Nutritional evaluation of fish protein hydrolysate and its application in piglet production

Abstract

Abstract This study was conducted to determine the digestible energy (DE), metabolizable energy (ME), and ileal digestibility of amino acids (AA) of fish protein hydrolysate (FPH), and to evaluate the effects of FPH on the performance of piglets. In Exp. 1, the available energy content of FPH was determined by difference methods: 12 barrows with an initial body weight (BW) of 40.0±2.1kg were randomly assigned into two dietary treatments with six replicates per treatment, the treatments contained a corn basal diet and an experimental diet in which 20% corn was replaced by FPH. The experiment was lasted for 12 days, with 7 days adaptation period followed by 5 days total collection of feces and urine. In Exp. 2, the standardized ileal digestibility (SID) of AA in FPH by the N-free method was determined, 12 barrows (initial BW of 35.3±1.8 kg) with ileal T-cannulas were randomly allotted into two treatments with six replicates per treatment, the dietary treatments consisted of an experimental diet and a N-free diet. The experiment was lasted for 7 days, with 5 days adaptation period followed by 2 days collection of ileal digesta. In Exp. 3, the effect of FPH on the performance of piglets was conducted. 192 piglets (initial BW of 8.10±1.8kg) were randomly allotted into four treatments with six replicates per treatment. The treatments were a control diet with fish meal (FM) and part or all FM was replaced by FPH, got diets containing 2%, 3% or 5% FPH. The experiment lasted for 28 days. Results showed that: In Exp. 1, the DE and ME of FPH were 21.12MJ/kg and 20.28MJ/kg. In Exp. 2, the SID of Lys, Met, Thr and Trp were 79.99%, 87.17%, 68.29%, and 71.53% respectively. In Exp. 3, addition of 3% FPH increased nutrient digestibility and volatile fatty acid content in feces. Addition of 5% FPH increased the average daily feed intake (ADFI), significantly increased (P<0.05) the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and immunoglobulin A (IgA), while significantly decreased (P<0.05) the average daily gain (ADG). In conclusion, FPH had a high value of digestible energy and ileal digestible essential amino acids, could improve nutrient digestibility, immunity, antioxidant capacity, and intestinal health of piglets, while adverse to nitrogen deposition in piglets.