Effects of protein and/or amino-acid levels on reproductive performance and metabolic profile of lactating sows

Three groups of 12 sows (high-productivity Goland hybrids) were fed from the 106thday of gestation to the end of lactation (27 ± 3 d) one of 3 diets: Cl, LP,, LPS, (experiment 1). Thediets differed in protein levels (CP (%DM): 16.7; 13.4; 14.1, respectively) and amino-acid content(lysine (%DM): 0.87; 0.48; 0.86; methionine + cystine (%DM): 0.57; 0.42; 0.56; threonine (%DM):0.70; 0.53; 0.53; tryptophan (%DM): 0.20; 0.12; 0.20). In a second experiment, 4 groups of 11 sowswere fed one of 4 diets (experiment 2): ,2C L,2P LPPS, L 2PS (CP (%DM): 17.2; 11.9; 13.3; 13.6,respectively; lysine (%DM): 0.77; 0.39; 0.54; 0.76; methionine + cystine (%DM): 0.59; 0.45; 0.52;0.55; threonine (%DM): 0.67; 0.45; 0.56; 0.66; tryptophan (%DM): 0.20; 0.12; 0.17; 0.20,respectively). The LPS, diet was supplemented with the synthetic amino acids, lysine, methionine,tryptophan, and LPPS and LPS2 were also supplemented with threonine. The different diets had nosignificant effects on sow performance and litter productivity. Low-protein and amino-acidsupplementeddiets significantly reduced both blood (experiment 1: C! 30.3; LP, 28.0; LPS, 22.1mg/dl; experiment 2: 2C 36.5; L 2P 31.4; LPPS 30.8; L 2PS 21.3 mg/dl) and milk urea values(experiment 2: 2C 20; L 2P 13; LPPS 9; L 2PS 10 mg/dl), which indicates a reduction in proteincatabolism.