Portal de Pesquisa da BVS Veterinária

Tese em Português | VETTESES | ID: vtt-216209

Resumo

This study evaluated the ability of Pirarucu (Arapaima gigas) to feed through self- demand feeders, and determining daily feeding rhythm and locomotor activity. Twenty-four fish (312.58 ± 9,55g, mean ± SEM) were distributed in six 250-liter outdoor tanks. Each tank was equipped with a feeder adapted to allow fish to self-feed. Self-feeders and occupancy sensors were connected to a computer to allow measurement of feeding and locomotor activity. First, the ability of Pirarucu to use the self-feeding system was assessed. The daily rhythm of feeding activity and locomotion of Pirarucu was then evaluated. The fish learned to trigger the feeders and feeding demand stabilized at 158.79 activations per day. Predominant daytime feeding activity was observed, with 110.86 ± 0.27 counts / day (70% of the total actions) seen during the day, versus 47.93 ± 0.11 counts / day (30%) at night. However, no rhythm in this daily locomotor activity was observed. These study results were based on food being freely available and should be taken into account to improve the supply schedule of the species. Chapter 2: Daily feeding rhythms and the ability of pirarucu (Arapaima gigas) to compose a balanced diet through macronutrient self-selection were evaluated. Twelve fish (1573.3 ± 74.4 g) were distributed in six tanks of 250 l, two fish per tank. First, three experimental diets were prepared using an incomplete mixture of macronutrients (75%protein/25%carbohydrate-PC, 75%protein/25%fat-PF and 10% protein/45%fat/45%carbohydrate-PFC). These diets were provided to fish through a self-feeding system connected to a computer to record feeding activity. After this procedure, fish were challenged with a 50% protein dilution (diets: PC50 and PF50). The results showed that pirarucu exhibited a strict diurnal feeding pattern with 95.4% of daily feeding activity observed in the daytime. Fish selected 56.3% P, 24.2% C, 19.5% F, and consumed 150-151 kJ/kg BW/day of energy. After protein dilution, fish sustained energy intake by increasing the consumption of PC50 and PF50 to maintain the target protein intake of the previous stage. When fish were protein-restricted, they failed to sustain previous energy intake. These findings can be used to design feeding regimes and for formulating aquafeed for pirarucu. Chapter 3: Daily feeding rhythms and the ability of pirarucu (Arapaima gigas) to compose a balanced diet through macronutrient self-selection were evaluated. Twelve fish (1573.3 ± 74.4 g) were distributed in six tanks of 250 l, two fish per tank. First, three experimental diets were prepared using an incomplete mixture of macronutrients (75%protein/25%carbohydrate-PC, 75%protein/25%fat-PF and 10% protein/45%fat/45%carbohydrate-PFC). These diets were provided to fish through a self-feeding system connected to a computer to record feeding activity. After this procedure, fish were challenged with a 50% protein dilution (diets: PC50 and PF50). The results showed that pirarucu exhibited a strict diurnal feeding pattern with 95.4% of daily feeding activity observed in the daytime. Fish selected 56.3% P, 24.2% C, 19.5% F, and consumed 150-151 kJ/kg BW/day of energy. After protein dilution, fish sustained energy intake by increasing the consumption of PC50 and PF50 to maintain the target protein intake of the previous stage. When fish were protein-restricted, they failed to sustain previous energy intake. These findings can be used to design feeding regimes and for formulating aquafeed for pirarucu.

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This study evaluated the ability of Pirarucu (Arapaima gigas) to feed through self- demand feeders, and determining daily feeding rhythm and locomotor activity. Twenty-four fish (312.58 ± 9,55g, mean ± SEM) were distributed in six 250-liter outdoor tanks. Each tank was equipped with a feeder adapted to allow fish to self-feed. Self-feeders and occupancy sensors were connected to a computer to allow measurement of feeding and locomotor activity. First, the ability of Pirarucu to use the self-feeding system was assessed. The daily rhythm of feeding activity and locomotion of Pirarucu was then evaluated. The fish learned to trigger the feeders and feeding demand stabilized at 158.79 activations per day. Predominant daytime feeding activity was observed, with 110.86 ± 0.27 counts / day (70% of the total actions) seen during the day, versus 47.93 ± 0.11 counts / day (30%) at night. However, no rhythm in this daily locomotor activity was observed. These study results were based on food being freely available and should be taken into account to improve the supply schedule of the species. Chapter 2: Daily feeding rhythms and the ability of pirarucu (Arapaima gigas) to compose a balanced diet through macronutrient self-selection were evaluated. Twelve fish (1573.3 ± 74.4 g) were distributed in six tanks of 250 l, two fish per tank. First, three experimental diets were prepared using an incomplete mixture of macronutrients (75%protein/25%carbohydrate-PC, 75%protein/25%fat-PF and 10% protein/45%fat/45%carbohydrate-PFC). These diets were provided to fish through a self-feeding system connected to a computer to record feeding activity. After this procedure, fish were challenged with a 50% protein dilution (diets: PC50 and PF50). The results showed that pirarucu exhibited a strict diurnal feeding pattern with 95.4% of daily feeding activity observed in the daytime. Fish selected 56.3% P, 24.2% C, 19.5% F, and consumed 150-151 kJ/kg BW/day of energy. After protein dilution, fish sustained energy intake by increasing the consumption of PC50 and PF50 to maintain the target protein intake of the previous stage. When fish were protein-restricted, they failed to sustain previous energy intake. These findings can be used to design feeding regimes and for formulating aquafeed for pirarucu. Chapter 3: Daily feeding rhythms and the ability of pirarucu (Arapaima gigas) to compose a balanced diet through macronutrient self-selection were evaluated. Twelve fish (1573.3 ± 74.4 g) were distributed in six tanks of 250 l, two fish per tank. First, three experimental diets were prepared using an incomplete mixture of macronutrients (75%protein/25%carbohydrate-PC, 75%protein/25%fat-PF and 10% protein/45%fat/45%carbohydrate-PFC). These diets were provided to fish through a self-feeding system connected to a computer to record feeding activity. After this procedure, fish were challenged with a 50% protein dilution (diets: PC50 and PF50). The results showed that pirarucu exhibited a strict diurnal feeding pattern with 95.4% of daily feeding activity observed in the daytime. Fish selected 56.3% P, 24.2% C, 19.5% F, and consumed 150-151 kJ/kg BW/day of energy. After protein dilution, fish sustained energy intake by increasing the consumption of PC50 and PF50 to maintain the target protein intake of the previous stage. When fish were protein-restricted, they failed to sustain previous energy intake. These findings can be used to design feeding regimes and for formulating aquafeed for pirarucu.

Biblioteca responsável: BR68.1