Variation in individual feed consumption rates of intensively reared pikeperch (Sander lucioperca L. 1758) under feeding hierarchy

The final stage of pikeperch ( Sander lucioperca L. 1758) domestication, which includes the implementation of selective breeding programs, has only recently started. Beyond growth rate, feed intake and efficiency are also significant economic aspects of the species during selective breeding. Quantifying them on an individual level is challenging, and it is further complicated by the biasing effect of the feeding hierarchy. Our results demonstrate that measuring the individual feed intake over seven consecutive days already achieves a correlation of 0.95 with total intake over the entire period. However, 14 days are required for ICC-based repeatability of the trait to reach 0.95. In our study, we observed 23 feeding hierarchies in 13 of the 18 tanks, resulting in 25 % dominants, 22 % subordinates, and 53 % intermediate individuals for a total of 72 pikeperch fingerlings. The feeding hierarchy influenced all production parameters (feed intake, body weight gain, SGR, FCR) except RFI and survival rate. This resulted in lower and more fluctuating daily feed intake and poorer growth, but similar feed conversion in the subordinate individuals. Since RFI was not influenced by hierarchy formation, it may prove to be a good metric for implementing a selection program for feed efficiency. • Individual feed intake is accurately measurable in the pikeperch over 14 days • Feeding hierarchy influenced all production parameters except RFI and survival • Similar individual feed efficiency was found in the dominant and subordinate fish • RFI may be a good metric for implementing a selection program for feed efficiency