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Hydrolyzed feather meal (FM) can be a source of AA for growing pig diets. However, FM is low in Lys, Met, His, and Trp. Thus, supplementation of FM with synthetic AA based on available or ileal digestible AA seems to be the most effective way to utilize FM for pig production. This study was conducted to determine the possibility of replacing soybean meal (SBM) in finisher pig diet completely with FM with blood by supplementing with amino acids (AA) based on standardized ileal digestible (SID) AA in FM. The specific objective was to determine the effects of corn-FM diets supplemented with AA based on SID AA in FM on growth performance, serum metabolites, carcass traits, and subjective meat quality scores. Corn–SBM, positive control (POS) diets were formulated to contain 6.6 and 5.2g true ileal digestible (TID)Lys/kg to satisfy the requirements during the finisher-1 and finisher-2 phases, respectively. Corn–FM negative control (NEG) diets were formulated to be iso-N and iso-caloric to the POS diets. The third diet (NRC) was similar to the NEG diet but it was supplemented with Lys and Trp to alleviate AA deficiencies based on TID of AA in FM. The last diet (SID) was formulated by supplementing the NEG diet with Lys and Trp to alleviate AA deficiencies based on the determined SID AA in FM. A total of 64 pigs with 50.0±2.9kg of BW were allocated to 32 pens with 2 gilts or 2 castrated males per pen, and pens were randomly assigned to 1 of 4 finisher-1 diets. At the end of the finisher-2 phase (107.7±3.3kg), blood samples were collected to determine serum metabolite profile and pigs were slaughtered to assess carcass characteristics.
Pigs fed the POS diets tended to have higher overall average daily feed intake (ADFI) and had greater total Lys intake (P=0.029) than those fed the SID diets, which may have resulted in a tendency for slightly greater average daily gain (ADG) in pigs fed the POS diets. Pigs fed the SID diets tended to have greater gain:feed (G:F) and had greater gain:total Lys intake (P<0.001) than those fed the NRC diets. Pigs fed the POS had greater ADG (P<0.001) and G:F (P<0.001) than those fed the NEG diets, but, as expected, they had lower gain:total Lys intake (P<0.001) mostly because of the increased total Lys intake (P<0.001). As expected, pigs fed the NEG diet had reduced total protein (P<0.001) and increased urea-N (P=0.001), triglyceride (P<0.001), and cholesterol (P<0.001) compared with those fed the POS diets. Pigs fed the POS diets had greater fat-free lean gain (P=0.020) that those fed the SID diets, but similar loin muscle area, fat-free carcass percentage, and efficiency of fat-free lean gain.
Results indicated that pigs fed the SID diets utilized feed and Lys as efficiently as those fed the POS diets, but they had slightly reduced body weight and fat-free lean gain.
Brotzge, S.D., Chiba, L.I., Adhikari, C.K., Stein, H.H., Rodning, S.P. and Welles, E.G. (2014). Complete replacement of soybean meal in pig diets with hydrolyzed feather meal with blood by amino acid supplementation based on standardized lleal amino acid digestibility. Livestock Science 163; 85–93. http://dx.doi.org/10.1016/j.livsci.2014.02.001