Effects of Diets with 28% or 32% Protein and Meat and Bone Meal or Corn Gluten Feed on Performance of Golden Shiners in Pools

Abstract

AbstractAlternative diets made without marine proteins and with more plant ingredients are being used in channel catfish Ictalurus punctatus with the goal of maintaining profitability. The potential to use similar diets for baitfish may be greater because they consume natural foods throughout production. We conducted a feeding trial in outdoor pools with golden shiners Notemigonus crysoleucas using four practical diets with 28% or 32% protein in formulas with porcine meat and bone meal (MBM) or corn gluten feed (CGF) and no animal protein. Groups of 200 fish with a total initial weight of 37.7 ± 0.9 g (mean ± SE) were stocked into each of four 4.1‐m3static pools per treatment and fed daily to apparent satiation for 8 weeks. Diet effects were assessed by measuring growth, survival, feed conversion, condition index, and body composition. Chlorophyll a and zooplankton were sampled to gauge natural productivity. Individual weight and total length of golden shiners were greater in fish fed diets with 32% protein than in those fed diets with 28% protein and in fish fed diets with CGF than in those fed diets with MBM. However, the differences were not commercially relevant as all fish would grade into the “small crappie minnow” category. Mean individual weight gain (based on group initial and final weights), feed intake, feed conversion, and survival were similar in golden shiners fed diets with 28% or 32% protein and MBM or CGF. However, golden shiners fed diets with MBM had more body fat, higher Fulton's K index, and higher relative weight than those fed diets with CGF. These traits may indicate greater robustness, which is more important in baitfish than rapid growth. The 28%‐protein diet with MBM was the least expensive option that increased body fat and condition of golden shiners. Natural productivity was positively correlated with fish growth, enhancing the potential to use less expensive diets in golden shiners in outdoor systems.