Rising raw material prices, an increased demand for high-quality food and the desire for sustainable and regional production require new approaches and suitable protein sources. One possibility is pork bone meal (PBM) that had been earlier studied in fish feed trials with Pacific white shrimp Litopenaeus vannamei (C. Hernández et al., 2008) and Hybrid Catfish Ictalurus punctatus × Ictalurus furcatus (Li et al., 2018)
In this trial, the proportions of animal and vegetable protein in a commercially used catfish feed were partially reduced and replaced with pork bone meal. The proportions of PBM in the three feeds used were 0 % (control), 15 % (PBM 15) and 30 % (PBM 30). The ingredients of the feeds are given in Table 1. Attention was paid to isonitrogenous and isoenergetic in the diets. Furthermore, care was taken to ensure that the essential amino acids did not fall below critical levels.
The extent to which protein substitution with PBM affects the growth performance, nutritional composition and welfare of the African catfish Clarias gariepinus was investigated.
The 60 days long experiment was carried out in a randomized block design in triplicates, with 25 individuals in each fish tank at the start of the experiment. The fish were fed once a day 80 % of a commercial protocol.
No significant differences were found between the groups for either the length or the weight of the fish. Differences in mortality can be attributed to the husbandry conditions during the trial and not to the diet fed.
The results of this trial revealed that a replacement up to 30 % PBM is possible, with no negative impact onto growth performance and survival. Application of PBM instead of imported soybean meal and replacement of poultry proteins with PBM as a regional waste product increases sustainability and cost efficiency of African catfish aquaculture in northern Germany.
Literature:
C. Hernández, M.A. Olvera-Novoa, K. Aguilar-Vejar,
B. González-Rodríguez, I.A. de la Parra (2008), Partial replacement of fish meal by porcine meat meal in practical diets for Pacific white shrimp (Litopenaeus vannamei)
Li, M.H., Bosworth, B.G. and Lucas, P.M. (2018), Evaluation of
Porcine Meat and Bone Meal in Diets for Pond-Raised Hybrid Catfish. North Am J Aquaculture, 80: 69-73. https://doi.org/10.1002/naaq.10008