Effects of an enzyme feed additive on extent of digestion and milk production of lactating dairy cows

Malted Barley as a Potential Feed Supplementation for the Reduction of Enteric Methane Emissions, Rumen Digestibility, and Microbiome Community Changes in Laboratory Conditions

Three sets of in vitro rumen fermentation experiments were conducted to determine the effects of diets that included malted barley (MB) and basal diets (grain- and forage-based) on the in vitro gas production, greenhouse gas (GHG) emissions, rumen fermentation profiles, and microbiome changes in the rumen when supplemented with feedlot or dairy rations. The first experiment (Exp. 1) was conducted to evaluate the effects of various levels of MB (0% [referred to as a control], 10%, 20%, and 30%, as-fed basis) supplemented with a grain-based diet in a feedlot ration (2.5 g/bottle) after 48 h ruminal incubation on the in vitro gas production, GHG emissions, and rumen fermentation rate. The second two sets of in vitro experiments (Exp. 2a, b) were conducted to determine (1) the effects of linear dose levels of malted barley (MB; 0%, 10%, 20%, 30%, and 40% as-fed) with two different basal diets (grain-based and forage-based) and (2) the effects of different sources of MB (control, Korean, Canadian, and the USA; 30% MB, as-fed) in a dairy ration after 24 h incubation on in vitro gas production, rumen fermentation profiles, GHG emissions (methane [CH4] and nitrous oxide [N2O]), in vitro dry matter disappearance rate (IVDMD), and microbiome changes. Commercially available α-amylase (0.2 g/100 mL) was used as a sub-control in Exp. 2a. Using gas chromatography, all gases were collected using an ANKOM Gas Production system and analyzed for CH4 and N2O. In Exp. 1, total gas production, cumulative gas, and GHG productions (CH4, N2O) linearly decreased (p ≤ 0.05) with increasing MB supplementation. In Exp. 2a, cumulative in vitro gas, total gas production, and rumen fermentation profiles (e.g., total VFA, acetate, butyrate, iso-butyrate, valerate, and iso-valerate) linearly decreased (p < 0.05-0.01) with increasing MB supplementation, with diet-treatment interactions (p < 0.001). In addition, CH4 and N2O production (mL/g DM) linearly and quadratically decreased (p < 0.01) with increasing MB supplementation across the diets. However, IVDMD linearly and/or quadratically increased (p < 0.01) with increasing MB, with diet-treatment interactions (p < 0.001). The average populations of Bacteroidetes, Proteobacteria, and Spirochaetes were significantly decreased (p < 0.01-0.001) for MB treatment groups compared to the control group. Therefore, it may be possible to suppress methane production directly and indirectly by adding MB and α-amylase by modifying ruminal fermentation profiles.

Can fecal characteristics be used to predict the digestibility of certain macro minerals in dry and lactating cows?

This study aims to evaluate the relationship between mineral digestibility and fecal characteristics and compare digestibility in dry and late-lactating cows. A total of 107 multiparous Holstein and Simmental cows were included, with 66 cows in late lactation and 41 cows in the dry period. The apparent digestibility of key macro minerals, dry matter content in feces, dirtiness scores, fecal characteristics, and serum macro mineral levels were determined. Cows consuming the same diet were arranged according to a completely randomized design. Results showed that, compared to the late lactation group, the dry period group had a significantly lower total dirtiness score, higher phosphorus digestibility, and elevated serum calcium levels (p < 0.05). Additionally, fecal consistency and fecal height were greater in the dry period group (p < 0.05). However, the increased phosphorus digestibility observed during the dry period was not significantly associated with fecal consistency (r = +0.225, p < 0.05) or the total contamination score (r = -0.339, p < 0.05). Consequently, this study reveals that understanding the differences in mineral digestibility between different physiological stages can enhance nutritional approaches for better dairy cow management.

Immuno-physiological role of exogenous enzymes supplementation in heat stressed growing calves

Twenty Crossbred (Baladi× Brown-Swiss) male growing-calves, 6 to 8 months old, weighing an average of 115 to 125 kg were subjected for evaluating ZADO supplementary effects on blood biochemical parameters, antioxidant status, thyroid activity, and growth efficiency of calves under semi-arid conditions. The experimental units were pinned equally in two groups. The control (G1) fed the basal ration, and the 2nd, treatment group (G2) fed the basal ration + a daily supplement of 10 g ZADO (exogenous enzymes) calf- 1 day- 1 in a powder form mixed well with ration. The results showed that ZADO treatment reduced (P < 0.001) each of respiration rate (RR), rectal temperature (RT), serum malondialdehyde (MDA), urea, creatinine, and cortisol. Also, caused a marked decline in oxidized glutathione (GSSG) and alanine aminotransferase (ALT) activities. However, supplemented ZADO to growing calves diets improved antioxidant status including reduced glutathione (GSH) and superoxide dismutase (SOD) activities, total antioxidant capacity, serum total protein, albumin, and globulin, as well as IgG and IgM besides. ZADO enhanced (P < 0.01) thyroid activity, and feed efficacy parameters. Finally, supplementing growing calves with ZADO under semi-arid circumstances alleviates the heat stress effect, and leads to an improvement in calves' growth performance.

Effect of the supplementation of exogenous complex non-starch polysaccharidases on the growth performance, rumen fermentation and microflora of fattening sheep

The objective of this study was to evaluate the effects of exogenous non-starch polysaccharidases (a mixture of cellulase, xylanase, β-glucanase and mannanase) on the growth performance and nutrient digestibility, rumen fermentation, and rumen microflora of sheep. The animal trial was conducted using 36 5-month-old female fattening hybrid sheep (Duolang♂ × Hu♀) who were randomly assigned into four groups comprising nine sheep per treatment: CON, T1, T2, and T3, with 0, 0.1, 0.3, and 0.5% NSPases/kg DM of TMR, respectively. This complex enzyme product was screened for optimal ratios based on previous in vitro tests and responded positively to the in vitro fermentation of the TMR. When treated with NSPases, there was a non-linear effect of average daily gain and feed conversion rate, with the greatest improvement observed in the T2 group. There were no significant differences (p > 0.05) in nutrient intake or apparent digestibility among the NSPase-supplemented groups. In addition, T2 group had a significantly higher acetate to propionate ratio and pH (p < 0.05) than the other groups, and NH3-N and microbial protein concentrations showed a quadratic curve. The results revealed that both immunoglobulins and serum hormones increased linearly with addition (p < 0.05). As the T2 group showed the best growth performance, the CON and T2 groups were subjected to rumen metagenomic analysis. The results showed higher abundance of bacteria and lower abundance of Viruses in the rumen microbiota of the T2 group compared to the CON group. In addition, Uroviricota and Proteobacteria abundance was significantly lower in the T2 group than in the CON group at the phylum level (p < 0.05). These results suggest that the supplementation of high-concentrate rations with NSPases enhance immunity, reduces virus abundance in the rumen, improves rumen health, and promotes rumen fermentation. Our findings provide novel insights for improving growth performance and alleviating inflammatory responses arising from high concentrate feeding patterns in ruminants. However, the biological mechanisms cannot be elucidated by exploring the composition of rumen microbe alone, and further studies are required.

Heating Drinking Water in Cold Season Improves Growth Performance via Enhancing Antioxidant Capacity and Rumen Fermentation Function of Beef Cattle

The research aimed to investigate the suitable drinking water temperature in winter and its effect on the growth performance, antioxidant capacity, and rumen fermentation function of beef cattle. A total of 40 beef cattle (640 ± 19.2 kg) were randomly divided into five treatments with eight cattle in each treatment raised in one pen according to initial body weight. Each treatment differed only in the temperature of drinking water, including the room-temperature water and four different heat water groups named RTW, HW_1, HW_2, HW_3, and HW_4. The measured water temperatures were 4.39 ± 2.546 °C, 10.6 ± 1.29 °C, 18.6 ± 1.52 °C, 26.3 ± 1.70 °C, and 32.5 ± 2.62 °C, respectively. The average daily gain (ADG) showed a significant linear increase during d 0 to 60 and a quadratic increase during d 31 to 60 with rising water temperature (p < 0.05), and the highest ADG of 1.1911 kg/d was calculated at a water temperature of 23.98 °C (R2 = 0.898). The average rectal temperature on d 30 (p = 0.01) and neutral detergent fiber digestibility (p < 0.01) increased linearly with increasing water temperature. Additionally, HW_2 reduced serum triiodothyronine, thyroxine, and malondialdehyde (p < 0.05), and increased serum total antioxidant capacity (p < 0.05) compared with RTW. Compared with HW_2, RTW had unfavorable effects on ruminal propionate, total volatile fatty acids, and cellulase concentrations (p < 0.05), and lower relative mRNA expression levels of claudin-4 (p < 0.01), occludin (p = 0.02), and zonula occludens-1 (p = 0.01) in the ruminal epithelium. Furthermore, RTW had a higher abundance of Prevotella (p = 0.04), Succinivibrionaceae_UCG-002 (p = 0.03), and Lachnospiraceae_UCG-004 (p = 0.03), and a lower abundance of Bifidobacteriaceae (p < 0.01) and Marinilabiliaceae (p = 0.05) in rumen compared to HW_2. Taken together, heated drinking water in cold climates could positively impact the growth performance, nutrient digestibility, antioxidant capacity, and rumen fermentation function of beef cattle. The optimal water temperature for maximizing ADG was calculated to be 23.98 °C under our conditions. Ruminal propionate and its producing bacteria including Prevotella, Succinivibrionaceae, and Lachnospiraceae might be important regulators of rumen fermentation of beef cattle drinking RTW under cold conditions.

Encapsulation of enzymes in food industry using spray drying: recent advances and process scale-ups

Enzymes are widely used in the food industry due to their ability in improving the functional, sensory, and nutritional properties of food products. However, their poor stability under harsh industrial conditions and their compromised shelf-lives during long-term storage limit their applications. This review introduces typical enzymes and their functionality in the food industry and demonstrates spray drying as a promising approach for enzyme encapsulation. Recent studies on encapsulation of enzymes in the food industry using spray drying and the key achievements are summarized. The latest developments including the novel design of spray drying chambers, nozzle atomizers and advanced spray drying techniques are also analyzed and discussed in depth. In addition, the scale-up pathways connecting laboratory scale trials and industrial scale productions are illustrated, as most of the current studies have been limited to lab-scales. Enzyme encapsulation using spray drying is a versatile strategy to improve enzyme stability in an economical and industrial viable way. Various nozzle atomizers and drying chambers have recently been developed to increase process efficiency and product quality. A comprehensive understanding of the complex droplet-to-particle transformations during the drying process would be beneficial for both process optimization and scale-up design.

Effects of exogenous amylolytic or fibrolytic enzymes inclusion on in vitro fermentation of lactating dairy cow diets in a dual-flow continuous-culture system

The objective of this study was to determine the effects of including exogenous amylolytic or fibrolytic enzymes in a diet for high-producing dairy cows on in vitro ruminal fermentation. Eight dual-flow continuous-culture fermentors were used in a replicated 4 × 4 Latin square. The treatments were control (CON), a xylanase and glucanase mixture (T1), an α-amylase mixture (T2), or a xylanase, glucanase, and α-amylase mixture (T3). Treatments were included at a rate of 0.008% of diet dry matter (DM) for T1 and T2 and at 0.02% for T3. All treatments replaced the equivalent amount of soybean meal in the diet compared with CON. All diets were balanced to have the same nutrient composition [30.2% neutral detergent fiber (NDF), 16.1% crude protein (CP), and 30% starch; DM basis], and fermentors were fed 106 g/d divided into 2 feedings. At each feeding, T2 was pipetted into the respective fermentor and an equivalent amount of deionized water was added to each fermentor to eliminate potential variation. Experimental periods were 10 d (7 d for adaptation and 3 d for sample collection). Composite samples of daily effluent were collected and analyzed for volatile fatty acids (VFA), NH₃-N, and lactate concentrations, degradability of DM, organic matter, NDF, CP, and starch, and flow and metabolism of N. Samples of fermentor contents were collected from each fermentor at 0, 1, 2, 4, 6, and 8 h after feeding to determine kinetics of pH, NH₃-N, lactate, and VFA concentrations over time. All data were analyzed using PROC GLIMMIX of SAS (SAS Institute Inc.), and the repeated variable of time was included for kinetics measurements. Treatment did not affect mean pH, degradability, N flow and metabolism, or the concentrations of VFA, NH₃-N, or lactate in the effluent samples. Treatment did not affect pH, acetate:propionate ratio, or the concentrations of lactate, NH₃-N, total VFA, acetate, propionate, butyrate, isobutyrate, valerate, or caproate. However, the concentration of total VFA tended to change at each time point depending upon the treatment, and T2 tended to have a greater proportion of 2-methylbutyrate and isovalerate than CON, T1, or T3. As 2-methylbutyrate and isovalerate are branched-chain VFA that are synthesized from branched-chain amino acids, T2 may have an increased fermentation of branched-chain amino acids or decreased uptake by fibrolytic microorganisms. Although we did not observe changes in N metabolism due to the enzymes, there could be changes in microbial populations that utilize branched-chain VFA. Overall, the tested enzymes did not improve in vitro ruminal fermentation in the diet of high-producing dairy cows.

Lactational performance, feeding behavior, ruminal fermentation and nutrient digestibility in dairy cows fed whole-plant faba bean silage-based diet with fibrolytic enzyme

Whole-plant faba bean silage has a high content in indigestible fiber. Improvement of fiber digestibility of faba bean silage would benefit animal production. However, there is no study on pretreating fibrolytic enzyme in whole-plant faba bean silage-based diet for dairy cows on animal performance. The objectives of this study were to evaluate the effects of pretreating whole-plant faba bean silage-baseddiet with fibrolytic enzyme (a mixture of xylanase and cellulase; AB Vista, UK) derived from Trichoderma reesei(FETR) on lactational performance, digestibility, ruminal fermentation characteristics, and feeding behavior of dairy cows. The animal trial was conducted using eight lactating Holstein cows (BW = 710 ± 44 kg and Days in Milk (DIM) = 121 ± 17 days) with four levels of FETR (0, 0.5, 0.75, and 1.0 mL of FETR/kg DM of silage) in a replicated Latin square design. These enzyme treatments were selected based on the previous in situ and in vitro findings that showed positive responses to the whole-plant faba bean silage. The enzyme treatments were directly applied on the silage prior to mixing process. The total mixed rations contained 31% of faba bean silage, 14% of grass hay, 3.5% of straw, 30% of barley and corn grain and 21.5% of concentrate. There was no significant difference of applying FETR on nutrient intake (P > 0.05) except for CP intake, which was reduced in FETR group compared to control (P < 0.01, 4.4 vs 4.54 kg/d). There was a linear effect found in NDF digestibility when treated with FETR, where maximum improvement was achieved with 0.5 mL of FETR application. The milk fat yield, percentage of milk fat and fat-corrected milk were linearly affected by the increasing level of enzyme. The cows fed a diet supplemented with enzymes tended to have a lower milk fat. Feed efficiency linearly responded to incremental levels of FETR. There was no enzyme effect on feeding behavior and nitrogen balance and utilization. Results from this study indicated that supplementing fibrolytic enzyme on whole-plant faba bean silage diets for dairy cows improved lactational performance, intake and digestibility with 0.5 mL of FETR application. However, adding higher enzyme level resulted in negative effects on animal performance.

Feeding Date-Palm Leaves Ensiled with Fibrolytic Enzymes or Multi-Species Probiotics to Farafra Ewes: Intake, Digestibility, Ruminal Fermentation, Blood Chemistry, Milk Production and Milk Fatty Acid Profile

The present experiment evaluated the feeding of date palm leaves (DPL) ensiled with fibrolytic enzymes (ENZ) or multi-species probiotics (MSP) on nutrient utilization and lactational performance of ewes. Fifty multiparous lactating Farafra ewes were used in a completely randomized design for 90 d. The treatments consisted of the control diet with a concentrate feed mixture and date palm leaves (at 60:40, DM basis) ensiled without additive (control) or DPL ensiled with ENZ or MSP replacing control DPL at 50 or 100%. Both ENZ and MSP increased (p < 0.01) DPL and total intakes, digestibility of all nutrients, concentrations of ammonia, total volatile fatty acids, acetate and propionate in the rumen. Increased milk production, concentrations of fat, lactose and energy in milk, and feed efficiency were observed with MSP and ENZ compared to the control treatment. Moreover, ENZ and MSP increased (p < 0.05) the concentrations of total n3, n6 fatty acids, polyunsaturated fatty acids and conjugated linoleic acids and decreased (p < 0.001) the atherogenicity. The differences between ENZ and MSP and between the low and high replacement levels were minor for all measured parameters. Ensiling of DPL with MSP or fibrolytic enzymes is recommended to improve feed efficiency and improve lactational performance of ewes.

Effects of Exogenous Fibrolytic Enzyme Derived from Trichoderma reesei on Rumen Degradation Characteristics and Degradability of Low-Tannin Whole Plant Faba Bean Silage in Dairy Cows

The objectives of this study were to (1) determine the effect of exogenous fibrolytic enzyme derived from Trichoderma reesei on dry matter (DM) and neutral detergent fibre (NDF) degradability of whole plant faba bean silage (Snowbird), (2) evaluate the effects of fibrolytic enzyme (FETR) on DM and NDF degradation kinetics of whole plant faba bean silage, and (3) compare the difference between in the vitro approach (DaisyII incubation method) and the in situ assay-biological approach (nylon bag technique) in the determination of degradability of dry matter (DMD) and neutral detergent fibre (NDFD). The fibrolytic enzyme from Trichoderma reesei was a mixture of xylanase and cellulase. The whole plant faba bean silage was treated with seven doses of fibrolytic enzyme, with 0 as a control and 0.25, 0.5, 0.75, 1, 1.25 and 1.5 mL of FETR/kg DM of silage. The results obtained from the in situ method show that fibrolytic enzyme cubically (p < 0.05) affected DMD and quadratically (p < 0.01) affected NDFD with increasing level of enzyme application. In vitro DM and NDF degradability were quadratically and cubically (p < 0.01) affected by the increasing dosage of enzyme. Correlation analysis between the in situ assay-biological approach and the In vitro DaisyII approach showed a strong correlation (r = 0.98, p < 0.01) on overall DMD and also a satisfactory relationship (r = 0.84, p < 0.01) was found on overall NDFD. The enzyme application showed a great impact on NDF rumen degradation kinetics by decreasing the undegradable fraction and increasing the potential degradable fraction and the effective degradable content of fiber. The washable (W) and potential degradation fraction (D) were linearly (p = 0.05) increased by the enzyme treatments. Therefore, the undegradable fraction was linearly decreased (p = 0.05) with increasing dosage of enzyme. Both bypass (BNDF) and effective degradable NDF (EDNDF) were cubically (p = 0.05) affected by fibrolytic enzyme. In conclusion, the exogenous fibrolytic enzyme derived from Trichoderma reesei highly impacted rumen degradation characteristics and degradability of whole plant faba bean silage and could be used to improve fibre digestion of whole plant faba silage in dairy cows.

Utilization of exogenous fibrolytic enzymes in fiber fermentation, degradation, and digestions and characteristics of whole legume faba bean and its plant silage

This article aims to review recent progress and update on utilization of exogenous fibrolytic enzymes in fiber fermentation, degradation, and digestions and nutritive and anti-nutritional characteristics of whole legume faba bean and its silage. The study focused on strategies to improve the utilization and bioavailability of fiber through pre-treating exogenous fibrolytic enzymes. The review includes features of nutrition and anti-nutritional factors and environment impact, forage fiber fermentation, degradation and digestion, legume bean in various diets, use of exogenous enzyme and factor affecting enzyme action in fiber digestion as well as exogenous enzyme response. This review also provides very recent research on effects of fibrolytic enzyme on rumen degradation characteristics of dry matter and fiber of whole plant faba bean silage and effect of exogenous fibrolytic enzyme derived from trichoderma reesei on lactational performance, feeding behavior, rumen fermentation and nutrient digestibility in dairy cows fed whole plant faba bean silage-based diet. This study provides an insight on nutritive and anti-nutritive characteristics of whole legume bean and its plant silage and utilization of exogenous fibrolytic enzymes in fiber fermentation, degradation, and digestions.

Effect of carbohydrate hydrolytic enzyme complex in combination with energy feed on rumen digestion, metabolism, productivity and fatty acid composition of milk fat in cows

The research was carried out on 2 groups of dairy cows of 30 heads on the farm with the formation of technological groups according to the timing of calving and milking on the unit with individual accounting of milk yield. Cows of the experimental group in the period two weeks before calving and for 2 months after calving were added to the diet, respectively, 150 and 300 ml / head / day energy feed based on propylene glycol and glycerin with a complex of enzymes cellulase, xylase, beta-gluconase and glucoamylase activity (EFEC). The main diet consisted of traditional feed and was designed to receive an average daily milk yield of 25 kg of milk. EFEC had practically no effect on the pH and ammonia content in the rumen chyme, but increased the content of VFA in it by 3.6%. It had no effect on the total microbial mass, but reduced the population of infusoria by 23.5% and increased the bacterial population by 27.8%. EFEC had a positive effect on protein-nitrogen metabolism, liver function, antioxidant activity, hormonal status and hematology. As a result, during 3 months of lactation, the average daily milk yield in cows of the experimental group was 19.9, 20.9 and 21.1 kg of milk (P<0.001), which was higher than in the control by 13.0, 9.4 and 16.5%, respectively.

Evaluating the effects of fibrolytic enzymes on rumen fermentation, omasal nutrient flow, and production performance in dairy cows during early lactation

This study was performed to evaluate the effects of pre-treating a barley-silage-based diet with an exogenous fibrolytic enzyme derived from Trichoderma reesei (FETR, a mixture of xylanase and cellulase) on lactation performance, omasal nutrient flow and digestibility, rumen fermentation characteristics, and rumen pH profile in Holstein dairy cows during early lactation. The dairy trial was conducted using nine Holstein dairy cows (averaging 46 ± 24 days in milk and 697 ± 69 kg body weight, six cows were fitted with a rumen cannula, and three were non-cannulated). Two groups of cows were randomly assigned to each of the dietary treatments in a crossover design: control (without FETR supplementation) and supplemented [with 0.75 mL of FETR·kg−1 dry matter (DM) of the diet based on our previous study]. The application of FETR tended to decrease the DM intake compared with control. There were no effects of FETR (P > 0. 10) on omasal nutrient flow and digestibility, rumen fermentation characteristics, and rumen pH profile. In conclusion, this study lacks evidence that the fibrolytic enzyme (at a level of 0.75 mL of FETR·kg−1 DM) can affect nutrient digestibility, ruminal fermentation, and the performance of early-lactation cows. Further study with larger animal trials are needed.

Influence of fibrolytic enzymes in total mixed ration containing urea-molasses-treated sugarcane bagasse on the performance of lactating Holstein-Friesian crossbred cows

The aim of this study was to determine the effect of different levels of fibrolytic enzyme on nutrient utilization and milk production in dairy cows. Four multiparous early-to-mid-lactation Holstein-Friesian crossbred cows were randomly allocated in a 4 × 4 Latin square design. Cows were fed a balanced total mixed ration (TMR) on a dry matter (DM) basis containing 0, 1.2, 2.4, and 3.6 g/kg DM of fibrolytic enzyme in TMR, where the TMR comprises 60% concentrate supplemented with a fibrolytic enzyme at 0, 2, 4, and 6 g/kg DM of concentrate, and 40% urea-molasses-treated sugarcane bagasse (UMSB) was used as a roughage source. Fibrolytic enzyme supplementation in TMR containing UMSB did not affect dry matter intake (DMI) of dairy cows (p > 0.05). There was a quadratic effect of fibrolytic enzyme levels on the digestibility of DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) (p < 0.05), and the maximal response was reached at 1.2-2.4 g/kg DM of fibrolytic enzyme added in the TMR. Furthermore, 3.5% fat-corrected milk, milk fat, total volatile fatty acids, and propionic acid were greater in a cow fed with 1.2-2.4 g/kg DM of fibrolytic enzyme, resulting in a lower ratio of acetic acid to propionic acid (p < 0.05). In conclusion, adding a fibrolytic enzyme in TMR containing UMSB improved nutrient utilization, rumen fermentation, and milk production of lactating dairy cows.

Partial Replacement of Concentrate with Olive Cake in Different forms in the Diet of Lactating Barki Ewes Affects the Lactational Performance and Feed Utilization

The present experiment aimed to evaluate the inclusion of dried olive cake treated or untreated with fibrolytic enzyme, partially replacing concentrates in the diet of ewes. Forty lactating Barki ewes, weighing 37.1 ± 4.0 kg, were assigned into four treatments (n=10) in a complete randomized design for 9 weeks. Ewes were stratified according to parity (2 ± 1 parity) and previous milk production (615 ± 11 g/d). The control diet consisted of concentrates and corn fodder at 60:40, respectively. For the experimental diets, 30% of the concentrates was replaced with dried olive cake (DOC treatment), olive cake silage (SOC treatment) or olive cake silage treated with fibrolytic enzymes (ESOC treatment). Without affecting intake, DOC, SOC and ESOC diets enhanced (P<0.05) dry matter, organic matter and non-structural carbohydrate digestibility; however, ESOC diets increased (P<0.05) neutral detergent fiber and acid detergent fiber digestibility. Additionally, DOC, SOC and ESOC diets increased (P<0.05) ruminal total volatile fatty acids, acetate and propionate without affecting ruminal pH and ammonia-N concentration. The ESOC diet increased serum glucose concentration (P=0.019). Both of SOC and ESOC diets increased (P<0.05) daily milk production and energy corrected milk as well as milk fat concentration (P=0.028). All of DOC, SOC and ESOC increased (P<0.05) feed (milk) efficiency compared with the control diet. It is concluded that 30% of concentrates can be replaced with olive cake without negative effects on performance but with better performance when olive cake was ensiled with or without fibrolytic enzymes.

Increasing doses of carbohydrases: Effects on rumen fermentation, nutrient digestibility, and performance of mid-lactation cows

The objective of this study was to evaluate the effects of exogenous enzymes on nutrient intake and digestibility, rumen fermentation, and productivity of mid-lactating cows. Experiment 1 was designed to test increasing doses [0, 0.5, 1.0, or 1.5 g/kg of dry matter (DM)] of a combination of 2 enzyme products with xylanase and β-glucanase activities (Ronozyme Wx and Ronozyme VP, respectively; DSM Nutritional Products) on rumen fermentation and total apparent digestibility. Enzyme combinations had a ratio of endo-1,3(4)-β-glucanase to endo-1,4-β-xylanase of 8:2 (wt/wt). For experiment 1, 8 rumen cannulated lactating cows were used into a double 4 × 4 Latin square design experiment with 14 d of diet adaptation and 7 d of sampling. Despite no differences in feed intake, carbohydrases linearly increased neutral detergent fiber digestibility. Treatments marginally affected rumen fermentation, where a linear trend for lower rumen pH and a linear trend for greater isobutyrate concentration were observed with increasing enzyme dose. A trend for lower rumen NH₃-N concentration was observed for cows receiving carbohydrases in comparison with control group. When comparing all enzyme treatments against control group, cows fed enzymes tended to produce more 3.5% fat-corrected milk (FCM), produced more milk fat, and had greater blood glucose concentration. Experiment 2 evaluated 3 doses (0, 0.5, or 0.75 g/kg of DM) of the same combination of enzyme products on performance of cows (n = 36) in a complete randomized block (n = 12) design. Cows received treatments for 9 wk. No interaction effects between treatments and time were observed for all variables assessed in this study. In agreement with experiment 1, no differences were detected for feed intake, but cows fed the enzyme products tended to produce more 3.5% FCM and milk fat compared with control. In addition, cows fed enzymes exhibited greater efficiency of FCM production (FCM ÷ DM intake) compared with control. No differences were detected for intake and productivity when comparing the 2 doses of carbohydrases. In summary, the enzyme products tested in this study may improve feed efficiency due to greater milk fat concentration.

Effects of a xylanase-rich enzyme on intake, milk production, and digestibility of dairy cows fed a diet containing a high proportion of bermudagrass silage

We previously reported that milk production in dairy cows was increased by adding a specific xylanase-rich exogenous fibrolytic enzyme (XYL) to a total mixed ration (TMR) containing 10% bermudagrass silage (BMD). Two follow-up experiments were conducted to examine whether adding XYL would increase the performance of dairy cows consuming a TMR containing a higher (20%) proportion of BMD (Experiment 1) and to evaluate the effects of XYL on in vitro fermentation and degradability of the corn silage, BMD, and TMR (Experiment 2). In Experiment 1, 40 lactating Holstein cows in early lactation (16 multiparous and 24 primiparous; 21 ± 3 d in milk; 589 ± 73 kg of body weight) were blocked by milk yield and parity and randomly assigned to the Control and XYL treatments. The TMR contained 20% BMD, 25% corn silage, 8% wet brewer's grain, and 47% concentrate mixture in the dry matter (DM). Cows were fed the XYL-treated or untreated experimental TMR twice per day for 10 wk after a 9-d covariate period. In Experiment 2, ruminal fluid was collected from 3 cannulated lactating Holstein cows fed a diet containing 20% bermudagrass haylage, 25% corn silage and 55% concentrate. In Experiment 1, compared with Control, application of XYL did not affect DM intake (24.0 vs. 23.7 kg/d), milk yield (35.1 vs. 36.2 kg/d), fat-corrected milk yield (36.1 vs. 36.9 kg/d), or yields of milk fat (1.29 vs. 1.31 kg/d) or protein (1.07 vs. 1.08 kg/d). However, intake of neutral detergent fiber (4.67 vs. 4.41 kg/d) tended to increase with XYL; consequently, milk protein concentration was increased by XYL (3.02 vs. 2.95%). Feed efficiency tended to be lower in cows fed XYL (1.57 vs. 1.52 kg of fat-corrected milk/kg of DM intake) compared with Control. In Experiment 2, XYL tended to increase the rate of gas production in the TMR, the molar proportion of propionate for corn silage, and that of valerate for the TMR. In addition, XYL increased in vitro DM, neutral detergent fiber, and acid detergent fiber degradability of BMD and corn silage. Application of XYL to a diet with a relatively high proportion of BMD tended to increase digestible neutral detergent fiber intake, increased milk protein concentration, and in vitro degradability of DM, neutral detergent fiber, and acid detergent fiber. However, XYL did not affect milk production and tended to decrease feed efficiency in early lactation cows.

Effect of date palm (Phoenix dactylifera L.) leaves on productive performance of growing lambs

Eighteen 4-month-old lambs, with a mean live weight (LW) of 19.47 ± 0.20 kg, were used to evaluate the nutritive value of date palm leaves (DPL) ensiled with different additives in a completely randomized design. Lambs were stratified into three groups of 6 lambs each and fed a control diet comprising 60% concentrate feed mixture (CFM) and 40% DPL silage (T1). In other treatments, the DPL silage (DPLS) of the control treatment was replaced with EM1 additive-treated DPLS (T2) or El-Mofeed additive-treated DPLS (T3). Apparent digestibility, total digestible nutrient, digestible crude protein, dry matter intake, daily weight gain (DWG), price of DWG, daily profit, and economics of feed efficiency were higher (P < 0.05) for the additives-treated DPLS relative to the control, with T2 enhancing these parameters compared with T3. With exception of ruminal pH, which was reduced, concentrations of ruminal NH3-N and total volatile fatty acids (VFA) increased 4 h post feeding. However, ruminal NH3-N and total VFA were greater (P < 0.05) for the additives-treated DPLS, with T2 producing higher values than T3. Ruminal pH and feed cost/kg LW gain were lower for T2 relative to other treatments. Blood constituents were within the normal ranges for lambs, though slightly altered by treatments. Whereas serum total protein, albumin, and globulin were affected (P < 0.05) in this rank order, T1 < T3 < T2, other serum parameters were not affected. Relative feed cost and relative daily profit were lower and higher respectively for T2 than for T3. It is concluded that additives-treated DPLS is nutritionally superior to untreated DPLS as a roughage source in total mixed rations fed to growing lambs. However, for improved performance of the lambs and economic benefits, EM1-treated DPLS is recommended.

Microbial lipases and their industrial applications: a comprehensive review

Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and microbiological. The uses of microbial lipase market is estimated to be USD 425.0 Million in 2018 and it is projected to reach USD 590.2 Million by 2023, growing at a CAGR of 6.8% from 2018. Microbial lipases (EC 3.1.1.3) catalyze the hydrolysis of long chain triglycerides. The microbial origins of lipase enzymes are logically dynamic and proficient also have an extensive range of industrial uses with the manufacturing of altered molecules. The unique lipase (triacylglycerol acyl hydrolase) enzymes catalyzed the hydrolysis, esterification and alcoholysis reactions. Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes. Immobilized enzymes depend on the immobilization technique and the carrier type. The choice of the carrier concerns usually the biocompatibility, chemical and thermal stability, and insolubility under reaction conditions, capability of easy rejuvenation and reusability, as well as cost proficiency. Bacillus spp., Achromobacter spp., Alcaligenes spp., Arthrobacter spp., Pseudomonos spp., of bacteria and Penicillium spp., Fusarium spp., Aspergillus spp., of fungi are screened large scale for lipase production. Lipases as multipurpose biological catalyst has given a favorable vision in meeting the needs for several industries such as biodiesel, foods and drinks, leather, textile, detergents, pharmaceuticals and medicals. This review represents a discussion on microbial sources of lipases, immobilization methods increased productivity at market profitability and reduce logistical liability on the environment and user.

MetaRNAseq analysis of surti buffalo rumen content reveals that transcriptionally active microorganisms need not be abundant

The present study describes rumen microbiota composition and their functional profiles in Indian Surti buffaloes by metagenomic (MG) and metatranscriptomic (MT) approaches. The study compares samples from buffaloes fed three different proportion of roughages; green and dry type of roughage; and different rumen liquor fractions. Irrespective of sample, Bacteroidetes and Firmicutes were the most predominant bacterial phyla, followed by Proteobacteria, Fibrobacteres and Actinobacteria while, Prevotella, Bacteroides, Ruminococcus and Clostridium were the most abundant genera. Different proportions of taxa were observed in both MG and MT approaches indicating the differences in organisms present and organisms active in the rumen. Higher proportions of fungal taxa were observed in MT while important organisms like Fibrobacter and Butyrivibrio and abundant organisms like Bacteroides and Prevotella were underrepresented in MT data. Functionally, higher proportions of genes involved in Carbohydrate metabolism, Amino acid metabolism and Translation were observed in both data. Genes involved in Metabolism were observed to be underrepresented in MT data while, those involved in Genetic information processing were overrepresented in MT data. Further, genes involved in Carbohydrate metabolism were overexpressed compared to genes involved in Amino acid metabolism in MT data compared to MG data which had higher proportion of genes involved in Amino acid metabolism than Carbohydrate metabolism. In all significant differences were observed between both approaches, different fractions of rumen liquor (liquid and solid) and different proportions of roughage in diet.

Improved dairy production through enzyme supplementation

The rumen ecosystem has the ability to transform low grade nutrients to high quality products owing to the numerous micro-flora colonies it harbours which produce different types of degrading enzymes. It has been assumed that normal rumen flora is able to digest only a small portion of the cellulosic biomass enteric rumen. This provides numerous opportunities for improving digestion via enhancing digestibility through degradation pathways in rumen. The modern animal nutrition science has utilized this knowledge to commercially harness enzymes for improving nutrient availability for production enhancement. Broadly categorized as fibrolytic, proteolytic and amylolytic, these enzymes act synergistically with the naturally available enzymes in rumen. Enzyme supplementations improve the digestibility of fibre and increase nutrient absorption and energy availability for production activities across physiological status of the animal. This review summaries response of large lactating ruminants to the external enzyme (in vivo) supplementation in terms of actual milk production, milk composition, body weights, dry matter intake and digestibility of nutrients, as well as to assess the economic benefit in terms of additional expenses incurred and benefit derived with increase in milk production.

Effects of a recombinant fibrolytic enzyme on fiber digestion, ruminal fermentation, nitrogen balance, and total tract digestibility of heifers fed a high forage diet1

A metabolism study was conducted using 8 ruminal cannulated beef heifers to investigate the effects of a recombinant fibrolytic enzyme (RFE; xylanase XYL10C) selected specifically for forage-fed ruminants on ruminal pH, fermentation, nitrogen balance, and total tract digestibility of heifers. The experiment was a cross-over design with 2 treatments and 2 periods. The 2 treatments were a basal diet containing 60% barley silage, 30% barley straw, and 10% supplement (DM basis) without (control) or with RFE. The enzyme was sprayed onto the barley straw at a rate of 6.6 × 104 IU·kg-1 DM 24 h before feeding. Each period comprised 2 wk of diet adaptation and 1 wk of sampling and data collection. Feed intake and total tract digestibility of DM, OM, NDF, and ADF were unaffected by RFE. Ruminal pH including mean, minimum, maximum, and duration pH <5.8, did not differ between treatments. Total VFA concentration, molar proportion of individual VFA, and acetate-to-propionate ratio were also not affected by RFE. However, ruminal NH3-N concentration (P < 0.06) and endoglucanase activity (P < 0.08) in ruminal fluid tended to be higher with RFE. Nitrogen utilization and microbial protein synthesis were not affected by treatment. These results indicate that XYL10C did not improve fiber digestion in heifers fed a high forage diet, despite the fact that it was specifically selected for this trait in laboratory assays. However, the increased ruminal NH3-N concentration suggests it potentially increased ruminal proteolytic activity.

Effects of in-feed enzymes on milk production and components, reproduction, and health in dairy cows

Our objectives were to characterize responses in the field to a mix of fibrolytic enzymes using large commercial dairy herds and sufficient study power to evaluate milk production and reproductive responses to an enzyme treatment started during the precalving period. We hypothesized that the use of the enzyme treatment would increase milk production when provided to dairy cows precalving and for approximately 200 d of lactation. The study was conducted on 7,507 cows, in 8 replicates and 16 pens, at 3 dairies in the United States. Eight pens were randomly allocated as control pens and received no enzyme, and another 8 pens received enzyme treatment at a dose of 750 mL/t of dry matter feed. Milk production and energy-corrected milk yield were increased with the enzyme treatment by 0.70 and 0.80 kg/d, respectively, across a 5-month period. Milk fat percentage was not significantly increased by enzyme treatment, but milk fat yield was significantly increased by 0.040 kg/d, compared with controls. Milk protein yield increased 0.010 kg/d with enzyme treatment despite a small reduction of 0.020 percentage units in milk protein percentage. We found no evidence of an increase in the ln somatic cell count for the enzyme-treated cows. Body weight overall was not increased for enzyme-treated cows, but we did observe a numerical increase in dry matter intake (0.20 kg/head per day) for enzyme-treated cows. Most production responses to the enzyme treatment were influenced by dairy. Compared with controls, milk yield in enzyme-treated cows was significantly higher by 3.6 kg/d in dairy 2 and numerically higher by 0.60 and 0.20 kg/d in dairies 1 and 3, respectively. Reproduction, health, and risk of removal or death were not significantly influenced by treatment, apart from a reduced time to first breeding. Production responses to the enzyme treatment varied by dairy from substantial to minor increases, but variation among dairies was not evident in differences in dry matter intake or in partitioning of body weight among enzyme-treated and control pens and cows. It appears likely that the increase in production reflected increased digestibility of feed; however, further work is needed to identify factors influencing the variation in production responses to enzymes.

Influence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter) - 1 of commercial fibrolytic enzymes (MAXFIBER-I ® , SHAUMANN GmbH, Wahlstedt, Germany) on in vitro fermentation of date palm (Phoenix dactylifera) by-products: date kernels, wasted dates, floral stems, and palm fronds. Rumen contents were obtained from two non-lactating Holstein cows. Enzyme supplementation to by-products was carried out 12 h prior to incubation. Compared to the control, the enzymatic supplementation quadratically increased the extent but not the gas production rate of date kernel fermentation. Indeed, the potential gas production increased notably by 14.8 % with the lowest enzymes dose following recorded gas production after 48, 72, and 96 h of incubation. The estimated organic-matter digestibility, metabolisable energy, and total volatile fatty acids in the incubation fluid tended to be increased with the lowest dose by 7.8 %, 8.4 %, and 13.9 % respectively. For the wasted dates, this feed additive tended to linearly increase the gas production rate of fermentation with the highest dose. On the other hand, this supplementation had no effect on the ruminal fermentation of the floral stems and palm fronds. The exogenous fibrolytic enzymes were more effective on fibrous but not on lignified date palm by-products.

The impact of direct-fed microbials and enzymes on the health and performance of dairy cows with emphasis on colostrum quality and serum immunoglobulin concentrations in calves

Thirty‐six cows were blocked by calving date and randomly assigned to one of three treatments. Cows were on treatments 3 weeks prepartum through 8 weeks post‐partum. Treatments were as follows: (i) no direct‐fed microbial (DFM) or cellulase and amylase enzymes (C), (ii) 45.4 g/day of DFM (D) or (iii) 45.4 g/day of DFM and 18.2 g/day of enzyme (DE). Total mixed ration fed and refused were measured daily to determine dry matter intake (DMI). Blood samples were taken three times weekly and analysed for β‐hydroxybutyrate, glucose and non‐esterified fatty acids. Body weight (BW) was measured weekly. Colostrum was weighed and analysed for IgA and IgG concentration. Calves were fed 4 L of colostrum within 2 hr of birth. Calf blood samples were taken at 0 and 24 hr for analysis of IgA and IgG concentrations and apparent efficiency of absorption. Milk yield was measured daily and samples collected weekly. Initial BW was different among treatments with D being lesser than C or DE treatments. Body weight, weight gain, efficiency of gain, DMI and blood parameters were unaffected. Treatment did not affect colostrum yield. Ash percentage of colostrum tended to increase with D and DE, while IgA and total solids yield decreased with D. Colostrum fat yield was decreased in D and DE. Treatments did not impact BW, serum IgA and IgG concentrations or apparent efficiency of absorption of calves. Post‐partum BW, DMI, blood parameters, milk production and composition were unaffected by treatment. However, cows on D gained more BW and tended to have greater efficiency of gain compared to those on DE, but were similar to C. Somatic cell scores were greatest for D. Results indicate that DFM and enzyme supplementation did not improve health and performance of dairy cattle during the pre‐ and post‐partum periods under conditions of this study.

In vitro evaluation of total mixed ration supplemented with exogenous fibrolytic enzymes for crossbred cows

Aim:

The study was conducted to evaluate the levels of exogenous fibrolytic enzymes (EFE) on in vitro digestibilities of dry matter (DM) and organic matter (OM), total gas production (TGP), metabolizable energy (ME) content, and microbial biomass production (MBP).

Materials and Methods:

The total mixed ration (TMR) was prepared using 30% each of sorghum hay and groundnut straw and 40% compound concentrate mixture to meet nutritional requirement of cow (500 kg) producing 12 kg fat corrected milk. The EFE was incorporated at 0, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, and 400 mg/kg TMR. The TMR substrates with different levels of EFE were in vitro incubated to ascertain their effect on digestibility, gas production, and nutritive values.

Results:

The significantly (p<0.05) higher and optimum in vitro digestibilities of DM (63.03%) and OM (63.62%) as well as TGP (72.35 ml/500 mg TMR) were observed at supplementation of 240 mg EFE/kg TMR, while ME (7.16 MJ/kg DM) and MBP (97.63 mg/500 mg TMR) were also better.

Conclusion:

The incorporation of EFE at 240 mg/kg TMR resulted significantly (p<0.05) higher and optimum in vitro digestibilities of DM and OM. The TGP, ME, and MBP were also better. The levels of EFE 240 mg/kg TMR were found suitable for further in vivo study in crossbred cows.

Effects of exogenous enzymes and application method on nutrient intake, digestibility and growth performance of Pelibuey lambs

Pelibuey sheep is the main breed in the tropical and subtropical regions of Mexico, and high demand of sheep meat has favored the finishing of lambs in feedlots with diets containing high levels of grains. The objective of this study was to evaluate the effects of exogenous enzymes (EE) and application method on nutrient intake and digestibility and performance of growing Pelibuey lambs. Treatments were based on comparison of two different methods of adding an enzyme product (sprayed on the total mixed ration or applied orally to the lambs) versus control treatment (no added enzyme). Twenty-one Pelibuey lambs, weighing 15.7 kg (SD = 1.8 kg) initial body weight, were individually housed in shaded pens and assigned randomly to one of the three enzyme treatments. At the end of study (lasting for 45 days), three lambs from each treatment were randomly selected and adapted to a pants and harness designed for fecal collection to measure nutrient digestibilities. Total body gain and average daily gain were affected (P < 0.05) by supplemental EE. The application method of EE had significant (P < 0.05) effect on FCE and FCR, but no effects were observed on nutrient intake. Supplemental EE did improve (P < 0.05) the digestibilities of dry matter, organic matter, neutral and acid detergent fiber, but no differences were observed in crude protein digestibility. The application method of EE had significant (P < 0.05) effect on the digestibility of acid detergent fiber. Supplemental EE can improve body weight gain and nutrient digestibilities without affecting nutrient intake in Pelibuey lambs, but the results of feed conversion efficiency and acid detergent fiber digestibility depend on the application method used of the EE.

Effect of exogenous fibrolytic enzymes on performance and blood profile in early and mid-lactation Holstein cows

The supplementation of exogenous fibrolytic enzymes (EFE) to dairy cows diets could be a strategy to improve fiber degradation in the rumen which is especially important for the early lactating cows characterized by a high milk energy output and an insufficient energy intake. The objective of this study was to examine the effects of a fibrolytic enzyme product (Roxazyme G2 Liquid, 3.8 and 3.9 mL/kg total mixed ration [TMR] DM) supplemented to a TMR on production performance and blood parameters of dairy cows during early (trial 1) and mid-lactation (trail 2). In addition, rumination activity was measured in trial 2. The nutrient digestibility of the experimental TMR was obtained by using wethers. In the digestibility trial, EFE was supplemented at a rate of 4.4 mL/kg Roxazyme G2 Liquid TMR-DM. The TMR contained 60% forage and 40% concentrate (DM basis). Twenty eight 50 ± 16 days in milk (DIM) and twenty six 136 ± 26 DIM Holstein cows were used in two 8-wk completely randomized trails, stratified by parity and milk yield level. One milliliter of the enzyme product contained primarily cellulase and xylanase activities (8,000 units endo-1,4-ß glucanase, 18,000 units endo-1,3(4)-ß glucanase and 26,000 units 1,4-ß xylanase). No differences in digestibility of DM, OM, CP, NDF and ADF were observed (P > 0.05) between the control and the EFE supplemented TMR. Addition of EFE to the TMR fed to early (trial 1) and mid-lactation cows (trial 2) did not affect daily dry matter intake (DMI), milk yield, 4% fat-corrected milk, energy-corrected milk (ECM), concentration of milk fat, protein, fat-protein-quotients, somatic cell score, energy balance, and gross feed efficiency of early and mid-lactation cows (P > 0.05). Mid-lactation cows (trial 2) fed with TMR enzyme showed a tendency of a slightly higher ECM yield (P = 0.09). The tested blood parameters were not affected by treatment in trials 1 and 2 (P > 0.05). Exogenous fibrolytic enzymes supplementation did not alter daily time spent ruminating in trial 2 (P = 0.44). In conclusion, under the conditions of this study, no positive effects of enzyme supplementation on dairy performance and health status of dairy cows during early and mid-lactation were observed.

Effects of Cellulase Supplementation on Nutrient Digestibility, Energy Utilization and Methane Emission by Boer Crossbred Goats

This study examined the effect of supplementing exogenous cellulase on nutrient and energy utilization. Twelve desexed Boer crossbred goats were used in a replicated 3×3 Latin square design with 23-d periods. Dietary treatments were basal diet (control, no cellulase), basal diet plus 2 g unitary cellulase/kg of total mixed ration dry matter (DM), and basal diet plus 2 g compound cellulase/kg of total mixed ration DM. Three stages of feeding trials were used corresponding to the three treatments, each comprised 23 d, with the first 14 d as the preliminary period and the following 9 d as formal trial period for metabolism trial. Total collection of feces and urine were conducted from the 4th d of the formal trial, and gas exchange measures were determined in indirect respiratory chambers in the last 3 d of the formal trial. Results showed that cellulase addition had no effect (p>0.05) on nutrient digestibility. Dietary supplementation of cellulase did not affect (p>0.05) N intake and retention in goats. Gross energy (GE) intake, fecal energy and urinary energy excretion, heat production were not affected (p>0.05) by the cellulase supplementation. Total methane emission (g/d), CH₄ emission as a proportion of live weight or feed intake (DM, organic matter [OM], digestible DM or digestible OM), or CH₄ energy output (CH₄-E) as a proportion of energy intake (GE, digestible energy, or metabolizable energy), were similar (p>0.05) among treatments. There was a significant (p<0.001) relationship between CH₄ and live weight (y = 0.645x+0.2, R² = 0.54), CH₄ and DM intake (y = 16.7x+1.4, R² = 0.51), CH₄ and OM intake (y = 18.8x+1.3, R² = 0.51) and CH₄-E and GE intake. Results from this study revealed that dietary supplementation of cellulase may have no effect on nutrient digestibility, nitrogen retention, energy metabolism, and methane emission in goat.