Prediction of body composition in mirror carp (<i>Cyprinus carpio</i>) by using linear measurements in vivo and computed tomography post-mortem

Abstract

Abstract. The mirror carp (Cyprinus carpio) belongs to the cyprinids, the world's largest and most important fish family in aquaculture. The fat content and the fillet yield are important parameters in the marketing of carp. Although the influence of the environment on the body composition of the carp has been well studied, there is little research in the field of breeding. For this purpose, precise phenotyping is indispensable. Therefore, during this study a total of 33 mirror carps were examined using computed tomography (CT) technology. First, the fish were examined alive. Total body weight and linear measurements such as lengths, height and circumferences were measured, and ultrasound was used to determine the back-fat thickness. The fish were then slaughtered and whole body scans of all fish using CT were made. The carps were filleted and the fillets with skin were chemically analyzed. In order to predict the chemical fillet fat content, thickness measurements and volume calculations of the back fat were carried out using CT. Compared to the CT-based back-fat thickness measurement correlated with the results from the chemical analysis (R2=0.62), the CT-based volume measurement of the back fat leads to a higher coefficient of determination (R2=0.85). Prediction results can still be improved by adding linear measurements. The in vivo ultrasound (US) examination of the back-fat thickness was compared with the CT back-fat thickness results. The measurements of the back-fat thickness took place at similar positions in the fish. Coefficients of determination (R2) of 0.63 to 0.77 were obtained. The back fat in mirror carp proved to be an interesting area for determining the fillet fat content. The evaluation of the fillet yield resulted in a mean value of 42.89 % with a standard deviation of ±2.43. Fillet yield (%) correlated with CT-based fillet thickness measurement resulted in a moderate coefficient of determination (R2 of 0.45). A similar coefficient of determination was achieved with selected linear measurements.

Evaluation of Diet Supplementation with Wheat Grass Juice on Growth Performance, Body Composition and Blood Biochemical Profile of Carp (Cyprinus carpio L.)

“…The fat content is one of the most important feature in the marketing of carp and is significantly influenced by the growing conditions. Due to the fact that the content of fat varies greatly (from 2.7% to 17.6%) and a content over 15% can adversely affect the taste of the meat, some countries only allow the marketing of carp with a content below 10% [ 41 , 42 , 43 ]. Moreover, the collagen and ash content were significantly higher in the same variant, which demonstrates the positive effects of WGJ administration in feeding of common carp.…”

A new approach for quantifying phosphorus requirement in Colossoma macropomum using CT scanning

“…In this view, the evaluation of bone density could be an important tool to assess and correctly interpret the data on P requirement studies, since bone mineralization is reduced by P deficiency with a concurrent reduction on bone density (Fjelldal et al, 2016). However, few studies have used this technique to evaluate P adequacy in fish (Maas et al, 2020) and, to the best of our knowledge, this is the first study to report the use of CT scan to determine the mineral requirement of TA B L E 5 Mineral composition of whole-body, bone vertebrae and scales of tambaqui fed diets containing graded levels of available phosphorus levels (g kg −1 for Ca, P and mg kg −1 for Mg; Mn and Zn) a fish species. In general, most of the studies use a qualitative measurement obtained by X-ray analysis.…”

“…This method uses X-ray shades to form cut images (slices) in different spatial planes, without overlapping structures (Cummings et al, 2002;Thrall, 2017). Although this method has been extensively used in studies on the developmental biology of bones in higher vertebrates (Thrall, 2017) and some fish species (Fiedler et al, 2021;Holm et al, 2020;Maas et al, 2020), few studies have used this technique to estimate the mineral requirement of fish to the best of our knowledge (Suarez-Bregua et al, 2021).…”

Genomics to accelerate genetic improvement in tilapia

“…In contrast, selection for high growth can result in a significant correlated increase in fillet weight (Nguyen et al, 2010). The use of advanced phenotyping technologies, including computed tomography scan or ultrasound (Vandeputte et al, 2017;Maas et al, 2020;Prchal et al, 2020) and automation of recording procedures (Ventura et al, 2020), will help to effectively measure fillet yield in the future and exploit this information for genetic selection. To date, genetic evaluations for tilapia breeding programs are primarily based on pedigree and phenotype information, which are well suited for traits that are directly measured in the selection candidates.…”