Effects of different dietary wheat starch levels on growth, feed efficiency and digestibility in grass carp (Ctenopharyngodon idella)

Abstract

An experiment was conducted to determine the effect of dietary wheat starch on grass carp (Ctenopharyngodon idella) in terms of growth performance, feed efficiency and digestibility. Five isoproteic (23.5%) and isolipidic (5.7%) diets with five supplemented levels of wheat starch (D20, D26, D33, D40 and D47 with 20, 26, 33, 40 and 47%, respectively) were fed to triplicate groups of grass carp (mean initial wet weight 6.9 ± 0.1 g) for 8 weeks. Results showed that weight gain (WG, %), feed efficiency (FE, %) and protein efficiency ratio (PER) in D20, D26 and D33 treatments were significantly higher than those in D40 and D47 treatments (P \ 0.05). Digestibility of carbohydrate and protein was significantly higher in D20, D26 and D33. No significant differences were found in serum glucose and triglyceride contents between treatments. Serum lipase activity of fish fed D40 and D47 was significantly higher than that of fish fed other diets. Wholebody, muscle and liver lipid contents increased with dietary starch level as did mesenteric fat index, hepatosomatic index and viscerosomatic index. In conclusion, when dietary protein level was 23%, the level of dietary wheat starch should maximum be 33% to support normal growth of grass carp. Fish growth was hampered by higher wheat starch ([33%) despite fish ate increasing levels of dietary digestible energy. Furthermore, excess digestible carbohydrate was to some extent converted to lipid that was deposited in various tissues. Most importantly, grass carp could endure high levels of cellulose without any negative effect on growth and digestibilities of dietary protein and carbohydrate.

Growth performance and thyroid hormones of Caspian kutum, Rutilus frissi, juveniles in response to dietary carbohydrate levels

“…Our results indicate that different levels of carbohydrate from 15 to 35 % significantly increased growth rate and PER. This is similar to those reported in rohu (Labeo rohita) and grass carp (Ctenopharyngodon idella) (Kumar et al 2007;Tian et al 2012). Better utilization of carbohydrate by fish may be related to anatomical and functional differences of the gastrointestinal tract and associated organs (Krogdahl et al 2005).…”

Regulations on glucose metabolism affected by dietary carbohydrate in different strains of juvenile gibel carp (Carassius gibelio)

“…Actually, there was significant difference in dietary carbohydrate utilization between fish species (Li, ; Panserat, Médale et al, ), especially for fish with different food habits. Most carnivorous fish can tolerate carbohydrate contents no more than 20% (Polakof et al, ; Wilson, ), while the optimum supplement level of dietary carbohydrate in gibel carp (omnivorous fish) was 30% (Li., ), and the herbivorous grass carp ( Ctenopharyngodon idellus ) could use dietary carbohydrate up to 50% (Lin, ; Tian, Liu, Yang, Liang, & Niu, ). Thus, more researches for a better understanding of the differences in the capacity of metabolizing glucose in different species need to be considered, and the diverse responses to dietary carbohydrate with different mechanism of the molecular regulation in glucose metabolic pathways should also be determined.…”

Ammonia nitrogen excretion in Mandarin Fish (Siniperca chuatsi) and Grass Carp (Ctenopharyngodon idellus) fed practical diets: the effects of water temperature

“…Besides, many fish species are of ornamental, aquacultural and economical values, and ammonia toxicity could be a major issue that leads to mass mortality under unfavourable culture conditions (Ip & Chew ). With the use of pelleted feed, however, high density and net‐cage monoculture of these species are common culture practice today (Tian, Liu, Yang, Liang & Niu ). Although the farms do not consume water, they alter its nutrient load by adding phosphorus, nitrogen, and particulate matter which enriching nutrients stimulate algae and plant growth, lowering pond or river water quality (Hardy ).…”