Effect of Maize Stover in Fermented Total Mixed Ration on Nutritive Value and Digestibility Quality in Vitro

The objective of this experiment was to investigate the effect of maize stover used as roughage source in fermented total mixed ration on nutritive value and digestibility quality by in vitro technique. The experimental compared between the feeds non-fermented total mixed ratio (TMR) group and fermented total mixed ratio (FTMR) group by fermentation 21 days, each group were ratio 60:40 and five replications. The results revealed that CF content of FTMR increased from 33.79% to 40.70% significantly different (P<0.05) and DM, CP, EE and ash were not significantly different between treatments (P>0.05). The digestibility quality were dry matter digestibility (%DMD) in FTMR higher than control group significantly different (P<0.05). Moreover total volatile fatty acids (VFAs) in FTMR increased from 15.00 to 39.50 mM higher than control group not significantly different (P>0.05) and N-NH3 concentrations were not significantly different (P>0.05). The gas production was recorded at 0, 6, 12, 18, and 24h of incubation. The cumulative gas production curve both of treatments was remarkable boost from 0h to 6h incubation of FTMR from 57.5 to 37 ml and then incubation time the cumulative gas production both of them were slowly decrease.


INTRODUCTION
Maize stover is one of the most abundant crop straw resources in the world, and is usually utilized as an important forage source for ruminants (Tang et al., 2011).Further, these the major crop residue in locally of South Sumatra Indonesia because main agricultural products of Indonesia mostly are rice palm oil and cassava.Maize stovers as crop residue left in field after the grain harvest.There are many in locally and the trend of quantities may increase in the future (Office of Agricultural Economics.2014).Previously, utilization of maize stover used as roughage source only in ruminant feeding for reduce the cost of production animals and enables efficient utilization of crop residue potentially useful feed resource (Walli et al., 2012).However, characterised of maize stover by high fiber content low digestibility and this limits their nutritive value for ruminants (Fon et al., 2012).Maize stover should be adjust of the quality by processing to increase nutritive value for animal requirement such as maize stover with urea an important feed for animals especially in the dry season .It was increase digestibility (Smith et al., 2002;Syomiti et al., 2011) and improved the chemical composition of diet (Egbu, 2014).By using maize stover use as roughage source in TMR (Total Mixed Ration) could be increase nutritive value and and digestibility but them can not to store available for a long time (Bureenok et al., 2009;Rajamma, 2014).There are no information about research in chemical composition and digestibility of maize stover roughage source in FTMR (fermented total mixed ration).Therefore, in this study the effects of utilization maize stover roughage source in fermented total mixed ration on nutritive value and digestibility quality in vitro.

Experimental Design and Treatment
The experimental design was a t-Test and the feeds has maize stover used as a roughage source and concentrate ratio (60:40).The feeds there are control group: nonfermented total mixed ratio (TMR) and 1 treatment group: fermented total mixed ratio (FTMR) by fermentation 21 days, each group has five replications, Concentrates were formulated to contain cassava by product, palm oil kernel cake, peel coffee, coconut kernel cake, premix mineral and molasses.Maize stover was collected from field after harvested of cereal grain at Indralaya, South Sumatra Province, Indonesia.Samples of maize stover chopped size 1 inch, Fermentation in plastic bag then vacuum and wrapped with tape.Samples has the evaluate of TMR and FTMR group, The fermentation period 21 days before used for chemical analysis and digestibility quality in vitro technique.The samples both of them sundried for 2 days and to grind through a fine grinder.The samples both of TMR and FTMR group were chemical analysis for dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE) and Ash using the procedures of AOAC (1998).The chemical compositions of concentrate in experiment are shown in Table 1.

In vitro Fermentation
Samples of 1.0 g of TMR and FTMR group were prepared bottles for each group, five replications.Ruminal fluid collected from animal was mixed with McDougall's buffer mixture by following the procedure of Tilley and Terry (1963) in a proportion 1:2 (200:400 mL) at temperature 39°C under continuous flushing with CO 2 and 25 mL of mixture solution were added 25ml into each bottle under CO 2 flushing, bottles were sealed with rubber stoppers and aluminum caps (under anaerobic conditions) and incubated at 39°C (24 hours) in water bath.During the incubation the bottles were gently mixed and each the bottles every 6 hours for gas production test and digestibility quality for dry matter digestibility (DMD), N-ammonia (N-NH 3 ) and total volatile fatty acids (VFAs).After 24 hours of fermentation the samples for centrifuged at 16,000 x g for 15 minutes and precipitate samples pour in the crucibles to dry at temperature 105°C for 2 nights and then weigh the samples and then can be calculated dry matter digestibility (DMD) and the supernatant was stored at -20°C before NH 3 -N analysis and volatile fatty acids (VFAs) analysis.

Statistical Analysis
The experimental the effect of maize stover in fermented total mixed ration on nutritive value and digestibility quality in vitro.All data from the experiment were analysis design was a t-Test to using type Two-Sample Assuming Equal Variance (twotail) by SPSS programmed software.

Chemical composition of diets
The chemical composition of maize stover in TMR and FTMR are shown in Table 2.The FTMR diet contained 99.75% DM, 0.88% CP, 40.70% CF, 8.23% EE and 2.13% ash respectively.In this study the DM, CP, EE and ash each groups were not significantly difference (p>0.05) but found that the DM content decrease in FTMR group when compared with TMR group from 99.78% to 99.75% similar to that reported by Khejornsart et al. (2015), Wongnen et al. (2009)  The CP content decreased in FTMR group when compared with TMR group from 0.91% to 0.88% found by Wongnen et al. (2009) and Vasupen et al. (2006).Similarly to that fermentation time were decreased CP content could be due to loss crude protein during fermentation time (Bureenok et al., 2009).
The EE content also decrease from 9.35% to 8.23% found by Vasupen et al. (2006) could be due to fermentation improved lipids in the diets (Tatsapong et al., 2013) Moreover it found that ash in FTMR group was increased 1.92% to 2.13% but nonsignificant also found that by Wongnen et al. (2009) and Chaiyasit et al. (2013).
The CF content in FTMR group was increased 33.79% to 40.70% significant (p<0.05) with TMR group.Sirisan et al. (2017) reported that CF content were related to digestibility.

In vitro Digestibility Quality
The in vitro digestibilities of dry matter digestibility (DMD), total volatile fatty acids (VFAs) and N-ammonia (N-NH 3 ) are given in Table 3.In this study was found that the treatment FTMR group (62.80%DMD) lower than the control TMR group (70.79%DMD) decreased significantly (p<0.05)similarly reported that DMD in the control TMR group was lower when compared with FTMR group (Vasupen et al., 2006;Wongnen et al., 2009).
Similarly Yuangklang et al. (2008) also reported that %DMD between FTMR and TRM group was different significantly.Palapom et al. (2015) explained that fermentation may be due to decreased dry matter digestibility.Sirisan et al. (2017) reported that CF content were related to digestibility.Addition in the present experiment total volatile fatty acids (VFAs) increased 15.00mM to 37.50mM nonsignificant each the treatments was no different on total VFAs but tend to be higher (Yuangklang et al., 2008) (2015) and Wongnen et al. (2009).Similarly reported that concentration of N-NH 3 increased in FTMR group and each the treatments was no different on N-ammonia concentration (Yuangklang et al., 2008;Palapom et al., 2015).

Cumulative Gas Production
The in vitro gas production technique during the incubation every 6 hours for gas production test (ml).In Figure 1 shown about cumulative gas production curves.The in vitro technique found that gas production both of them has a remarkable boost from 0 hour to 6 hour incubation time.At 6 hour found that gas production in FTMR has increased higher when compared to TMR group of 7.5 ml but then after 6 hour of incubation time gas production decreased in FTMR group gas production and at 24 hour gas production lower than TMR group at 2.45 ml attributed to FTMR has high crude fiber content were obstruct of activities microorganism decreased cumulative gas production (Sallam et al., 2007;Roddoung et al., 2011) fermentation the diets were cumulative gas production lower then non fermented group and in FTMR has high crude fiber and ash were low digestibility (Tatsapong et al., 2013).Moreover was found that both of FTMR and TMR group no different of cumulative gas production could probably due to proportion of the total mixed ration was similar (Sallam et al., 2007).The decreasing in cumulative gas production thought to be due to reduced substrates availability.

CONCLUSION
Based on experimental data, FTMR is a conceivable method to improve the quality of TMR for long time storage, ensiling of maize stover in fermented total mixed ration improve the physical and quality of feed, both of TMR and FTMR were chemical composition consisted of DM, CP, EE and Ash no different and also found that low N-ammonia but FTMR tended to be increase total VFAs.It could be concluded that utilization crop residue maize stover as roughage source in fermented total mixed ration.Maize stover would be an alternative to feed of ruminant.However these findings should be applied further in in vivo experiment and in order to find efficiency of ruminant animals for the result more reliable.

Figure 1 .
Figure 1.Effect of Maize stover in TMR and FTMR on cumulative gas production at different time of incubation.

Table 1 .
Chemical composition of concentrate used in the experiment.

Table 2 .
Effect maize stover in total mixed ration and fermented total mixed ration on chemical composition.

Table 3 .
Effect of maize stover in total mixed ration and fermented total mixed ration on digestibility quality by in vitro technique.