Digestibility of nutrients and energy in ingredients for bullfrogs during different phases of development

Abstract

The ability of frogs to digest dietary nutrients changes with growth, with the animals becoming more or less demanding. The objective of this study was to determine the apparent digestibility coefficients of protein, energy and ether extract of 14 ingredients used in bullfrog diets (spray-dried blood meal, hydrolysed feather meal, poultry by-product meal, red blood cell concentrate, tilapia by-product meal, sardine fishmeal, salmon fishmeal, meat and bone meal, corn gluten meal, soybean meal, corn, wheat bran, soy protein concentrate and soybean oil). A total of 2,325 bullfrogs (Lithobates catesbeianus) in different phases of development were used: early phase (mean weight of 30-50 g), growth phase (80-110 g) and finishing phase (150-200 g). Faeces were collected using the method of dissection. Marked differences in digestibility of the ingredients were observed between the different phases of frog development. Among the ingredients studied, salmon fishmeal and corn gluten meal showed good utilization of the protein (78.9% and 86.7%, respectively) and energy fraction (89.4% and 83.3%, respectively). The salmon fishmeal, poultry by-product meal, sardine fishmeal, soy protein concentrate, wheat bran and soybean oil exhibited good ether extract utilization (81.2%-92.8%), recommending their use in bullfrog diets. K E Y W O R D Sapparent digestibility coefficients, energy, ether extract, feeds, Lithobates catesbeianus, protein

The interplay between voluntary food intake, dietary carbohydrate-lipid ratio and nutrient metabolism in an amphibian, (Xenopus laevis)

“…On the other hand, protein digestibility in this study was relatively low, possibly due to the ingredients utilised in the diets. Values obtained from the lipogenic diet agreed with diets including feather (55.1%), and sardine meal (54.4%) [16]. Conversely, shrimp meal (the major ingredient of the diets in the present study) has shown 65% protein digestibility in vitro , as well as 22% chitin digestibility [56]; ingredient composition may have resulted in the low coefficients obtained through poor digestibility of the shrimp exoskeleton constituent [57].…”

“…Fat digestibility agreed with previously-reported values for R . catesbeiana frogs fed diets based on poultry by-products, meat and bone, as well as soybean meals [16].…”

“…In anurans, apparent digestibility coefficients for dry matter, protein, fat, energy and amino acids have been obtained for the cultivated bull frog R . catesbeiana [15,16,17]. However, those studies are focused on productive performance of growing animals comparing different foodstuffs, rather than the biochemical pathways underlying those processes.…”

Gaining insights in the nutritional metabolism of amphibians: analyzing body nutrient profiles of the African clawed frog,Xenopus laevis

“…During the six month trials, animals were fed three times per week a pelleted diet made in the Laboratory of Animal Nutrition, composed of shrimp meal (66.0%), soy bean meal (30.25%), calcium phosphate (0.75%), beef fat (1%), multivitamin supplement (0.50%) and rice syrup (1.5%). The composition of this diet was based on studies performed in bullfrogs, Rana ( Lithobates ) catesbeiana (Silva et al., 2014; Mansano et al, 2016; Zhang et al, 2015). The nutrient composition of the diet is presented in Table 1.…”

Importance of Optimum Water Quality Indices in Successful Frog Culture Practices

“…In raniculture, commercial feed is usually used for carnivorous fish with average levels of 45% crude protein [42]. In addition to the increase in the amount of feed offered according to the growth of the animals, there is also a change in the use of this feed in each developmental stage of the animal [43].…”