The physical quality of elephant grass silage with tannin extract from coffee husk

Forage is a major feed that determines the success of livestock farming, especially ruminants. The silage is one technique to preserve forage to maintain the availability of forage all year. Microbes have an important role in the silage process, microbes can break down nutrient components of silage, including protein. Protein is one of the primary nutrients for animals, tannin compound of coffee husk can be used to maintain protein compounds in the silage. Tannin is a bioactive compound from the extract of coffee husk that is non-toxic, organic, and classified as polyphenols. This research purpose was to know the effect of adding an additive of tannin coffee husk on the physical quality of elephant grass silage. The research was analyzed using a T-Test design with 2 treatments and 5 replications (T0: elephant grass + 2% molasses; T1: elephant grass + 2% molasses + coffee husk tannin). The results indicated that no significant difference in the added tannin extract on the final and initial pH value and organoleptic characteristics of elephant grass silage. The conclusion of the research was the tannin extract of coffee husk can maintain the protein content of elephant grass silage in the ensilage process.


Introduction
One of the key components of providing for the needs of animals in livestock agriculture, particularly ruminants, is feed.Nutrient fiber is necessary for ruminant diets, particularly in the rumen organ.Forage, which is typically provided in the form of grass, is the source of fiber for ruminants.In Indonesia, the wet season brings an abundance of grass, whereas the dry season brings less of it.Farmers are aware of this, which is why a substitute is required to keep fodder available.The silage method is an approach that can be used to process fodder.Using the idea of anaerobic fermentation, silage is a technique for preserving feed [1].Reforming the feed during the ensilage process is one of the steps involved in the manufacturing of silage.This change may result in a deterioration in the forage's nutrient quality, particularly nutrient protein.
Protein is very beneficial to the growth of cattle.The ability to use protein as a nutrition for growth and animal production is one of its advantages.The higher the output of the livestock, the more balanced the protein provided [2].The decreased of protein and the purchase of protein source feed for ransum results in increased costs because form excess protein overhaul during the ensilage process, furthermore protein source feed is expensive compared to other.Forage protein must therefore be preserved during the ensilage process by offering protein protection.Tannins can be supplied to achieve this protection.
A tannin is a class of polyphenolic substances that can create interaction with protein and can reduce the degradation of protein in the ensilage process [3].Microorganisms have a hard time breaking down the complex connections that bind proteins and tannins during the ensilage process.Plants can be used to extract tannin chemicals; coffee husk is one such plant [4].However, no study has been conducted so far on the quality of silage including tannin additions derived from coffee husks.The research aimed to find out the physical characteristics of elephant grass silage with coffee husk tannins.The issue of environmental pollution can be solved by making use of coffee husks, which are a waste product on coffee plantations.

The Coffee Husk Waste is Extracted using Soxhlet Method
Grinding coffee husk waste method is the first stage [4].Following grinding, the ground coffee husk waste is extracted using the Soxhlation process [5].The Whatman paper was then made, 20 g of coffee husk flour was added, and strep was applied.Using 70% ethanol, the sample was dissolved in up to 375 mm.A temperature of 90°C was employed for the extraction process until the solution in the upper Soxhlet apparatus turned clear.Using an evaporator at 60°C produced evaporated extraction results, causing the solution to thicken.After pouring the material into a petri dish, it was baked at 60°C.When producing elephant grass silage, the raw material used to make the tannin extract product is coffee husk.

Elephant Grass Silage was Make with Coffee Husk Tannin Additive Product
Unit Pelaksana Teknis (UPT) Animal Husbandry of Politeknik Negeri Jember as supply elephant grass was used for the study.Elephant grass is withered for 24 hours, chopped into 3-5 cm pieces, and weighed up to 300 kg.For T0 (control), each piece weighs 5x30 kg, while with T1 (tannin addition), it weighs 5x30 kg.The grass-based source of dissolved carbohydrates is combined with up to 2% molasses and fermented anaerobically for a duration of 21 days.The following information was included in the two treatments and five replications that made up the treatment: T0: 30 kg elephant grass + 2% molasses T1: 30 kg elephant grass + 2% molasses + 9 g coffee husk tannin flour/kg elephant grass

Silage Physical Quality Test
The quality harvest analysis came from a 21-day incubation period for the silage.Initial and final pH values were measured as part of physical tests, while color, fungal presence, scent, and texture observations were made as part of an organoleptic test.Fifteen panelists conducted the organoleptic test, using a questionnaire based on the silage organoleptic criteria; and scanning electron microscope (SEM) samples of elephant grass leaves from silage [6].

Data analysis
The research used a T Test design with two treatments and five replications.The data processing procedure employing SPSS version 16.If the results show a significant, then will difference continue with Duncan's Multiple Range Test (DMRT).

The Initial and Final pH of Elephant Grass Silage with Addition of Tannins from Coffee Husk
Silage quality is determined by the pH value.There wasn't real difference between the initial pH value of elephant grass and the addition of tannin of the research for result (Table 1).After silage process, there was also no significant difference in the pH value for control silage and silage with coffee husk tannin additives.The results showed that the addition of tannin did not affect the pH value of the silage produced.The pH value of silage without added tannin ranged on average to 4.1 ± 0.4, while silage with added tannin produced an average pH of 3.8 ± 0.0.Both are still in normal condition.According to [6] that low pH due to acid production from Latic Acid Bacteria (LAB) is very necessary in the ensilage process to achieve a stable condition of silage (as long as it is under anaerobic conditions).At critical pH (pH 3.8 -4), acid will inhibit the growth of other harmful bacteria.On the other hand, the tannin and protein complex bonds are stable at pH 3.5 -7.0 [7][8].This showed that the addition of tannins extracted from coffee husk does not inhibit the growth of lactic acid bacteria during the fermentation process.This was because tannin was not toxic and only functioned a role in protecting part of the surface of the feed material from protein degradation by microbes [9].LAB degrades feed and produces lactic acid which then shows an acidic pH in the range of 2-4.The role of coffee husk tannins in protecting Elephant Grass proteins from microbial degradation that develops during fermentation by covering part of the grass surface (Figure 1).To support the development of LAB by adding dissolved sugar in the form of molasses when making silage.

Organoleptic Observation of Elephant Grass Silage with Coffee Husk Tannin Additive
The addition of coffee husk tannin additives had no significant effect (P>0.05) on silage color (Table 2).The color of silage in the observations is yellowish green.The yellowish green color indicates that the ensiling process had occurred normally.Normal silage color indicates that respiration during ensilage in the silo occurs rapidly due to the lack of oxygen trapped in the silo.This also illustrates that the compaction process when making silage was quite good.During the silage making process, excessive or prolonged respiration should not occur in the silo.According to [10] that prolonged respiration is usually caused by a large amount of oxygen trapped in the silo which results in the temperature inside the silo becoming high due to the breakdown of carbohydrates and proteins.If the respiration process is prolonged, the silo temperature will increase, resulting in damage to the silage color.The bonding of tannins with the protein content of silage grass is strong bonds than compared with protein bonds with other bioactive compounds such as glycoproteins, and globular proteins [11][12].The stronger bond causes the larger molecular of tannin to extract more weight than proteins and are also larger than glycol and globular.The characteristics of tannins were influenced by several factors, such as the type of sugar, the number of gallic acid, and the number and type of bonds between gallic acid units.Tannin has characteristics by flavan-3-ol oligomers that can oxidize the A and C rings of their respective monomers.In addition, the monomer and C-3 linkage occur the possibility of forming a tannin-protein bond which is quite large and was called C-4 chirality [12].
The aroma produced after the fermentation process is an indicator for assessing the physical quality of a sample, this can show whether the fermentation process is going well or not.The quality of silage is declared good if it has a fresh sour smell because it contains lactic acid, not a strong odor.The results of the observation of aroma on elephant grass silage did not have a significant difference (P>0.05) between with or without coffee husk as tannin additives.The aroma of the silage produced in this study showed a fresh sour smell that did not emit the aroma of alcohol (ethanol) with the highest score (Table 2), in silage without the addition of tannin or with the addition of tannin.According to [13] the expected lactic acid bacteria (LAB) are homofermentative.Homofermentative lactic acid bacteria produce two lactic acids from one glucose molecule, while heterofermentative lactic acid bacteria convert glucose molecules into lactate, ethanol and carbon dioxide.Ethanol is an alcoholic compound produced by a heterofermentative fermentation process.Heterofermentative lactic acid bacteria will ferment hexose via the 6-phosphogluconate or phosphoketolase pathway.
The texture and fungus of the elephant grass silage were not significantly different with supplementation coffee husk tannin additives (P>0.05).This research is in agreement with [14], that the use of tannins did not influence the presence of fungi in silage.The texture of the elephant grass silage with or without tannin extract is flexible and easily broken.The results represent the quality of the silage on the normal value.The fungal was not found in all treatments.Nutrient degradation caused by microbes is adaptive so it does not have a negative impact such as toxicity to silage microbes due to the existence of tannin-protein complex bonds.The results in agreement with [15], tannins have the characteristic of not causing toxicity to microbes such as yeast, bacteria, and fungi.Tannin from coffee husk waste has been proven to be used as a feed additive for fermented feed (silage).

Conclusion
The study's conclusion was that the organoleptic quality and initial and final pH values of elephant grass silage were not significantly affected by the addition of tannin extract derived from coffee husk.Coffee husk tannins do not impact the ability of microorganisms to degrade feed in terms of the physical quality of silage because they are stable in their ability to bind protein during the ensilage process.

Figure 1 .
Figure 1.Upper leaf surface of Elephant Grass silage with the addition of tannin extract from coffee husk; (a)T0=Elephant Grass silage without tannin; (b)T 1= Elephant Grass silage with tannin 9g/kg fresh silage (b)

Table 1 .
Value of pH of elephant grass (Pennisetum purpureum) silage with the addition of tannin extract from coffee husk.

Table 2 .
Organoleptic quality of elephant grass silage with the addition of tannin extract from coffee husk