Effects of supplemental dietary l-carnitine and ractopamine on the performance of juvenile rainbow trout, Oncorhynchus mykiss

Abstract

This study was carried out to investigate a possible protein‐sparing action of l‐carnitine and ractopamine in rainbow trout, Oncorhynchus mykiss. An 8‐week feeding trial was carried out to evaluate the effects of supplementation of three levels of l‐carnitine (0, 1 and 2 g kg−1) and two levels of ractopamine (0 and 10 mg kg−1) on growth performance, fillet fatty acid compositions and blood biochemical parameters in a 3 × 2 factorial experimental design. Ractopamine and 1 g kg−1 carnitine improved the specific growth rate (1.03% and 1.05% day−1), feed conversion ratio (FCR, 1.3 and 1.29), protein efficiency ratio (PER, 1.88 and 1.85) of fish and crude protein (73.5 and 73.8) content of fish fillet. l‐carnitine and ractopamine increased the levels of albumin, total protein and globulin in the serum of fish. Apart from eicosapentaenoic acid and docosahexaenoic acid, other fatty acids of fish fillet were increased by ractopamine, while total saturated fatty acids were almost intact. However, the total n‐3 poly unsaturated fatty acids were reduced by l‐carnitine supplementation (P<0.05). The present study showed that 1 g kg−1l‐carnitine and 10 mg kg−1 ractopamine each can improve the performance of rainbow trout and their combination in diet could enhance the protein level and change the fatty acids profile in fillet muscle.

Effects of dietary L-carnitine level on growth performance, body composition and antioxidant status in beluga (Huso husoL. 1758)

“…; Jalali Haji‐abadi et al . ), hence producing a sparing effect on blood glucose level. In comparison with the 50 and fish fed 350 mg kg −1 diet, cholesterol level in plasma was increased by L‐carnitine supplementation ( P > 0.05).…”

Effects of dietary soybean and sunflower oils with and without L-carnitine supplementation on growth performance and blood biochemical parameters of broiler chicks

“…Acetyl-CoA is the source of all the carbon atoms in cholesterol; on the other hand, Bouyeh (2012) reported that the higher dietary level of lysine and methionine (two precursors of L-carnitine) in comparison to the National Research Council for poultry (1994) level increase cholesterol, LDL and HDL in the serum of broiler chicks. The increasing serum protein (albumin or globulin) with the dietary Lcarnitine supplement reported previously may be related to its protein sparing action (Jalali et al, 2010) and reduced using the amino acid precursor (lysine and methionine) for L-carnitine biosynthesis. The concentration of BUN in the serum of chicks was altered by dietary treatments and soybean oil reduced it (Table 5).…”

“…Concentrations of albumin (ALB), total protein (TP), triglyceride (TG), cholesterol (CHO), High-density lipoprotein (HDL), low-density lipoprotein (LDL) and blood urea nitrogen (BUN) in the serum were measured by an enzymatic method based on ZiestChem Diagnostics kits (Technicon RA1000, Tehran, Iran). Globulin (GLO) was calculated by subtracting the albumin values from the total protein as described by Jalali et al (2010).…”

Effect of ractopamine on Nile tilapia in the end of grow-out period

“…Interestingly, channel catfish presented positive response to weight gain when fed ractopamine Lovell 1993, 1995) and reported improvement on feed efficiency of rainbow trout. Haji-Abadi et al (2010) also reported increase of weight and SGR in juvenile rainbow trout. Following the same trend, with regard to the ractopamine influence on carcass and fish body yield, no differences were observed to Nile tilapia in the present study (Table 3).…”

“…In protein metabolism, it may have an anabolic effect, hypertrophy of muscle fibers, and frequency changes in the type of muscle fibers (Beermann and Dunshea, 2005). Ractopamine has been tested in few species of fish, such as channel catfish Lovell, 1993, 1995) Dugan et al, 2003;Lortie et al, 2004;Haji-Abadi et al, 2010), pacu (Bicudo et al, 2012;Oliveira et al, 2014), and Hungarian carp (Devens et al, 2012). Thus, further studies are needed to test it in fishes of economic importance, such as the Nile tilapia, to determine the optimal dosage and time of supplementation.…”