Carcass yield of Oreochromis niloticus deformed by inbreeding process evaluated by morphometry

Abstract

Genetic improvement is the main responsible for the increase in tilapia production in the last decades. However, the tools used in broodstock selection have increased the mating of related animals, and as a consequence, animals with morphometric anomalies have appeared. In view of the above, this work was carried out with the objective of evaluating the effect of body deformities on the meat yield of tilapia. A total of 106 animals from assisted reproduction of the UFLA tilapia breeding program were used, among which 53 had visible deformities. The animals were weighed, measured, and photographed with a digital camera and had their body areas measured using computer software. Afterward, the animals were slaughtered and the fillet from the left side was removed to measure weights and yields. On the right side, cuts were made to measure the meat volume in the carcass. The residues were weighed separately to analyze processing losses. Using the software R-studio the normality test was applied to all data and afterwards, the tests of means and correlations between morphometries and yields were performed. No morphometric differences were identified between the groups, but deformed animals showed smaller caudal areas and caudal peduncles and high correlations with fillet weight. However, normal fish showed higher fillet yield and lower residue production. It is concluded that the anomalies imply lower filet yield and a higher amount of processing residues