Urinary excretion of purine derivatives in dry buffalo and Fresian cows

Cricket (Gryllus bimaculatus) meal pellets as a protein supplement to improve feed efficiency, ruminal fermentation and microbial protein synthesis in Thai native beef cattle

OBJECTIVE

Replacing soybean meal (SBM) with cricket (Gryllus bimaculatus) meal pellets (CMP) in concentrate diets was investigated for feed efficiency, ruminal fermentation and microbial protein synthesis in Thai native beef cattle.

METHODS

Four male beef cattle were randomly assigned to treatments using a 4×4 Latin square design with four levels of SBM replaced by CMP at 0%, 33%, 67%, and 100% in concentrate diets.

RESULTS

Results revealed that replacement of SBM with CMP did not affect dry matter (DM) consumption, while digestibilities of crude protein, acid detergent fiber and neutral detergent fiber were significantly enhanced (p<0.05) but did not alter digestibility of DM and organic matter. Increasing levels of CMP up to 100% in concentrate diets increased ruminal ammoniacal nitrogen (NH3-N) concentrations, blood urea nitrogen, total volatile fatty acids and propionate concentration (p<0.05), whereas production of methane and protozoal populations decreased (p<0.05). Efficiency of microbial nitrogen protein synthesis increased when SBM was replaced with CMP.

CONCLUSION

Substitution of SBM with CMP in the feed concentrate mixture at up to 100% resulted in enhanced nutrient digestibility and rumen fermentation efficiency, with increased volatile fatty acids production, especially propionate and microbial protein synthesis, while decreasing protozoal populations and mitigating rumen methane production in Thai native beef cattle fed a rice straw-based diet.

Colostrum Composition, Characteristics and Management for Buffalo Calves: A Review

In this review, the composition, characteristics, and management of dairy buffalo calves were examined and compared with bovines. The neonatal period is critical for buffalo calves and is characterized by a high mortality rate (more than 40%). The early intake of high-quality colostrum (IgG > 50 mg/mL) is the one way to improve the immune system of calves (serum IgG > 10 mg/mL after 12 h), thus increasing their chances of survival. Mainly in intensive farms, the availability of high-quality colostrum is necessary; thus, good quality colostrum is often stored to provide newborn calves which cannot be fed by their mothers. Also, the manipulation of the immunological status of animals through vaccination has been depicted since the quality of colostrum tended to be influenced by vaccination against pathogens. Buffalo breeding is constantly expanding in Italy, mainly thanks to the Mozzarella cheese production that represents the excellence of the "Made in Italy" and is exported worldwide. Indeed, high calf mortality rates directly affect the profitability of the business. For these reasons, the aim of this review was to examine specific research on buffalo colostrum that, compared with other species, are scarce. Improving the knowledge of buffalo colostrum, in terms of characteristics and management, is critical to guarantee buffalo newborns' health in order to reduce their mortality rate. Importantly, considering the knowledge on cattle valid also for buffalo is a widespread, and often erroneous, habit in several fields, including colostrum feeding. Therefore, the two species were compared in this review.

Defatted silkworm pupae meal as an alternative protein source for cattle

Silkworm pupae meal (SWP) is a protein-rich by-product of the silk reeling industry, available in a significant quantity. However, there has been little and insignificant research into the use of SWP in ruminants to date. In this view, the present study was conducted in two phases to evaluate the effect of different inclusion levels of defatted silkworm pupae meal (DSWP) on rumen fermentation, microbial protein synthesis and nutrient utilisation in cattle fed on finger millet straw (FMS)-based diet. Four isonitrogenous concentrate mixtures (CM) were prepared with DSWP replacing soybean meal (SBM) protein at 0 (T0), 10 (T1), 20 (T2) and 30% (T3). In phase I, a rumen fermentation experiment was conducted in a 4 × 4 Latin square design using four crossbred steers to study the effect of different levels of DSWP on rumen fermentation. No significant difference (P > 0.05) was observed in rumen fermentation parameters such as pH, ammonia nitrogen (NH₃-N) and total volatile fatty acids (VFA) among the experimental groups. In phase II, the digestibility trial was conducted in 20 crossbred cattle (311.2 ± 4.81 kg), which were divided into four experimental groups of five animals each in a completely randomised design to study the effect of different rations (T0, T1, T2, T3) on microbial protein synthesis and nutrient utilisation. The intake and digestibility of nutrients, excretion of urinary purine derivatives and microbial protein synthesis were not significantly different among the experimental groups. In addition, feeding DSWP revealed no significant (P > 0.05) change in the blood biochemical parameters of animals. Furthermore, at the same price as SBM, DSWP provides two units more crude protein. Therefore, the results of the present study indicated that DSWP can be incorporated into the ration of cattle up to 30% by replacing SBM without affecting rumen fermentation pattern and nutrient utilisation.

Effect of Cereals and Legumes Processing on In Situ Rumen Protein Degradability: A Review

The determination of the ruminal degradability rate of feeds, mainly starch and crude protein, is one of the most common methods to evaluate the nutritional value of ruminant feed. The protein requirements for ruminants are met from microbial protein and undegraded dietary protein digested in the small intestine. In order to reach maximum productivity, high-quality proteins are needed, and the requirement for undegraded dietary protein increases with the performance of the animal. This protein can be supplied by reducing the ruminal degradation to increase the amount of protein digested post-rumen, but the form in which a feed is administered influences degradability, and grain processing, especially, is a common practice to improve feed efficiency. Despite these aspects, studies on the effects of feed processing methods on protein degradability are limited, even though more and more ruminants are fed with processed feeds. For these reasons, this review investigated the protein degradability of different processed cereals and legumes in ruminants based on the analysis of available literature in order to take stock of the state of the art on this topic. Results showed that: First, the majority of the papers are focused on the energy aspects mainly due to carbohydrate-rich feeds; second, the majority of the studies in the literature are quite old, probably because the changes occurred in the animal testing legislation that made in vivo studies more and more difficult in the last 20 years; third, as a consequence, the few data available in recent years concern in vitro experiments; fourth, we found a high variability of the experimental conditions thus affecting protein degradability and making it quite difficult to compare the different results.

Phytonutrient pellet supplementation enhanced rumen fermentation efficiency and milk production of lactating Holstein-Friesian crossbred cows

The objective of this experiment was to investigate the effects of inclusion of dragon fruit peel pellet (DFPP) and dietary non-protein nitrogen (NPN) on nutrients digestibility, rumen fermentation efficiency, plasma antioxidant activity, microbial protein synthesis, milk yield and composition in lactating Holstein-Friesian crossbred cows. Four animals were randomly allotted to 4 dietary treatments according to a 2 × 2 factorial arrangement in 4 × 4 Latin square design. The treatments were as follows: 300 g DM of DFPP +100 g of urea (T1), 300 g DM of DFPP + 200 g of urea (T2), 400 g DM of DFPP + 100 g of urea (T3), and 400 g DM of DFPP + 200 g of urea (T4), respectively. The results showed that intake of rice straw was increased (P < 0.01) by the DFPP addition. Including DFPP and urea did not affect (P > 0.05) the NDF and ADF digestibilities, but increased the apparent digestibilities of dry matter, organic matter, and crude protein (P < 0.01). Rumen fermentation process, especially the propionate concentration, was significantly increased by the DFPP levels. The plasma antioxidant activity was increased (P > 0.05) with the addition of DFPP. The DFPP improved (P < 0.01) microbial protein synthesis. The supplementation of DFPP and urea increased (P < 0.05) milk fat, whereas milk yield and 3.5% fat corrected milk were only increased (P < 0.05) by the DFPP supplementation. Based on these results, addition of DFPP at 400 g/animal per day with urea at 100 g/animal per day improved rumen fermentation, plasma antioxidant activity, milk yield and milk fat percentage.

Effect of Caragana korshinskii Kom. as a partial substitution for sheep forage on intake, digestibility, growth, carcass features, and the rumen bacterial community

The aim of this study was to verify that Caragana korshinskii Kom. (CK) as a component of sheep forage influences lamb digestibility and rumen fermentation by altering the rumen microbial community. Hence, 12 female Tan sheep were allocated into 2 groups: receiving (CK group) or not (control group) 10% of the diet forage fraction with CK. During the 60-day experiment, growth performance, apparent digestibility, rumen volatile fatty acids (VFAs), and nitrogen balance were measured. Meanwhile, the rumen bacterial community diversity and composition were detected by the 16S rRNA sequence. The results indicated that the apparent digestibility of acid detergent fibre (ADF) tended to be higher (0.05 < P < 0.10), and the feed conversion efficiency was improved (P < 0.05) when CK was offered. Compared to those under alfalfa, the composition and abundance of the rumen microbial community were altered in the CK group, and the phylum Firmicutes, which is involved in promoting fibre digestion, increased in abundance. Moreover, VFAs tended to decrease (0.05 < P < 0.10), and the molar proportion of butyrate declined; similarly, levels of hypoxanthine and xanthine were lower (P < 0.05) in the sheep fed CK and may have been responsible for the decreased abundance of Fibrobacter spp., which are cellulolytic ruminal bacteria associated with VFA production.

Creatinine as a Urinary Marker of the Purine Derivatives Excretion in Urine Spot Samples of Lambs Fed Peach Palm Meal

The objective was to evaluate the influence of diets on lambs using different levels of peach palm meal as a replacement for maize (0, 10, 40, 60, and 85% of diet dry matter) on the endogenous creatinine clearance (CC), urine concentration ratio of purine derivatives to creatinine (PDC index), and daily creatinine excretion (DCE) as a marker to estimate purine derivatives (PD) excretion from urinary spot samples collected at different time points (4, 8, 12, 16, 20, 24 h after morning feeding) compared to 24-h total urine collection. The measured parameters were voluntary intake, urinary volume, CC, DCE, the concentration of plasma creatinine, and PD and purine derivatives’ excretion (PDE). Five lambs were allocated to metabolic cages and distributed in a 5 × 5 Latin square. Urine collection was taken daily on days 16 to 19 of each experimental period. The inclusion of peach palm meal linearly reduced the intake of dry matter (g kg BW−0.75, p = 0.005), crude protein (g kg BW−0.75, p = 0.010), metabolizable energy (MJ kg BW−0.75, p = 0.010) and CC (p < 0.0001). It also quadratically affected the urinary volume (p = 0.008) and DCE (p = 0.004). There was a linear decrease for PDC index (p = 0.032) and PDE (p < 0.0001) measured in the 24-h total urine with peach palm meal levels. The different times of spot urine sampling did not affect (p > 0.05) the PDC index and PDE. Peach palm meal decreases the CC thereby compromising the use of a mean value of DCE as a PDE marker in spot urine samples. There is greater accuracy when using different values of DCE obtained for each diet as markers for the PDE in spot urine samples. Unconventional foodstuffs of low palatability affecting the voluntary intake of feed change the renal function.

Lignin degradation by water buffalo

So far, few animals with the ability of lignin degradation have been reported except termite and longicorn. In this study, it was found that the crude fiber and acid detergent lignin (ADL) of rice straw can be degraded dramatically higher by buffalo than those by cattle. In order to further study this ability of buffalo, the digestion of roughages in buffalo rumen was studied using rumen nylon bag experiment, scanning electron microscopy (SEM), and Van Soest fiber analysis. The SEM results showed that the degradation degree of rice straw was dramatically higher in buffalo than that in cattle. The digestibility of crude fiber was significantly higher in buffalo than that in cattle (P < 0.01). The digestibility of ADL, cellulose, hemicellulose, acid detergent, fiber, and neutral detergent fiber of rice straw in buffalo rumen was significantly higher than that in cattle (P < 0.05). The ADL degradation rate of rice straw in buffalo rumen was significantly higher than that in cattle rumen, indicating that buffalo was capable of utilizing lignin and had superior utilizing capability than cattle. It was observed that various roughages can be dramatically digested by buffalo rumen with the ranking of ADL degradation rate: peanut vine (15.04%) > rice silage > maize silage > rice straw > corn stover > wheat stalk > bract leaf > potato vine (7.22%), verifying that buffalo rumen possessed the ability to digest universal roughages. In conclusion, this study revealed that buffalo was more efficient in ADL degradation compared with cattle.

Empirical Evaluation and Prediction of Protein Requirements for Maintenance and Growth of 18-24 Months Old Thai Swamp Buffaloes

Simple Summary

Thai swamp buffalo is a domesticated swamp buffalo (Bubalus bubalis) which has a functional significance for the livestock production system and for the economic benefit of Thailand. For instance, meat supply derived from Thai swamp buffalo is a secondary consideration in recently years. Therefore, there is mounting interest concerning the regulation of the nutrient requirements of Thai swamp buffalo to optimize their production. However, no systematic report is available on the nutrient requirements of the growing Thai swamp buffalo. This study investigates and predicts protein requirement systems that can provide an abundant energy intake and can be included in the 18–24 months old Thai swamp buffalo’s diet, as well as supply the recommended amount of net nitrogen or crude protein requirement to optimize their growth and maintenance. Protein requirement, nutrient utilization, and microorganism profile are included to corroborate the influences mentioned.

Abstract

In some geographical areas and in certain breeding situations, the interpretation of increased gain in the bovine is difficult to investigate. Due to their inherent genetic variations, their energy and protein needs vary as a function of inherent genetic differences, making these requirements difficult to accurately assess in bull species, e.g., Thai swamp buffalo. The study aimed at investigating and predicting protein requirement systems, by the provision of an abundant energy intake of 2.2 Mcal/kg DM for the maintenance and growth of Thai swamp buffaloes using a comparative prolonged feeding trial for 90 days. Sixteen bull Thai swamp buffaloes at the initial (Age: 18–24 months; BW: 233 ± 25.0 kg) were assigned into four treatment groups, four buffaloes each, fed 5.4, 6.6, 8.5, and 10.5% DM crude protein (CP). CP intake, BW, and physiological fluid were determined. The net CP requirements for maintenance and growth of Thai swamp buffaloes were 5.41 g CP/kg W^0.75 and 0.46 g CP/g average daily gain (ADG), respectively. Our results indicated that CP requirement increases when the BW increases. An increased dietary CP resulted in increased amounts of blood urine nitrogen (N), N absorption, total volatile fatty acid, urinary purine derivative, and the microbial N. Notably, the net CP requirement for growth of Thai swamp buffalo was higher than it reported in NRC, but the maintenance was lower.

Effect of additive fermented residues from factory on rumen fermentation and microbial population in beef cattle

Context Suboptimal beef production resulting from poor growth performance of the animals in Thailand may be due to insufficient energy and protein in the animal feed. Therefore, there is a need to find new, locally available and economical nutrient-rich feed resources. By-products from the agri-industry could be one such alternative to improve livestock feed quality. The aim of the study was to evaluate the feed intake, nutrient digestibility, rumen fermentation and microbial population of additive fermented cassava pulp with residues from noodle factory (CN). Four beef cattle at ~2–3 years of age were randomly assigned according to a 4 × 4 Latin square design. Four feed treatments had cassava pulp:residue ratios of 0:0 (NCN), 70:30 (CN1), 60:40 (CN2), 50:50 (CN3). In conclusion, feeding with CN at 60:40 might be an alternative to improve rumen fermentation efficiency, estimated energy, apparent digestibility and bacteria population. Aims The aim of the present study was to determine feed intake, nutrient digestibility, rumen fermentation and microbial population of cattle fed additive fermented cassava pulp with residues from noodle factory (CN). Methods Four beef cattle of ~2–3 years of age and of initial bodyweight of 150 ± 40 kg were randomly assigned to the following four treatments, according to a 4 × 4 Latin square design: cassava pulp:residue at ratios of 0:0 (NCN), 70:30 (CN1), 60:40 (CN2) and 50:50 (CN3) was added. All animals were fed concentrated 16% crude protein and cassava pulp–residue at 1% of bodyweight of animals. Rice straw, water and mineral salt block were offered ad libitum. Key results Feed intake and bodyweight change were not affected, while estimated energy intake and nutrient digestibilities increased (P &lt; 0.05) after animals were fed CN2 and CN3. Ruminal pH, ruminal temperature, ammonia nitrogen and blood urea nitrogen were not altered by CN, whereas total volatile fatty acids and the proportion of propionate increased with an increasing proportion of residues from noodle factory (P &lt; 0.05). Simultaneously, methane production was reduced by CN. In addition, bacterial population and efficiency of microbial nitrogen synthesis were increased (P &lt; 0.05) by CN. Real-time polymerase chain reaction showed that the populations of total bacterial and F. succinogenes increased (P &lt; 0.05), whereas populations of protozoa, R. flavefaciens and R. albus were not significantly different among the treatments. Conclusions It is concluded that feeding with CN can improve rumen fermentation efficiency, estimated energy, apparent digestibility and bacterial population. Feeding with CN2 is recommended because it showed the best response Implications Agri-industry by-products such as cassava pulp and residues from noodle factory can provide an economical alternative to improve feed quality and, hence, beef animal performace in Thailand.

Manipulating rumen fermentation, microbial protein synthesis, and mitigating methane production using bamboo grass pellet in swamp buffaloes

Bamboo grass (Tiliacora triandra Diels) pellet (BP) was assessed as a rumen modifier on feed intake, rumen fermentation, nutrient digestibilities, microbial population, and methane production in swamp buffaloes. Four male swamp buffaloes with 350 ± 10 kg of body weight (BW) were allotted according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. The treatments were as follows: roughage to concentrate ratio (R:C) at 70:30 (T1), R:C at 70:30 with BP supplementation at 150 g/day (T2), R:C at 30:70 (T3), and R:C at 30:70 with BP supplementation at 150 g/day (T4). All animals were restricted to 2.5% of BW. The findings revealed that ruminal pH was reduced by the R:C at 30:70 fed groups (T3, T4); however, the rumen pH was enhanced (P < 0.05) in BP supplemented (T4) and there was an interaction between R:C and BP groups (P < 0.05). The propionate (C3) concentration was increased by the R:C ratio at 30:70 and BP fed groups (P < 0.01), and it was the highest at R:C ratio of 30:70 with BP supplemented group. Total VFA and buterate (C4) concentation were not changed (P > 0.05), while acetate (C2) concentration was reduced (P < 0.05) in the BP fed groups and there was an interaction (P < 0.05). Estimation of CH₄ production in the rumen was remarkably reduced by the R:C ratio with BP supplementation (P < 0.01). Furthermore, apparent digestibilities of DM, OM, CP, NDF, and ADF were significantly increased in the R:C ratio 30:70 (P < 0.01). Nitrogen absorption and nitrogen retention were also significantly altered by R:C at 30:70 (P < 0.01) and nitrogen absorption was an interaction (P < 0.01). Based on this study, it could be concluded that supplementation of BP resulted in improvement of ruminal pH, enhanced C3, and reduced CH₄ production. Thus, BP could be a dietary rumen enhancer.

Pleurotus Ostreatus and Volvariella Volvacea Can Enhance the Quality of Purple Field Corn Stover and Modulate Ruminal Fermentation and Feed Utilization in Tropical Beef Cattle

This objective is to elucidate the effect of purple field corn stover treated with Pleurotus ostreatus and Volvarialla volvacea on feed utilization, ruminal ecology, and CH4 synthesis in tropical beef cattle. Four male Thai native beef cattle (100 ± 30 kg of body weight (BW) were assigned randomly as a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A (roughage sources) was rice straw and purple field corn stover and factor B was species of white-rot fungi (P. ostreatus and V. volvacea). After fermentation, crude protein (CP) was increased in rice straw and purple field corn stover fermented with P. ostreatus and V. volvacea. The unfermented purple field corn stover contained 11.8% dry matter (DM) of monomeric anthocyanin (MAC), whereas the MAC concentration decreased when purple field corn stover was fermented with white rot fungi. There were no changes (p > 0.05) in DM intake of body weight (BW) kg/d and g/kg BW0.75 among the four treatments. The organic matter (OM), CP, and acid detergent fiber (ADF) intake were different between rice straw and purple field corn stover and were the greatest in the purple field corn stover group. Moreover, the current study showed that neutral detergent fiber (NDF) and ADF digestion was higher in purple field corn stover than in rice straw, but there were no significant differences between P. ostreatus and V. volvacea. There were significant effects of roughage sources on ammonia nitrogen (NH3-N) at 4 h after feeding. Bacterial population was changed by feeding with purple field corn stover fermented with P. ostreatus and V. volvacea. On the other hand, the number of protozoa was reduced by approximately 33% at 4 h after feeding with purple field corn stover (p < 0.01). Propionic acid concentration was different between roughage sources (p < 0.01) enhanced with purple field corn stover fermented with P. ostreatus and V. volvacea. In addition, methane production decreased by 15% with purple field corn stover fermented with P. ostreatus and V. volvacea compared to rice straw. There were significant differences on all nitrogen balances parameters (p < 0.05), except the fecal N excretion (p > 0.05) were not changed. Furthermore, microbial crude protein and efficiency of microbial N synthesis were enhanced when purple field corn stover fermented with P. ostreatus and V. volvacea was fed compared to rice straw group. Base on this study, it could be summarized that P. ostreatus or V. volvacea can enhance the quality of purple field corn stover and modulate rumen fermentation and feed digestion in Thai native beef cattle.

Supplementation of Flemingia macrophylla and cassava foliage as a rumen enhancer on fermentation efficiency and estimated methane production in dairy steers

Four rumen-fistulated dairy steers, 3 years old with 180 ± 15 kg body weight (BW), were randomly assigned according to a 4 × 4 Latin square design to investigate on the effect of Flemingia macrophylla hay meal (FMH) and cassava hay meal (CH) supplementation on rumen fermentation efficiency and estimated methane production. The treatments were as follows: T1 = non-supplement, T2 = CH supplementation at 150 g/head/day, T3 = FMH supplementation at 150 g/head/day, and T4 = CH + FMH supplementation at 75 and 75 g/head/day. All steers were fed rice straw ad libitum and concentrate was offered at 0.5 % of BW. Results revealed that supplementation of CH and/or FMH did not affect on feed intake (P > 0.05) while digestibility of crude protein and neutral detergent fiber were increased especially in steers receiving FMH and CH+FMH (P < 0.05). Ruminal pH, temperature, and blood urea nitrogen were similar among treatments while ammonia nitrogen was increased in all supplemented groups (P < 0.05). Furthermore, propionic acid (C3) was increased while acetic acid (C2), C2:C3 ratio, and estimated methane production were decreased by dietary treatments. Protozoa and fungi population were not affected by dietary supplement while viable bacteria count increased in steers receiving FMH. Supplementation of FMH and/or FMH+CH increased microbial crude protein and efficiency of microbial nitrogen supply. This study concluded FMH (150 g/head/day) and/or CH+FMH (75 and 75 g/head/day) supplementation could be used as a rumen enhancer for increasing nutrient digestibility, rumen fermentation efficiency, and microbial protein synthesis while decreasing estimated methane production without adverse effect on voluntary feed intake of dairy steers fed rice straw.

Effects of Supplementation of Eucalyptus (E. Camaldulensis) Leaf Meal on Feed Intake and Rumen Fermentation Efficiency in Swamp Buffaloes

Four rumen fistulated swamp buffaloes were randomly assigned according to a 4×4 Latin square design to investigate the effects of Eucalyptus (E. Camaldulensis) leaf meal (ELM) supplementation as a rumen enhancer on feed intake and rumen fermentation characteristics. The dietary treatments were as follows: T1 = 0 g ELM/hd/d; T2 = 40 g ELM/hd/d; T3 = 80 g ELM/hd/d; T4 = 120 g ELM/hd/d, respectively. Experimental animals were kept in individual pens and concentrate was offered at 0.3% BW while rice straw was fed ad libitum. The results revealed that voluntary feed intake and digestion coefficients of nutrients were similar among treatments. Ruminal pH, temperature and blood urea nitrogen concentrations were not affected by ELM supplementation; however, ELM supplementation resulted in lower concentration of ruminal ammonia nitrogen. Total volatile fatty acids, propionate concentration increased with the increasing level of EML (p<0.05) while the proportion of acetate was decreased (p<0.05). Methane production was linearly decreased (p<0.05) with the increasing level of ELM supplementation. Protozoa count and proteolytic bacteria population were reduced (p<0.05) while fungal zoospores and total viable bacteria, amylolytic, cellulolytic bacteria were unchanged. In addition, nitrogen utilization and microbial protein synthesis tended to increase by the dietary treatments. Based on the present findings, it is suggested that ELM could modify the rumen fermentation and is potentially used as a rumen enhancer in methane mitigation and rumen fermentation efficiency.

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.