The aim of this study was to investigate the effects of increased dietary rumen degradable protein( RDP) level on rumen microbial nitrogen( MN) yield and nitrogen retention of finishing Kazakh sheep under inferior forage feeding condition. Three lambs weighed( 30.0 ± 2.8) kg were fed three diets with different RDP levels [7.94%( TM R1),9.02%( TM R2) and 10. 10%( TM R3) ]. A 3 × 3 Latin square experimental design was adopted. There were three periods with 10-day pre-test period and 5-day test period in each ...