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.
Keywords:
In vitro dry matter digestibility, lime, maize replacement, olive meal
