Effect of lime treatment of olive meal on in vitro utilization of total mixed ration containing olive meal as partial maize replacer

Abstract

Aim: Present study pertains to lime treatment of olive meal to improve its digestibility. The objective of the present study was to assess the in vitro dry matter degradability of total mixed ration containing lime treated olive meal at varied levels of maize replacement to know the optimum level of lime and treated olive meal as maize replacement in small ruminant diets. Materials and methods: Study was carried out in two phases. In phase I, A complete diet was formulated and treated with lime at variable concentrations (0-8%) at 25% of maize replacement and subjected to in vitro studies as per Tilley and Terry. On the basis of the results of this phase, a concentration of lime for olive treatment was selected and tested at variable levels of maize replacement (0-50%) by treated olive cake in phase II. Data was analyzed as per the procedures suggested by Snedecor and Cochran. Results: The in vitro dry matter digestibility (IVDMD) of composite diet increased from 43.95% at 0% lime treatment to 48.68% on treating with 8% lime with significant (P<0.05) increase at 6% treatment level. Lime treatment beyond 6% had no further significant effect on improving the digestibility. Graded levels of maize replacement by olive meal treated with 6% lime (lime percentage selected from phase I) showed that the in vitro digestibility of mixed ration was not compromised up to 40% replacement level of maize by treated olive meal. Improved digestibility with lime treatment may be due to weakening of internal Hydrogen bonding, thereby disrupting the fiber structure in olive meal. Further lime may be saponifying the high level of fat present in olive meal, which may otherwise negatively impact the digestibility values. Conclusion: It can be concluded that the treatment with up to 6% of lime can effectively increase the digestibility of olive meal. Treated olive meal can replace up to 40% of maize from daily ration without affecting the digestibility of composite ration. Thus incorporating lime treated olive meal may prove beneficial to livestock producers.