Effect of feeding Lagerstroemia speciosa and conventional fodder based rations on nutrient utilization,ruminal metabolites and body weight gain in mithun (Bos frontalis)

The aim of the present study was to evaluate the effect of feeding green fodder, rice straw and concentrate‐based total mixed rations (TMR) on dry matter (DM) intake (DMI), nutrient utilization, rumen fermentation patterns and body weight (BW) gain (BWG) in mithun (Bos frontalis) calves. In a randomized block design, male mithun calves (n = 18, 8–10 months of age, 121 ± 2 kg BW) were randomly divided into three experimental equal groups (six animals in each group) and fed isonitrogenous TMRs ad libitum for 120 days. The TMR₁ contained 30% Napier grass and 30% rice straw, TMR₂ contained 60% rice straw and TMR₃ contained 30% tree leaves (Lagerstroemia speciosa) and 30% rice straw (DM basis). All the TMRs contained 40% concentrate mixture (DM basis). The results indicated that the BWG, DMI and feed conversion efficiency were significantly (p < 0.01) increased with the inclusion of green fodder in TMRs. The apparent digestibility of DM, crude protein, ether extract, crude fibre and nitrogen free extract were also improved significantly (p < 0.01) with the inclusion of green fodder in TMRs. The higher concentration of total nitrogen and total volatile fatty acid in rumen liquor, but low ruminal pH were evident in animals fed green fodder supplemented TMRs. An increased (p < 0.01) molar proportion of acetic acid was evident in animals fed rice straw‐based TMR. In contrast, the molar proportion of propionic and butyric acids were significantly (p < 0.01) higher in animals fed green fodder supplemented TMRs. On the basis of higher DMI and higher daily BWG, it is concluded that Napier grass and L. speciosa tree leaves may be incorporated upto 30% (DM basis) in TMR of growing mithuns for feeding in complete confinement system.     

Variations in the survival of Fasciola gigantica eggs in bovine dung stored in the sun as opposed to the shade

Eggs of F. gigantica were placed in dung heaps that were located in the shade or exposed to sun light, and examined at intervals for up to 14 weeks. The rate and extent of decline in viability of eggs was greater in dung exposed to sun light than in shaded dung. This difference was attributed the higher temperature in dung in sun light, owing to the effect of direct sunlight and to a higher rate of fermentation in exposed than in shaded dung. It was concluded that strategies for storing dung that would reduce the risk it poses for infecting L. rubiginosa with F. gigantica when used as fertilizer in rice fields include storing dung in sun light rather than in the shade, preferably in a thin layer to allow sunlight to heat and desiccate it, and mixing a carbohydrate with the stored dung to increase heat through fermentation.     

Seasonal differences in the incidence of infection with Fasciola gigantica in cambodian cattle

Farmer's cattle were treated with triclabendazole and used as tracer animals to detect new infections with Fasciola gigantica in three villages located on the bank of the Bassac River (a major tributary of the Mekong River) and in a fourth village located on farmland away from the river, from April 1999 until January 2001. The month of infection was estimated by subtracting 4 months from the date when eggs of F. gigantica were detected in faeces. Farmers were interviewed each month to record the nature of the agricultural and animal husbandry activities that occurred during the previous month, especially events that might have exposed cattle to infection with F. gigantica. Results support the conclusions that infection of cattle in riverbank villages acquired from about August or September until November originated from herbage and water in irrigation canals and dams on the riverbank, and that the progressively increasing monthly incidence from December until April (up to 87% per month in April 2000) was derived from herbage and water in recently harvested rice fields and lakes adjacent to the riverbank. The abrupt cessation of new infection in riverbank villages in May coincided with flooding of low-lying land, the movement of cattle to land above flood height on the riverbank, and a change of diet to dry-land crop residues, stored dry rice stalks, and herbage and water that were unlikely to contain metacercariae. It was concluded that snails in dams and canals on the riverbank became infected with F. gigantica after cattle were moved to the riverbank in May, and cercariae shed from these snails provided the new infections that occurred in cattle in August and September. In the village located away from the river, infection of cattle between September and March coincided with the rice harvest, supporting the conclusion that feeding of fresh rice stalks and stubble after the rice was harvested was the main source of infection. The low monthly incidence observed (up to 6.4% per month) was consistent with the hypothesis that snails did not survive in the dry rice fields between crops and that few snails would have been available from the small number of aquatic refuges that persisted through the dry season to recolonize rice fields during the wet season. Between April and August there was no opportunity for new infection because cattle were fed forage from around houses and headlands, and on dry-land crop residues and stored dry rice stalks. Control of fasciolosis was proposed using a single treatment of cattle with triclabendazole in riverbank villages in May when cattle were moved to the riverbank, and after harvest of the last rice field in villages located away from the river.     

The effect of temperature and humidity on longevity of metacercariae of Fasciola gigantica

Studies were undertaken on the viability of the metacercariae of Fasciola gigantica when stored in water at 13^˚C for periods up to 23 weeks, exposed to the sunlight for up to 8 h or stored at a range of temperatures and humidities for up to 10 weeks. Excysted metacercariae were catergorized microscopically as viable (motile and undamaged), dubious (not motile and undamaged) or dead (visible necrosis). The infectivity of viable and dubious metacercariae and unselected reference metacercariae held in water at 7^˚C for 20 days or longer was assessed by comparing numbers of flukes recovered from infected Merino sheep. Mean recovery rates were 54.6%, 7.2% and 37.2%, respectively, for viable, dubious and unselected metacercariae. Metacercariae immersed in water remained viable longer than those allowed to desiccate. Viability was promoted by decreasing temperature and increasing humidity. Exposure to direct sunlight killed metacercariae within 8 h. Results indicated that in lowland Indonesian irrigated rice paddies, metacercariae immersed in water are likely to survive for less than 5 weeks while those that become desiccated will survive less than 2 weeks. This information, together with the option of exposing fresh rice stalks to direct sunlight before feeding them to livestock, can assist farmers in reducing infection with F. gigantica.     

The prevalence and economic significance of Fasciola gigantica and Stilesia hepatica in slaughtered animals in the semi-arid coastal Kenya

Fasciola gigantica and Stilesia hepatica constrain ruminant productivity. The prevalence and economic losses caused by F. gigantica and S. hepatica in the ruminant production systems of Taveta division of Kenya were estimated in a retrospective appraisal of the slaughter records on the total number of animals slaughtered and livers condemned over the period 1989 to 2004. Only liver condemnations based on infestation by F. gigantica and S. hepatica were considered for purposes of this study. Liver condemnation rates differed significantly between bovines, caprines and ovines (p≤ 0.05) for F. gigantica (26%, 6.6% and 5.2%, respectively) and for S. hepatica (0.4%, 22% and 28%, respectively). The total loss through condemnation of both F. gigantica and S. hepatica infested livers was 4 408 272 KES (Kenyan shillings) (US$ 72 272). The proportion of loss in bovines, caprines and ovines, was 76%, 17% and 7%, respectively. Fasciolosis contributed 3 505 410 KES (79.5%) and S. hepatica infestation 903 210 KES (20.5%) to the total losses due to liver condemnations. The authors feel strongly that there is a need for more work on the two parasites using live animals to determine the prevalence in animals of various ages, species and breeds and the economics of disease control at farm level.     

谷秆两用稻稻草饲养肉牛效果研究

15N示踪结果表明 :谷秆两用稻稻草中的蛋白质能够有效地转化为鱼体蛋白和小白鼠的体蛋白 ;谷秆两用稻稻草饲养草鱼和小白鼠的饲料消化率、动物体15N回收率、动物吸收饲料蛋白的量分别比一般稻草高 13 8%、9 6%、2 4 3 2 %和16 5 %、6 0 %、47 2 % ,而动物粪便的15N回收率却比一般稻草分别低 3 2 5 %和 6 5 %。用该稻草饲养肉牛分别比用一般稻草和氨化一般稻草饲养肉牛日增重分别提高 2 8 1%和 12 2 % ,二者差异均显著 (P <0 0 5 )     

Adding sweet potato vines improve the quality of rice straw silage

Rice straw and sweet potato vines are the main by‐products of agricultural crops, and their disposal creates problems for the environment in the south of China. In order to establish an easy method for making rice straw silage successfully, experiments were conduct to evaluate fermentation quality and nutritive value of rice straw silages ensiled with or without sweet potato vine. Paddy rice straw (PR) and upland rice straw (UP) were ensiled alone or with sweet potato vines (SP) by a ratio of 1:1 (fresh matter basis), over 3 years. Compared with rice straw silages ensiled alone, the mixed‐material silages (PR + SP, UR + SP) showed higher fermentation quality with lower propionic acid content and NH₃‐N ratio of total N, and higher (P < 0.05) concentrations of lactic acid and acetic acid, resulting in decrease (P < 0.05) of dry matter loss and higher (P < 0.05) in vitro ruminal dry matter digestion. When the fermentation quality, chemical composition and in vitro rumen fermentation characteristics were considered, ensiling would be an effective way of utilization of rice straw and sweet potato vines in the regions where rice and sweet potato are harvested at same season, and the sweet potato vines have the potential to improve rice straw fermentation quality with low water soluble carbohydrate content in south of China.     

Use of bean husk as an easily digestible fiber source for activating the fibrolytic rumen bacterium Fibrobacter succinogenes and rice straw digestion

A series of in sacco and in vitro studies were carried out to evaluate bean husks for activation of fibrolytic rumen bacteria and rice straw digestion. First, lablab bean husk, chickpea husk and rice straw were suspended in the rumen of sheep to analyze the bacterial consortium developed on each fiber source. Known members of fiber‐associating bacteria were found on both lablab bean husk and rice straw, but some of these bacteria were lacking on chickpea husk. Second, a pure culture study was carried out using six strains of Fibrobacter succinogenes. Both husks stimulated the growth of all tested strains, including a strain that did not grow on rice straw. The strain OS128 that showed the highest growth on rice straw displayed even higher growth on lablab bean husk without a time lag. Finally, two‐step incubations were carried out to determine whether prior incubation of rumen fluid with husks stimulates subsequent rice straw digestion. Higher digestibility of rice straw was recorded in the second‐round incubation following the first incubation with bean husks. These results suggest that the tested bean husks improve the digestion of rice straw by activating fibrolytic F. succinogenes and other associated bacteria.     

A comparison of highveld fodders and fodder flows for growing out long yearling steers

Abstract

A fodder flow/animal experiment 40,8 ha in extent (7,5 ha irrigated), with 19 paddocks, was carried out over a two and a half year period.

The aims were: firstly, to compare fodder crops within seasons, and fodder flows over three seasons (winter‐spring‐summer), by means of pasture and animal parameters; secondly, to make economic comparisons between different fodder flows, for growing out beef steers.

The conclusions were that: Digitaria eriantha ssp. eriantha is superior to Eragrostis curvula cv. Ermelo for animal production; maize residue gives economically favourable results due to low costs and compensatory growth of cattle; an irrigated pasture providing fodder in more than one season of a flow, for example, Festuca foggage — Festuca pasture — Digitaria pasture, gives a very profitable fodder flow, because the costs of production are divided between two seasons; dryland fodder flows with the sequence maize residue — silage or hay — Digitaria or, with silage or hay replacing the maize residue, were also very profitable; and, the fodder flow giving the highest livemass gain per steer, is not necessarily the most economic. Different kinds and classes of livestock require different fodder flows.     

Effects of treating rice straw with urea or urea and calcium hydroxide upon intake, digestibility, rumen fermentation and milk yield of dairy cows

Three, multiparous Holstein crossbred dairy cows with initial body weight of 385 ± 19 kg were randomly allocated to 3 treatments of rice straw (T1 = untreated rice straw; T2 = 5.5% urea-treated rice straw (5 g urea in 100 ml water to 100 g air-dry (91% DM) straw); T3 = 2.2% urea + 2.2% calcium hydroxide treated rice straw (2.0 g urea and 2.0 g Ca(OH)₂ in 100 ml to 100 g air-dry (91% DM) straw) according to a 3 × 3 Latin square design. Each period lasted for 21 days in which feed, feces and rumen fluid were collected during the last 7 days for chemical analyses. The findings revealed significant improvements in dry matter intake and digestibility by using 5.5% urea-treated rice straw and 2.2% urea + 2.2% calcium hydroxide treated rice straw. Ruminal pH and NH₃-N were found higher (P < 0.05) as compared with urea-treated rice straw fed group, while blood urea nitrogen and milk urea nitrogen were in normal ranges. Volatile fatty acid concentrations especially those of acetic acid were decreased (P < 0.05) and those of propionic acid were increased (P < 0.05), thus acetic acid:propionic acid was subsequently lowered (P < 0.05) in cows fed with 5.5% urea-treated rice straw and 2.2% urea + 2.2% calcium hydroxide treated rice straw, respectively. Moreover, ruminal viable and cellulolytic bacterial counts were enhanced by urea and calcium hydroxide treatments. Milk protein and fat concentrations were additionally increased by respective treatments while 3.5% fat-corrected milk was highest; ranking from 2.2% urea + 2.2% calcium hydroxide treated rice straw, 5.5% urea-treated rice straw and urea-treated rice straw fed groups. Based on this study, implications could be made that using 2.2% urea + 2.2% calcium hydroxide treated rice straw for straw treatment could be an alternative treatment to 5.5% urea treatment with regards to its effectiveness and treatment cost for lactating dairy cows.     

Optimization of the procedure for counting the eggs of Fasciola gigantica in bovine faeces

This paper describes a method for counting eggs of F. gigantica in bovine faeces that optimizes the proportion of eggs recovered and the repeatability of estimates. The method uses 3 g of faeces suspended in 0.05% Tween 20. The suspension is passed through three 6 cm diameter sieves in tandem to remove fibrous debris, with respective apertures of 1 mm, 450 μm, and either 266 or 200 μm. The filtrate is allowed to sediment for 3 min in a conical flask; the sediment is recovered, then resuspended in 200 ml of 0.05% Tween 20 and allowed to sediment. After 3 min the sediment is washed in a sieve with an aperture of 53 μm, which retains the eggs. Eggs suspended in 15 ml of 1% methylene blue are counted using a dissecting microscope. Use of Tween 20 instead of water as the suspending agent for faeces gave a significant threefold increased the proportion of eggs recovered and reduced variability between repeated counts. This method is able to detect about one-third of the eggs present. It was concluded that the high proportion of F. gigantica eggs lost may be due to the presence of hydrophobic and covalent bonds on the eggs that bind them to debris, with which they are discarded.     

Feeding fodder beet (Beta vulgaris L.) with either barley straw or pasture silage to non-lactating dairy cows

AIMS: To determine the suitability of diets containing either approximately 85% fodder beet (Beta vulgaris L.) with barley straw or 65% fodder beet with pasture silage when fed to non-lactating dairy cows, by measuring intakes, digestibility, rumen function including microbial growth, and N excretion.

METHODS: Holstein-Friesian cows fitted with permanent rumen fistulae were fed either 65% fodder beet with pasture silage (Silage; n=8) or 85% fodder beet with barley (Hordeum vulgare L.) straw (Straw; n=8) in an indoor facility over a 9-day period, for measurement of intakes, digestibility, rumen function and urine production. The cows were adapted to the diets over 2 weeks before the indoor measurements. Feed was available for about 6 hours/day, as practiced commercially for wintering non-lactating cows.

RESULTS: Five cows fed the Straw diet had to be removed from the trial because of acute acidosis; four on Day 1 of the measurement period and one on Day 7. One cow allocated to the Silage diet refused to eat fodder beet bulbs and was also removed from the trial. Two cows fed the Silage diet were also treated for acidosis. DM intakes were lower with the Straw than Silage diets (6.4 (SE 0.4) vs. 8.3 (SE 0.5) kg/day) and organic matter (OM) digestibility was lower with the Straw than Silage diets (77 (SE 1) vs. 83 (SE 1) g/100g). The N content of the two diets was 1.14 and 1.75?g/100?g DM and there was a net loss of N by cows fed the Straw diet (?22.7 (SE 7) g/day). Rumen microbial N production was much lower in cows fed the Straw than the Silage diet (6.6 (SE 1.3) vs. 15.8 (SE 0.7) g microbial N/kg digestible OM intake). Concentrations of ammonia in rumen liquid collected on Days 5–6 were below detection limits (<0.1?mmol/L) in 36/48 (75%) samples collected from cows fed the Straw diet and in 27/48 (56%) cows fed the Silage diet. Mean urinary N excretion was lower in cows fed the Straw than the Silage diet (52.0 (SE 5.8) vs. 87.7 (SE 5.9) g/day).

CONCLUSION AND CLINICAL RELEVENCE: An over-wintering diet for dry cows comprising about 65% fodder beet with 35% pasture silage provided adequate nutrition, although there was some risk of acidosis. In contrast, the diet containing about 85% fodder beet with barley straw resulted in lower DM intakes, poor rumen function, negative N balance so that both nutrition and welfare were compromised.     

Using indirect ELISA to assess different antigens for the serodiagnosis of Fasciola gigantica infection in cattle, sheep and donkeys

An indirect enzyme-linked immunosorbent assay (iELISA) was evaluated for its diagnostic capability in detecting antibodies against Fasciola gigantica infection in cattle, sheep and donkeys sera using crude worm, excretory–secretory and glutathione S-transferase antigens prepared from adult liver fluke. Presence of F. gigantica worms at post-mortem examination of cattle, sheep and donkey’s livers was taken as a gold standard for the evaluation of the assay. The diagnostic sensitivity, specificity and accuracy percentages of iELISA were determined for each antigen. Excretory–secretory antigen gave the best results for the serodiagnosis of F. gigantica infection in cattle, sheep and donkeys using iELISA with diagnostic sensitivity percentages of 93.3%, 94.9% and 93.3%, respectively, while the specificity percentages were 96.7%, 97.2% and 96.3%, respectively, whereas the accuracy percentages were 95%, 96% and 95.7%, respectively. The diagnostic sensitivity percentages of iELISA using crude worm antigen were 96.7%, 100% and 93.3%, respectively, while the specificity percentages were 80%, 83.3% and 85.2%, respectively, whereas the accuracy percentages were 88.3%, 86.7% and 87%, respectively. The diagnostic sensitivity percentages of iELISA using glutathione S-transferase antigen were 66.7%, 71.8% and 60%, respectively, while the specificity percentages were 70%, 77.8% and 77.8%, respectively, whereas the accuracy percentages were 68.3%, 74.7% and 73.9%, respectively. Conclusively, excretory–secretory antigen dependent iELISA can be used as a reliable serodiagnostic test for F. gigantica infection in cattle, sheep and donkeys.     

Investigation into the durability of washed rice straw for equine bedding and the repetitive use of washing water

The present experiment investigated durability during the repetitive use of washed rice straw, as bedding material, and washing water as a model study. Residual nitrogen levels, elasticity, and water suction rates for washed rice straw‐adhered urea were measured. In addition, outflow levels of nitrogen and mineral ions (Na⁺, NO₂^‐ + NO₃^‐, SO₄^2?, PO₄^3?, Cl^‐) for washing water were measured to determine durability. Nitrogen levels of rice straw significantly (P < 0.05) decreased after two washings. There was no significant change in elasticity of repetitively used rice straw. Suction rates of rice straw after the second and third washings increased significantly (P < 0.05) compared to the first time. With regard to the number of washings, the mineral ion outflow level in the washing water for nitrogen, Na⁺, NO₂^‐ + NO₃^‐ and PO₄^3? after each washing was not significant. However, nitrogen outflow level tended to decrease after the third washing. SO₄^‐ and Cl^‐ did significantly decrease (P < 0.05) with the number of washings. In this study, it was considered that rice straw and washing water could be used repetitively three times. Furthermore, in order to maintain effluent standards, washing water from the first washing needs to be processed in a septic tank.     

Nutrient digestibility and ruminal fermentation characteristic in swamp buffaloes fed on chemically treated rice straw and urea

The experiment was conducted to determine effects of urea–lime-treated rice straw and urea levels in concentrate on rumen fermentation, apparent nutrient digestibility, and cellulolytic bacteria population of 4-year-old, rumen-fistulated swamp buffaloes. All animals were randomly assigned according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design to receive four dietary treatments: factor A, two sources of roughage (rice straw and 2%urea + 2%lime-treated rice straw); factor B, two levels of urea in concentrate mixture (0% and 4%). Roughages were given ad libitum together with 0.3% BW of concentrate. It was found that voluntary feed intake, the digestibility of DM, OM, CP, NDF, acetate, and propionate concentration were significantly increased (P < 0.05) by treated rice straw, while NH₃-N, BUN, and propionic acid concentration were increased by both factors of treated rice straw and 4% urea in concentrate. The real-time PCR quantification of Fibrobacter succinogenes and Ruminococcus albus population, and anaerobic fungi were greater (P < 0.05), but the population of Ruminococcus flavefaciens, protozoa, and methanogenic bacteria were reduced (P > 0.05) as influenced by treated rice straw and urea level. In conclusion, the combined use of urea–lime-treated rice straw and fed with concentrate (4% urea) could improve rumen ecology, rumen fermentation efficiency, and nutrient digestibility in swamp buffaloes.     

Effects of adding urea on fermentation quality of pruned persimmon branch silage and its digestibility,preference, nitrogen balance and rumen fermentation in beef cattle

Four cattle were used in a 4 × 4 Latin square design experiment to study digestibility, ruminal fermentation, nitrogen retention and preference of ensiling pruned persimmon branch (PPB) chips treated with urea. After 60 days of ensiling, urea‐treated PPB showed higher (P < 0.05) pH, acetic acid and ammonia‐N levels than no‐urea PPB. Both urea‐treated PPB and rice straw diets showed higher (P < 0.05) apparent digestibility and digestible nutrient content in cattle than no‐urea PPB diet. Neither mold nor yeast was detected in any urea‐treated PPB. Urinary and fecal excretion as well as nitrogen retention in cattle fed urea‐treated PPB were higher (P < 0.05) than in those fed no‐urea PPB and rice straw. With the exception that ruminal ammonia‐N levels in cattle fed urea‐treated PPB were higher (P < 0.05) than in those given no‐urea PPB and rice straw, ruminal pH, volatile fatty acid concentrations, and the acetic : propionic acid ratio of rumen content were unaffected by diets. The rank order of preference was rice straw > low‐urea > no‐urea > high‐urea. The results suggested that urea treatment of PPB inhibited growth of mold and yeast during silage storage, enhanced its digestibility and had nutritive value almost equivalent to that of rice straw.     

Effect of Supplementation with Leguminous Crop Residues or Concentrates on the Voluntary Intake and Performance of Kirdi Sheep

Twenty young Kirdi (West African Dwarf) rams, averaging 22 kg live weight and 15 months of age, were randomly assigned to four feeding groups of 5 animals each. The groups were subjected to an 8-week feeding trial to determine the effect of different protein supplements on their voluntary intake of rice straw and on their performance. The animals in one of the groups were maintained on a daily basal diet of rice straw given ad libitum and 250 g of rice bran per animal (control). Other groups were fed the basal diet, supplemented with 300 g of groundnut haulms (GH diet), 45 g of cotton seed cake (CSC diet) or 210 g of chopped cowpea vines (CPV diet) per animal per day. The average daily weight gains of the animals feeding on the control, GH, CSC and CPV diets were 20.00, 48.93, 52.14 and 49.29 g, respectively. The gains in live weight of the supplemented groups did not differ significantly (p>0.05), but there was a difference (p<0.05) in live weight gain between the supplemented groups and the control. The differences in intake of rice straw among the groups were highly significant (p<0.01). Cotton seed cake increased (p<0.01) the intake, while feeding crop residues tended to depress the intake of rice straw. Variations in the height at withers, heart girth and scapulo-ischial length did not differ significantly (p>0.05) among the groups. In terms of live weight gain and intake of rice straw, cotton seed cake was the most effective supplement, but, since the crop residues are more readily available to farmers in this area of the country, they merit more attention.     

Improving the quality of rice straw by urea and calcium hydroxide on rumen ecology,microbial protein synthesis in beef cattle

Four rumen‐fistulated beef cattle were randomly assigned to four treatments according to a 4 × 4 Latin square design to study the influence of urea and calcium hydroxide [Ca(OH)₂] treatment of rice straw to improve the nutritive value of rice straw. Four dietary treatments were as follows: untreated rice straw, 50 g/kg urea‐treated rice straw, 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw and 30 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw. All animals were kept in individual pens and fed with concentrate at 0.5 g/kg of BW (DM), rice straw was fed ad libitum. The experiment was conducted for four periods, and each period lasted for 21 days. During the first 14 days, DM feed intake measurements were made while during the last 7 days, all cattle were moved to metabolism crates for total faeces and urine collections. The results revealed that 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw improved the nutritive value of rice straw, in terms of dry matter intake, digestibility, ruminal volatile fatty acids, population of bacteria and fungi, nitrogen retention and microbial protein synthesis. Based on this study, it could be concluded that using urea plus calcium hydroxide was one alternative method to improve the nutritive value of rice straw, rumen ecology and fermentation and thus a reduction of treatment cost.     

Interaction of rumen bacteria as assumed by colonization patterns on untreated and alkali‐treated rice straw

Colonization patterns of representative rumen bacteria were compared between untreated rice straw (UTS) and sodium hydroxide‐treated rice straw (SHTS). UTS and SHTS were incubated in the rumen of sheep for 10 min, 1, 2, 6, 12, 24, 48 and 96 h using the nylon bag method. The population sizes of 13 representative bacterial species or groups were quantified by real‐time PCR. The total bacterial population size (abundance) was similar in both UTS and SHTS. Fibrobacter succinogenes showed a higher population size compared to other fibrolytic species and was detected at a higher level in SHTS (3.7%) than in UTS (2.6%). Ruminococcus albus and Ruminococcus flavefaciens were also detected at higher levels in SHTS (0.15% and 0.29%) than in UTS (0.03% and 0.18%). Population sizes of non‐fibrolytic species, such as Selenomonas ruminantium, Anaerovibrio lipolytica and Succinivibrio dextrinosolvens were higher in UTS than in SHTS. Coefficient of determination (r²) on population changes between bacterial species or groups were higher in UTS than in SHTS, suggesting the necessity of stronger bacterial interactions for UTS digestion. Therefore, not only colonization of fibrolytic species, but also synergistic interactions between different bacterial species may be key to the ruminal digestion of rice straw.     

Bean husks as a supplemental fiber for ruminants: Potential use for activation of fibrolytic rumen bacteria to improve main forage digestion

This study evaluated the suitability of easily digested fiber sources as a supplemental fiber to improve overall fiber digestion in ruminants. First, the degradation of five fibrous feedstuffs and the stimulatory effects on rumen bacteria were examined in situ. Chickpea and lablab bean husks were selected for their potential use due to their large degradable fraction (> 94%), which had a stimulatory effect on fibrolytic rumen bacteria such as Fibrobacter succinogenes. Second, a possible improvement in the digestibility of rice straw diet by husk supplementation was monitored in vivo. Four dietary treatments comprising RS (rice straw and concentrate), CHM (RS supplemented with Myanmar chickpea husk), CHE (RS with Egyptian chickpea husk) and LH (RS with lablab bean husk) were allocated to four wethers. The digestibility of acid detergent fiber was 3.1–5.5% greater in CHM and LH than RS. Total volatile fatty acid concentration was higher in LH than other treatments. Acetate proportion was higher in LH than RS. Ruminal abundance of F. succinogenes was 1.3–1.5 times greater in CHM and LH than RS. These results suggest that bean husk supplementation, especially lablab bean husk, might improve the nutritive value of rice straw diet by stimulating fibrolytic bacteria.