of the fed diet. However it was also shown that there was a disproportional retention of some fatty acids relative to others (notably LOA,. By examining the body mass independent retention of different fatty acids with differential levels of intake of each, the marginal efficiencies of the use these nutrients by this species were able to be determined. The differential retention of fatty acids in the meat was also examined allowing the determination of oil blending strategies to optimise meat n-3 LC-PUFA levels.

The influence of dietary fatty acid and fasting on the hepatic lipid metabolism of barramundi (Lates calcarifer)

“…It is known that changes in the diet FA profile generally influence the FA composition of tissues and also affect processes like digestibility, β‐oxidation, elongation and desaturation of FA, lipid transport and signalling and synthesis of eicosanoids (Glencross ; Torstensen & Tocher ; Salini, Irvin et al . ). This pattern was observed for most FA particularly for the MUFA in fish fed the PO diet, and LC‐PUFA, such as DHA and EPA in fish fed with FO diets.…”

“…Similarly, a recent study found a reduction in EPA retention in the fillet (Salini, Irvin et al . ). This result is consistent with the results of liver FA composition in the present study and potentially indicates that EPA is elongated to 22:5n3.…”

“…Poultry oil (PO) has been used as an alternative lipid source in fish diets for many years due to stable production levels and lower cost compared with FO. Experiments conducted with barramundi (Lates calcarifer), rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) showed that partial or even complete replacement of FO by PO did not interfere with growth, feed intake, feed conversion ratio (FCR) or survival (Greene & Selivonchick 1990;Higgs et al 2006;Salini, Irvin, Bourne, Blyth, Cheers, Turchini & Glencross 2015). Similarly, complete replacement of FO with rice bran oil in barramundi (Lates calcarifer) diets did not affect growth, feed intake, FCR or survival (Glencross, Blyth, Irvin, Bourne, Campet, Boisot & Wade 2016).…”

Eicosapentaenoic Acid, Arachidonic Acid and Eicosanoid Metabolism in Juvenile Barramundi Lates calcarifer

“…A recent study has already suggested that the marginal efficiency of LC-PUFA utilisation are low compared to other fatty acids in growing barramundi (Salini et al, 2015a). The present study describes a more up to date and relevant assessment of the marginal efficiency of EPA and ARA assessed in a dose-response manner, while simultaneously controlling for other LC-PUFA (rather than FO substitution).…”

Replacement of Menhaden Fish Meal by Poultry By‐Product Meal in the Diet of Juvenile Red Porgy

“…Salini et al. () demonstrated that poultry lipid can completely replace fish oil in diets for Barramundi Lates calcarifer , with no irregularities in fish growth performance or feed utilization; however, the poultry fat had a clear impact on long‐chain PUFA content in the fillet.…”