Protein sources and digestive enzyme activities in jundiá (Rhamdia quelen)

Abstract

Digestive enzymes activity influence feed utilization by fish, and its understanding is important to optimize diet formulation. This study reports the digestive enzyme activities of jundiá juveniles fed diets with protein sources. Fish were fed six experimental diets for 90 days: MBY (meat and bone meal + sugar cane yeast), SY (soybean meal + sugar cane yeast), S (soybean meal), MBS (meat and bone meal + soybean meal), FY (fish meal + sugar cane yeast) and FS (fish meal + soybean meal), and then sampled every 30 days and assayed in two intestine sections for digestive enzymes -trypsin, chymotrypsin and amylase -activities; gastric protease was assayed in the stomach. Digestive and hepatosomatic index, intestinal quotient, digestive tract length and weight gain were also measured. Trypsin and chymotrypsin activities were higher (p < 0.0001) in fish fed diets containing animal protein sources (MBY, MBS, FY and FS diets). Alkaline proteases were negatively affected by dietary soybean meal in the SY and S diets. Amylase activity had greater variation between diets and intestine sections. Fish fed MBY and MBS diets showed higher gastric protease activity (p < 0.0001). Weight gains were higher in fish fed the MBS and FS diets (p < 0.05). Highest values (p < 0.05) of digestive tract length were observed in fish fed MBS and FY diets, but no correlation with enzymes activities was found. Hepatosomatic index (HSI) was affected by diet composition. Dietary composition influenced digestive enzymes activities of jundiá. Key words: digestion, nutrition, soybean meal, meat and bone meal, fish mealFontes protéicas e atividade de enzimas digestivas em jundiás (Rhamdia quelen) RESUMO: As enzimas digestivas influenciam a utilização dos alimentos em peixes, e seu conhecimento é importante para otimizar a formulação de dietas. Este trabalho descreve a atividade de enzimas digestivas em juvenis de jundiá alimentados com fontes protéicas. Os peixes foram alimentados com seis dietas (90 dias): MBY (farinha de carne e ossos + levedura de cana), SY (farelo de soja + levedura de cana), S (farelo de soja), MBS (farinha de carne e ossos + farelo de soja), FY (farinha de peixe + levedura de cana) e FS (farinha de peixe + farelo de soja). A cada 30 dias, foram analisadas as enzimas digestivas (tripsina, quimiotripsina e amilase) no intestino. No estômago, foi mensurada a protease ácida. Foram estimados os índices digestivo e hepato-somático, quociente intestinal, comprimento do trato digestório e ganho em peso.

Different feeding habits influence the activity of digestive enzymes in freshwater fish

“…The knowledge of the feeding habits of different fish species associated with enzymes activities in the digestive tract is important to provide an appropriate diet for each species because digestive enzymes activity very reflects the changes in dietary (PERETTI & ANDRIAN, 2008;LAZZARI et al, 2010;2015).…”

“…The protein content of crude extracts was determined by the method of LOWRY et al (1951), using bovine serum albumin as a standard. For more details, see the technical of study LAZZARI et al (2010).…”

“…The digestive potential of fish is highly variable, changing with species, age, size, food and feeding history, stage of maturity and temperature (GARCÍA-CARREÑO et al, 2002). The analysis of digestive enzymes provides information on fish nutritional physiology and on their ability to take advantage of the different nutritional fractions of the feed (TENGJAROENKUL et al, 2000;ODEDEYI & FAGBENRO, 2010;LAZZARI et al, 2010;2015).…”

Farelo de crambe nas formas in natura ou reduzida em antinutrientes na dieta do jundiá

“…A protease ácida foi analisada no estômago e tripsina, quimotripsina e α-amilase, determinadas no intestino, de acordo com os protocolos descritos em LAZZARI et al (2010). Lipase intestinal foi quantifi cada conforme GAWLICKA et al (2000).…”

Substituição do farelo de soja pelo farelo de linhaça em dietas para a piava (Leporinus obtusidens)

“…Em trabalhos realizados com jundiá, a atividade de tripsina e quimiotripsina foi menor em peixes alimentados com dietas contendo farelo de soja e levedura de cana, e dietas com farelo de soja (LAZZARI et al, 2010). A atividade de tripsina em carpas capim (Ctenopharyngodon idella) foi maior nos peixes alimentados exclusivamente com capim, sendo que as carpas que receberam somente ração tiveram a menor atividade desta enzima (COSTA et al, 2011).…”