Twenty four Barki lambs with an average body weight of 20.7 ± 0.17 kg were used in a complete randomized design to evaluate the effects of replacing clover (Trifolium alexandrinum L) hay as a traditional basal diet (C) with moringa tree stalks (MS) treated with fungi (Trichoderma reesei) (MF) and yeast (Saccharomyces cervisiae) (MY) under solid-state fermentation on nitrogen and water metabolism, rumen fermentation and economic efficiency of feeds. Lambs were divided into three groups each with eight lambs depending on their live weight. Concentrate feed mixture was similar for all groups and was offered at 2% of live weight with the basal roughage offered ad libitum. The results show that the rations had significant effects (P < 0.05) on DM, crude protein and nitrogen free extract digestibility. Percentage total digestible nutrients was not affected (P < 0.05) by the experimental rations and the values ranged between 0.62 and 0.64. The MY ration had the highest (P < 0.05) digestible crude protein followed by C and MF. The roughage intake expressed as a percentage of total feed intake for MF and MY groups were higher by 4 and 2%, respectively compared to the control group. Average daily gains were 173, 139 and 146 g/head/day, for C, MF and MY groups, respectively. Average dressing percentages based on either fasting weight or empty weight were not affected by the experimental rations. There were no differences (P < 0.05) among groups in N and water balance. Rumen NH3-N concentrations for the MF and MY groups peaked (P < 0.05) at 3 h post feeding whereas for the control it peaked at 6 h post feeding. Rumen TVFA’s concentrations for all treatments increased gradually from zero to 6 h post-feeding. MY diet recorded the highest (P < 0.05) economical feed efficiency compared with MF and control diet. These results suggest that treatment of moringa stalks with S. cerevisiae for 21 days in a solid-state fermentation system improved its nutritive value and is more suitable for practical feeding in sheep rations.

Studies have shown that meat from indigenous chicken is more preferred than that of convectional broilers because of it is chewy low fat content attributed to the low n-6/n-3 fatty acids ratio compared to broiler meat.Broiler meat products may attain this low fat content by allowing the birds access to outside ground to scavenge.This study aimed to bridge this gap by producing broiler meat that simulates that of the indigenous chicken in terms of taste.In a completely randomized block design experiment, 240 day-old chicks were randomly assigned to four free-range strategies (FRR) or treatments.In FRR A, FRR B and FRR C, day-old chicks were allowed free-range access at 2, 3 and 4 weeks of age, respectively.In FRR D (the control), day-old chicks were fed the commercial broiler starter and finisher diet for the entire experimental period of 8 weeks without outside access.Clean drinking water was offered ad libitum.The live weight of the chicken was recorded weekly and at 6, 7and 8 weeks of age three birds from each treatment slaughtered for sensory evaluation.The FRR had a significant impact on the aroma, flavour and overall acceptability of the meat (P<0.0001) with the chickens allowed free-range access at 2 weeks of age being the most preferred and the control without free-range access the least preferred.These results suggest that the longer broilers are exposed to outside access the tastier is their meat.

The cecal gas (GP) and methane (CH4) production and cecal fermentation kinetics when corn grain (CG) was replaced with prickly cactus (PC) in a horse’s diet at different levels of Salix babylonica (SB) extract was investigated. Three total mixed rations where CG was replaced with PC at three levels (/kg): 0 g (Control), 75 g (PC75) or 150 g (PC150) were prepared and SB extract added at four levels: 0, 0.6, 1.2 and 1.8 mL/g dry matter (DM) of substrates. No ration type × SB extract dose interaction was observed (P > 0.05) for GP kinetics and CH4 production. Increasing the level of PC in the ration quadratically increased (P < 0.01) the asymptotic GP and decreased (P < 0.01) the rate and lag time of GP. Increasing the level of PC in the ration, increased GP values (P < 0.05). Increasing the level of SB extract linearly decreased (P = 0.001) the lag time of GP of all diets without affecting the asymptotic GP or the rate of GP. Ration type and SB level had no effect (P > 0.05) on CH4 production; however, at 36 h of incubation, SB extract decreased CH4 production. The rations PC75 and PC150 increased cecal pH compared with the control ration. The PC150 ration had the highest (P < 0.05) DM degradability, short chain fatty acids production, and gas yield after 24 h of incubation, with no effect (P > 0.05) of SB inclusion on all investigated fermentation kinetic parameters. It is concluded that increasing the level of PC in the diet of horse and replacing CG up to 60%, increased GP and improved cecal fermentation kinetics without affecting CH4 production. Inclusion of S. babylonica extract in the tested rations had weak effects on fermentation kinetics although it decreased the lag time of GP.

The current study aimed to evaluate the chemical composition and in vitro digestibility of almond tree (Prunus dulcis D. A. Webb syn. Prunus amygdalus; var. Shokoufeh) leaves versus hulls, and green versus dry leaves as feed for ruminants. The fresh green almond hulls (GAH) and leaves (GAL) were harvested and spread under a shade to dry. Dry almond leaves (DAL) were collected from under the trees where as dry almond hulls (DAH) were collected 4 weeks after harvesting the fresh samples. The chemical composition of substrates was determined using standard approaches and the metabolisable energy (ME), in vitro dry matter (DMD) and in vitro organic matter (OMD) digestibility were measured using the in vitro gas production (GP) technique. The GAL contained 81 g crude protein (CP) kg−1 DM while DAH contained 103 g CP kg−1 DM. The CP was higher (P = 0.0003) in dry (leaves and hulls) than in green (leaves and hulls) samples. The ash content ranged from 99.2 to 181.5 g kg−1 DM in DAH and DAL, respectively, (P = 0.0041). The ether extract content ranged from 27 for DAH to 65 g kg−1 for DAL (P = 0.0018). The acid detergent fibre and neutral detergent fibre content ranged from 185 to 304 and 444 to 620 g kg−1 DM (P = 0.04), for GAL and DAH, respectively. The DAH had the highest (P = 0.0001) GP24 and GP96. The DAH had the highest (P = 0.0001) potential GP (i.e., b), while the GP rate was highest for GAL and GAH (P = 0.034), ME was highest for DAH (P = 0.0001), and in vitro OMD was highest for DAH (P = 0.0001). The highest DMD (P = 0.0001) values were obtained with DAH followed by GAL, DAL and GAH, respectively. It can be concluded that almond hulls and leaves have a good nutritional potential to cover the maintenance nutrient requirements of small ruminants. Almond hulls and leaves can also be used as supplement to low quality mature pasture and/or crop residues. However, more studies are warranted to better characterize these feeds in in vivo animal feeding trials.

In a completely randomised design, twenty four 12-months old Mongolian breed male lambs averaging 21.6 ± 0.48 kg of body weight (BW) were used to evaluate the effects of exogenous cellulase and xylanase enzyme preparations on feed intake, digestibility of nutrients, growth and economics of rearing lambs. The lambs were randomly assigned to six treatment groups with four animals per treatment. The treatment combinations comprised: i) two enzyme preparations, i.e. cellulase vs. xylanase (ENZc, ENZx), ii) two ration types, i.e. wheat straw + wheat bran (diet W) vs. barley straw + wheat bran (diet B) and iii) two control diets (diet W and diet B without enzyme preparations, –ENZ). Lambs were fed the cellulase and xylanase treated wheat and barley straws ad libitum whereas the wheat bran was offered at 400 g DM per day. Significant effects were observed for nutrient intake of diet B+ENZc, and for crude protein (CP) and neutral detergent fibre (NDF) digestibility of diet W+ENZc. The average daily gain (ADG) increased in all enzyme treated groups with highest values found in diet B+ENZc, but without significant differences found between the two enzyme preparations. Both enzyme preparations had positive effects on feed conversion ratio (FCR) of both diets, where by the highest values were found for diet B +ENZc. Enzyme preparation had no effect on the total feed cost for both diet types and showed positive effects on other economic parameters, where by cellulase yielded better results than xylanase. These results suggest that cellulase addition is effective for improving digestibility of nutrients, growth performance and net revenue ingrowing lambs.

Mitigation of methane (CH4) and carbon dioxide (CO2) emissions as well as ruminal fermentation parameters of a total mixed ration in the presence of Schizochytrium microalgae (SA) and sunflower oil (SO) or their mixture (SASO) as unsaturated fatty acid sources was investigated. Rumen liquor from two rumen cannulated Holstein steers and two rumen cannulated Creole goats was used as inoculum. Interactions between inoculum source x additive type, and inoculum source x additive type x dose were observed for gas, CH4 and CO2 production and fermentation parameters. Additives affected the fermentation parameters in a dose-dependent manner. With goats' inoculum, the inclusion of SO (1,2,4, 5%), SA (2,3,5%) and SASO (1,3%) increased gas production (GP) and decreased the rate of GP, while with the steer inoculum, SO at 1 and 4% increased GP and the rate of GP. All levels of SA and SASO decreased the asymptotic GP and increased the rate of GP. The goat inoculum decreased CH4 at different doses of SO, SA and SASO whereas the steer inoculum decreased CH4 production. At all doses, additives decreased fermentation pH, protozoal counts, and increased ammonia-N, DM degradability and total bacterial counts. Sunflower oil (i.e., SO) at 1-3%, SA at 1-2%, and SASO at 1-2% were the most efficacious in the nutrition of goats, compared with SO at 1 to 2 in steers. The results suggest that Schizochytrium microalgae and sunflower oil could be a valuable means of sustainably mitigating CH4 and CO2 emissions for improved environmental conditions. (C) 2017 Elsevier Ltd. All rights reserved.

The aim of this study was to determine the effect of anaerobic ensiling of raw agricultural wastes with a fibrolytic enzyme cocktail (EZ) as a cleaner and sustainable biological product for animal feed. Ten 1-kg samples of wheat straw, corn stalks and sugarcane bagasse were chopped at 5 cm length and mixed with EZ at three levels of 0, 1 or 3 L enzyme/ton of feed, moistened to a relative humidity of approximately 50% and ensiled in plastic bales for 30 days. Additionally, fibrous samples were incubated for 72 h with rumen liquor to determine the digestion of dry matter (DM), neutral detergent fibre and acid detergent fibre. Increasing enzyme level lowered ether extract and nitrogen-free extract contents of fibrous feeds and increased the biodegradation of acid detergent lignin of wheat straw. Anaerobic ensiled corn stalks and sugarcane bagasse with EZ improved the biodegradation of DM and fibre fractions. It could be concluded that ensiling fibres of the three wastes with EZ improved and enhanced their ruminal digestion with the biodegradation rate at 3 L/ton and subsequently produced a cleaner product for animal feed from agriculture wastes.

SUMMARY The aim of the current study was to assess the effects of adding Chlorella vulgaris algae at different levels on in vitro gas production (GP) of three total mixed rations (TMR) with different concentrate (C): maize silage (S) ratios (25C : 75S, 50C : 50S, 75C : 25S). Chlorella vulgaris was added at 0, 20, 40 and 80 mg/g dry matter (DM) of the TMR and total gas, methane (CH4) and carbon dioxide (CO2) production were recorded after 2, 4, 6, 8, 10, 12, 24 and 48 h of incubation in three runs. Increasing concentrate portion in the TMR linearly increased the asymptotic GP and decreased the rate of GP without affecting the lag time. Addition of C. vulgaris at 20 mg/g DM to the 25C : 75S TMR increased the asymptotic GP, CH4, CO2 and GP at 48 h. Addition of C. vulgaris to the 50C : 50S TMR decreased the asymptotic GP and GP at 48 h. Higher CH4 production was observed at 48 h of incubation when C. vulgaris was included at (per g DM): 20 mg for the 25C : 75S ration, 40 mg for the 50C : 50S ration and 80 mg for the 75C : 25S ration. Inclusion of C. vulgaris linearly increased CH4 production for the 50C : 50S ration and increased CO2 production at 10 and 12 h of incubation for the 50C : 50S ration, whereas 20 and 40 mg C. vulgaris/g DM of the 75C : 25S TMR decreased CO2 production. The 25C : 75S TMR had the highest in vitro DM disappearance with C. vulgaris addition. Chlorella vulgaris addition was more effective with rations high in fibre content than those high in concentrates. It can be concluded that the optimal level of C. vulgaris addition was 20 mg/g DM for improved ruminal fermentation of the 25C : 75S TMR.

Ruminants are one of the major generators of methane, a greenhouse gas (GHG) with a global warming potential, 25-fold that of carbon dioxide. Methane production by ruminants also reduces the gross feed energy intake utilization by about 2–12%. The present study aimed to test the effects of different levels of a ruminal fermentation modulator (RFM) on in vitro ruminal fermentation and GHG production of five total mixed rations (TMR) with different silage (S) to-concentrate (C) ratios (0S:100C, 25S:75C, 50S:50C, 75S:25C, and 100S:0C). The RFM contained mainly calcium propionate and malate, and monopropylene glycol. The rumen inoculum was collected from a Brown Swiss cow fed a TMR of concentrate and alfalfa hay (1:1 dry matter (DM)) ad libitum. Gas production (GP) measurements were recorded up to 72 h of incubation. There were interactions (P < 0.05) between ration type and RFM dose for GP until 18 h and for partitioning factor and gas yield at 24 h of incubation. The 100S:0C TMR had the highest asymptotic GP (linear and quadratic effects; P < 0.05) compared with other TMR. The 0S:100C TMR had the lowest GP rate (linear effect; P = 0.003). Ration type and RFM inclusion had no effect (P > 0.05) on methane production. The DM digestibility increased (linear effect; P = 0.003) as silage level increased. Overall, increasing silage in the TMR lowered the asymptotic GP and DM digestibility. The asymptotic GP was higher with the addition of the RFM without any effect on fermentation kinetics. These results suggest that the RFM can be used as an environmental cleaner product in animal farming due to its ability to improve ruminal fermentation of feedstuffs and to reduce methane emissions.

The generation of poultry slaughterhouse waste from poultry production is not only unavoidable but the amount and kinds of waste can cause environmental problems. In the present study, the potential rumen digestion of poultry slaughterhouse waste which consists of protein-rich organic residues was evaluated. The chemical composition, amino acid profile and Cornell Net Carbohydrate and Protein System fractions of these wastes was determined. Rumen digestion of poultry slaughterhouse waste was compared with two common protein sources (fish meal and roasted soybean). Three poultry slaughterhouse waste samples were collected from industrial poultry slaughter-houses and the in situ degradation was done using rumen cannulated sheep. The protein (50-63%), ether extracts (18-27%) and ash (9-15.5%) contents of different poultry slaughterhouse waste samples were different (P < 0.05). Methionine and lysine contents were similar among different poultry slaughterhouse waste sources. Difference were observed for cystine (1.2-1.7%), threonine (1.9-2.2%), arginine (3-3.5%), leucine (3.5-4.1%) and valine (2.8-3.3%) (P < 0.05). Ruminal degradation rate for dry matter, organic matter and protein were different among poultry slaughterhouse waste, fish meal and roasted soybean. The degradation parameter for protein degradation was 76% for poultry slaughterhouse waste, 79% for fish meal and 98% for roasted soybean (P < 0.05). Results revealed that there was great variation in chemical composition, protein fractioning, and amino acid profiles of different poultry slaughterhouse waste sources. Poultry slaughterhouse waste is slowly-degraded protein in the rumen and thus can be an economical and rich source of rumen undegradable protein in ruminant nutrition. This implies that the use of poultry slaughterhouse waste in ruminant nutrition has a huge potential as a cleaner product of animal feeding and prevention environmental pollution. However, further studies are warranted to evaluate the digestibility of poultry slaughterhouse waste amino acids escaping the rumen into the intestine in ruminants and to compare the biological values for the amino acids in these waste material with common ruminant feedstuffs. (C) 2017 Elsevier Ltd. All rights reserved.

Chlamydia abortus is obligate intracellular bacteria that cause a wide range of reproductive and respiratory diseases in animals and humans. Serologic and molecular evidences of C abortus in Mexico have been reported in sheep and goats. The presence of C abortus antibodies in horses (n = 301) was detected by a commercial indirect enzyme-linked immunosorbent assay test. Additionally, C abortus antibodies in bovines (n = 25), goats (n = 8), and sheep (n = 94) reared with horses were detected to identify probable animal species that could infect horses. The prevalence obtained was 1.32% for horses, 48% for bovines, 12.5% for goats, and 29.7% for sheep. The 75% of horses seropositive to C abortus were obtained from farms with the presence of sheep seropositive to C. abortus. These results suggest that the presence of C abortus in horses from Mexico exist and can be related with the presence of sheep positive to C abortus. (C) 2017 Elsevier Inc. All rights reserved.

In a randomized block design experiment, the effect of fecal inocula from horses supplemented with live yeast (Saccharomyces cerevisiae) in diets containing 50% oat straw on in vitro total gas (gas production [GP]), methane (CH4), and carbon dioxide (CO2) productions as indicators of hindgut activity was assessed. Three commercial products of S. cerevisiae were tested (1) Biocell F53 (YST53), (2) Procreatin 7 (YST07), and (3) Biosaf SC47 (YST047). For the incubations, each product was added at 0 (control without yeast addition), 2, or 4 mg/g dry matter (DM). Fecal inocula for incubations with each treatment was obtained from Quarter Horse mares fed the same yeast additives for 15 days, resulting in four different fecal inocula (FI53, FI07, FI47, and FI00). The fecal content mixed with the culture media were used to inoculate three identical runs of incubation in bottles containing 1-g DM of substrate (a mixture of concentrate and oat straw [1: 1 DM]). The GP, CH4, and CO2 productions were measured at 2, 4, 6, 8, 10, 12, 24, and 48 hours post-incubation. Addition of additives YST53 and YST07 at 2 mg/g DM resulted in higher asymptotic GP (linear effect, P = .021) and GP during the first 12 hours of incubation (linear effect, P < .05) compared with control without yeast addition, with the highest value being for the dose 2 mg/g DM with the fecal inoculum FI53. The additive YST47 at all doses with fecal inoculum FI47 had lower GP (linear effect, P < .05) at different incubation hours compared with control. The additive YST53 increased GP, CH4, and fermentation kinetics at the dose 2 mg/g DM with decreasing CH4 production by 78% at 4 mg/g DM at 24 hours of incubation. Addition of YST53 at 2 and 4 mg/g DM with fecal inoculum FI53 enhanced fermentation kinetics (P < .05) compared with control and other additives at different doses. It can be concluded that the yeast additive Biocell F53 was the most effective at doses of 2 and 4 mg/g DM compared with other Saccharomyces strains to attain a more favorable hindgut fermentation to digest fibrous roughages by horses. (C) 2016 Elsevier Inc. All rights reserved.

The current study aimed to evaluate the chemical composition and in vitro digestibility of almond tree (Prunus dulcis D. A. Webb syn. Prunus amygdalus; var. Shokoufeh) leaves versus hulls, and green versus dry leaves as feed for ruminants. The fresh green almond hulls (GAH) and leaves (GAL) were harvested and spread under a shade to dry. Dry almond leaves (DAL) were collected from under the trees where as dry almond hulls (DAH) were collected 4 weeks after harvesting the fresh samples. The chemical composition of substrates was determined using standard approaches and the metabolisable energy (ME), in vitro dry matter (DMD) and in vitro organic matter (OMD) digestibility were measured using the in vitro gas production (GP) technique. The GAL contained 81 g crude protein (CP) kg DM while DAH contained 103 g CP kg DM. The CP was higher (P = 0.0003) in dry (leaves and hulls) than in green (leaves and hulls) samples. The ash content ranged from 99.2 to 181.5 g kg DM in DAH and DAL, respectively, (P = 0.0041). The ether extract content ranged from 27 for DAH to 65 g kg for DAL (P = 0.0018). The acid detergent fibre and neutral detergent fibre content ranged from 185 to 304 and 444 to 620 g kg DM (P = 0.04), for GAL and DAH, respectively. The DAH had the highest (P = 0.0001) GP24 and GP96. The DAH had the highest (P = 0.0001) potential GP (i.e., b), while the GP rate was highest for GAL and GAH (P = 0.034), ME was highest for DAH (P = 0.0001), and in vitro OMDwas highest for DAH (P = 0.0001). The highest DMD (P = 0.0001) values were obtained with DAH followed by GAL, DAL and GAH, respectively. It can be concluded that almond hulls and leaves have a good nutritional potential to cover the maintenance nutrient requirements of small ruminants. Almond hulls and leaves can also be used as supplement to low quality mature pasture and/or crop residues. However, more studies are warranted to better characterize these feeds in in vivo animal feeding trials. M. Y. Elahi H. Kargar M. S. Dindarlou Department of Animal Science, Faculty of Agriculture, University of Zabol, P.O. Box 98615-538, Zabol, Iran A. E. Kholif Dairy Science Department, National Research Centre, 33 Bohouth St. Dokki, Giza, Egypt M. M. Y. Elghandour A. Z. M. Salem (&) Faculty of Veterinary Medicine and Livestock, Autonomous University of the Mexico State, Toluca, Mexico e-mail: asalem70@yahoo.com S. Rojas-Hernández Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Guerrero, Chilpancingo, Mexico N. E. Odongo Department of Animal Sciences, School of Agriculture, Pwani University, Kilifi, Kenya 123 Agroforest Syst (2017) 91:773–780 DOI 10.1007/s10457-016-9964-5 Author's personal copy

Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a 3×4 factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, 0.25×10(7), 0.50×10(7), and 0.75×10(7) colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen (NH3-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The NH3-N concentration and CH4 production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be 0.25×10(7) cfu/500 mg substrates in vitro.

Ruminal fermentation is accompanied by production of methane (CH4) and carbon dioxide (CO2) which aretreenhouse gases (GHG) that cause environmental pollution. The effect of natural feed additives on the in vitro fermentation and production of CH4 and CO2 in dairy calf has had less attention. Therefore, this study aimed to evaluate the effect of garlic oil, xylanase enzyme, and yeast on in vitro biogas production from dairy calves fed a high concentrate diet. Rumen contents from 60-d old Holstein calves fed a concentrate diet were used as inoculum source. Garlic oil was included at 30,120, 250 and 500 Lig dry matter (DM), while xylanase was included at 3 and 6 Lig DM and yeast at 2 and 4 mgig DM. The substrate used was the same as the diet fed to calves. Garlic oil linearly decreased (P < 0.05) in vitro DM digestibility and there were no differences among levels of either xylanase or yeast. Garlic oil decreased (P < 0.05) DM degradability while xylanase and yeast had no effect. The lag phase was linearly increased (P < 0.05) with increasing level of garlic oil. Garlic oil quadratically decreased CH4 and CO2 production. The control treatment had the highest CH4 and CO2 production followed by xylanase, yeast and garlic oil. Increasing level of xylanase and yeast increased (P < 0.05) CO2 production. It can be concluded that garlic oil followed by yeast and then xylanase can be used to mitigate in vitro CH4 and CO2 production from dairy calves fed a high concentrate diet. However, further research is warranted to establish the efficacy of such feed additives in in vivo trials. (C) 2016 Elsevier Ltd. All rights reserved.

This study was designed to assess the effectiveness of dietary cellulase (243 U/g, derived from Neocallimastix patriciarum) and a Saccharomyces cerevisiae fermentation product (yeast product) on ruminal fermentation characteristics, enteric methane (CH4) emissions and methanogenic community in growing goats. The experiment was conducted in a 5 × 5 Latin square design using five Xiangdong black wether goats. The treatments included a Control and two levels of cellulase (0.8 g and 1.6 g/kg dry matter intake (DMI), i.e. 194 U/kg and 389 U/kg DMI, respectively) crossed over with two levels (6 g or 12 g/kg DMI) of the yeast product. There were no significant differences regarding feed intake, apparent digestibility of organic matter, neutral detergent fibre and acid detergent fibre among all the treatments. In comparison with the Control, the ruminal ammonia N concentration was decreased (p = 0.001) by cellulase and yeast product addition. The activities of carboxymethylcellulase and xylanase were decreased after cellulase addition. Moreover, dietary cellulase and yeast product addition led to a significant reduction (p < 0.05) of enteric CH4 emissions although the diversity and copy numbers of methanogens among treatments were not dissimilar. The present results indicate that the combination of cellulase and yeast fermentation product can reduce the production of CH4 energy and mitigate the enteric CH4 emissions to a certain degree.

Susana Ballinas, Abdelfattah Z.M. Salem, Ahmed E. Kholif, Alberto Barbabosa, Mona M.Y. 3 Elghandour, Miguel Mellado, Nicholas Odongo 4 5 1 Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, 6 México 7 2 Dairy Science Department, National Research Centre, 33 Bohouth St. Dokki, Giza, Egypt 8 Autonomous Agrarian University Antonio Narro, Department of Animal Nutrition, Saltillo, 9 Mexico 10 Department of Animal Sciences, School of Agriculture and Environmental Sciences, Pwani 11 University, P. O. Box 195-80108, Kilifi, Kenya 12