Uji In Vitro Ransum yang In Vitro Experiment on Diets Supplemented by Anorganic and Organic Chromium

Abstract

Chromium is a trace element which has been considered essential for humans and animals since 1959. However, the effect of chromium on rumen microorganisms has Dot been yet known. This experiment was conducted to detennine the effect of chromium on rumen microorganisms which was measured in vitro by supplementation to agroindustrial waste diets. Chromium supplementation was done in anorganic and organic forms (incorporation to Rhizopus sp. fungi). Two experimental designs were used in this experiment. A Completely Randomized Design with 10 treatments and 3 replications was used to measure dry matter and organic matter digestibilities (DMD and OMD). A Factorial Randomized Block Design 10 x 3 was used to measure total VFA and NH3 productions. Factor A was diet treatments and Factor B was fermentation period. Rumen fluid was used as block (replication). Treatments consisted of KI (Control diet), K2 (KI + Non mineral Rhizopus 'p. fungi), A (K2 + Anorganic Cr) with 4 levels of anorganic Cr (I, 2, 3 and 4 ppm) and 0 (KI + Organic Cr) with 4 levels of organic Cr (I, 2, 3 and 4 ppm). Incubation period was carried out for 1,3 and 5 hours. The addition of non mineral Rhizopus 'p. fungi (K2) decreased total VF A production from 110 to 59 mM (p<O,05) and increased NH, production from 9,97 to 13,28 mM (p<O,05). Supplementation of anorganic Cr decreased DMD and OMD compared to K2 (P<O,05), but organic Cr supplementation increased DMD and OMD. Optimum level of organic Cr supplementation was 1 ppm and 4 ppm for anorganic Cr. Ibis mean that supplementation of organic Cr four times more efficient than that of anorganic Cr. Key words: Chromium, in vitro, anorganic, organic