Insights into Metatranscriptome, and CAZymes of Buffalo Rumen Supplemented with Blend of Essential Oils.

The aim of this study was to investigate the rumen microbial diversity and functionality in buffaloes fed with a blend of essential oils (BEO) using LSD switch over design. The BEO consisting of blend of Trachyspermum copticum (Ajwain) oil, Cymbopogon citratus (lemon grass) oil and Syzygium aromaticum (clove bud) oleoresin mixed in equal proportion, was fed at the rate of 0, 0.75 and 1.5 ml/100 kg of body weight in 0 (control), 0.75 and 1.5 groups, respectively. The metatranscriptomic libraries of the rumen microbiome were represented by 7 domains, 84 phyla, 64 archeal genera and 663 bacterial genera with Bacteroidetes and Firmicutes constituting 80% of phyla abundance irrespective of feeding regime. Methanogenic archaea was represented by 22 phyla with Methanobrevibacter as the major genus. BEO feeding reduced the abundance of Methanococcus and Thermoplasma (P < 0.05) at all levels. The results revealed that the feeding of BEO shifted the archeal and bacterial population at very low magnitude. The study explored the vast diversity of buffalo rumen bacteria and archaea, and the diverse wealth of rumen enzymes (CAZymes), which revealed that a major part of CAZymes comes from the less known rumen microbes indicating alternative paths of fiber degradation along with the very well known ones.

Effect of feeding of blend of essential oils on methane production, growth, and nutrient utilization in growing buffaloes.

OBJECTIVE: An experiment was conducted to study the effect of a blend of essential oils (BEO) on enteric methane emission and growth performance of buffaloes (Bubalus bubalis). METHODS: Twenty one growing male buffaloes (average body weight of 279±9.3 kg) were divided in to three groups. The animals of all the three groups were fed on a ration consisting of wheat straw and concentrate mixture targeting 500 g daily live weight gain. The three dietary groups were; Group 1, control without additive; Group 2 and 3, supplemented with BEO at 0.15 and 0.30 mL/kg of dry matter intake (DMI), respectively. RESULTS: During six months feeding trial, the intake and digestibility of dry matter and nutrients (organic matter, crude protein, ether extract, neutral detergent fibre, and acid detergent fibre) were similar in all the groups. The average body weight gain was tended to improve (p = 0.084) in Group 2 and Group 3 as compared to control animals. Feeding of BEO did not affect feed conversion efficiency of the animals. The calves of all the three groups were in positive nitrogen balance with no difference in nitrogen metabolism. During respiration chamber studies the methane production (L/kg DMI and L/kg digestible dry matter intake was significantly (p<0.001) lower in Group 2 and Group 3 as compared to control animals. CONCLUSION: The results indicated that the BEO tested in the present study have shown potential to reduce enteric methane production without compromising the nutrient utilization and animal performance and could be further explored for its use as feed additive to mitigate enteric methane production in livestock.

Impact of levels of total digestible nutrients on microbiome, enzyme profile and degradation of feeds in buffalo rumen.

The present study was aimed at understanding a shift in rumen microbiome of buffaloes fed various levels of total digestible nutrients. To understand the process, the metagenomics of rumen microbes, in vivo and in vitro rumen fermentation studies were carried out. Three rumen fistulated adult male Murrah buffaloes were fed three isonitrogenous diets varying in total digestible nutrients (70, 85 and 100% of TDN requirement) in 3X3 switch over design. On dry matter basis, wheat straw/ roughage content were 81, 63 and 51% and that of maize grain was 8, 16 and 21% in three diets respectively. After 20 d of feeding, rumen liquor and rumen contents were sampled just before (0h) and 4h post feeding. Ruminococcus flavefaciens and R. albus (estimated with real time PCR) were higher in high roughage diets. The predominant phyla in all the three groups were Bacteroidetes, Firmicutes followed by Proteobacteria, Actinobacteria and Fibrobacteres. A core group of more than fifty rumen bacteria was present in all the animals with very little variations due to level of TDN. The most predominant bacterial genera reported in order of decreasing abundance were: Prevotella, Bacteroides, Clostridium, Ruminococcus, Eubacterium, Parabacteroides, Fibrobacter, Butyrivibrio etc. The higher diversity of the enyzmes families GH 23, GH 28, GH 39, GH 97, GH 106, and GH 127 (the enzymes active in fibre and starch degradation) were significantly higher on 100%TDN diet while CE 14 (required for the hydrolysis of bond between carbohydrate and lignin) was higher on low TDN (70%) diet, indicating ester bond cleavage was better in animals fed high roughage (wheat straw) diet.

Effect of feeding tannin-degrading bacteria Streptococcus gallolyticus strain TDGB 406 on meat quality of goats fed with Quercus semicarpifolia leaves.

The effect of feeding tannin-degrading bacteria (Streptococcus gallolyticus strain TDGB 406) on carcass characteristics of goats fed with oak (Quercus semicarpifolia) leaves was studied on 18 male goats (4 months old, average body weight 9.50 ± 1.50 kg), distributed into three groups of six animals each. The animals of group 1 served as control, while the animals of groups 2 and 3 were given (at 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (10(6) cells/ml), respectively. The animals were fed with oak leaves as a basal roughage source and maize hay along with fixed quantity of concentrate mixture. After 4 months of feeding, the animals were slaughtered for carcass studies. The feeding of live culture of isolate TDGB 406 did not cause any effect (P > 0.05) on pre-slaughter weight, empty body weight, carcass weight, dressing percent, and yield of wholesale cuts (neck, rack, shoulder, breast, shank, loin, leg, and flank) of the goat meat. The chemical composition of longissimus dorsi muscle was comparable (P > 0.05) among the groups. The organoleptic evaluation of pressure-cooked meat in terms of tenderness and overall palatability was increased significantly (P < 0.05) in the meat of group 3 where live culture was supplemented. The other attributes were similar among the groups. It was concluded that supplementation of tannin-degrading bacteria S. gallolyticus strain TDGB 406 to goats fed with oak leaves did not affect the carcass characteristics and meat quality.

Effect of feeding tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on nutrient utilization, urinary purine derivatives and growth performance of goats fed on Quercus semicarpifolia leaves.

To study the effect of supplementation of tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on growth performance, nutrient utilization and urinary purine derivatives of goats fed on oak (Quercus semicarpifolia) leaves. For growth study, eighteen billy goats (4 month old, average body weight 9.50 ± 1.50 kg) were distributed into three groups of six animals each. The animals of group 1 served as control while animals of groups 2 (T1) and 3 (T2) were given (@ 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (10(6) cells/ml) respectively. The animals were fed measured quantity of dry oak leaves as the main roughage source and ad libitum maize hay along with fixed quantity of concentrate mixture. The feeding of live culture of isolate TDGB 406 (probiotic) did not affect dry matter intake and digestibility of nutrients except that of dry matter and crude protein, which was higher in T2 group as compared to control. All the animals were in positive nitrogen balance. There was no significant effect of feeding isolate TDGB 406 on urinary purine derivatives (microbial protein production) in goats. The body weight gain and average live weight gain was significantly higher (p = 0.071) in T2 group as compared to control. Feed conversion efficiency was also better in the goats fed on live culture of TDGB 406 (T2). The feeding of tannin degrading bacterial isolate TDGB 406 as probiotic resulted in improved growth performance and feed conversion ratio in goats fed on oak leaves as one of the main roughage source.

Effect of Terminalia chebula and Allium sativum on in vivo methane emission by sheep.

A study was conducted to evaluate some plant parts (already tested for their antimethanogenic activity in in vitro gas production test in the authors' laboratory) as feed additive to combat methane emission from sheep. Sixteen male sheep with average body weight of 29.96±1.69 kg (22 months of age) were divided into four groups in a randomized block design. The animals were fed on a diet containing forage to concentrate ratio of 1:1. The concentrate fraction composed (in parts) of maize grain, 32; wheat bran, 45; deoiled soybean meal, 20; mineral mixture, 2 and common salt, 1. The four treatments were control (without additive), seed pulp of Terminalia chebula (Harad), bulb of Allium sativum (Garlic) and a mixture (Mix) of the latter two in equal proportions at the rate of 1% of dry matter (DM) intake. There was no effect on DM intake due to the inclusion of these feed additives. The digestibilities of DM and organic matter tended to be higher (p<0.1) in the groups with T. chebula and A. sativum, whereas, neutral detergent fibre (NDF), acid detergent fibre (ADF) and cellulose digestibilities were higher (p<0.05) in all the three experimental groups compared with control. The nitrogen balance and plane of nutrition were not affected by inclusion of any of the feed additives. Methane emission (L/kg digested DM intake) as estimated by open circuit respiration chamber and methane energy loss as per cent of digestible energy intake tended to be lower in T. chebula (p=0.09) and Mix (p=0.08) groups compared with control. The data indicated that T. chebula showed antimethanogenic activity, whereas both T. chebula and A. sativum improved nutrient digestibility. Therefore, these two plants appear to be suitable candidates for use as feed additive to mitigate methane emission and to improve nutrient utilization by sheep.

Pre- and postweaning attributes in faunated and ciliate-free calves fed calf starter with or without fish meal.

In a 2 x 2 factorial design, 24 newborn, crossbred (Bos indicus x Bos taurus) calves were distributed in 4 equal groups involving dietary treatments of prestarter diets with (FM) or without fish meal (NFM) in a faunated (F) or ciliate-free (D) ruminal environment to study the ruminal fermentative development in pre-and postweaning periods. Defaunation was achieved by rearing calves in isolation and its effect was studied after first appearance of ciliate protozoa (observed after 8 wk of age) in the faunated animals. Calves were fed colostrum for 24 h and whole milk until weaning at 8 wk of age. Ruminal content samples were collected on d 4, 1 wk, weekly to 8 wk, and then biweekly at 9, 11, and 13 wk of age. The samples were analyzed for fermentation products [pH, total volatile fatty acids (VFA) and ammonia N] and enzyme [carboxymethyl (CM) cellulase, xylanase, beta-glucosidase, alpha-amylase, beta-galactosidase, proteases, and urease] activities. Weekly feed intake increased with age, but was similar in both groups. Ruminal pH declined steadily during 0 to 4 wk of age and then stabilized. The total VFA concentration increased with the age. The ammonia N (mg/dL) concentration increased from 14.9 on d 4 to 32.4 at 4 wk, decreased to 17.6 at 8 wk, and then steadied during the postweaning period. Samples collected on d 4 had no fibrolytic activity. Xylanase (U/dL) appeared first (1 wk) followed by beta-glucosidase (U/dL) and CM cellulase (U/dL), which increased steadily from a low of 4.69, 0.08, and 2.95 to 31.8 (6 wk), 5.92 (7 wk), and 19.8 (8 wk), respectively, and the concentrations showed nonsignificant alterations during postweaning periods. The concentration of alpha-amylase (U/dL) increased from 34.3 on d 4 to 87.2 at 8 wk, and then decreased to 56.6 (13 wk). beta-Galactosidase increased up to 6 wk then decreased to trace level (0.20 U/dL) at 13 wk of age. The concentrations of proteases and urease reached a steady state after 1 wk of age. The effect of diet type on ruminal fermentation products and enzyme parameters was nonsignificant. However, a steady and proportional alteration in both parameters in response to dry feed intake with the advancement of age was seen in all calves. Defaunation increased total VFA (97.3 vs. 75.8 mM/L) and alpha-amylase activity (80.3 vs. 61.4 U/dL) and decreased ammonia N (16.4 vs. 21.1 mg/dL), whereas the effect on other parameters was nonsignificant. Ruminal fermentative changes responded to dry feed intake, but did not differ in response to animal protein in prestarter diet.

Effect of phenolic monomers on biomass and hydrolytic enzyme activities of an anaerobic fungus isolated from wild nil gai (Baselophus tragocamelus).

AIMS: To test the anaerobic fungus, Piromyces sp. FNG5, for its tolerance to phenolic monomers released in the rumen by degradation of lignocellulosic poor-quality feeds. METHODS AND RESULTS: Effects of phenolic monomers on biomass and fibrolytic enzyme activities of a pure culture of lignocellulolytic anaerobic fungus (Piromyces sp. FNG5) isolated from faeces of wild nil gai (blue bull, Baselophus tragocamelus) were evaluated. There was a reduction in fungal biomass at 1 mm concentration of catechol with complete inhibition at 10 mm. p-Coumaric acid caused a reduction in biomass at 10 mm and no growth was observed above 20 mm concentration. The fungal isolate could tolerate up to 5 mm of ferulic acid without any reduction in biomass level, and was able to grow to some extent up to the highest level of ferulic acid tested (20 mm). Vanillic acid had no effect on biomass of the fungus even up to 50 mm level. The phenolic monomers varied in their potential to inhibit the secretion of carboxymethyl cellulase, xylanase, beta-glucosidase and acetyl esterase activities with catechol being the most inhibitory and vanillic acid being the least inhibitory. After 14 days of incubation, 38.49-65.14%p-Coumaric acid, 65.22-74.10% ferulic acid and 34.13-66.78% vanillic acid disappeared from the medium under anaerobic conditions. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: It is concluded that the anaerobic fungus Piromyces sp. FNG5 is tolerant to phenolic monomers and has ability to degrade them. Therefore, such anaerobic fungi may play an important role in fibre degradation in the rumen.

Microbial status and rumen enzyme profile of crossbred calves fed on different microbial feed additives.

AIMS: To test various microbial cultures as cattle feed additives. METHODS AND RESULTS: Four groups of newly born crossbred calves (average body weight 23.5 kg) were reared on green berseem and calf starter which was devoid of cereal grains. Milk was fed up to 8 weeks of age, starting with one tenths and gradually reducing to one twentieths of the body weight. One hundred millilitres of microbial feed additive or 100 g fermented feed was fed to the animals of group 2 (curd containing lactic acid bacteria at 10(8) cfu x ml(-1)), group 3 (Saccharomyces cerevisiae NCDC-49 at 10(6) cfu x ml(-1)) and group 4 (Lactobacillus acidophilus-15 at 10(8) cfu x ml(-1)). Group 1 served as control. The incidence and duration of diarrhoea was lower in the animals of probiotic fed groups as compared to control group. Out of three microbial feed additives, yeast feeding showed maximum suppression of diarrhoea followed by Lactobacillus and curd. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: There was no effect of probiotic feeding on the log number of cells of lactic acid bacteria, yeast and coliform bacteria in the faeces and rumen liquor at any age. The activities of carboxymethylcellulase, xylanase, beta-glucosidase, alpha-glucosidase, alpha-amylase, protease, urease and pH of the rumen liquor remained unaffected by probiotic feeding at all ages tested in this experiment.

Selection of Saccharomyces cerevisiae strains for use as a microbial feed additive.

Saccharomyces cerevisiae ITCCF 2094, NCIM 3052, 1031, 1032, NCDC 42, 45, 47, 49 and 50 were screened for their tolerance to pH 2.0-7.0, various concentrations (0.00, 0.10, 0.25 0.50 and 1.0%) of a mixture of acetic, propionic and butyric acids (70:20:10), and bile salts (0.00, 0.30, 0.60 and 0.90%). Low pH (2.0-4.0) and addition of organic acids or bile salts in the medium inhibited the growth of all the strains tested, but the percentage of inhibition was variable in the different strains of yeast. Two of the strains showing maximum tolerance, 42 and 49, were further tested for in vitro dry matter degradability (IVDMD) using green berseem, wheat straw and oat hay as substrates. Saccharomyces cerevisiae 49 enhanced the IVDMD of berseem and wheat straw whereas S. cerevisiae 42 was ineffective. Based on the results of the present experiment, S. cerevisiae NCDC 49 can be considered as the best strain which might tolerate the adverse conditions in the gastrointestinal tract when used as a live microbial feed supplement in the diet of the animals.

Lactic fermentation of poultry droppings with molasses and wheat straw.

The pH of wastelage inoculated with Lactobacillus plantarum and Streptococcus faecalis was more than 5.4 and the off-flavour of poultry droppings, at 51% of dry matter, was not completely removed after 20 days' fermentation. By varying the amount of poultry droppings from 15 to 45% in the pre-mix and by including wheat straw, the pH and total volatile fatty acid production were increased, lactic acid synthesis decreased, and the off-flavour was completely abolished. Poultry droppings can be included in a pre-mix at less than 25% of total dry matter provided 10% molasses is added to give good quality wastelage.