Yeast hydrolysate supplementation improved performance During the 8-week growth period of trial 1, the inclusion of yeast hydrolysate significantly increased average daily weight gain by 36%, and the feed consumption of the fish by 28% on average (Table 1). Yeast hydrolysate supplementation did not affect the FCR or survival rate in this study. White blood cell count was lowest in the group receiving the higher dose of the ingredient. The other measured immune parameters did not show significant differences between the treatments. The average intestinal villi length of foregut was higher in the groups receiving yeast hydrolysate than in the control group (Table 1). The inclusion of Progut in the diets of growing seabass in commercial field conditions significantly improved growth and FCR in trial 2 (Table 2). The effect of the supplement on these performance parameters was increasing during the trial period and was statistically significant from 8 to 12 weeks in the trial. The survival rate was 100% in all treatment groups. The superoxide dismutase (SOD) tended to be higher (p=0.068) in all groups of fish fed with Progut. Acting as an antioxidant, SOD converts the harmful superoxide radical into oxygen and hydrogen peroxide. The activity of antimicrobial lysozyme enzyme was numeri- cally higher in the groups fed with the 0.15 – 0.20% doses. The other measured blood parameters did not differ between the treatments. The average intestinal villi length of the fore- gut was higher in the groups receiving the product than in the control group.
Conclusions These two trials suggest that yeast hydrolysate supplementa- tion improves the feed intake and growth performance of Asian seabass. In growing fish significantly improved feed conversion was observed, and the magnitude of the effect increased towards the end of the study. The improved growth performance by the yeast hydrolysate supplementation may be mediated by its positive effects on
Table 2 – Main results of trial 2. Parameter
Weight, g/fish
Period Start
ADG, g/fish FCR, kg/kg
Lysozyme(U/ml) SOD activity (U/ml) Mean villi length (µm)
4 weeks 8 weeks 12 weeks 12 weeks 8 weeks 12 weeks 12 weeks 12 weeks 12 weeks
Control 265.65a 342.60a 437,87b 550.13b 3.39b 2.78a 2.86a
300.60a 4.99a
448.20
Figure - 1 8 weeks Control Progut® 0.15%
Weight gain FCR Mortality Blood analysis Villi length
Progut® 0.30%
Measurements Feed intake
Figure - 2 12 weeks Control Progut® 0.10%
Weight gain FCR Mortality Blood analysis Villi length
Progut® 0.15%
Measurements Feed intake
Progut® 0.20%
intestinal morphology, immunity and killing pathogens, as judged by the effects on the intestinal villus length, and activities of the enzymes SOD and lysozyme. In conclusion, Progut supplementation at 0.1 – 0.2% im- proved the growth performance of Asian seabass, with possible benefits for immunological capacity and intestinal morphology.
Progut® 0.10% 273.98a 414.40a 491.40ab 617.48a 4.09 a 2.21 b 2.31 b
346.93a 7.67a
734.47
Progut® 0.15% 266.42a 419.33a 515.13a 626.25a 4.28a 1.87b 2.21b
421.25a 8.79a
724.19
Progut® 0.20% 272.67a 419.00a 516.00a 639.79a 4.37 a 1.91b 2.18b
571.00a 7.83a
678.46 ▶ ALL ABOUT FEED | Volume 29, No. 5/6, 2021 35
P- value 0.903 0.127 0.046 0.010 0.017 0.013 0.014 0.371 0.068
5 x 10 fish
5 x 10 fish
5 x 10 fish
5 x 10 fish
4 x 30 fish
4 x 30 fish
4 x 30 fish
13 g
270 g
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