I Komang Gede Wiryawan

Prof. Dr. I Komang Gede Wiryawan


Research Focus & Metrics

Academic Career Length

57Years (1970-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2019 in IOP Conference Series: Materials Science and Engineering
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TWTeguh Wahyono
Teguh Wahyono
DADewi Apri Astuti
Dewi Apri Astuti
IWI Komang Gede Wiryawan
I Komang Gede Wiryawan
ISIrawan Sugoro
Irawan Sugoro
AJAnuraga Jayanegara
Anuraga Jayanegara
G5 and G8 are two sorghum mutant lines projected as sorghum varieties for ruminant’s feed. However, most of the sorghum panicles contains phenolic compounds, especially in the form of condensed tannins. The objective of this research was to investigate the phenolic and tannin compounds from the panicles of two sorghum mutant lines. The second objective was to identify tannin content by Fourier Transform Mid-Infrared (FTIR) Spectroscopy in the sorghum panicles. The two mutant lines were compared with Pahat variety. This research was arranged into a randomized complete block design with two factors. The first factor was the sorghum variety/mutant lines, whereas the second factor was the generative phase of harvesting time (flowering, soft dough and hard dough). The results showed that the panicles of G5 sorghum contained the lowest total phenol compounds (P<0.01). The average mean of G5 and G8 mutant lines produced lower total tannin content (27.3 and 18.2%, respectively) than Pahat variety (P<0.01). Generally, total phenol and total tannin in all variety/mutant lines increased with the increasing maturity stage (P<0.01). All the spectra of the sorghum panicle samples in different harvesting age investigated shared certain special similarities. A band due to alkane medium (C-H) stretch was observed at 2937-2854 cm−1. At 1521-1514 and 1446-1408 cm−1, a band due to the C-C aromatic compounds was observed. Based on those findings, it can be concluded that G5 and G8 mutant lines produced less total phenol and total tannin contents than Pahat variety. Meanwhile, FTIR could be used to describe the profile of tannin compounds qualitatively.

1 February 2022 in Animal Bioscience
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Journal Article
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DADewi Apri Astuti
Dewi Apri Astuti
IWI Komang Gede Wiryawan
I Komang Gede Wiryawan
This paper is a review of some experiments using black soldier fly (BSF) and its by-product to explore their nutritional value, production potential in Indonesia and its application in the ration of ruminants. Evaluation on the effect of milk replacer, creep feed containing BSF, BSF frass and the possibility to use lactic acid bacteria from BSF as probiotics are presented. Utilization of BSF larvae in milk replacer as skim and cream milk substitute showed that there were similarity on physiological, hematological status and performance of goat kids compared to those offered goat milk or commercial milk replacer. In addition, BSF larvae can be used to substitute soybean meal in the creep feed for post weaning goat kids without any differences in weight gain and blood profiles. However, utilization of BSF frass in the fattening goat ration resulted lower digestibility of dry matter and organic matter due to the chitin content in the frass. Black soldier fly larvae grown on chicken manure harbour lactic acid bacteria (LAB) which have potential as probiotics for ruminants. In general, BSF larvae has potential as ingredient for milk replacer, creep feed, fattening ration, and source of LAB for probiotics.

1 January 2019 in Asian-Australasian Journal of Animal Sciences
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MPMinyu PIAO
Minyu PIAO
HLHyun Jung Lee
Hyun Jung Lee
Hae In YongHae In Yong
Hae In Yong
SBSeok-Hyeon Beak
Seok-Hyeon Beak
HKHyun Jin Kim
Hyun Jin Kim
MBMyunggi Baik
Myunggi Baik
This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. Twelve LT samples (about 500 g each) of KC with an average age of 31±0.42 months, an average carcass weight of 431±12.5 kg, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of 24±0.54 months, an average carcass weight of 402±7.81 kg, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at 4°C for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds.

14 February 2015 in Asian-Australasian Journal of Animal Sciences
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RRRoni Ridwan
Roni Ridwan
IRIman Rusmana
Iman Rusmana
YWYantyati Widyastuti
Yantyati Widyastuti
IWI Komang Gede Wiryawan
I Komang Gede Wiryawan
Bambang PrasetyaBambang Prasetya
Bambang Prasetya
MOMoriya Ohkuma
Moriya Ohkuma
Calliandra calothyrsus preserved in silage is an alternative method for improving the crude protein content of feeds for sustainable ruminant production. The aim of this research was to evaluate the quality of silage which contained different levels of C. calothyrsus by examining the fermentation characteristics and microbial diversity. Silage was made in a completely randomized design consisting of five treatments with three replications i.e.: R0, Pennisetum purpureum 100%; R1, P. purpureum 75%+C. calothyrsus 25%;, R2, P. purpureum 50%+C. calothyrsus 50%; R3, P. purpureum 25%+C. calothyrsus 75%; and R4, C. calothyrsus 100%. All silages were prepared using plastic jar silos (600 g) and incubated at room temperature for 30 days. Silages were analyzed for fermentation characteristics and microbial diversity. Increased levels of C. calothyrsus in silage had a significant effect (p<0.01) on the fermentation characteristics. The microbial diversity index decreased and activity was inhibited with increasing levels of C. calothyrsus. The microbial community indicated that there was a population of Lactobacillus plantarum, L. casei, L. brevis, Lactococcus lactis, Chryseobacterium sp., and uncultured bacteria. The result confirmed that silage with a combination of grass and C. calothyrsus had good fermentation characteristics and microbial communities were dominated by L. plantarum.

8 January 1999 in Animal Feed Science and Technology
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Journal Article
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IWI Komang Gede Wiryawan
I Komang Gede Wiryawan
JDJ.G Dingle
J.G Dingle

1 June 2023 in Animal Bioscience
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Journal Article
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ISIrwan Susanto
Irwan Susanto
IWI Komang Gede Wiryawan
I Komang Gede Wiryawan
SSSri Suharti
Sri Suharti
YRYuli Retnani
Yuli Retnani
RZRIKA ZAHERA
RIKA ZAHERA
Anuraga JayanegaraAnuraga Jayanegara
Anuraga Jayanegara
Objective: This study was conducted to evaluate the use of <i>Megasphaera elsdenii</i> (<i>M. elsdenii</i>) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis.Methods: A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while <i>M. elsdenii</i> supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05〈p〈0.10.Results: Supplementation with <i>M. elsdenii</i> increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p<0.05) due to the <i>M. elsdenii</i> supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, <i>M. elsdenii</i> supplementation had negligible effects on blood and urine metabolites of ruminants.Conclusion: Supplementation of <i>M. elsdenii</i> is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.