This study aimed to perform a meta-analysis on the effect of 3-nitrooxypropanol (3-NOP) on enteric methane (CH 4 ) emissions from ruminants. A total of 12 in vivo studies from 10 articles were integrated into a database. Ruminant species included were dairy cows, beef cattle and sheep. Concentration of 3-NOP in diets varied from 0 to 280 mg/kg dry matter intake (DMI). Parameters included were CH 4 emissions, rumen fermentation, microbial population, nutrient digestibility and animal performance. Meta-analysis of data was performed by using mixed model methodology in which different studies were treated as random effects whereas 3-NOP addition levels in diets of ruminants were treated as fixed effects. Results showed that increasing level of 3-NOP addition in diets of ruminants decreased enteric CH 4 emissions per unit of body weight, CH 4 /DMI, CH 4 /milk produced, CH 4 /digested organic matter or CH 4 /gross energy intake (p < .05). Production of H 2 was higher with increasing level of 3-NOP addition (p < .001). Addition of 3-NOP decreased total VFA concentration (p < .01), and decreased and increased proportions of C 2 and C 3 , respectively (p < .001). Addition of 3-NOP decreased archaea population (p < .01) but it did not change total bacteria and protozoa populations. The substance had minor effect on digestibility of nutrients. Production performance of dairy cows and beef cattle was limitedly influenced by the addition of 3-NOP in the diets, and it had no negative effect on DMI of ruminants. It is concluded that 3-NOP is an effective feed additive to mitigate enteric CH 4 emissions without compromising productive performance of ruminants.

ABSTRAKPenelitian ini bertujuan untuk mengevaluasi kandungan nutrien, fermentasi rumen, kecernaan dan emisi metana secara in vitro sejumlah serangga yakni jangkrik (JFC), ulat hongkong (MW) dan larva black soldier fly berumur 1 dan 2 minggu (BSF1 dan BSF2). Sampel serangga dikeringkan pada suhu 60 o C selama 24 jam, kemudian digiling berukuran 1 mm. Sampel yang telah digiling kemudian dianalisis kandungan nutriennya serta diuji secara in vitro. Inkubasi in vitro dilakukan pada water bath pada suhu 39ºC selama 48 h, serta dilakukan dalam tiga ulangan di mana masing-masing ulangan direpresentasikan dengan dua botol inkubasi. Hasil menunjukkan bahwa semua serangga yang diujikan mengandung protein kasar yang tinggi yakni di atas 40% BK. Proporsi neutral detergent insoluble CP (NDICP) dan neutral detergent insoluble CP (ADICP) pada serangga lebih tinggi dibandingkan dengan bungkil kedelai, terutama sangat tinggi pada BSF2. Konsentrasi NH 3 tertinggi terdapat pada inkubasi JFC dibandingkan dengan yang lain (P<0,05) dan paling rendah pada BSF2. Semua sampel serangga memiliki KCBK dan KCBO yang lebih rendah dibandingkan dengan bungkil kedelai (P<0,05). Emisi metana dari serangga pada jam inkubasi ke-12, 24 dan 48 jam lebih rendah dibandingkan dengan bungkil kedelai (P<0,05). Disimpulkan bahwa serangga tinggi akan protein dan menghasilkan emisi metana yang rendah, namun kecernaannya relatif rendah sehingga dapat membatasi penggunaannya. Kata Kunci: serangga, jangkrik, ulat hongkong, black soldier fly, fermentasi rumen ABSTRACTThis experiment was aimed to evaluate chemical composition, in vitro rumen fermentation, digestibility and methane emissions of some insects, i.e. Jamaican field cricket (JFC), mealworm (MW) and black soldier fly larvae age 1 and 2 weeks (BSF1 and BSF2). Insect samples were oven-dried at 60 o C for 24 h, and ground to pass a 1 mm sieve. The ground samples were used subsequently for chemical composition determination and in vitro rumen fermentation test. Incubation was carried out in a water bath maintained at 39 ºC for 48 h in three replicates. Results revealed that all insect meals contained high crude protein, i.e. above 40% DM. Proportions of neutral detergent insoluble CP (NDICP) and neutral detergent insoluble CP (ADICP) were high in the insect meals than that of soybean meal (SBM), and these were particularly very high in BSF2. All insect meals had lower IVDMD and IVOMD than that of SBM (P<0.05). All insect meals had lower methane emissions as compared to SBM at 12, 24 and 48 h (P<0.05). It can be concluded that insect meals are potential protein supplements and have low methane emissions in vitro. However, their digestibility is rather low and may limit their utilization.

Objective: This study aims to evaluate the influence of dietary flavonoids on the growth performance, blood and intestinal profiles, and carcass characteristics of broilers by employing a meta-analysis method.Methods: A database was built from published studies which have reported on the addition of various levels of flavonoids from herbs into broiler diets and then monitored growth performance, blood constituents, carcass proportion and small intestinal morphology. A total of 42 articles were integrated into the database. Several forms of flavonoids in herbs were applied in the form of unextracted and crude extracts. The database compiled was statistically analyzed using mixed model methodology. Different studies were considered as random effects, and the doses of flavonoids were treated as fixed effects. The model statistics used were the p-values and the Akaike information criterion. The significance of an effect was stated when its p-value was <0.05.Results: Dietary flavonoids increased (quadratic pattern; p<0.05) the average daily gain of broilers in the finisher phase. There was a reduction (p<0.01) in the feed conversion ratio of the broilers both in the starter (linear pattern) and finisher phases (quadratic pattern). The mortality rate tended to decrease linearly (p<0.1) with the addition of flavonoids, while the carcass parameter was generally not influenced. A reduction (p<0.001) in cholesterol and malondialdehyde concentrations (both linearly) was observed, while super oxide dismutase activity increased linearly (p<0.001). Increasing the dose of flavonoids increased (p<0.01) the villus height (VH) and villus height and crypt depth (VH:CD) ratio (p<0.05) in the duodenum. Similarly, the VH:CD ratio was elevated (p<0.001) in the jejunum following flavonoid supplementation.Conclusion: Increasing levels of flavonoids in broilers diet leads to an improvement in growth performance, blood constituents, carcass composition and small intestinal morphology.

This study was aimed to analyze neutral detergent insoluble crude protein (NDICP) and acid detergent insoluble crude protein (ADICP) contents of various commonly used forage and concentrate feedstuffs in Indonesia. A number of forages and concentrates, i.e. gliricidia, trichantera, indigofera, calliandra, papaya leaves, cassava leaves, leucaena, rapeseed meal, corn gluten feed, soybean meal, copra meal, palm kernel meal, fish and bone meal and wheat bran were subjected to proximate analysis, cell wall nitrogen determination and in vitro rumen fermentation evaluation. Chemical composition analysis was done in duplicate. The in vitro incubation was conducted in 14 treatments and 3 replicates by following a randomized complete block design. Variables measured after the incubation were total volatile fatty acid (VFA), ammonia, dry matter digestibility (DMD), organic matter digestibility (OMD) and crude protein digestibility (CPD). Results revealed that among the forages, cassava leaf had the highest proportion of NDICP while corn gluten feed was the highest among the concentrates. Different from that of NDICP, the highest proportion of ADICP was obtained in papaya leaf and copra meal for the forages and concentrates, respectively. Higher proportion of NDICP tended to decrease CPD (P<0.1). Although higher ADICP apparently tended to decrease CPD as well, the relationship was insignificant due to the higher variation of the dependent variable. It was concluded that cell wall protein proportion in feed may be used as an indicator to determine the quality of protein and its utilization in the rumen.

Chitosan is a natural compound obtained from deacetylation of chitin, which is a biopolymer present in the exoskeleton of crustaceans such as crabs and shrimp. The present study aimed to perform a meta-analysis from published studies regarding the effects of chitosan on methane emission and rumen fermentation profile of in vitro batch culture experiments. A total of 41 studies from 12 articles were integrated into a database. Parameters included were gas production, methane emission, rumen fermentation characteristics, microbial population, nutrient digestibility, and fatty acid profile. Data were analyzed according to mixed model methodology in which different studies were treated as random effects and chitosan addition levels were treated as fixed effects. Results showed that chitosan addition was able to reduce enteric methane emissions (p<0.001). Such methane decrease was accompanied by a decline in the protozoa population (p<0.05) and a tendency of methanogen reduction (p<0.1). The increasing chitosan level was associated with a decrease in total VFA and ammonia concentrations (both at p<0.001). Chitosan addition decreased acetate proportion (p<0.001) while elevated propionate proportion (p<0.001). Chitosan was associated with an increase of dry matter digestibility, crude protein digestibility, and neutral detergent fiber digestibility (p<0.001). Chitosan increased concentrations of C 18:3n3 (p<0.05), conjugated linoleic acid (p<0.01) and polyunsaturated fatty acids (p<0.01) while decreased concentration of saturated fatty acids (p<0.001). It can be concluded that chitosan addition can mitigate enteric methane emission and alters rumen fermentation profiles in a favorable direction.