Rumen Modifier Research Articles

Study of Local Herb Potency as Rumen Modifier: The Effect of Red Ginger (Zingiber officinale Var.Rubrum) on Parameters of Ruminal Fermentation In Vitro

Essential oil is one of rumen modifier alternatives due to its antimicrobial property. Red ginger is one of local herbs with high essential oil content. The effect of red ginger on rumen fermentation parameters was studied in this research using in vitro gas production method. Five level of red ginger meal was added to the diet to meet final essential oil concentration in fermentation medium of 0, 25, 50, 75 and 100 mg/L. Substrate of fermentation as microbial feed composed of Penisetum hybride, rice bran, and wheat pollard in ratio 60:20:20 DM basis. Fermentation was carried out for 24 h at 39°C. Total gas production was measured at the end of incubation and sample for methane analysis was taken. Medium sample was taken for analysis of pH, ammonium and VFA concentration, microbial protein and protozoa number. Data showed that addition of red ginger in the diet did not affect the pH, ammonia and VFA concentration, microbial protein and also protozoa number. However, red ginger addition significantly decrease ammonia concentration in all treatment. It could be concluded that addition of red ginger in the diet reduced degradation protein in the rumen as illustrated in lower ammonia concentration.

In vitro antimicrobial activity of narasin against common clinical isolates associated with canine otitis externa.

Antimicrobial resistance and antimicrobial stewardship are of ever-increasing importance in veterinary medicine. Re-purposing of old drugs that are not used in human medicine is one approach that addresses the emergence of multidrug resistance in canine skin and ear infections, and can reduce the use of critically important human antibiotic classes. To determine the antimicrobial activity of narasin, a polyether ionophore conventionally used as a rumen modifier and anticoccidial agent in production animals, against common clinical isolates of canine otitis externa (OE). Clinical isolates (n = 110) from canine OE were tested, including 17 meticillin-susceptible Staphylococcus pseudintermedius (MSSP), 13 multidrug-resistant Staphylococcus pseudintermedius (MDRSP), and 20 each of β-haemolytic Streptococcus spp., Pseudomonas aeruginosa, Proteus mirabilis and Malassezia pachydermatis. Bacterial and yeast isolates were subcultured, suspended in broth and inoculated into 96-well plates. Organisms were tested against concentrations of narasin ranging from 0.03 to 128 μg/mL. Minimal inhibitory concentrations (MICs) were determined after overnight incubation. Narasin MICs for staphylococcal and streptococcal isolates ranged from 0.06 to 0.25 μg/mL; MIC50 and MIC90 values for both organisms were 0.125 μg/mL. No MICs were achieved for Pseudomonas or Proteus isolates. There was a weak antifungal effect against M. pachydermatis isolates (MIC 32 to >128 μg/mL). Narasin was effective against Gram-positive bacteria and had antifungal activity at higher concentrations against M. pachydermatis. However, the lack of Gram-negative activity would prevent its use as a sole antimicrobial agent in cases of canine OE.

COMPLETE RUMEN MODIFIER SUPPLEMENTATION IN CORN COB SILAGE BASAL DIET OF LAMB REDUCES METHANE EMISSION

<p>Feeding animal with fibrous materials such as corn cob will emit methane. Complete rumen modifier (CRM) is an improved feed additive comprised a mixture of Sapindus rarak, sesbania, albizia leaves and minerals that functions as a methane inhibitor. The study aimed to determine the effect of CRM supplementation on the feed intake, nutrient digestibility, rumen fermentation, methane emission and growth of lambs. The experiment was designed in a complete randomized block, four levels of CRM (0%, 1%, 2%, and 3%), six group of 24 male lambs per treatment based on the body weight. Basal diet used was corn cob silage ad libitum and concentrate (500 g/day) as a supplement. The results showed that CRM supplementation did not affect feed consumption and average daily gain, but significantly decreased the dry matter, as well as organic matter and protein digestibility. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibility linearly decreased with increasing level of CRM. Ruminal pH, ammonia concentration and volatile fatty acid (VFA) concentration were not affected by the CRM supplementation. Methane production expressed in kJ/MJ gross energy (GE) or digestible energy (DE) intake significantly decreased by 32% at the 2–3% CRM supplementation and reduced by 39% when methane production was expressed in g/kg digested NDF. It can be concluded that 2% CRM supplementation in the corn cob basal diet did not affect nutrient intake and growth rate of the lamb, as well as rumen fermentation. The study suggests that CRM is an environmentally friendly feed additive for lamb</p>

Comparison of feed additive technologies for preconditioning of weaned beef calves.

Our objective was to evaluate the response of weaned calves to different supplemental feed additives in a supplement to affect calf performance and mitigate stress response observed during weaning and preconditioning. At weaning in each of 2 yr, 160 Angus and Brangus calves (203 and 227 ± 2.3 and 2.5 kg) were stratified by BW, sex, and breed and were randomly allotted to 1 of 4 treatments ( = 40 calves/treatment): 1) supplement without feed additives (control, CON), 2) supplemented with chlortetracycline, 350 mg/d (CTC), 3) supplemented with monensin, 175 mg/d (RUM), and 4) supplemented with rumen modifier, 5 g/d (ACT). Calves were held by treatment in 1 of 4 drylot pens for 7 d after weaning and were offered ad libitum access to hay and 2.27 kg/d of supplement before placement in one of thirty-two 0.8-ha pastures (5 calves/pasture). On pasture calves were supplemented with 2.27 kg/d (yr 1) or supplemented at 1.0% BW (yr 2). Calf BW and blood samples were collected following weaning (d 0, 1, 4, 7, 11 in yr 1; d 0, 1, 3, 7, 14 in yr 2), at the conclusion of the preconditioning period (d 50, 51 in yr 2), and after transportation (d 52, 55, 59, 65 in yr 2) for analysis of acute phase protein (APP) concentrations. In yr 2, after 44 d on pasture, calves were loaded on 2 semitrucks and transported for 24 h. On return, calves were placed in 4 pastures with hay and fed their respective supplements for 14 d. For each year, data were analyzed with the MIXED procedure of SAS. The model included the main effect of treatment, and pasture was the experimental unit. All variables quantified by day were analyzed using repeated measures. In yr 1, ACT and CTC had greater (P <0.05) 52-d ADG than RUM, whereas CON was intermediate. However, in yr 2, over the 50-d postweaning period there was no difference (P = 0.20; 0.52 kg/d) in ADG response among treatments. After transportation, 7- and 14-d ADG were improved (P < 0.05) for ACT and CTC compared with CON and RUM. In both years, postweaning plasma concentrations of haptoglobin were similar (P > 0.05) among treatments; however an effect of day after transport (P < 0.001) was observed. Feed cost of gain and income over production cost (P ≥ 0.15; mean = $0.51/kg and $73.51, respectively) were not different among treatments. Use of supplemental additives may improve calf performance during a preconditioning period of this duration, but no additive was effective at mitigating stress postweaning. Additives were equally effective in supporting calf growth performance during a posttransportation period.

Gross Pathology, Biochemistry and Histopathology of Selected Organs of Camels Suffering from Suspected Monensin Toxicosis in Australia

The rumen modifier monensin is widely used in Australia cattle production systems. In addition to its anti-coccidial action monensin improves energy efficiency and nitrogen metabolism in rumen bacteria, and reduces the incidence of metabolic disorders such as acidosis and bloat. While monensin is considered safe for cattle, swine and poultry, it is extremely toxic to horses and incidents of toxicity have also been reported in camels. In this study, we are reporting for the first time monensin toxicosis in a camel herd in South-West Queensland, Australia (~267 km west of Brisbane). The camels were fed a cattle breeder supplements containing 250 mg/kg monensin, formulated to ensure effective concentrations if the supplement is consumed by breeder cattle at levels of 200-500 g/head/d. Blood samples were collected from 13 camels with clinical signs of monensin toxicosis and 12 healthy camels that had no exposure to monensin. Post-mortem examinations were carried out on two camels immediately after death, these animals had marked ascites. Monensin toxicoses resulted in marked decreases in albumin and increases in ALP, LDH and CPK when compared to physiologically normal healthy camels. Other parameters in the blood profile remain within normal limits. Minor to no histopathological changes were observed in the two necropsied camels however death due to rapidly developing congestive heart failure is suspected. Skeletal muscle was not examined histologically. However, the biochemical changes could be consistent with muscle necrosis.

Thyme and cinnamon essential oils: Potential alternatives for monensin as a rumen modifier in beef production systems

Four ruminally cannulated Holstein steers (540±35kg initial body weight) were used in a 4×4 Latin square design over 21-day periods to examine effects of supplementing a basal diet (CON) with thyme oil (THY, 500mg/kg DM) or cinnamon oil (CIN, 500mg/kg DM) on nutrient digestibility, ruminal fermentation characteristics and rumen microbial populations. Monensin (MON, 33mg/kg DM) was used as positive control. Steers were fed a basal diet as total mixed ration (TMR) ad libitum. The results indicated that dry matter intake (DMI) and apparent digestibility of nutrients were not affected by additives. Dietary supplementations did not affect ruminal pH and ammonia nitrogen concentration. Total volatile fatty acid (VFA) concentrations and proportions of acetate and butyrate were not affected by essential oils (EO), but there was a trend (P<0.10) for a reduced concentration of total VFA and proportion of butyrate with MON supplementation compared to CON. Propionate proportion increased (P<0.05) with THY and MON supplementation and the ratio of acetate to propionate decreased (P<0.05) with EO and MON. The relative abundances of protozoa and methanogens decreased (P<0.01) in the rumen of steers when supplemented with additives. Ruminal population of Ruminococcus flavefaciens was not affected by treatments, but populations of Fibrobacter succinogenes and Ruminococcus albus decreased (P<0.05) by supplementation of EO or MON, respectively. Results from this study suggest that THY or CIN can be considered as potential alternatives to MON and might be useful as rumen fermentation modifiers in beef production systems.

Effects of essential oils supplementation on in vitro and in situ feed digestion in beef cattle

The objective of this study was to investigate the effect of lemongrass oil (LMO) and a mixture of garlic and ginger oil (CEO) on gas production (GP) and feed digestibility using the batch culture and in situ ruminal technique. Four feeds: wheat distillers dried grains with solubles (DDGS), barley grain, grass hay, and a total mixed ration (TMR) were tested with varying essential oil (EO) dosages. The TMR consisted of 350g/kg grass hay, 150g/kg alfalfa hay, 200g/kg barley grain, 100g/kg corn DDGS, 100g/kg wheat DDGS, 50g/kg canola meal, and 50g/kg vitamin and mineral supplement. The in vitro study was a complete randomized design with 2×4 factorial arrangement of two EO (LMO and CEO) combined with four dosages of EO (i.e., 0, 100, 200, and 300mg/kg substrate DM). Digestibilities of DM (DMD) and neutral detergent fibre (NDFD) were measured at 24h and 48h post incubation, while GP was read at 3, 6, 12, 24, 36, and 48h post incubation. In situ ruminal degradability was measured using three ruminally fistulated beef heifers with incubation time of 4, 12, 24 or 48h. There was no interaction on in vitro DMD and NDFD between EO source and its dose. The DMD and NDFD were greater with CEO compared to LMO for wheat DDGS (P<0.01; 48h) and barley grain (P<0.01; 24h), but lower for TMR (P<0.05; 24 or 48h). Increasing the dosage of EO linearly (P<0.01) increased the DMD of wheat DDGS and barley grain at 24h post incubation, and linearly (P<0.01) and quadratically (P<0.05) improved in vitro DMD and NDFD of grass hay and TMR with addition of LMO and CEO at 24 or 48h post incubation. The cumulative GP was overall affected (P<0.01) by both LMO and CEO in quadratic manner after 24, 36 or 48h of incubation. In situ ruminal DMD of wheat DDGS and barley grain were higher (P<0.05) at 4 or 24h of incubation with CEO than with control or LMO which had no differences in DMD. However, the in situ DMD of grass hay and TMR were improved by both LMO and CEO supplementation after 24h (P<0.01) or 48h (P<0.05) post incubation. The dose of 200mg/kg DM was likely cost-effective to improve DMD for both LMO and CEO. The LMO and CEO appeared to be more effective to improve the DMD of fibrous feeds since the in vitro DMD and NDFD of grass hay and TMR were consistently improved at 24h or 48h post incubation. These results suggested that the LMO and CEO used in the present study could be potentially developed as rumen modifier to improve feed digestibility in the rumen.

Effects of Essential Oils on In Vitro Methanogenesis and Feed Fermentation with Buffalo Rumen Liquor

Seven essential oils (EOs): garlic (Allium sativum), clove (Syzygium aromaticum), lemongrass (Cymbopogon citratus), wild turmeric (Curcuma aromatica), turmeric (Curcuma longa) and cinnamon (Cinnamomum zeylanicum) were evaluated as rumen modifier to mitigate methane emission. The lowest level of EOs tested in this experiment (167 μl l−1 of incubation medium) was the most appropriate level of inclusion as higher doses were detrimental for feed digestibility and fermentation. At this level, methane inhibition was maximum (38.5 %) with garlic oil (GO) followed by cinnamon bark oil (CiBO; 34.9 %), wild turmeric oil (15.5 %), clove bud oil (CBO; 12.9 %), clove leaf oil (8.0 %), lemongrass oil (7.3 %) and turmeric oil (no effect). Feed digestibility was significantly hampered by CBO and CiBO. The response of GO was different from that of other oils as inclusion of GO at 167 μl l−1 of incubation medium resulted in 38.5 % decrease in methane production, significant increase in total volatile fatty acids and propionate production, a decrease in acetate to propionate ratio and had no effect on feed digestibility. All the oils suppressed ammonia production. Partitioning factor, which indicates efficiency of microbial biomass production, was also increased by inclusion of all the seven oils. The CiBO was detrimental for feed fermentation even at the lowest dose of 167 μl l−1 of incubation medium. The data indicated that GO was the most promising feed additive which caused maximum methane inhibition and had the minimum adverse effect on feed digestibility.

Effects of nordihydroguaiaretic acid on in vitro fermentation profiles of rumen bacteria1

Nordihydroguaiaretic acid (NDGA) is a secondary plant metabolite with antimicrobial properties, and therefore may have potential as a rumen modifier. Two in vitro experiments were conducted to determine the usefulness of NDGA as a rumen modifier. Exp. 1 evaluated the effect of adding 0, 5, 10, 50, and 100 mg/mL NDGA on growth of pure and mixed cultures of rumen bacteria. Growth of all cultures except Butyrivibrio fibrisolvens H17c was inhibited at 50 mg/mL NDGA (P < 0.05). Cultures from whole rumen fluid and B. fibrisolvens H17c were inhibited with 100 mg/mL NDGA (P < 0.05). Exp. 2 evaluated additions of NDGA on IVDMD (48 h) and VFA production. Three dietary substrates simulating different resources available for livestock production and 5 concentrations of NDGA were compared with monensin (47.5 μg/mL, MON, Elanco Animal Health, Indianapolis, IN). Substrates included (DM basis) 100% meadow hay (H100), 50% alfalfa with 50% ground corn (H50), and 90% ground corn with 10% alfalfa (H10). Treatments were 0 (Control; CON), 20, 40, 60, 80 μg/mL NDGA and MON. Treatment means were compared using 2 single degree of freedom contrasts (0 μg/mL NDGA vs. MON and NDGA vs. MON) and orthogonal polynomial contrasts within NDGA concentrations. Monensin fermented with H100 had the least (P < 0.01) IVDMD. A linear increase in IVDMD was observed for H50 (P < 0.01) but not H10 or 100 (P > 0.40). Acetate was quadratic for all substrates tested with NDGA (P < 0.01) and adding NDGA vs. MON resulted in 9% greater values (P < 0.01). Propionate increased by addition of MON compared with CON, which was opposite for acetate. Propionate showed the greatest increase with addition of MON and was dependent on diet vs. CON (H100 vs.H50 vs. H10; 22.5%, 44.4%, and 30.2%, respectively). When H100 was used, total VFA declined linearly by 61% with increasing NDGA (P < 0.01), whereas H50 and H10 were quadratic (P < 0.01) with the greatest total VFA resulting from 40 and 80 mg/mL NDGA for H50 and H10, respectively. Addition of NDGA tended to decrease total VFA (P =0.06) for H100 and H10 by 18.5% and 9.0%, respectively; however, H50 did not differ (P = 0.82) compared with MON. Butyrate increased linearly with increasing NDGA for H10 (P < 0.03) and quadratic for H50 and H100 (P < 0.01). The lowest overall acetate:propionate ratio was obtained with addition of MON to H10 (1.35) and the greatest ratio resulted from adding 60 μg/mL NDGA to H100 (3.63). Rumen fermentation was responsive to NDGA, and the response is dependent on diet.

Garlic as a rumen modifier for eco-friendly and economic livestock production

Allium sativum (garlic) has been very popular in Asian kitchen as one of the major spices. The strong smelling juice of bulb contains volatile oils composed of sulphur-containing compounds: allicin, diallyl disulfide and diallyl trisulfide, which are responsible for anti-microbial activity. Recently garlic, its oil, extracts in different organic and aqueous solvents and individual components of essential oils have been examined as a feed additive to manipulate rumen function for controlling enteric methane emission and improving feed conversion efficiency. The results reported so far indicate that garlic and its essential oils inhibit methanogenesis significantly accompanied with a lower acetate to propionate ratio indicating a diversion of fermentation in a favourable direction. As methanogenesis is the major hydrogen sink in the rumen, its inhibition requires the disposal of reducing equivalents produced during fermentation of feed. The propionate synthesis serves as an alternate hydrogen sink. The anti-microbial compounds present in garlic appear to be selective inhibitors of methanogenesis, as there is no adverse effect on feed degradation in the rumen. Garlic and its oil adversely affect the protein degrading bacteria and deamination activity of the rumen contents. Only a few in vivo experiments have been conducted using garlic as a feed additive, and it appears to have good potential for rumen manipulation for eco-friendly (with minimum methane emission) and economic livestock production.

Garlic: A potential alternative for monensin as a rumen modifier

The effects of supplementing a basal diet (CTR) with raw garlic (GAR) or garlic oil (GO) on rumen fermentation were evaluated. Monensin (MON, 33mg/kg DM) was used as positive control. Four ruminally fistulated sheep were used in three experiments arranged as 4×4 Latin squares with a 28-day period. Experiments 1 and 2 differed in the dose of GAR (75 versus 100g/kg DM) and GO (500 versus 750mg/kg DM) included in the basal diet while experiment 3 was designed to compare the two doses of each additive. The results revealed that dry matter intake and rumen fluid pH were not affected by additives although organic matter (OM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibility were slightly depressed by GO but not by GAR supplementation. MON had a similar depressing effect but was restricted mainly to ADF digestibility. Ruminal protozoa population was reduced by MON supplementation and to lesser extent by GAR100 and GO in a dose-independent manner. This effect was reflected in a lower rumen ammonia concentration. Total volatile fatty acid concentrations were not affected by any of the additives. However, individual VFAs were significantly altered by MON and to lesser extent by GAR and GO (P<0.05), enhancing the concentration of propionate and the propionate to acetate ratio (P<0.05). Although the capability of GAR and GO is lower than MON in decreasing the acetate to propionate ratio, they can be considered as potential alternatives to MON.

THE UTILIZATION OF THE COMPLETE RUMEN MODIFIER ON DAIRY COWS

An experiment on the use of Complete Rumen Modifier (CRM) to improve dairy cowproductivity and to mitigate enteric methane production has been conducted. Sixteen lactating dairycows were distributed into 4 groups by using compelete randomized design (CRD). Group I (Control)fed by basal diet consisted of elephant grass and concentrate 7.5 kg/hd/dy (CP 16% and TDN 70%),Group II (Pro. Woodii) fed by basal diet + probiotic Woodii, Group III (Pro.Noterae) fed by basal diet +probiotic Noterae; Group IV (CRM-Noterae) fed by basal diet + CRM + Pro.Noterae. Measurementswere conducted on body weight gain, average daily gain, feed conversion ratio, milk and methaneproduction. Results showed that CRM-Noterae increased ADG by 72% (1.29 vs 0.75 kg) and improvedFCR (9.2 vs 15.6). Probiotic noterae as single treatment or combined with CRM increased fat and totalsolid content of milk from 3.18% and 10.58% in control group to become 3.91%; 11.31% and 3.55%;11.02%, respectively. The lowest methane production was recorded in Group IV. The combination ofCRM and Noterae reduced percentage of methane production by 14%. It is concluded that combinationof CRM and Noterae can improve dairy cow performance and decrease methane production. ProbioticNoterae improved milk quality.

Effect of complete rumen modifier (CRM) and Calliandra calothyrus on productivity and enteric methane productions of PE dairy goat.

Methanogenesis in the rumen is thought to represent 2-12% loss of energy intake. The energy loss as methane can decrease animal productivity and feed efficiency. In addition, methane is potentially involves in global warming that affects the atmosphere adversely. A research to improve PE dairy goat productivity and reduce enteric methane emission by supplementation of calliandra and complete rumen modifier (CRM) was conducted for 6 months. In this experiment 20 PE dairy goats were divided into five blocks according to body weight. The experimental design used was a randomized block design that consisted of four treatments, A). Elephant grass 50% + concentrate 50% (control), B). Elephant grass 40% + concentrate 40% + calliandra 20%, C). Elephant grass 50% + concentrate 48% + CRM 2% and D). Elephant grass 40% + concentrate 38% + calliandra 20% + CRM 2%. Data were analyzed statistically using ANOVA and Duncan test. The result showed that calliandra and CRM did not affect nutrient consumption, except that protein consumption increased (P < 0.05) in calliandra treatments (B and D). Nutrient digestibility increased in CRM (C) treatment, while other treatments did not differ from control. CRM also increased total bacteria (36.84%), milk production (67.21%), milk fat (25.0%), and reduced enteric methane production (65.71%). The improvement of milk production in CRM treatment (C) was followed by better feed efficiency than other treatments. In conclusion, CRM was more effective than calliandra in improving milk production of PE dairy goats and reduced enteric methane emission, but its effectivity was reduced in combination with calliandra. Key Words : Dairy Goat, Calliandra, Rumen Modifier, Methane, Productivity

Dose response to eugenol supplementation in growing beef cattle: Ruminal fermentation and intestinal digestion

Eugenol (EUG; 4-allyl-2-methoxyphenol; C 10H 12O 2) is a phenolic compound with wide-spectrum antimicrobial activity against gram-positive and gram-negative bacteria. This study was conducted to determine whether EUG could be used as a rumen modifier in growing beef heifers fed high concentrate diets. The experiment was designed as a 4 × 4 Latin square using four ruminally and duodenally cannulated beef heifers with four treatments being: control (no EUG added); 400 mg/d EUG (low); 800 mg/d EUG (medium); and 1600 mg/d EUG (high), and four 21 d periods. The diets consisted of 150 g/kg barley silage, 800 g/kg dry-rolled barley grain, and 50 g/kg supplement (dry matter [DM] basis). Feed intake, rumen pH and fermentation characteristics, site and extent of digestion, microbial crude protein (CP) synthesis, blood metabolites and acute phase protein status were measured. Intake of DM averaged 9.6 kg/d and was not affected by EUG supplementation. Degradabilities of organic matter (OM) and starch in the rumen and the digestibilities in the total digestive tract were not affected. However, ruminal degradability of neutral detergent fibre linearly decreased and ruminal degradability of CP tended ( P=0.09) to linearly decrease with increasing dose of EUG. Flows (g/d) of microbial N to the duodenum tended ( P=0.08) to quadratically increase with EUG supplementation even though the amount of ruminal fermented OM did not differ. Rumen pH, concentration of total volatile fatty acids (VFA), and protozoa counts were not affected, whereas concentration of acetate linearly declined, and the molar proportion of propionate ( P=0.09), and ratio of acetate to propionate, tended ( P<0.10) to linearly decrease with increasing EUG supplementation. Plasma concentrations of non-esterified fatty acids, triglyceride, glucose and urea N were not changed by feeding EUG. Acute phase proteins including serum amyloid A and lipopolysaccharide in plasma were not affected by EUG, although plasma haptoglobin tended ( P<0.07) to linearly decrease with increasing EUG. Results indicate that supplementation of a high concentrate diet with EUG tended to provide more protein by tending to increase microbial CP production and lowering CP degradation in the rumen. Positive changes in ruminal N dynamics ( i.e., more rumen undegraded CP flowing to the small intestine) and VFA pattern of fermentation ( i.e., lower acetate to propionate ratio) were small, but may be enough to improve the growth rate of cattle. Overall, results indicate that EUG may have limited potential to improve the growth rate of cattle fed high concentrate diets.

Utilization of complete rumen modifier on sheep fed high fibrous forages.

A research to improve livestock productivity and lower enteric methane production on ruminant was conducted by manipulation approach on rumen system using a complete rumen modifier ( CRM ). An in vivo experiment was carried out using twenty four sheep ( mean weight 18 kg) which were distributed into 3 treatment groups of feed additive: I. control ( without treatment: K); II: K + CRM -LG; III: K + CRM -EL. Diet given consisted of fermented rice straw ( ad libitum ) + concentrate containing 16 % protein (400 g/head/day), and drinking water was given ad libitum . The experiment was conducted for 14 weeks based on completely randomized design. By the end of the experiment, animals were placed in the metabolism cages for 2 weeks (ie. 1 week for adaptation and 1 week for data collection). Rumen liquid of each treated animal was taken for the measurement of rumen characteristics. Parameter measuremed were: total gas production; gas composition of CO 2 and CH 4 ; in vitro DMD; NH 3 and VFA contents; pH; bacterial and protozoal counts; consumption/ DMI; in vivo DMD; ADG and FCR. The results showed that productivity of sheep was improved by CRM treatments followed by lowered enteric methane production. The ADG values of CRM treatments (71.4 to 73.5 g) were significantly higher (P < 0.05) than that of control (50 g). The improvement of average daily gain was followed by a better feed conversion (P < 0.05) (ie. 10.6 vs. 12.8). The CRM treatments lowered the percentage of CH 4 by 24% compared to Control (P < 0.05). The total and composition of VFA of CRM -treated rumen liquor were significantly different (P<0.05) compared to that of rumen liquor of Control (ie. the total VFA: 85.3 vs 73.5 mM and the percentage of acetic acid: 67.8 vs 60.3%). It is concluded that CRM treatment resulted in positive effects on growth of ruminant fed high fibrous forages such as rice straw and could lower enteric methane production. Key Words : Rumen Modifier, Productivity, Enteric Methane, Sheep, Rice Straw

Effect of peppermint ( Mentha piperita) oil on in vitro methanogenesis and fermentation of feed with buffalo rumen liquor

The effect of inclusion of peppermint ( Mentha piperita) oil (at 0, 0.33, 1.0 and 2.0 μl/ml of incubation medium) on gas and methane production, fermentation of feed and microbial profile was studied in in vitro gas production test, using 200 mg of wheat straw and concentrate mixture in equal proportion as substrate in a 100 ml graduated syringe. The buffalo rumen liquor was used as inoculum and the observations were recorded at 24 h of incubation. Methane emission was reduced (P<0.001) by 19.9%, 46.0% and 75.6% at 0.33, 1.0 and 2.0 μl levels, respectively. The concentration (mM/100 ml) of total volatile fatty acids was reduced (P<0.01) by inclusion of peppermint oil at higher levels (1.0 and 2.0 μl) whereas at 0.33 μl level there was no effect. The proportion of acetate increased (P<0.05) and that of propionate decreased (P<0.001) at 1.0 and 2.0 μl levels of peppermint oil. There was a fall (P<0.001) in carboxymethylcellulase and xylanase activities and the inhibition increased with the increasing level of peppermint oil which resulted in a dose dependent decrease (P<0.05) in in vitro true digestibility of feed. At 0.33 μl level of peppermint oil, the population density of total bacteria was similar to that of control but fungi, Ruminococcus flavefaciens and methanogens increased by 4-, 6- and 2-folds, respectively, as determined with real-time PCR. At 1.0 and 2.0 μl levels the population density of total bacteria, fungi, Fibrobacter succinogens and methanogens decreased drastically and fell below the control values. The numbers of holotrichs and spirotrichs were reduced (P<0.001) by increasing dose of peppermint oil. The higher doses of peppermint oil were toxic for the rumen microbes but the lower levels could be further explored in in vivo experiments as rumen modifier to reduce methanogenesis.