Effect of blocks with calcium propionate on lamb productive performance and in vitro GHG

Objective. Evaluate multinutritional blocks with and without calcium propionate (Ca-Pr) on digestibility and live weight changes of lambs and in the green house emission in vitro. Materials and methods. Twelve lambs were used (20.17±2.35 Katahdin x criollo) in three treatments: Basal diet (BD 70% oat straw, 30% concentrate), BD+ Block without Ca-Pr and BD+ Block with 1.5% Ca-Pr in 50 days assay. In vitro gas production (GP) and kinetic parameters were estimated (Vmax, S, Lag). In vitro and in vivo, CH4, CO2 and digestibility were estimated. Results. The dry matter intake was the lowest (p<0.0001) in lambs without block (753 g/d) compared lambs supplemented with block without (839 g) or with Ca-Pr (828 g); including blocks increased methane (16.16 and 16.18 g/d; 0 and 1.5% Ca-Pr respectively) than BD (13.93 g/d). The GP in vitro was higher (p=0.0001) with BD (380.76, ml) than with blocks without differences among blocks (335.76 and 341.13 ml, 0 and 1.5% Ca-Pr respectively), and the BD had higher (p=0.0001) production of CH4 (47.16 mol) and CO2 (200.04 mol) than with blocks (42.25 and 41.58 mol CH4; 179.21 and 176.39 mol CO2; 0 and 1.5% Ca-Pr respectively). Conclusions. Block supplementation improved dry matter intake. Blocks reduced in vitro gas production and increased digestibility by reducing CH4 and CO2