An enhanced magnetocaloric effect is being reported in a strain-engineered ferrite-manganite heterostructure driven by a low temperature magnetostructural phase transition. An ultrathin (\ensuremath{\sim}20 nm) epitaxial $\mathrm{Co}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}/{\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ (CFO/LSMO) heterostructure was grown on single crystal MgO (100) substrate using pulsed laser deposition. Both temperature dependent x-ray diffraction and magnetization measurements revealed a broad second-order-type magnetostructural phase transition near around 80 K in the CFO/LSMO heterostructure. From detailed theoretical analysis of the experimental data it is confirmed that the phase transition around 80 K is second-order in nature, unlike the first-order transition observed in the bulk CFO materials. Thermodynamic analyses of magnetization reveal extremely broad isothermal entropy changes \ensuremath{\Delta}S(T) about a wide range of temperatures $(40lTl160\phantom{\rule{0.16em}{0ex}}\mathrm{K})$ resulting in enhanced relative cooling powers which are higher than those reported so far on most magnetocaloric materials. We propose that an interfacial strain-induced magnetostructural coupling of the CFO layer with the underlying LSMO layer gives rise to these hitherto unobserved enhanced magnetocaloric effects in the CFO/LSMO heterostructure system. The work provides fundamental insight into the low temperature phase transitions in ferrite-manganite thin films and adds on to the design of artificial heterostructures with novel and enhanced magnetocaloric properties.