LAUSR

BACKGROUND This study was aimed to investigate the effects of low protein diets with balanced 4 amino acids on growth performance, meat quality and cecal microflora of finishing pigs. Fifty-four healthy hybrid barrows (Duroc × Landrace × Yorkshire) with an average body weight of 70.12 ± 4.03 kg were randomly assigned to one of the three dietary treatments with 6 replicate pens per treatment (3 barrows per pen). The three dietary treatments included a normal protein diet (NP), a low protein diet (LP), and a very low protein diet (VLP). RESULTS The average daily gain, average daily feed intake and feed conversion ratioof pigs were not significantly changed with the LP and VLP diets compared with the NP diet (P > 0.05). The water holding capacity and shear force of longissimus dorsi muscle were decreased, while the intramuscular fat (IMF) content of the longissimus dorsi muscle was increased (P < 0.05) in pigs fed with the LP and VLP diets than the NP diet. The contents of saturated fatty acids in muscle were decreased (P < 0.05), while the content of polyunsaturated fatty acids in muscle was increased (P < 0.01) with the VLP diet compared with NP diet. The contents of histamine, spermidine, spermine and tyramine of muscle were decreased with the VLP diet than NP diet (P < 0.05). The relative abundance of Turicibacter, Terrisporobacter, Clostridium_sensu_stricto_1 and UCG-005 was higher (P < 0.05) while the relative abundance of Lactobacillus and Streptococcus was lower (P < 0.05) in pigs fed with the LP and VLP diets than the NP diet. Based on the correlation of cecal microbiota and cecal biogenic amine, the content of tyramine, spermidine and histamine were negatively correlated with the abundance of Terrisporobacter (P < 0.01) and the content of histamine was positively correlated with the abundance of Lactobacillus (P < 0.01). CONCLUSION With balanced four essential amino acids, the VLP diet with CP levels decreased by more than 4% increased the IMF content, changed fatty acid and amino acid composition of longissimus dorsi muscle and the profile of cecum microbiota and reduced the content of cecum bioamine, with no negative effect on the growth performance of pigs. This article is protected by copyright. All rights reserved.