Dietary raw starch to gelatinized starch ratios: Effects on the growth performance, digestive functions, intestinal histology and growth hormone‐insulin‐like growth factor‐I axis of blunt snout breamMegalobrama amblycephala

Abstract

Carbohydrates are considered to be the most economical energy source in feed due to its wide source, low price and protein-saving effect. Adding high levels of carbohydrates to feed is favoured by the aquaculture industry, as it usually reduces feed cost coupled with an improvement of the pelleting quality (Romano & Kumar, 2019).However, unlike terrestrial animals, it is commonly believed that fish (especially carnivore ones) are usually glucose intolerant and show a poor ability to use carbohydrates for energy (Krogdahl, Hemre, &

Effects of native and pregelatinized starches on feed physical properties, digestibility, growth, nutrient utilization and histology of liver and intestine of juvenile tinfoil barb ( Barbonymus schwanenfeldii , Bleeker 1853)

“…Although it was statistically insignificant, fish fed dietary pregelatinized starch in the present study exhibited increasing trend of α‐amylase activity in the midgut and hindgut compared with those fed native starches. This finding was consistent with the intestinal α‐amylase activity of M. amblycephala fed 20% gelatinized and non‐gelatinized wheat flour (Zhang, Li, et al, 2020). On the contrary, bagrid catfish Hemibagrus nemurus fed 14.3% native corn or sago starch shows higher amylase activity than those fed pregelatinized starches supposedly due to starch source differences (Hamid et al, 2011).…”

“…Absorption and transportation of digested nutrients are closely linked with the intestinal villus development which reflects on the growth of animals (Wang et al, 2020) because loss of villus area affects the absorptive function of intestine (Sinha et al, 2011). According to Zhang, Li, et al (2020), M. amblycephala fed 20% pregelatinized wheat starch has comparable villus development, feed conversion and growth to those fed 20% native starch. However, the villus height together with the growth and feed efficiency increase when 25% of native starch is replaced with its pregelatinized form.…”

“…However, protein digestibility is independent of dietary native or pregelatinized starch in blackspot seabream Pagellus bogaraveo (Figueiredo‐Silva et al, 2009) and D. labrax (Peres & Oliva‐Teles, 2002). Likewise, partial or complete replacement of native starch with pregelatinized form in the diet favourably influences intermediate metabolism, glucose tolerance and body growth in L. rohita (Kumar et al, 2008), brook trout Salvelinus fontinalis (Xu et al, 2020) and blunt snout bream Megalobrama amblycephala (Zhang, Li, et al, 2020; Zhang, Liu, et al, 2020). On the other hand, striped catfish Pangasianodon hypophthalmus (Asemani et al, 2019) and yellowfin seabream Sparus latus (Wu et al, 2007) effectively utilize native starches than their pregelatinized forms.…”

The growth performance and metabolic responses of juvenile spotted rose snapper (Lutjanus guttatus) fed diets with different precooked cornstarch to protein ratio

“…Thus, α-glucosidase activity improves the digestibility of carbohydrates in teleost fish (Papoutsoglou & Lyndon 2006). Furthermore, the high levels of α-glucosidase activity recorded in the distal intestine show the importance of this intestinal region for disaccharide digestion and carbohydrate absorption, as previously reported for other carnivorous fish (Papoutsoglou & Lyndon 2006, Zhang et al 2020. Unfortunately, the digestibility of the diets was not evaluated in this study.…”