Advances in Animal and Veterinary Sciences

Download PDF Download ePUB



Research Article


Digestibility of Nutrient and Performance of Kacang Goats which are Given Fermented Oil Palm Fronds Extract


Dewi Febrina*, Zumarni, Rahmi Febriyanti, Jepri Juliantoni, Yendraliza, Irdha Mirdhayati, Elfawati, Muhammad Rifai, Ibrahim Khan, Ret Prasiyo

Department of Animal Science, Faculty of Agriculture and Animal Sciences, State Islamic University of Sultan Syarif Kasim Riau, Jl. H.R Soebrantas No 155 KM 15 Tuah Madani Tampan-Pekanbaru 28293 Indonesia.


Abstract | The influence of administration of FOPFE (Fermented Oil Palm Fronds Extract) on digestibility and goat performance of Kacang goat is the aims of this study. The fermentation process of oil palm fronds is carried out by adding 10% poultry manure for 21 days with, then extracted with methanol solvent. Twelve male goats>1 year were used in this research, were placed in a metabolic caged which were equipped with feedbox and drink. Randomized block design, 4 treatments with 3 groups was used in this research namely : P0 = complete ration + 0% FOPFE; P1 = complete ration + 0.1% FOPFE; P2 = complete ration + 0.2% FOPFE and P3 = complete ration + 0.3% FOPFE. The measured parameters were digestibility of nutrient (organic matter, dry matter, crude fiber, crude protein, extract eter, ADF, NDF, hemicellulose and cellulose) and goat performance of kacang goats (body weight gain, intake of dry matter, body weight gain, conversion of feed and efficiency of ration). The results showed that FOPFE to 0.3% has no significant effect (P>0.05) on average daily gain, nutrient digestibility, feed conversion and feed efficiency but significantly effect (P<0.05) on goat performance. The administration of 0.3% of FOPFE can maintain nutrient digestibility and goat performance.


Keywords | Fermented oil palm fronds extract, Nutrient digestibility, Feed conversion, Conversion, Goat performance


Received | September 16, 2020; Accepted | December 08, 2020; Published | January 15, 2021

*Correspondence | Dewi Febrina, Department of Animal Science, Faculty of Agriculture and Animal Sciences, State Islamic University of Sultan Syarif Kasim Riau, Jl. H.R Soebrantas No 155 KM 15 Tuah Madani Tampan-Pekanbaru 28293 Indonesia; Email:

Citation | Febrina D, Zumarni, Febriyanti R, Juliantoni J, Yendraliza, Mirdhayati I, Elfawati, Rifai M, Khan I, Prasiyo R (2021). Digestibility of nutrient and performance of kacang goats which are given fermented oil palm fronds extract. Adv. Anim. Vet. Sci. 9(3): 422-428.


ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright © 2021 Febrina et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.



Oil palm fronds contain high lignin, namely 30.18% (Febrina et al., 2016a, b) so that their use as feed is very limited but oil palm fronds can be used as antioxidants (Imsya et al., 2013); anti-microbial (Febrina et al., 2018, 2020); and feed (Suyitman et al., 2020). The lignin content in oil palm fronds can be lowered through processing biologically, physically, chemically and by a combination. Febrina et al. (2020) reported that fermented oil palm fronds with 10% of poultry manure reduced the lignin content by 33.93% (decreased from 30.18% to 19.94%).


One part of plant polyphenols are tannins, which can precipitate protein (Hagerman, 2012), bind minerals and reduce the bioavailability of minerals (Naumann et al., 2017). Tannins are grouped into 2 groups, namely condensed tannins (CT) and hydrolyzable tannins (HT) (Patra and Saxena, 2010). Hydrolyzed tannins have a negative effect on livestock because they reduce the ability to degrade by rumen microbes and protein solubility, thereby reducing digestibility (Min et al., 2000). The addition of Quercus pyrenaica leaves which contain hydrolyzed tannins inhibits the digestion of cattle (Doce et al., 2013), this is because more protein is bound to hydrolyzed tannins than condensed tannins (Jayanegara et al., 2015). Condensed tannins have lower toxic effects than hydrolyzed tannins (Corral et al., 2020).


Extract ethanol of oil palm fronds contains compounds of steroid and tannin (Febrina et al., 2018); and methanol extract from oil palm frond fermented with poultry manure containing tannins, steroids and phenolic compounds (Febrina et al., 2020). The administration of tannin extract to livestock effect on nutrient digestibility and performance. Supplementation of acacia tannin extract in Holstein bulls increased the amino acids flow into the duodenum (Orlandi et al., 2015). The administration of 1-6% Quebracho Tannin Extract (QTE) of dry matter in adult heifers, affects the digestibility of crude protein (Ahnert et al., 2015). The administration of 2/3quebracho extract + 1/3 chesnut extract (tannin mixture) with a concentration of 0.45; 0.90 and 1.8% of dry matter decreased the digestibility and milk protein but increased the efficiency of milk production (Aguerre et al., 2016). The addition of condensed tannins by more than 5% decreased palatability and ration consumption, nutrient digestibility, feed efficiency and performance (Naumann et al., 2017).


The tannin extract also functions as an antihelmintic (Engström et al., 2016; Naumann et al., 2014). The results of Quijada’s et al. (2015) research reported that condensed tannins from the prodelphinidin subunit had higher anthelmintic activity than procyanidin. Ethanol extract of Artemisia vulgaris is antihelmintic against Haemonchus contortus in goats (Karim et al., 2019).


The minerals bound by condensed tannins such as: Zn, P, Mn, Mg, Fe, Cu, Co, Ca and Al and reduce production of rumen methane (Naumann et al., 2017). The administration of pine bark (containing condensed tannins) decreased the digestibility of Cu, S and K minerals but increased the digestibility of Fe, Mg, Mn, P and Zn in goat meat (Min et al., 2015). The addition of Azadirachta indica (13,8%) and Ficus bengalensis (26%) (containing condensed tannins) reduced the rumen microbial population (ciliated) (Bhatta et al., 2015). The administration of 20% palm oil and 80% canola oil does no affect the intake and digestibility of nutrient in goats (Adeyemi et al., 2016). The administration of 3% activated charcoal (AC), does not affect the digestibility of nutrients in goats (Al Kindi et al., 2017).


Research on the effect of tannin on livestock metabolism has been reported by several researchers but the information about the effect of tannin contained in FOPFE (Fermented Oil Palm Fronds Extract) on the digestibility of nutrient and goat performance of kacang goat has not been reported. Therefore this research aims to determine the effect of administration of FOPFE (Fermented Oil Palm Fronds Extract) on the digestibility of nutrient and goat performance of goat (Kacang).




Animal and feed

The provision of rations is 4% of body weight (NRC, 1981). The ration consisted of 60% concentrate (rice bran, fermented oil palm fronds and tofu waste) and 40% forage (Elephant grass) and drinking water is given as ad libitum. Oil palm fronds are fermented for 21 days with 10% poultry manure and extracted with methanol solvent 96% (Febrina et al., 2020). The administration of FOPFE with different doses (0; 0.1%; 0.2% and 0.3%) (modified Sunarjoko, 2015) is the treatment in this study. Diluted of FOPFE by adding aquadest then given to the goats through a syringe.


Twelve 12 male goats aged ± one year with an initial weight of 13.1±1.1 kg. The goats are placed in a metabolic cage equipped with a feedbox and drinker. The provision of rations is carried out at 08.00 AM; 16.00 PM (twice a day), FOPFE was given 2 hours after feeding.


This research was conducted at the UARDS (University Agriculture Research and Development Station) research of State Islamic University of Sultan Syarif Kasim Riau (Faculty of Agriculture and Animal Science). The analysis of nutrition and fecal content was carried out at State Islamic University of Sultan Syarif Kasim Riau (Laboratory of Nutrition and Chemistry, Faculty of Agriculture and Animal Science), the composition and nutritional content of ration are shown in Table 1.


Table 1: The composition of ration and nutritional content of ration.


Composition of ration Composition Dry matter Crude protein Crude fiber TDN
%   %
Fermented oil palm frond 40.00 91.29 6.63 28.71 62.56
Tofu Waste 35.00 28.40 19.08 19.80 73.21
Rice Bran 24.00 90.24 7.28 19.80 74.38
Salt 1.00 - - -  
Complete ration 100.00 68.11 11.08 23.17 68.50


Experimental design and data collection

This study consisted of 4 treatments, 3 groups using a Randomized Block Design. The treatments i.e: P0; complete ration + 0% FOPFE; P1 : complete ration + FOPFE 0.1%; P2: complete ration + FOPFE 0.2% and P3: complete ration + FOPFE 0.3%. Parameters measured: digestibility of nutrient (organic matter, dry matter, crude fiber, crude protein, ADF, NDF, hemicellulose and cellulose) and performance of Kacang goat (intake of dry matter, average daily gain, ration efficiency and feed conversion).


This research consists of 2 phases, namely the adaptation phase (1 month) and the phase of data collection (28 days). Ration consumption is calculated every day during the collection period by reducing the ration given with the remaining ration. Animal weighing is done on days 1 and 28, in the morning before feeding. Feces collected on days 22-28 (for 7 days), with all the feces released by animals for 24 hours, weighed and taken 10%, dried, milled and then analyzed. Analysis of the nutritional content of rations and feces (crude fiber, crude fiber, dry matter and crude protein) based on AOAC (2006) while the fiber fraction content uses Foss Fibretec (based on Van Soest et al., 1991). Data were analyzed by ANOVA (Analysis of Variance) (Steel and Torrie, 2002), then DMRT (the Duncan’s Multiple Range Test) is carried out if there are differences between treatments.




Digestibility of nutrient

Table 2 shows the administration of FOPFE 0-0.3% in the ration did not significantly affect (P>0.05) on the nutrients digestibility. Treatment P0 (without FOPFE) results in lower digestibility compared to treatments P1, P2 and P3. The addition of 0.1-0.3% FOPFE in the ration showed a tendency of increased digestibility.


Goats performance

The addition of FOPFE in ration (Table 3) affected (P<0.05) on dry matter. Treatment 3 showed the lowest of dry matter intake and not different (P>0.05) with P2. The highest intake of dry matter at P3 and it the same as P0 (P>0.05) and P1 was different with P3 (P<0.05). Dry matter intake at P3 showed the same result as P0 (P>0.05) but P1 was different than P3 (P<0.05) higher consumption compared to the P1 and P2 treatments. This shows that the more FOPFE is given, the consumption will also increase. The addition of FOPFE 0-0.3% in the ration did not significantly (P>0.05) on body weight gain, conversion of feed and efficiency of ration of goats.




Digestibility of nutrient of goats, which were given FOPFE as shown in Table 2.


In the absence of the effect of adding FOPFE to the digestibility of nutrient, it is assumed that the FOPFE dose in the ration was still low (0-0.3%) and the low tannin content in FOPFE (0.33%, analysis of the Balitnak Laboratory, 2018) so that it did not interfere with microbial growth and rumen digestion. The administration of extract tannin did not affect on dry matter digestibility (Jolazadeh et al., 2015), administration of Dalea purpurea at Condensed


Table 2: Digestibility of nutrient.


No Digestibility (%) Treatment


P1=CR+0.1% FOPFE

P2=CR+0.2% FOPFE

P3=CR+ 0.3% FOPFE

1 Dry Matter 69.66±7.05 72.19±1.66 73.35±1.12 72.12± 0.69
2 Organic Matter 79.32±4.71 80.94±1.23 81.89±0.80 80.94±0.44
3 Crude Protein 80.77±4.49 81.76±0.13 83.72±0.57 82.06±0.97
4 Crude Fiber 59.72±10.08 58.05±4.87 62.10±3.09 66.94±8.54
5 Extract Eter 71.84±8.02 67.25±1.20


6 NDF 72.65±5.97 75.11±0.68 76.29±1.49 75.29±0.91
7 ADF 68.79±5.75 71.89±1.26 73.35±0.57 72.32±2.91
8 Hemicelulose 81.83±7.38 82.78±0.70 83.29±5.44 82.38±4.03
9 Celulose 69.88±2.65 73.71±0.19 75.64±2.62 73.17±4.67

Notes: CR: Complete ration; FOPFE: Fermented Oil Palm Fronds Extract.


Table 3: Goats Performance of Kacang.


No Performances Treatment

P0 = CR+ 0% FOPFE

P1= CR+ 0.1% FOPFE

P2= CR+ 0.2% FOPFE

P3 = CR+ 0.3% FOPFE

1 Dry matter intake (g/h/d)





2 Average Daily Gain (g/h/d) 31.43±7.89 32.32±8.23 32.74±7.21 39.76±11.59
3 Feed conversion 24.03±3.55 20.58±4.71 21.38±4.81 21.76±7.29
4 Feed efficiency 4.2±0.006 4.9±0.011 4.8±0.010 4.9±0.013

Notes: CR: Complete ration; FOPFE: Fermented Oil Palm Fronds Extract.


Tannin (CT) concentration 6-9% dry matter, does not affect the digestibility of crude protein and dry matter (Jin et al., 2012) but the administration of Quebracho Tannin (QT) extract reduces nutrient digestibility on crossbred steers (Norris et al., 2020). Tannins in low concentrations do not affect rumen ecosystems and digestibility (Husnaeni et al., 2015). Tannins in high doses affect rumen digestibility and fermentability (Jayanegara et al., 2012; Min et al., 2015) this is because tannin binds minerals and proteins and interferes with Fe absorption (Fajrina et al., 2016).


Rumen pH in this study was 7.74-8.15. The same was reported by other researchers rations containing 30% elephant grass and 70% concentrate in Madura cattle and Onggole Peranakan’s produce rumen pH of 7.6-8.4 (Umar et al., 2011). The rumen pH is still within the normal range for microbial growth and does not interfere with the stability of complex tannin-protein. This is beneficial because the supply of feed protein is protected by rumen degradation, so the addition of 0-0.3% FOPFE in the ration does not affect nutrient digestibility. The same research was reported by Lima et al. (2019) that supplementation of tannin in sheep did not affect the digestibility. The bond between tannin and protein will be released at a low pH that occurs in abomasum and protein will be hydrolyzed by pepsin so that amino acids will be utilized by livestock (Jayanegara et al., 2008).


The administration of 0.1-0.3% FOPFE in the ration showed a tendency of increased digestibility. This shows that goats can tolerate FOPFE in low doses, even increasing digestibility. This is because tannin can function as a defaunation agent that inhibits the growth of rumen protozoa, thus encouraging the growth of bacteria to degrade feed, thereby increase the digestibility. Tannin supplementation reduces protozoa populations (Tan et al., 2011) and increases organic matter digestibility (Wahyuni et al., 2014).


The administration of 0.1% FOPFE (Table 3), that reducing intake of dry matter compared without the administration of FOPFE (P0). This shows the reduced palatability of the ration caused by tannin has a chelate taste so that the increase in FOPFE in the ration, causes a decrease on dry matter intake. The increase in FOPFE from 0.1% to 0.3% has led to an increase in dry matter intake. This is because livestock has adapted to the taste of chelat in tannins so that an increase in FOPFE in rations also increases the consumption of dry matter. Different results were reported (Tseu et al., 2020) administration of tannins 0.00; 0.75; 1.50 and 2.25% of dry matter significantly decreased the feed intake in the of Nellore cows this was due to the astringent properties of tannins.


Consumption of dry matter in P0 treatment (without the addition of FOPFE) was 736.83 g/h/d and did not differ from treatment P2 (0.2% FOPFE) and P3 (0.3% FOPFE). This shows that the dose of tannin contained in the extract is still low (0.33%) so it does not affect the consumption of rations. Tannins in low quantities do not affect consumption (Frutos et al., 2004), but the addition of 4% Quebracho Tannins Extract affects on digestibility of organic matter, digestibility dry matter and intake of dry matter on crossbred heifers (Vazquez et al., 2018). Tannins have a chelate taste (Silanikove et al., 2001), but the addition of FOPFE in the ration does not affect ration consumption, this is thought because goats are more tolerant of a bitter taste than sheep (Lamy et al., 2011) and the proline content in saliva which can maintain the stability of the feed (Delimon et al., 2017).


In this study all treatments received the same type of ration, the difference was the FOPFE dose of 0-0.3% in the ration so that the palatability and consumption of ration were the same. Factors affecting ration consumption are palatability (Restitrisnani et al., 2013; Suparman et al., 2016) and feed nutrition (Ngwa et al., 2007; Tafsin et al., 2019). The ration consumption (dry matter intake) in this study was 645.97-809.21g/h/day, the same as reported by Rostini and Zakir (2017) and Lawa and Lazarus (2015).


The average daily gain of goats given 0-0.3% FOPFE in the ration was 31.43-39.76 g/h/d and did not differ between treatments. The same researchers were reported by Brown et al. (2018) that the provision of 30-40% tanniniferous Acacia karroo leaf on goats did not have an effect on body weight gain namely 34 and 36 g/h/d. The average daily gain in this study was lower than research by Astuti et al. (2011); Febrina et al. (2017) and Adhianto et al. (2020).


Feed efficiency is the ratio between average daily gain and intake of dry matter. Feed efficiency of goat given FOPFE 0-0.3% in the ration was 4.23-4.99. The administration of FOPFE in ration did not affect the ration of consumption and average daily gain so it did not affect the feed efficiency. Increasing the consumption of dry material will increase feed efficiency (Houlahana et al., 2019). The sheep which were supplemented with soybean meal protected by tannin liquid of banana stems in ration showed an increase of balanced body weight with the ration consumed (Yulistiyani et al., 2011).


Feed conversion in goats which were given FOPFE 0-0.3% in the ration was 20.58-24.03 and did not differ between treatments, this was due to body weight gain and feed efficiency which was not different. The lowest ration conversion score shows the more efficient the cattle use their rations. The addition of tannin in the ration influences the performance and efficiency of the ration (Ebber et al., 2017; Yisehak et al., 2016;Aboagye et al., 2018). Jayanegara et al. (2012) stated that the addition of tannins that exceed 5% in the ration had a negative impact on the digestibility and performance of livestock so that their use in the ration needed to be limited. Providing the right dose of tannin has a beneficial effect on the metabolism of ruminants (Frutos et al., 2004).




Fermented Oil Palm Fronds Extract (FOPFE) can be fed to goats, because it does not negatively affect on digestibility and performance of Kacang goats. Administration of 0.2% FOPFE gave the best results assessed from nutrient digestibility and dry matter intake.




The author would like to thank State Islamic University of Sultan Syarif Kasim Riau (Institute for Research and Community Service) of the which funded this study under contract number 0932/R/2018.


Author’s Contribution


All authors contributed to conducting research and writing

this manuscript.




The authors have declared no conflict of interest.




  • Aboagye IA, Oba M, Castillo AR, Koenig KM, Iwaasa AD, Beauchemin KA (2018). Effects of hydrolyzable tannin with or without condensed tannin on methane emissions, nitrogen use, and performance of beef cattle fed a high-forage diet1, 2. J. Anim. Sci., 96: 5276–5286.
  • Adeyemi KD, Sazili AQ, Ebrahimi M, Samsudin AA, Alimon AR, Karim R, Karsani SA, Sabow AB (2016). Effects of blend of canola oil and palm oil on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids in goats. Anim. Sci. J., 87(9): 1137-1147.
  • Adhianto K, Muhtarudin, Saputra A, Surya SPA, Suprayogi D, Hamdani MDI (2020). The effect of palm oil waste based rations enriched with cassava leaves silage and organic micro minerals on growth and nutrients digestibility of goat. Adv. Anim. Vet. Sci., 8(11): 1154-1160.
  • Aguerre MJ, Capozzolo MC, Lencioni P, Cabral C, Wattiaux MA (2016). Effect of quebracho-chestnut tannin extracts at 2 dietary crude protein levels on performance, rumen fermentation and nitrogen partitioning in dairy cows. J. Dairy Sci., 99: 4476-4486.
  • Ahnert S, Dickhoefer U, Schulz F, Susenbeth A (2015). Influence of ruminal Quebracho tannin extract infusion on apparent nutrient digestibility, nitrogen balance, and urinary purine derivatives excretion in heifers. Livest. Sci., 177: 63-70.
  • Al‐Kindi, Schiborra A, Buerkert A, Schlecht E (2017). Effects of quebracho tannin extract and activated charcoal on nutrient digestibility, digesta passage and feces composition in goats. Anim. Physiol. Anim. Nutr., 101(3): 576-588.
  • AOAC (2006). Official methods of analysis of AOAC International. 18th Ed., AOAC International, Gaithersburg, MD., USA
  • Astuti DA, Baba AS, Wibawa IWT (2011). Rumen fermentation blood metabolites and performance of sheep feed tropical browse plants. Media Peternakan. 34(3): 201-2016.
  • Bhatta R, Saravanan M, Baruah L, Prasad CS (2015). Effects of graded levels of tannin-containing tropical tree leave on in vitro rumen fermentation, total protozoa and methane production. J. Appl. Microbiol., 118: 557-564.
  • Brown D, Ng’ambi JW, Norris D (2018). Effect of tanniniferous Acacia karroo leaf meal inclusion level on feed intake, digestibility and live weight gain of goats fed a Setaria verticillata grass hay-based diet. J. Appl. Anim. Res., 46(1): 248–253.
  • Corral MF, Oliveira PG, Pereira AG, Lopes CL, Lopez CJ, Prieto MA, Gandara JS (2020). Technological application of tannin-based extracts (Review). Molecules, 25(614): 1-27.
  • Delimont NM, Rosenkranz SK, Haub MD, Lindshield BL (2017). Salivary proline-rich protein may reduce tannin-iron chelation: A systematic narrative review. Nutr. Metab., 14(47): 1-16.
  • Doce RR, Belenguer A, Toral PG, Hervás G, Frutos P (2013). Effect of the administration of young leaves of Quercus pyrenaica on rumen fermentation in relation to oak tannin toxicosis in cattle. J. Anim. Physiol. Anim. Nutr., 97: 48-57.
  • Ebert PJ, Bailey EA, Shreck AL, Jennings JS, Cole NA (2017). Effect of condensed tannin extract supplementation on growth performance, nitrogen balance, gas emissions, and energetic losses of beef steers. J. Anim. Sci., 95: 1345–1355.
  • Engström MT, Karonen M, Ahern JR, Baert N, Payré B, Hoste H, Salminen JP (2016). Chemical structures of plant hydrolyzable tannins reveal their in vitro activity against egg hatching and motility of Haemonchus contortus Nematodes. J. Agric. Food Chem., 64: 840-851.
  • Fajrina A, Junuarty, Stevani S (2016). Penetapan kadar tanin pada teh celup yang beredar dipasaran secara spektrofotometri UV-VIS. J. Farmasi Higea, 8(2): 133-142.
  • Febrina D, Febriyanti R, Zam SI, Handoko J, Fatah A, Juliantoni J (2018). Antibacterial activity testing and ethanol extract characterization of oil palm fronds (Elaeis guineensis Jacq). Pak. J. Nutr., 17(9): 427-433.
  • Febrina D, Febriyanti R, Zam SI, Zumarni, Juliantoni J, Fatah A (2020). Nutritional content and characteristics of antimicrobial compounds from fermented oil palm fronds (Elaeis guineensis Jacq.). J. Trop. Life Sci., 10(1): 27-33.
  • Febrina D, Jamarun N, Zain M, Khasrad (2016a). The effects of P, S and Mg supplementation of oil palm fronds fermented by Phanerochaete chrysosporium on rumen fluid characteristics and microbial protein synthesis. Pak. J. Nutr., 15: 299-304.
  • Febrina D, Jamarun N, Zain M, Khasrad (2016b). Effects of Calcium (Ca) and Manganese (Mn) supplementation during oil palm frond fermentation by Phanerochaete chrysosporium on in vitro digestibility and rumen fluid characteristics. Pak. J. Nutr., 15: 352-358.
  • Febrina D, Jamarun N, Zain M, Khasrad (2017). Effects of using different levels of Oil Palm Fronds (FOPFS) fermented with Phanerochaete chrysosporium plus minerals (P, S and Mg) instead of Napier Grass on nutrient consumption and the growth performance of goats. Pak. J. Nutr., 16(8): 612-617.
  • Frutos P, Hervas G, Giraldez GJ, Mantecon R (2004). Review. Tannin and ruminant nutrition. Spanish J. Agric. Res., 2: 191- 202.
  • Hagerman AE (2012). Fifty years of polyphenol-protein complexes. In: Recent advances in polyphenol research. vol. 3. 3rd ed. Cheynier, V.; Sarni-Manchado, P. and Quideau, eds. John Wiley and Sons, Ltd., Oxford, UK. p.71-97.
  • Houlahana K, Schenkel FS, Miglior F, Oliveira Jr GA, Fleming A, Chud TCS, Baes CF (2019). Comparing the use of dry matter intake and residual feed intake to improve feed efficiency in Holstein cattle. Interbull. Bull., 55: 50-57.
  • Husnaeni, Sunarso, Nuswantara LK (2015). Perkiraan pasokan nitrogen mikrob pada domba ekor tipis yang diberi bungkil kedelai terproteksi tanin. J. Vet., 16(2): 212-21.
  • Imsya A, Laconi EB, Wiryawan KG, Widyastuty Y (2013). Identification of phenolic compounds and its antioxidant activity from lignin and palm oil frond fermented with Phanerochaete chrysosporium. Proceedings of the 4th International Conference on Sustainable Animal Agriculture for Developing Countries (SAADC 2013) 27–31 July 2013. Lanzhou University Lanzhou, China. pp. 310-312.
  • Jayanegara A, Goel G, Makkar HPS, Becker K (2015). Divergence between purified hydrolyzable and condensed tannin effects on methane emission, rumen fermentation and microbial population in vitro. Anim. Feed Sci. Technol., 209: 60-68.
  • Jayanegara A, Leiber F, Kreuzer M (2012). Meta-analysis of the relationship between dietary tannin level and methane formation in ruminants from in vivo and in vitro experiments. Anim. Physiol. Anim. Nutr., 96: 365–375.
  • Jayanegara A, Togtokhbayar N, Makkar HPS, Becker K (2008). Tannins determined by various methods as predictors of methane production reduction potential of plants by an in vitro rumen fermentation system. Anim. Feed Sci. Technol., 150: 230-237.
  • Jin L, Wang Y, Iwaasa AD, Xu Z, Schellenberg MP, Zhang YG, Liu XL, McAllister TA (2012). Effect of condensed tannins on ruminal degradability of purple prairie clover (Dalea purpurea Vent.) harvested at two growth stages. Anim. Feed Sci. Technol., 176: 17-25.
  • Jolazadeh AR. Dehghan-banadaky, Rezayazdi MK (2015). Effects of soybean meal treated with tannins extracted from pistachio hulls on performance, ruminal fermentation, blood metabolites and nutrient digestion of Holstein bulls. Anim. Feed Sci. Technol., 203: 33-40.
  • Karim MA, Islam MR, Lovelu MA, Nahar SF, Dutta PK, Talukder MH (2019). In vitro evaluation of anthelmintic activity of tannin-containing plant Artemisia extracts against Haemonchus contortus from goat. J. Bangladesh Agric. Univ. 17(3): 363–368.
  • Lamy L, Rawel H, Schweigert FJ, e Silva FC, Ferreira A, Costa AR, Antunes C, Almeida AM, Coelho AV, Baptista ES (2011). The effect of tannins on mediterranean ruminant ingestive behavior: The role of the oral cavity. Molecules, 16(4): 2766–2784.
  • Lawa EDW, Lazarus EJL (2015). Suplementasi tepung ikan terproteksi ekstrak tanin hijauan kabesak kuning, kabesak hitam dan kihujan dalam ransum terhadap pertumbuhan ternak kambing. J. Zootek. 35(2): 368-378.
  • Lima PR, Apdini T, Freire AS, Santana AS, Moura LML, Nascimento JCN, Rodrigues RTS, Dijkstra J, Neto ABG, Queiroz MAA, Menezes DR (2019). Dietary supplementation with tannin and soybean oil on intake, digestibility, feeding behavior, ruminal protozoa and methane emission in sheep. Anim. Feed Sci. Technol., 249: 10-17.
  • Min BR, Mcnabb WC, Barry TN, Peters JS (2000). Solubilization and degradation of ribulose-1,5- bisphosphate carboxylase/ oxygenase (EC; Rubisco) protein from white clover (Trifolium repens) and Lotus corniculatus by rumen microorganisms and the effect of condensed tannins on these processes. J. Agric. Sci. (Camb.), 134: 305–317.
  • Min BR, Wilson EA, Solaiman S, Miller J (2015). Effects of condensed tannin-Rich Pine Bark Diet on experimentally infected with Haemonchus Contortus in meat goats. Int. J. Vet. Health Sci. Res., 3(3): 49-57.
  • Naumann HD, Armstrong SA, Lambert BD, Muir JP, Tedeschi LO, Kothmann MM (2014). Effect of molecular weight and concentration of legume condensed tannins on in vitro larval migration inhibition of Haemonchus contortus. Vet. Parasitol., 199: 93-98.
  • Naumann HD, Tedeschi LO, Zeller WE, Huntley NF (2017). The role of condensed tannins in ruminant animal production: advances, limitations and future directions (Invited Review). R. Bras. Zootec., 46(12): 929-949.
  • Ngwa AT, Dawson LJ, Puchala R, Detweiler G, Merkel RC, Tovar-Luna I, Sahlu T, Ferrell CL, Goetsch AL (2007). Effect of initial body condition of Boer×Spanish yearling goat wethers and level of nutrient intake on body composition. Small Rum. Res., 73: 13-26.
  • Norris AB, Tedeschi LO, Foster JL, Muir JP, Pinchak WE, Fonseca MA (2020). Influence of quebracho tannin extract fed at differing rates within a high-roughage diet on the apparent digestibility of dry matter and fiber, nitrogen balance, and fecal gas flux. Anim. Feed Sci. Technol., Volume 260.
  • NRC (1981). Nutrient requirements of goats: Angora, dairy and meat goats in temperate and tropical countries. Washington, DC: National Academic Press. pp. 99.
  • Orlandi T, Kozloski GV, Alves TP, Mesquita FR, Ávila S (2015). Digestibility, ruminal fermentation and duodenal flux of amino acids in steers fed grass forage plus concentrate containing increasing levels of Acacia mearnsii tannin extract. Anim. Feed Sci. Technol., 210: 37-45.
  • Patra AK, Saxena J (2010). A new perspective on the use of plant secondary metabolites to inhibit methanogenesis in the rumen. J. Phytochem., 71: 1198–1222.
  • Quijada J, Fryganas C, Ropiak HM, Ramsay A, Mueller-Harvey I, Hoste H (2015). Anthelmintic activities against Haemonchus contortus or Trichostrongylus colubriformis from small ruminantsare influenced by structural features of condensed tannins. J. Agric. Food Chem., 63: 6346-6354.
  • Restitrisnani V, Purnomoadi A, Rianto E (2013). The production and body composition of Kacang Goat feed different quality of diets. J. Indones. Trop. Anim. Agric., 38(3): 163-170.
  • Rostini T, Zakir I (2017). Performans produksi, jumlah nematoda usus, dan profil metabolik darah kambing yang diberi pakan hijauan rawa Kalimantan. J. Vet., 18(3): 469-477.
  • Silanikove N, Perevolotsky A, Provenza FD (2001). Use of tannin-binding chemicals to assay for tannins and their negative postingestive effects in ruminants. Anim. Feed Sci. Technol., 91: 69–81.
  • Steel RGD, Torrie JH (2002). Prinsip dan prosedur statistik suatu pendekatan biometrik edisi kedua. PT. Gramedia. Jakarta.
  • Sunarjoko TUP (2015). Penambahan ekstrak tanin asal chestnut pada ransum terhadap performa domba, pola fermentasi dan metabolit darah. Tesis. Sekolah Pascasarjana Institut Pertanian Bogor, Bogor.
  • Suparman H, Hafid, Ode BL (2016). Kajian pertumbuhan dan produktivitas kambing Peranakan Ettawa jantan yang diberi pakan berbeda. J. Ilmu dan Teknol. Peternakan Tropis (JITRO). 3(3): 1-9.
  • Suyitman, Warly L, Rahmat A, Pazla R (2020). Digestibility and performance of beef cattle fed ammoniated palm leaves and fronds supplemented with minerals, cassava leaf meal and their combinations. Adv. Anim. Vet. Sci., 8(9): 991-996.
  • Tafsin M, Hanafi ND, Sadeli A, Hamdan, Sari SF (2019). Provision of complete feed fermented peel cassava (Manihot esculenta Crantz) male kacang goat performance. J. Phys. Conf. Ser., 1542(2020): 012033 IOP Publishing.
  • Tan HY, Sieo CC, Abdullah N, Liang JB, Huang XD, Ho YW (2011). Effect of condensed tanins from Leucaena on methane production, rumen fermentation and populations of methanogens and protozoa in vitro. J. Anim. Feed Sci. Tech., 168: 185-193.
  • Tseu RJ, Junior FP, Carvalho RF, Sene GA, Tropaldi CB, Peres AH, Rodrigues PHM (2020). Effect of tannins and monensin on feeding behavior, feed intake, digestive parameters and microbial efficiency of Nellore cows, Ital. J. Anim. Sci., 19(1): 262-273.
  • Umar M, Arifin M, Purnomoadi A (2011). Ruminal condition between Madura Cattle and Ongole Crossbred cattle raised under intensive feeding. J. Indon. Trop. Anim. Agric., 36: 213-218.
  • Van Soest PJ, Robertson JB, Lewis BA (1991). Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci., 74: 3583–3597.
  • Vázquez ATP, Jiménez-Ferrer G, Alayon-Gamboa JA, Chay-Canul AJ, Ayala-Burgos AJ, Aguilar-Pérez CF, Ku-Vera JC (2018). Effects of quebracho tannin extract on intake, digestibility, rumen fermentation, and methane production in crossbred heifers fed low-quality tropical grass. Trop. Anim. Health Prod., 50: 29–36.
  • Wahyuni IMD, Muktiani A, Christiyanto M (2014). Kecernaan bahan kering dan bahan organik dan degradabilitas serat pada pakan yang disuplementasi tanin dan saponin. Agripet, (2)2: 115-124.
  • Yisehak K, Kibreab Y, Taye T, Lourenço MRA, Janssens GPJ (2016). Response to dietary tannin challenges in view of the browser/grazer dichotomy in an Ethiopian setting: Bonga sheep versus Kaffa goats. Trop. Anim. Health Prod., 48: 125–131.
  • Yulistiani D, Mathius I-W, Puastuti W (2011). Bungkil kedelai terproteksi tanin cairan batang pisang dalam pakan domba sedang tumbuh. J. Ilmu Ternak dan Vet. 16(1): 33-40.