Energia digestí­­vel e inclusão da glicerina bruta em dietas para juvenis de curimbatá

Abstract

The curimbatá is an important fishery resource, however, little is known about its nutritional requirements. This work aimed to determine the apparent digestibility coefficient (ADC) and the effect of the inclusion of crude glycerin (CG) in the diet for curimbatá (Prochilodus lineatus) juveniles. Feces were collected from fish fed with reference diet based on ingredients of plant origin and a test diet, having the inert marker chromium (III) oxide (0.1%). In the growth experiment, 750 juveniles (18.71 ± 2.70 g) were used in a completely randomized design, with six treatments (diets containing 0, 4, 8, 12, 16, and 20% CG) and five repetitions, for 64 days. For P. lineatus, CG presented ADC of 0.76 for crude energy and digestible energy of 2,850.99 kcal kg -1 of the diet. The different levels of inclusion affected the final weight (FW), feed conversion rate (FCR), specific growth rate (SGR), and weight gain (WG), in addition to blood levels of glucose and triglycerides. Regression analysis showed a negative linear effect of the diets on FW, SGR, and WG, and a positive linear effect on FCR. Crude glycerin can be used as an energy source and its inclusion in 4% of the diet improves the productive performance of curimbatá.Key words: Characiformes; non-protein energy; glycerol; native fish RESUMO O curimbatá é um importante recurso pesqueiro, porém pouco se sabe sobre suas exigências nutricionais. O objetivo deste trabalho foi determinar o coeficiente de digestibilidade aparente (CDA) e o efeito da inclusão da glicerina bruta (GB) em dietas para juvenis do curimbatá Prochilodus lineatus. Foram coletadas fezes de peixes alimentados com dieta-referência, baseada em ingredientes de origem vegetal, e com dieta-teste, tendo o marcador inerte óxido de cromo III (0,1%). No experimento de crescimento foram utilizados 750 juvenis (18,71±2,70 g) em delineamento experimental inteiramente casualizado, com seis tratamentos (dietas contendo 0, 4, 8, 12, 16 e 20% GB) e cinco repetições, durante 64 dias. Para P. lineatus, a GB apresentou CDA de 0,76 para energia bruta e energia digestível de 2.850,99 kcal kg -1 da dieta. Os diferentes níveis de inclusão afetaram o peso final (PFM), conversão alimentar (CAA), taxa de crescimento específico (TCE) e ganho de peso (GPM), além dos níveis sanguíneos de glicose e de triglicerídeos. A análise de regressão mostrou efeito linear negativo das dietas sobre PFM, TCE e GPM e efeito linear positivo sobre CAA. A glicerina bruta pode ser utilizada como fonte de energia e sua inclusão em 4% da dieta promove um melhor desempenho produtivo do curimbatá. Palavras-chave:Characiformes; energia não-proteica; glicerol; peixe nativo.

Use of glycerol in fish nutrition: a review

“…In most surveys, the formulation of diets for fish containing the inclusion of glycerol is based on the replacement of corn (Li et al, 2010; Meurer et al, 2016; Moesch et al, 2016; Balen et al, 2017; Santos et al, 2019; Theisen et al, 2020). However, some authors choose to formulate fish diets differently.…”

“…The processing may be done by extrusion or pelleting, taking into account the food habit of the target species. The matrix sizes used to obtain the pellets vary according to the species and age of the fish (Neu et al, 2013; Moesch et al, 2016; Balen et al, 2017; Santos et al, 2019).…”

“…The use of glycerol as an energy source in fish varies according to fish species and size (Neu et al, 2013), possibly due to the gastrointestinal tract formation and the composition of the product (Fernandes et al, 2016). It is a potential source of energy for Nile tilapia (Meurer et al, 2012; Neu et al, 2012b; Costa et al, 2015; Gonçalves et al, 2015; Meurer et al, 2016; Moesch et al, 2016; Santos et al, 2019), common carp (Fernandes et al, 2016), channel catfish (Li et al, 2010), jundiá, pacu (Balen et al, 2014) and curimbatá (Balen et al, 2017) (Table 3).…”

“…Variations in digestibility results may be related to inter‐species feeding habits differences, as well as differences between the degrees of purity presented by the tested ingredient, since the physical, chemical and nutritional characteristics of the type of glycerol depend on the types of fatty acids and catalysis used in biodiesel production (Balen et al, 2017).…”

Effect of dietary crude glycerin on the productive performance of Nile tilapia fingerlings

“…The increase in world biodiesel production has led to an increase in crude glycerin stocks, the most important by-product obtained during oil transesterification (Stelmachowski 2011). The main glycerin component is glycerol, and both terms are treated as synonyms in several scientifi c studies (Balen et al 2017).…”