以玉米秸秆为粗料的绵羊日粮中添加多聚包被尿素以及膨润土的影响
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
本试验旨在研究以玉米秸秆为粗料的绵羊日粮中添加多聚物包被尿素以及膨润土对绵羊生产性能的影响。
     试验一:采用4只装有瘤胃瘘管的杜泊×小尾寒羊杂交羯羊,按照4×4拉丁方试验,研究以玉米秸秆为主的粗料型日粮中添加多聚物包被尿素(Optigen Ⅱ)以及膨润土对绵羊采食量、营养物质消化率、氮沉积、瘤胃发酵以及微生物蛋白质合成量的影响。试验羊只单栏独饲,每期试验持续24天,包括14天的适应期以及10天的采样期(第l到5天进行消化代谢试验,第6天羊只休息,第7天采瘤胃液,第8到10天进行尼龙袋试验),消化代谢试验开始前4天将试验羊只上代谢笼进行环境适应。试验设计了4种等氮等能日粮,均含60%玉米秸秆和40%精料(干物质基础)。各处理间精料组成均不同:对照组(CON)包含大麦、麸皮和豆粕;多聚物包被尿素(PCU)组包含大麦、麸皮、玉米和Optigen;豆粕添加组(SB)在CON基础上额外补充2%的豆粕;多聚包被尿素-豆粕组(PCUSB)在PCU基础上额外补充2%的豆粕。试验数据按4×4拉丁方数据,使用SAS的MIXED模型(SAS,1999)进行方差分析。试验结果表明,PCU组的有机物(OM)表观消化率(P=0.03)、真消化率(P=0.04)和氮消化率(P<0.01)显著高于CON和SB组,氮的消化率在PCU组要高于CON、SB和PCUSB组(P<0.01),在SB和PCUSB组也要高于CON组,但干物质采食量(DMI)和其他营养物质消化率无显著差异。SB组的羊只仅氮消化率发生了改变。日粮处理并未影响氮采食量、尿氮排出量,但PCU组的粪氮排出量有下降趋势(P=0.09),氮沉积有上升趋势(P=0.09)。另外,尿嘌呤衍生物(PD)和微生物氮产量未受日粮处理的影响。PCU组的瘤胃液丙酸浓度显著升高(P<0.01),但额外补充豆粕并未改变该比例。瘤胃pH和总挥发性脂肪酸(VFA)均不受日粮处理的影响。PCU组的瘤胃液氨氮水平持续上升,在饲喂后3小时达到峰值,并持续7小时。PCU和SB组的玉米秸秆24小时干物质消化率显著高于CON组,48小时干物质消化率显著高于CON或PCUSB组(P<0.01);CON组的干物质消化率在72小时最低(P<0.05)。PCU和SB组的DM有效降解率显著高于其他组(P<0.05)。由此可见,Optigen作为一种新型的非蛋白氮饲料代替豆粕,能够提高绵羊对粗料型日粮OM和氮的消化率以及有效降解率。尽管SB组提高了有效降解率,但除氮之外并未影响其他营养物质的消化率,Optigen中添加豆粕并未提高营养物质消化率、氮沉积、微生物氮合成量、瘤胃发酵以及玉米秸秆的有效降解率。
     试验二:材料和方法同试验一,设计4种高精料型等能等氮日粮,含60%精料和40%玉米秸秆(干物质基础)。结果表明,SB和PCUSB组的OM表观消化率显著低于其他组(P=0.06),SB组的氮(P=0.02)和OM(P=0.04)真消化率显著低于其他组。SB和PCUSB组氮沉积(P=0.03)和瘤胃微生物氮产量(P=0.03)显著低于CON组。SB组瘤胃氨氮水平(P=0.03)显著低于其他各组。PCUSB组的瘤胃总VFA(P=0.052)高于CON组,且与其他组相比,显著降低了瘤胃液乙酸比例(P=0.03)和乙酸:丙酸的比例(P=0.01),增加了丙酸比例(P=0.02)和戊酸比例(P<0.02)。PCU组瘤胃液氨氮水平上升,在饲喂后3小时达到最高水平,并持续9小时。以Optigen代替豆粕对饲喂高精料日粮绵羊的营养物质消化率、微生物氮、瘤胃发酵指数和有效降解率并无副作用,然而在Optigen中额外添加豆粕并未提高营养物质消化率、氮沉积、微生物氮和玉米秸秆的有效降解率,同时降低了乙丙比。
     试验三:本试验旨在研究不同水平Optigen替代豆粕对舍饲羔羊采食量、生长性能和血液生化指标的影响。试验选用64只杜寒杂交羔羊[27±3.3(s.d.)kg],采用完全随机试验设计分为四个处理组,每组包含4个圈舍,每个圈舍4只羔羊。设计4种含60%精料和40%玉米秸秆(干物质基础)的等氮(CP=13.5%)等能(ME=8.2Mj/kg)日粮,并以0%(PCUO)、33%(PCU33)、67%(PCU67)和100%(PCU100)的Optigen替代豆粕,试验期70天。结果表明,以33%和67%的Optigen代替豆粕对干物质采食量无影响,但PCUl00组显著降低了干物质采食量(P=0.04)。PCU33组和PCUO组的日增重不差异,但随Optigen替代水平的增加,日增重显著降低(P<0.01),因此与PCUO组相比,增重/饲料消耗的比例(G/F)在PCU33组未发生改变,但在PCU67和PCU100组显著升高(P=0.02)。随Optigen替代水平的升高,血浆尿素氮呈线性上升趋势(P=0.09)。与PCUO组相比,PCU33和PCU67组的血浆总蛋白水平并未改变,但PCU100组的血浆总蛋白水平最低(P=0.02)。试验表明舍饲羔羊日粮可用部分Optigen代替豆粕,当替代比例为33%时,对于以40%玉米秸秆为粗料的舍饲羔羊的生长性能和血液生化指标无不利影响。
Three experiments were conducted to investigate the effects of polymer coated urea and sodium bentonite on sheep fed corn stalk as basal roughages diet, therefore three experiments has been done. Experiment1:Four ruminally cannulated Dorper x thin-tailed Han crossbred wethers were used in a4x4Latin square design experiment to evaluate the effect of polymer-coated urea (Optigen II) and sodium bentonite (SB) on intake, nutrient digestibility, nitrogen retention, rumen fermentation and microbial nitrogen production in sheep fed high levels of corn stalk. Wethers were housed in an enclosed, climate-controlled room in individual pens. Each period lasted24days(d) with14d of diet adaptation and10d of sampling (5d for digestibility and1d of rest before rumen fluid sampling to prevent interference with the digestibility trial,1d for rumen fluid collection, and3d for the in situ trial). Four days prior to the digestibility trial, animals were placed in individual metabolism cages and allowed to adapt to their cages.Four isonitrogenous and isocaloric diets were formulated with60%corn stalk and40%concentrate (DM basis). The control diet (CON) consisted of barley, wheat bran, and soybean meal, the polymer-coated urea diet (PCU) consisted of barley, wheat bran, corn, and Optigen (soybean meal replaced by Optigen), and the SB diet (SB) was comprised of the control diets supplemented with2%SB, and the PCUSB diet was based on the PCU diet with an additional2%SB. Data were analyzed by analysis of variance for a4x4Latin square design using the MIXED procedure from SAS (1999) with variance components and a covariance structure Sheep on PCU treatment showed a greater OM digestibility (P=0.03), true OM digestibility (P=0.04) compared to CON and SB treatment. Nitrogen digestibility in PCU was greater (P<0.01) compared to CON, SB and PCUSB treatments, also it was higher in SB and PCUSB than CON, but digestibility of other nutrients and DMI did not change. SB did not alter nutrient digestibility except for nitrogen. Dietary treatments did not affect nitrogen intake, or its urinary excretion, but fecal N tended to be lower (P=0.09) for PCU. Nitrogen retention tended to increase (P=0.09) in sheep fed Optigen. Moreover, urinary purine derivatives (PD) and ruminal microbial nitrogen production were not influenced by treatments. Ruminal propionate proportions were increased (P<0.01) in diets that included Optigen, but an addition of SB to Optigen did not alter the ratios. The values of ruminal pH and total VFA were also not influenced by treatments. Ruminal NH3-N levels in PCU continuously increased, with the highest level achieved3h after feeding, and sustained for up to7h. Ruminal DM disappearance of corn stalk increased in PCU and SB treatments compared to CON at24h, was greater than CON or PCUSB at48h (P<0.01), but was lowest at72h for the CON treatment (P<0.05). The effective degradability (ED) of corn stalk DM increased in PCU and SB (P<0.05). Therefore, using Optigen as a source of non-protein nitrogen (NPN) to replace soybean meal in sheep fed high levels of corn stalk improved the digestibility of OM, nitrogen, and ED of corn stalk DM. Although SB improved ED of corn stalk DM, it had no effect on nutrient digestibility except for nitrogen. Adding SB to Optigen had no beneficial effects on nutrient digestibility, nitrogen retention, microbial nitrogen, or rumen fermentation and ED of corn stalk DM.
     Experiment2:This experiment was designed as same as Expt.1, but the ratio of concentrate to roughages changed to60:40. Four isonitrogenous and isocaloric diets consisting of60%concentrate and40%corn stalk (dry matter basis) were formulated. Apparent digestibility of OM tended to be lower (P=0.06) for sheep on the SB and PCUSB diets. True OM digestibility and N digestibility was lower (P=0.04and0.02, respectively) for SB treatment than other treatments. N retention and ruminal microbial nitrogen production were lower (P=0.03) in SB or PCUSB-fed sheep than that of CON. Ruminal NH3-N concentration was decreased in SB-fed sheep (P=0.03) compared to other treatments. The ruminal concentration of total VFA tended to be greater (P=0.052) in PCUSB-fed sheep than CON. PCUSB treatment decreased the ruminal concentration of acetate (P=0.03) and the ratio of acetate to propionate (P=0.01), but increased the ruminal concentration of propionate (P=0.02) and valerate (P<0.02) when compared with the other treatments. Ruminal NH3-N concentrations in PCU continuously increased, with a peak level achieved3h after feeding, and sustained for up to9h. replacing soybean meal with Optigen for sheep fed high levels of concentrate had no adverse effects on nutrient digestibility, microbial nitrogen, rumen fermentation and ED of corn stalk DM. However, adding SB to Optigen had no beneficial effects on nutrients digestibility, N retention, microbial N and ED of corn stalk DM.
     Experiment3:The objective of this experiment was to evaluate the effects of replacing different levels of soybean meal by Optigen II on feed intake, growth performance and blood parameters of fattening lambs. Sixty-four Dorper x thin-tailed Han crossbred lambs were blocked by BW [27±3.3(s.d.) kg] and allocated in a randomized complete block design to4treatments. Each treatment had4pens with4lambs per pen. The treatments were control (PCUO), PCU33, PCU67, and PCU100with0,33%,67%, and100%substitution rate of soybean meal nitrogen by Optigen II (DM basis), respectively. Four isonitrogenous (CP=13.5%) and isocaloric (ME=8.2Mj/Kg) dietary treatments contained60%concentrate and40%corn stalk (DM basis) and were offered ad libitum as TMR to ensure approximately5%ort. Lambs were fed56d after14d adaptations twice daily in two equal portions at7:00and19:00h. Data were analyzed as a RCBD using the GLM procedure of SAS (pen was as the experimental unit). Substitution of33and67%of soybean meal nitrogen with Optigen had no effects on DMI, but PCU100significantly decreased DMI (P=0.04). There was no difference in average daily gains (ADG) between PCU33and CON. ADG were significantly decreased by increasing dietary Optigen (P<0.01). The ratio of gain to feed (G/F) was not influenced by replacing33%of soybean meal nitrogen with Optigen, but G/F was decreased (P=0.02) in PCU67or PCU100compared to CON. Blood urea nitrogen tended to linearly increase (P=0.09) with increasing Optigen in the diet. Substitution of33and67%of soybean meal nitrogen by Optigen had no effect on plasma total protein, but it was lowest (P=0.02) in PCU100. The results showed that soybean meal could be partly replaced by Optigen in the diet of feedlot lambs. Substitution of33%soybean meal nitrogen by Optigen had no negative effects on growth performance or blood parameters in feedlot lambs fed diets containing40%corn stalk.
引文
1. Abdel-mawla S. M., EL-kerdawy D. M.A., and Salem F. A. F. Productive performance and blood constituents of lactating goats fed diets supplemented with sodium bentonite. Egypt. J. Nutr.and Feeds 1998,1:53.
    2. Abdul Majid Katme. An Assessment of the Muslim Method of Slaughter, presented at the UFAW Symposium on Humane Slaughter and Euthanasia, held at the Zoological Society of London, Regent's Park, September 18-19th 1986. http://www.guidedways.com/articles/halalslaughtermethod.php#dhabh.
    3. Aghashahi A., Nikkhah A., Mirhadi A., Zahedifar M. and Mansori H. Effects of different levels of unprocessed bentonite, processed bentonite and clinoptilolite at different rumen degradable protein level, on ammonia concentration, soluble and digestible protein (Invitro).Pajouhesh Sazandegi 2006,70:80-90.
    4. Aghashahi A., Nikkhah A., Mirhadi S.A. and Moradi-Shahrbabak M. The effects of natural and processed sodium bentonite on feedlot performances, rumen fermentation parameters and on carcass characteristics of Holstein bulls. Proc. of the 1st Cong, on Anim. and Aquatic Sci., Tehran, Iran 2004, 119-123.
    5. Aguilera J. I., Ramirez R. G, Arechiga C. F., Lopez M. A., Banuelos R., Duran M. and Rodriguez E. R. Influence of wet brewers grains on rumen fermentation, digestion and performance in growing lambs. J. Anim. Vet. Adv 2007,6:641-645.
    6. Aguilera-Soto J. I., Ramirez R. G., Arechiga C. F., Mendez-Llorente F., Lopez-Carlos M. A., Silva-Ramos J. M., Rincon-Delgado R. M., and Duran-Roldan F. M. Effect of feed additives in growing lambs fed diets containing wet Brewers grains. Asian-Aust. J. Anim. Sci.2008,21:1425-1434.
    7. Akay V., Tikofsky J., Holtz C., and Dawson K. A. Optigen 1200:controlled release of non-protein nitrogen in the rumen. Proceedings of Alltech's 20th annual symposium:re-imaging the feed industry 2004,179-185.
    8. Alexandroa N., Banskaliera V., Angeleva I., Laleva S., and Slalova P. Meat quality characteristics and fatty acid composition of triacyglycerols in out-of-season born lambs.42nd International Congr. of Meat Sci. and Techn 1996,1:204-205.
    9. Alhassan W. S., Karbo N., Aboe P. A. T, and Oppong-Anane K. Ghana's Savanna Ranglands; Agro-Ecology, Current Improvement and Usage, Practices, Research Needs and Sustainable Management Criteria. Council for Scientific and Industrial Research, Accra, Ghana 1999.
    10. AMSA (American Meat Science Association, National Live Stock, Meat Board).Guidelines for Meat Colour Evaluation. Chicago, IL, USA:American Meat ScienceAssociation 1991.
    11.Anke M., Muller M., Kramer K., and Glei M.Effect of oral bentonite (Fenamin-R) on major and trace element incorporation in various tissues and milk of ruminants.l.Cadmium.Mengenund Spurenele12 Arbeitstagung Leipzig 12/13 Dezember 1992,427-434.
    12.Anonymous. Acid detergent and neutral detergent fiber using ANKOM's fiber analyzer F200. AnkomTechnology Corporation, Fairport, NY 1995.
    13.AOAC. Official Method of Analysis.16th ed. Assoc. Off. Anal. Chem., Arlington, VA 1995.
    14.AOAC. Official methods of analysis.15th ed. Assoc. Off. Anal. Chem., Arlington, VA,1990.
    15.ARC. The Nutrient Requirements of Ruminant Livestock, Supplement No.1. Report of the Protein Group of the ARC Working Party, Publishers Commonwealth Agriculture Bureau, Farnham Royal, Slough, SL23BN, UK 1984.
    16. Archibald J.G Feeding urea to dairy cows. Amherst, Massachusetts Agricultural Experiment Station. Bulletin 406,1943.
    17.Bach A., Calsamiglia S., and Stern M. D. Nitrogen metabolism in the rumen. J. Dairy Sci.2005, 88:9-21.
    18.Barnett A. J. G, and Reid R. L. Studies on the production of volatile fatty acids from grass by rumen liquor in an artificial rumen:The volatile fatty acid production from grass. J. Agric. Sci. Cam 1957, 48:315-321.
    19. Bartley E.E., Davidovich A., Barr GW. et al. Ammonia toxicity in cattle. I. Rumen and blood changes associated with toxicity and treatments methods. J. Anim. Sci.1976,43:835-841.
    20.Bartos S., Marounek M., Petrzik J., Kopecny L., Kolouch F.M., and Kalacnjuk GI. The effect of bentonite on rumen fermentation and nitrogen metabolism in ruminants. Biol. Chem. Vet.Praha 1982, ⅩⅧ:333.
    21.Bates R. L., and Jackson J. A.Glossary of geology.2th ed. American Geological Institute, Alexandria, VA, USA 1980.
    22.Becker T. Consumer perception of fresh meat quality:A framework for analysis.British Food Journal 2000,102:158-176.
    23.Belasco I. J. Comparison of urea and protein meals as nitrogen sources for rumen microorganisms: urea utilization and cellulose digestion. J. Anim. Sci.1954,13:739-747.
    24.Bergen W. G. and Yokoyama M. T. Productive limits to tureen fermentation. J. Anim. Sci.1977, 45:573..
    25.Berthiaume R. R., Ivan M., and Lafreniere C.Effects of sodium bentonite supplements on growth performance of feedlot steers fed direct-cut or wilted grass silage based diets. Can. J. Anim. Sci. 2007,87:63-638.
    26.Bhattacharya N.A. and Khan A. R. Growing-Fattening Sheep Wheat Straw and Urea in Pelleted Rations for.J.Anim Sci.1973,37:136-140.
    27.Bickerstaffe R.,Bekhit A.E.D., Robertson LJ., Roberts N.and Geesink GH. Impact of introducing specifications on the tenderness of retail meat.Meat Science 2001,59:303-315.
    28.Blumel M., and (?)rskov E. R.Comparison of in vitro gas production and nylon bag degradability of roughages in predicting feed intake in cattle. Anim. Feed Sci. Technol.1993,40:109-1019.
    29.Bourg B.M., Tedeschi L.O., Wickersham T.A.,and Tricarico J.M. Effects of a slow-release urea product on performance, carcass characteristics, and nitrogen balance of steers fed steam-flaked corn. J. Anim Sci.2012,90:3914-3923.
    3O.Braman, W. L., Hatfield E. E., Owens F. N., and Lewis J. M..Protein concentration and sources for finishing ruminants fed high-concentrate diets. J. Anim. Sci.1973,36:782.
    31.Britton, R. A., Colling D. P., and Klopfenstin T. j. Effect of complexing sodium bentonite with soybean meal or urea in vitro ruminal ammonia release and nitrogen utilization in ruminants. J. Ainm. Sci.1978,46:1738-1747.
    32.Britton, R. A., Colling D. P., and Klopfenstin T. j.Effect of complexing sodium bentonite with soybean meal or urea in vitro ruminal ammonia release and nitrogen utilization in ruminants. J. Ainm. Sci.1978,46:1738-1747.
    33.Broderick G.A., Craig W. M, and Ricker D. B.Urea Versus True Protein as Supplement for Lactating Dairy Cows Fed Grain Plus Mixtures of Alfalfa and Corn Silages. J. of dairy sci.1993,76: 2266-2274.
    34.Broderick G. A., Stevenson M. J., and Patton R. A. Effect of dietary protein concentration and degradability on response to rumen-protected methionine in lactating dairy cows. J. of dairy sci.2009, 92:2719-2728.
    35.Broderick, G. A., and Kang J. H. Automated simultaneous determination of ammonia and amino acids in ruminal fluids and in vitro media. J. Dairy Sci.1980,63:64-72.
    36.Bryant, M. P. Nutritional requirements of the predominant rumen cellulolytic bacteria. Fed. Proc. 1973,32:1809-1813.
    37.Burroughs W., Nelson D. K., and Mertens D. R.Protein physiology and its application in the lactating cow:The metabolizable protein feeding standard. J.Anirn. Sci.1975,41:933.
    38.Calzado J. F., and Rolz C.Estimation of the growth rate of Pleurotus on stocked straw. J. Ferment. Bioeng.1990,69:70-71.
    39.Campbell, J. R., Howe W. M., Martz F. A., and Merilan C. P. Effects of frequency of feeding on urea utilization and growth characteristics in dairy heifers. J. Dairy Sci.1963,46:131.
    40.Cao, Y. C, and Yang H. j. Ruminal digestibility and fermentation characteristics in vitro of fenugreek and alfalfa hay combination with or without the inoculation of Neocallimastix sp. YAK11. Anim Feed Sci. Technol.2011,169:53-60.
    41.Carmen Sdnchez. Lignocellulosic residues:Biodegradation and bioconversion by fungi.Research Centre for Biological Sciences, Universidad Aut6noma de Tlaxcala, Tlaxcala, Mexico, Biotechnology Advances 2008,27:185-194. http://dx.doi.org/10.1016/j.biotechadv.2008.11.001.
    42.Castro F.B., Selmer-Olsen I.,(?)rskov E.R., Johnsen F. Lignin as a carrier for feed grade controlled-release urea. In:Proceedings of the Vth International Symposium on Nutrition of Herbivores, San Antonio, TX, USA,11-16 April 1999,836 pp.
    43.Chapa A.M., Fernandeza J.M., Whitea T.W., Buntingb L.D., Gentrya L.R., Lovejoyc J.C., Owen K.Q. Infuence of dietary carnitine in growing sheep fed diets containing non-protein nitrogen. Small Ruminant Research 2001,40:13-28.
    44.Chaudhry A. S. Nutrient composition, digestion and rumen fermentation in sheep of wheat straw treated with calcium oxide, sodium hydroxide and alkaline hydrogen peroxide. Anim. Feed Sci. Technol.1998,74:315-328.
    45.Chen X. B., and Gomes M. J. Estimation of Microbial Protein Supply to Sheep and Cattle Based on Urinary Excretion of Purine Derivatives-an Overview of the Technical Details. Occasional publication of the International Feed Resources Unit, Rowett Research Institute, Bucksburn, Aberdeen, UK.1992.
    46.Chen X. b., Mathieson J. D., Hovel F. Deb., and Reeds P. J. Measurement of purine derivatives in urine of ruminants using automated methods. J. Sci. Food Agric.1990,53:23-33.
    47.Chenost M. and Kayouli C. Roughage Utilisation in Warm Climates. FAO Animal Production and Health Paper 135, FAO:Rome 1997,135:1-226.
    48.Cherdthong A. and Wanapat M. Development of Urea Products as Rumen Slow-Release Feed for Ruminant Production:A Review, Australian J. of Basic and Applied Sciences 2010,4:2232-2241.
    49.Cherdthong A., Wanapat M., and Wachirapakorn C. Effects of urea-calcium mixture in concentrate containing high cassava chip on feed intake, rumen fermentation and performance of lactating dairy cows fed on rice straw. Livest. Sci.2011,136:76-84.
    50.Cherdthong A., Wanapat M., Wachirapakorn C, and Van Amburgh M. E. Evaluation of urea calcium mixtures (UCM) as slow-release:I. Fermentation characteristics using in vitro gas technique. Page 138 in Proc.1lth Confe. of the Agri. Univ., Khon Kaen, Thailand 2010.
    51.Chicco C. F., Shultz T. A., Carnevali A. A., Oropeza L., and Ammerman C. B. Biuret and urea in supplements for bovines fed green chop elephant grass. J. Anim. Sci.1971,33:133-136.
    52.Clark J. H., Klusmeyer T. K., and Cameron M. R,. Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows. J. Dairy Sci.1992,75:2304-2323.
    53.Cobon D. H., Stephenson R.GA., and Hopkins P. S. The effect of oral administration of methionine, bentonite, methionine/bentonite and methionine/oil homogenates on wool production of grazing and penned sheep in a semi-arid tropical environment Aust. J. Exp. Agric.1992,32:435-441.
    54.Cocimano M. R. and Leng R. A. Metabolism of urea in sheep. Brit. J. Nutr.1967,21:353.
    55.Cole N. A., and Hutcheson D. P. Influence of dietary protein concentrations on performance and nitrogen repletion in stressed calves. J. Anim. Sci.1990,68:3488-3497.
    56.Colling, D. P., Britton R. A., Farlin S. D., and Nielsen M. K. Effects of adding sodium bentonite to high grain diets for ruminants. J. Anim. Sci.1979,48:641-648.
    57.Colomer-Rocher R, Morand-Fehr P., and Kirton A. H. Standard methods and procedures for goat carcass evaluation, jointing and tissue separation. Livest.Produ.Sci.1987,17:149-159.
    58.De Paula A.A.G., Ferreira R. N., Orsine G F.,Guimaraes L. O., and Oliveira E. R. Urea polymer and urea salt as soluble nitrogen source in rumen:ruminal and plasma parameters. Ci. Anim. Bras.2009, 10:1-8. (Eng. abstr.).
    59.Dehority B.A. Evaluation of subsampling and fixation procedures used for counting rumen protozoa. Appl. Environ. Microbial 1984,48:182-185.
    6O.Demigne C., Yacoub C., Morand C., Remesy C. Interactions between propionate and amino acid metabolism in isolated sheep hepatocytes. Br. J. Nutr.1991,65:301-317.
    61.Devendra C. Crop residues for feeding animals in Asia:Technology development and adoption in crop/livestock systems. In:Crop Residuals in Sustainable Mixed Crop/livestock Farming System (Ed. C. Renard). CAB International; Wallingford, UK.1997,241-267.
    62.Devendra C, and Thomas D., Crop-animal interactions in mixed farming systems in Asia. Agric. Syst.2002,71:27-40.
    63.Deyoe, C.W., Bartley E.E., Pfost H.B., Baren F.W., Perry H.B., Anstaett F.R., Helmer L., Stiles D., Sung A.C.and Meyer R.An improved urea product for ruminants.J.Anim. Sci.1968,27:116.yoe, C. W., E. E. Bartley, H. B. Pfost, F. W. Boren,
    64.Dhiman T. R., and Satter L. D., Yield response of lactating dairy cows fed different proportions of alfalfa silage and corn silage. J. Dairy Sci.1997,80:2069-2082.
    65.Dias da Silva A. A., Upgrading of low quality feeds by means of urinary urea. In:Urinea wasted, renewable natural resources (Ed. F. Sundstel and E. Owen). Noragric occasional papers series c, development and environment 1993,12:42-49.
    66.Doyle P.T., Devendra C., and Pearce GR., Rice Straw as a Feed for Ruminants. International Development Program of Australian Universities and Colleges Ltd. IDP, Canberra, Australia 1986, 117 pp.
    67.Eck T. P., Bartle S. J., Preston R. L., Brandt R. T., and Richardson C. R. Protein source and level for incoming feedlot cattle. J. Anim. Sci.1988,66:1871-1876.
    68.Egan AR, Boda K, Varady J. Regulation of nitrogen metabolism and recycling. In:Milligan LP, Grovum WL, Dobson A editor. Control of Digestion and Metabolism in Ruminants. Englewood Cliffs, NJ:Prentice-Hall; 1986; 386-404.
    69.Ehrlich W. K., and Davison T. M. Adding bentonite to sorghum-basedsupplements has no effect on cow milk production. Aus. J. Exp. Agric.1997,37:505-508.
    70.Elkholy M. El.H., Hassanein E.I., Edrees N., Eleraky W., Elgamel M.F.A., and Ibraheim D. Nutritional aspects of recycling plants by-products and crop residues (corn stalk) in sheep. Pak. J. Nutr.2009,8:1834-1841.
    71.Elseed F. A. M. A. Effect of supplemental protein feeding frequency on ruminal characteristics and microbial N production in sheep fed treated rice straw. Small Rumin. Res.2005,57:11-17.
    72.E1-Shahat A.A., Hessein A.H., Omar H.A.A., Khalafallah M.A., Morad A.A.A.,and Fadel M., Effect of feeding biological treated corn stalks on growth performance and carcass characteristics of growth rabbits. J. Agric. Sci. Mansoura Univ.2006,31:6173-6185.
    73. Emtenan M., Hanafi H.H., Khadrawy E.I., Ahmed W.M., and Zaabal M.M. Some Observations on Rice Straw with Emphasis on Updates of its Management,. World Applied Sciences Journal 16 2012,3:354-361.
    74.Eriksson K-EL, Blanchette R. A., and Ander P., Microbial and enzymatic degradation of wood and wood components. Springer, Berlin, Heidelberg, New York 1990.
    75.Eun J.-S., Beauchemin K. A., Hong S.-H., and Bauer M. W. Exogenous enzymes added to untreated or ammoniated rice straw:Effects on in vitro fermentation characteristics and degradability. Anim. Feed Sci. Technol.2006,131:86-101.
    76. FAO, Non protein nitrogen in the nutrition of ruminants.1968. http://www.fao.org/DOCREP/004/AC149E/AC149EOO.HTM.
    77.FAO, Report of the FAO technical consultation on new feed resources held in Rome from 22 to 24 November 1976. FAO Meeting Report AGA-806,1976. Rome, FAO, pp.1,2,28 and 29.
    78.FAO, Treating Straw for Animal Feeding-an Assessment of its Technical and Economic Feasibility 1978. http://www.fao.org/docrep/003/x6510e/x6510eOO.htm FAO Animal Production and Health Paper.
    79.FAO/IAEA. Applications of gene-based technologies for improving animal production and health in developing countries. Final Report of International Symposium. Vienna, Austria, October 2003. Retrieved on March 28,2006 from the website http://www.iaea.org/programmes/nafa/d3/mtc/final-report-int-symposium.pdf.
    8O.Fazaeli H. Effect of fungal treatment on the nutritive value of wheat straw and its use in the diet of dairy cattle.2001, PhD Diss. Agricultural Faculty of Putra Univ. Putra, Malaysia.
    81.Fazaeli H., Azizi A., and Amile M., Nutritive value index of treated wheat straw with Pleurotus fungi fed to sheep. Pak. J. Biol. Sci.2006,9:2444-2449.
    82.Fellner V. Reactions in the Rumen-Limits and Potential for Improved Animal Production Efficiency. In Proceedings of The Southwest Nutrition and Management Conference. The University of Arizona, Tuczon, February 2009.26-27.
    83.Feng. Y. H., Zhao X.L., Guo Y., Yang G., Xi J.,and Ren, G Changes in the material characteristics of maize straw during the pretreatment process of methanation. Hindawi Publishing Corporation J. Biomed. and Biotechnol.2012;2012:325426
    84.Fenn P. D., and Leng R. A. The effect of bentonite supplementation on ruminal protozoa density and wool growth in sheep either fed roughage based diets or grazing. Aust. J. Agric.Res.1990,41:167.
    85.Fenn P. D., and Leng R. A.Wool growth and sulfur amino acid entry rate in sheep fed roughage based diets supplemented with bentonite and sulfur amino acids. Aust. J. Agric. Res.1989,40:889-896.
    86.Firkins J. L. Maximizing microbial protein synthesis in the rumen. J. Nutr.1996,126:1347-1354.
    87.Firkins J.L., Yu Z., Morrison M. Ruminal nitrogen metabolism:perspectives for integration of microbiology and nutrition for dairy J. Dairy Sci.2007,90:1-16.
    88.Fisher A. V., and De Boer H. The EAAP standard method of sheep carcass assessment; Carcass measurements and dissection procedures. Li vest. Prod. Sci.1994,38:149-159.
    89.Fisher L.J., and Mackay V. G. The investigation of sodium bicarbonate or bentonite as supplements in silages fed to lactating cows. Can. J. Anim. Sci.1983,63:939-947.
    90.Fonnesbeck PV, Kearl LC, Harris LE. Feed grade biuret as a protein replacement for ruminants:a review. J. Anim. Sci.1975;40:1150-1184.
    91.Gaber A. A., Shehata E. L., Ahmed M. E., and Azzam M. H. Performance and carcass trials of Rahmani lambs fed rations containing dried poultry manure with addition of bentonite clay. Egyptian J. Nutr., and feeds 2003,6:173-188.
    92.Gabriella A. V., and Kolver E. S. icrobial and animal limitations to fiber digestion and utilization, Department of Dairy and Animal Science, Pennsylvania State University, University Park, PA 16802. American Society for Nutritional Sciences 1997.
    93.Galina M. A., Perez-Gil R, Ortiz R. M. A., Hummel J. D., and (?)rskov R. E. Effect of slow release urea supplementation on fattening of steers fed sugar cane tops (Saccharum officinarum) and maize (Zea mays):ruminal fermentation, feed intake and digestibility. Livest. Prod. Sci.2003,83:1-11.
    94.Galo E., Emanuele S. M., Sniffen C. J., White J. H., and Knapp J. R. Effects of a polymer-coated urea product on nitrogen metabolism in lactating Holstein dairy cattle. J. Dairy Sci.2003,86:2154-2162.
    95.Galyean M. L. and Chabot R. C. Effects of sodium bentonite, buffer salts, cement kiln dust and clinoptilolite on rumen characteristics of beef steers fed a high roughage diet. J. Anim. Sci.1981, 52:1197-1204.
    96.Galyean M., and Hubbert M. Effects of season, health, and management on feed intake by beef cattle. In:Symposium:Intake by feedlot cattle, Oklahoma agricultural experiment station 1995,226-234.
    97.Garrett J., Miller-Webster T., Hoover W., Sniffen C, and Putnam D.Encapsulated slow release urea in lactating dairy cow diets impacts microbial efficiency and metabolism in continuous culture. J. Anim. Sci.2005,83:321.
    98.Golombeski GL., Kalscheur K.F., Hippen A.R., and Schingoethe D.J. Slow-release urea and highly fermentable sugars in diets fed to lactating dairy cowsl J. Dairy Sci.2006,89:4395-4403.
    99.Grant P.G, Phillips T.D. Isothermal adsorption of aflatoxin B(1) on HSCAS clay. J. Agric. Food Chem.,1998,46:599-605.
    100. Griswold K.E., Hoover W. H., Miller T. K., and Thayne W.V. Effect of form of nitrogen on growth of ruminal microbes in continuous culture. J. Anim. Sci.1996,74:483-491.
    101. Hadjipanayiotou M. Effect of level and type of alkali on the digestibility in vitro of ensiled, chopped barley straw. Agric. Wastes1984,10:187-194.
    102. Han Y. W. and Ciegler A. Use of nuclear wastes in utilization of lignocellulosic biomass. Process Research 1982,17:32-38.
    103. Hanafi E.M.. El Khadrawy H.H., Ahmed W.M., and Zaabal M.M. Some Observations on Rice Straw with Emph(?)Updates of its Management. World Applied Sciences Journal 2012,16: 354-361.
    104. Harrison G. A. and Karnezos T. P.Can we improve the efficiency of nitrogen utilization in the lactating dairy cow, In:Recent Advances in Animal Nutrition in Australia. School of Rural Science and Agriculture, University of New England.2005,15:146-154.
    105. Hart E.B., Bohestedt G., Deobald H.J., Weqner M.I.The utilization of simple nitrogenous compounds such as urea and ammonium bicarbonate by growing calves. J. Dairy Sci.1939,22: 785-798.
    106. Hatakka A. Lignin-modifying enzymes from selected white-rot fungi:production and role in lignin degradation.FEMS Microbiol. Rev.1994,13:125-135.
    107. Heijnen C. E., Hok-A-Hin C. H., and Van Veen J. A. Protection of rhizobium by bentonite clay against predation by flagellates in liquid cultures. FEMS Microbiol. Ecol.1991,85:65-72.
    108. Helal F. I. S. and Abdel-Rahman K. A.Productive performance of lactating ewes fed diets supplementing with dry yeast and/or bentonite as feed additives. World J. Agric. Sci.2010,6:489-498.
    109. Helal F.I.S. and Abdel-Rahman K.A. Productive performance of lactating ewes fed diets supplementing with dry yeast and/or bentonite as feed additives. World J.Agric. Sci.2010,6:489-498.
    110. Hernandez-Cruz L., Ramirez-Bribiesca J.E., Guerrero-Legarreta M.I., Hernandez-Mendo O., Crosby-Galvanl M.M., Hernandez-Calva L.M. Effects of crossbreeding on carcass and meat quality of Mexican lambs. Arq. Bras. Med. Vet. Zootec.2009,61:475-483.
    111.Herrera-Saldana R., Gomez-Alarcon R., Torabi M., and Huber J. T. Influence of synchronizing protein and starch degradation in the rumen on nutrient utilization and microbial protein synthesis. J. Dairy Sci.1990,73:142-148.
    112. Hersom M. J. Opportunities to enhance performance and efficiency through nutrient synchrony in forage-fed ruminants.J. Anim. Sci.2008,86:306-317.
    113. Highstreet A., Robinson P.H., Robison J., and Garrett J.G Response of Holstein cows to replacing urea with with a slowly rumen released urea in a diet high in soluble crude protein. J. Livest Sci. 2010,129:179-185.
    114. Hills D. J., and Roberts D. W. Anaerobic digestion of dairy manure and field crop residues, J. Agri. Wastes 1981,3:179-189.
    115. Hodgson J.C. and P. C. Thomas. A relationship between the molar proportion of propionic acid and the clearance rate of the liquid phase in the tureen of sheep. Brit. J. Nutr.1975,33:447.
    116. Hoffman L. C, M. Muller, S. W. P.Cloete, and D. Schmidt. Comparison of six crossbred lamb types:Sensory, physical and nutritional meat quality characteristics. Meat Sci.2003,65:1265-1274.
    117. Holder P., Buttery P. J., and Garnsworthy P. C.The effect of dietary synchrony on rumen nitrogen recycling in sheep. Proc. Br. Soc. Anim. Sci.1995,70 (Abstr.).
    118. Holder Vaughn B. The Effects of Slow Release Urea on Nitrogen Metabolism InCattel.Ph.D Thesis and Dissertations-Animal and Food Sciences 2012.
    119. Homer B.Sewell. Urea Supplements for Beef Cattle, Department of Animal Sciences, University of Missouri-Columbia, Agricultural publication G2071:A Review. Accessed Oct.1,1993. http://www.feedbarnstore.com/animalscience/beef/G02071.PDF.
    120. Honikel K. O. Reference methods for the assessment of physical characteristics of meat. Meat Science,1998.49:447-457.
    121. Hoover W. H. Chemical factors involved in ruminal fiber digestion. J. Dairy Sci.1986.69:2755-2766.
    122. Horwitz W., Albert R., Deutsch M. J., and Thompson J. N. Precision parameters of methods of analysis required for nutrition labeling. Part 1. Major nutrients, J. AOAC Int.1990,73:661-680.
    123. Howard R. L., Abotsi E., Jansen E. L., and Howard S. Lignocellulose biotechnology:Issues of bioconversion and enzyme production. Afr. J. Biotechnol 2003,2:602-619.
    124. Hume I. D., Moir R. J., and Somers M. Synthesis of microbial protein in the rumen. Influence of the level of nitrogen intake. Australian J. Agr. Res.1970,21:283.
    125. Hungate R. E. The Rumen and its Microbes. Academic Press, New York 1966.
    126. Huntington G B., Harmon D. L., Kristensen N. B., Hanson K. C., and Spears J. W. Effects of a slow-release urea source on absorption of ammonia and endogenous production of urea by cattle. Anim. Feed Sci. Technol.2006,130:225-241.
    127. Huntington GB., Emerick R.J., and Embry L.B. Sodium bentonite, effects when fed at various levels with high concentrate diets to lambs. J. Anim. Sci.1977,45:119.
    128.Huntington, J. A., and Givens D. I., Studies on in situ degradation of feed in rumen:The effect of bag numbers incubated and post-incubation processing of residues. Anim. Feed Sci. Technol.1997, 68:115-129.
    129. Huston J. E., Shelton M., and Breuer L. H. Effect of rate of release of urea on its utilization by sheep. J. Anim. Sci.1974,39:618-628.
    130.ICF Consulting, Potential concentrations of optigen residues in the environment and a comparison to similar residues from other sources. Technical report, Alltech Inc., Catnip Hill Pike, Nicholasville, KY.2004.
    131. Ichinohe T. and Fujihara T. Adaptive changes in microbial synthesis and nitrogen balance with progressing dietary feeding periods in sheep fed diets differing in their ruminal degradation synchronicity between nitrogen and organic matter. Anim. Sci. J.2008,79:322-331.
    132. Iiyama K., Lam T. B. T., and Stone B. A. Phenolic acid bridges between polysaccharides and lignin in wheat internodes. Phytochem.1990,29:733-737.
    133. Inostroza J. F., Cabrera V. E., Shaver R. D., and Tricarico J. M. Evaluation of the economic impact of Optigen(?) use in commercial dairy herd diets with varying feed and milk prices. J. Dairy Sci. 2009,92(Suppl.1):43 (Abstract).
    134. Inostroza J.F., Shaver R.D., Cabrera V.E., and Tricarico J.M. Effect of diets containing a controlled release urea product on milk yield, milk composition, and milk component yields in commercial Wisconsin dairy herds and economic implications. Professional Anim Sci.2010,26:175-180.
    135. Ivan M., Dayrell M. D. S., Mahadevan S., and Hidiroglou M. Effects of bentonite on wool growth and nitrogen metabolism in fauna-free and faunated sheep. J.Anim. Sci.1992,70:3194-3202.
    136. Ivan M., Neill L., Alimon R., and Jalaludin S. Effects of bentonite on rumen fermentation and duodenal flow of dietary components in sheep fed palm kerne] cake by-product. Anim. Feed Sci. and Tec.2001,92:127-135.
    137. Jacques K. A., Axe D. E., Harris T. R., Harmon D. L., Bolsen, K. K., and Johnson D. E. Effect of sodium bicarbonate and sodium bentonite on digestion, solid and liquid flow, and ruminal fermentation characteristics of forage sorghum silage based diets fed to steers. J. Anim. Sci.1986, 63:923-932.
    138. Jalc D., Straw enrichment for fodder production by fungi. In:The Mycota XI Agricultural Applications (Ed. F. Kempken). (?)Springer-Verlag, Berlin, Heidelberg.2002,19-38.
    139. Jeronimo E., Alves S.P., Martins S.V., Prates J.A.M., Bessa R.J.B., Santos-Silva J. Effect of sodium bentonite and vegetable oil blend supplementation on growth, carcass quality and intramuscular fatty acid composition of lambs. Anim. Feed Sci. Technol.2010,158:136-145.
    140. Jones S. D. M., Jeremiah L. E., Tong A. K. W., Robertson W. M., Gibson L. L. Estimation of lamb carcass composition using an electronic probe, a visual scoring system and carcass measurements.Can. J. Anim. Sci.1992,72:237-244.
    141.Jooste A.M., Effect of diets differing in rumen soluble nitrogen on poor quality roughage utilization by sheep, MSc thesis 2012, Faculty of Natural and Agri.l Sci. Uni. of Pretoria.
    142. Jung H.J., Casler M.D. Maize stem tissues:Cell wall concentration and composition during development. Crop. Sci.2006,46:1793-1800.
    143. Kabak B., Dobson A. D.,and Var, I. Strategies to prevent mycotoxin contamination of food and animal feed:a review.Crit. Rev. Food Sci. Nutr.2006,46:593-619.
    144. Kahlon S.S., Dass S.K. Biological conversion of paddy straw into feed. Biological Wastes 1987,22: 11-21.
    145. Kalivoda M.Additives as production promotants and preventive and curative agents in ruminant diseases. Krmiva 1987,29:11-12:(259-266) (C.F. Nutr. Abstr. andRevi. series-B (1989)059.
    146. Karsli M. A. and Russell J. R. Effects of source and concentrations of nitrogen and carbohydrate on ruminal microbial protein synthesis. Turk. J. Vet. Sci.2002,26:201-207.
    147. Karsli M.A., and Russell J.R. Effects of Some Dietary Factors on Ruminal Microbial Protein Synthesis. Turk J.Vet Anim Sci.2001,25:681-686.
    148. Karunanandaa K., and Varga G A. Colonization of rice straw by white-rots fungi (Cyathus stercoreus):Effect on ruminal fermentation pattern, nitrogen metabolism, and fiber utilization during continuous culture. Anim. Feed Sci Technol.1996,61:1-16.
    149. Karunanandaa K., Varga G. A., Akin D. E., Rigsby L. L., and Royse D. J. Botanical fractions of rice straw colonized by white-rot fungi:Changes in chemical composition and structure. Anim. Feed Sci. Technol.1995,55:179-199.
    150. Kaswari T., Peter L., Flachowsky G, and Meulen U. T. Studies on the relationship between the syntheses in the rumen of dairy cows. Anim. Feed Sci. Technol.2006,139:1-22.
    151. Kennedy P. M. and Milligan L. P. Transfer of urea from the blood to the rumen of sheep.Br. J. Nutr. 1978,40:149-154.
    152. Kertz A. F. Review:Urea Feeding to Dairy Cattle:A Historical Perspective and Review. The Professional Anim. Sci.2010,26:257-272.
    153. Kertz A. F., Davidson L. E., Cords B. R., and Puch H. C. Ruminal infusion of ammonium chloride in lactating cows to determine effect of pH on ammonia trapping. J. Dairy Sci.1983,66:2597- 2601.
    154. Khandaker Z.H. and Tareque A.M.M. Effect of rumen degradable protein in straw based ration on purine derivatives excretion and microbial nitrogen supply in cattle. Australian J. Anim. Sci.1997, 10:364-370.
    155. Kibon A. and (?)rskov E. R. The use of degradation characteristics of browse plants to predict intake and digestibility by goats. Anim. Produc.1993,57:247-251.
    156.Kim K. H., Lee S. S., Jeon B. T., and Kang C. W. Effects of the pattern of energy supply on the efficiency of nitrogen utilization for microbial protein synthesis in the non-lactating cows consuming grass silage. Asian-Aust. J. Anim. Sci.2000,13:962-966.
    157. Kim S. C, Adesogan A. T., and Arthington J. D. Optimizing nitrogen utilization in growing steers fed forage diets supplemented with dried citrus pulp. J Anim. Sci.2007,85:2548-2555.
    158. Kiran D. Factors regulating urea-nitrogen recycling in ruminants. University of Saskatchewan Electronic Thesis and Dissertations 2010.
    159. Kirton, A. H. Principles of classification and grading. In:Meat Production and Processing (Ed. R. W. Purchas, B. W. Butler-Hogg, A. S. Davies). New Zealand Soc. Anim. Prod. Occasional Publication 1989,11:143-157.
    160. Komarek A.R. A filter bag procedure for improved efficiency of fiber analysis. J. Dairy Sci.1993, 76(Sppl.1):250.
    161. Kononoff P. J., Heinrichs A. J., and Gabler M. T. The effects of nitrogen and forage source on feed efficiency and structural growth of prepubertal Holstein heifers. Prof. Anim. Sci.2006,22:84-88.
    162. Kononoff P.J., Ivan S., Matzke W., Grant R.J., Stock R., and Klopfenstein T.J. Milk production of dairy cows fed a wet corn gluten feed during the dry period and lactation. J. Dairy Sci.2006, 89:2608-2617.
    163.Koster H. H., Cochran R. C, Titgemeyer E. C., Vanzant, Nagaraja T. G., Reikemeier K.K., and Jean G. S. Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers. J. Anim. Sci.1997,75:1393-1399.
    164. Krebs K. Der Wirt der Amide bei der Futterung des Rindes. Biedermanns Z. Tierernahr.1937,9: 394-507.
    165. Kwan K.C.E., Coppock GB., Lake M.J., Fettman L.E., Chase R.E., McDowell. Use of Urea by Early Postpartum Holstein Cows. J. Dairy Sci.1977,60:1706-1724.
    166. Lam T. B. T., Kadoya K. and Iiyama K. Bonding of hydroxycinnamic acids to lignin:ferulic and p-coumaric acids are predominantly linked at the benzyl position of lignin, not the b-position, in grass cell walls. Phytochem 2001,57:987-992.
    167. Lapierre H., and Lobley G. E.Nitrogen recycling in the ruminant:A review. J. Dairy Sci.2001,84 (E Suppl.):223-236.
    168. Lardy G. P., Ulmer D. N., Anderson V. L., and Caton J. S. Effect of increasing level of supplemental barley on forage intake, digestibility, and ruminal fermentation in steers fed medium quality grass hay. J. Anim. Sci.2004,82:3662-3668.
    169. Lascano G.J., Velez M., Tricarico J.M., Heinrichs A.J. Nutrient utilization of fresh sugarcane-based diets with slow-release nonprotein nitrogen addition for control-fed dairy heifers. J. Dairy Sci.2012,95:370-376.
    170. Lazzarini I., Detmann E., Sampaio C. B., Paulino M. F., Valadares Filho S. C., Souza M. A., and Oliveira F.A. Intake and digestibility in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds. Rev. Bras. Zootecn.2009,38:2021-2030.
    171. Lemerle C, Stockdale C.R., Trigg T.E. Effect of sodium bentonite on the productivity of lactating dairy cows fed good quality pasture supplemented with a high energy concentrate. Proc. Aust. Soc. Anim. Prod.1984,15:424-427.
    172.Leng R.A. and Nolan J.V. Nitrogen metabolism in the rumen. J. Dairy Sci.1984,67:1072-1089.
    173. Lindberg J. E. and Jansson C. A rapid automated analysis of allantion in ruminant urine. Swedish J. Agric. Res.1989,19:163-167.
    174. Liu J. X., Orskov E. R. and Chen X. B. Optimization of steam treatment as a method for upgrading rice straw as feeds. Anim. Feed Sci. Technol.1999,76:345-357.
    175. Liu J. X., Susenbeth A., and Sudekum K. H. In vitro gas production measurements to evaluate interactions between untreated and chemically treated rice straws, grass hay, and mulberry leaves. J. Anim. Sci.2002,80:517-524.
    176. Lbest C. A., Titgemeyer E. C., Drouillard J. S., Lambert B. D., and Trater A. M.Urea and biuret as no protein nitrogen sources in cooked molasses blocks for steers fed prairie hay. Anim. Feed Sci. Technol.2001,94:115-126.
    177. Loosli J. K., and McDonald I. W. Nonprotein Nitrogen in the Nutrition of Ruminants.1968, p.94. (FAO:Rome.) Agricultural Studies No.73. http://www.fao.org/DOCREP/004/AC149E/AC149EOO.HTM
    178. Ludden P. A. and Cecava M.J. Supplemental protein sources for steers fed corn-based diets:1. Ruminal characteristics and intestinal amino acid flows. J. Anim. Sci.1995,73:1466-1475.
    179. Magalhaes K.A., Valadares Filho S.C., Paulino P.V.R., Paulino M.F., and Valadares R.F.D., Performance, digestibility and carcass characteristics of feedlot dairy steers fed diets with different urea levels. Arq. Bras. Med. Vet. Zootec.2006,58:860-867.
    180. Mailer O., Specific Appetite. In The Chemical Senses and Nutrition. M. R. Kare and O. Maller, ed. John Hopkins Press, Baltimore, MD.1967,54.
    181. Mancini R.A., Hunt M.C. Current research in meat color Mancini Meat Science 2005,71:100-121. Review.
    182. Mapato C., Wanapat M., and Cherdthong A., Effects of urea treatment of straw and dietary level of vegetable oil on lactating dairy cows. Tropical Animal Health and Production 2010,1635-1642.
    183. Martin L. C., Clifford A.J., and Tillman A. D, Studies on sodium bentonite in ruminant diets containing urea. J. Anim. Sci.1969,29:777-782.
    184. McCullough M.E.1974. Improving urea utilization in ruminants. Georgia Agricultural Research, 15(No.3):10.
    185. McDonald I. A revised model for the estimation of protein degradability in the rumen. J. Agric. Sci. Camb.1981,96:251-252.
    186. McPherson W., and Witt H. Feed and livestock transport cost relationships.Transportation Journal 1968,8:25-36.
    187. Miller E. L. Protein nutrition requirements of farmed livestock and dietary supply. Animal production and health. In:Proceeding of EAO Protein Sources for the Animal Feed Industry: Expert Consultation and Workshop, Bangkok 2002, Thailand. http://www.fao.org/docrep/007/y5019e/y5019e06.htm#TopOfPa.
    188. Mohini M.,Singh GP, Kewalramani N. Effect of bentonite on growth in crossbred calves fed diet containing urea,The Indian j.Anim Sci.1999,69:10.
    189. Mohsen M.K. and Tawfik E.S. Growth performance, rumen fermentation and blood constituents of goats fed diets supplemented with bentonite. Faculty of Agriculture, Kafr El-Sheikh, Tanta University, Egypt 2002, pp:7. http://www.tropentag.de/2002/abstracts/full/!.pdf.
    190. Moorby J. M., Dewhurst R. J., Evans R. T, and Danelon J. L., Effects of dairy cow diet forage proportion on duodenal nutrient supply and urinary purine derivative excretion. J. Dairy Sci.2006, 89:3552-3562.
    191. Moore V.J., and Young O.A., The effects of electrical stimulation, thawing, ageing and packaging on the colour and display life in lamb chops, Meat Sci.1990,30:131-145.
    192. Mould F. L., Orskov E. R., and Mann S. O. Associative effects of mixed feeds. I. Effects of type and level of supplementation and the influence of the rumen fluid pH on cellulolysis in vivo and dry matter digestion of various roughages. Anim. Feed Sci. Technol.1983,10:15-30.
    193. Muller L. D., Colenbrander V. F., Martin T. G, Garverick H. A., and Carlton W. W. Carcass Traits of Dairy Steers Effects of Feeding Urea on Physiological, Pathological and J. Anim Sci. 1971,33:677-681.http://www.journalofanimalscience.Org/content/33/3/677.
    194. Mulligan F. J., Caffrey P. J., Rath M., and Kenny M. J. The effect of dietary protein content and hay intake level on the true and apparent digestibility of hay. Livest. Prod. Sci.2001,68:41-52.
    195. Murray P. J., Winslow S. G, and Rowe J.B. Effect of dry hydrate bentonite on the wool growth and live weight gain of sheep fed wheat chaff. Aust. J. Exp. Agric.1992,32:595-600.
    196. National Research Council. Nutrient requirement of beef cattle.7th ed. Natl. Acad. Press, Washington, DC.2000.
    197. Neal H.D.C., Dijkstra J. and Gillm M. Simulation of nutrient digestion, absorption and outflow in the rumen:modle evaluationJ.Nutr.1992,122:2257-2272.
    198. Nocek J. E. andRussell J. B. Protein and energy as an integrated system. Relationship ruminall protein and carbohydrate availability to microbial protein synthesis and milk production. J. Dairy Sci.1988,71:2070-2107.
    199. NRC, Nutrient Requirements of Small Ruminants. National Research Council, National Academies Press, Washington, DC.2007.
    200. NRC.Nutrient Requirements of Dairy Cattle:Seventh Revised Edition,2001. The National Academies Press.
    201. Oltjen J.W., and Beckett J.L. Role of ruminant livestock in sustainable agricultural systems.J. Anim Sci.1996,74:1406-9.
    202. Oltjen R. R., Slyter L. L., Kozak A. S., and Williams E. E. Evaluation of Urea,Biuret, Urea Phosphate and Uric Acid as NPN Sources for Cattle. The J.Nutr.1968,94:193-202.
    203.(?)rskov E. R. Protein nutrition in ruminants.2nd Ed. Academic Press 1992, New York.
    204.(?)rskov E.R. Supplement strategies for ruminants and management of feeding to maximize utilization of roughages. Prev. Vet. Med.1999,38:179-185.
    205.(?)rskov E. R., and McDonald I. The estimation of protein degradability in the Rumen from incubation measurements weight according to rate of passage. J. Agric. Sci.1979.92:499-503.
    206. Osuji P. O., Nsahlai I. V., and Khalili Y. H. Feed Evaluation. ILCA Manual 5. International Livestock Centre for Africa, Addis Ababa, Ethiopia 1993. http://www.ilri.org/html/trainingMat/FEEDMAN.PDF
    207.Ousterhout I. E. Nutritional effect of clays in feed.Feedstuffs,1970,42:34.
    208. Owen E.C., Smith J.A.B., and Wright N.C. Urea as a partial protein substitute in the feeding of dairy cattle. Biochem. J.1943,37:44-53.
    209. Owens F.N., Lusby K.S., Mizwick K. i, and Forero O. Slow ammonia release from urea:Rumen and metabolism studies. J. Anim. Sci.1980,50:527-531.
    210. Perez J., Munoz-Dorado J., De-la-Rubia T., Martinez J. Biodegradation and biological treatments of cellulose, hemicellulose and lignin:an overview. Int Microbiol 2002,5:53-63.
    211. Perry, F. R. Anstaett, L. Helmer, D. Stiles, A.nd R. Meyer.1968. An improved urea
    212. Phillips T.D., Lemke S.L., Grant P.G Charakterization of clay-based enterosorbents for prevention of aflatoxicosis. Adv. Exp. Med. Biol.2002,504,157-171.
    213. Pinos-Rodriguez J. M., Pena L. Y., Gonzalez-Munoz S.S., Barcena R., and Salem A. Effects of a slow-release coated urea product on growth performance and ruminal fermentation in beef steers. Italian J. Anim. Sci.2010, DOI:10.4081/ijas.
    214. Polan C. E., Miller C. N., and McGilliard M. L.Variable Dietary Protein and Urea for Intake and Production in Holstein Cows. J. of dairy sci.1976,59:1910-1914.
    215. Pradhan R., Tobioka H. and Tasaki I. Effect of moisture content and different levels of additives on chemical comp(?) and in vitro dry matter digestibility of rice straw. Anim. Feed Sci. Technol.1997,68:273-284.
    216. Prasad D., and Pradhan K. Effect of feeding pour quality roughage combined with varying levels of concentrate mixture on rumen metabolic profiles in cattle, buffalo and sheep. Ind. J. Anim. Sci. 1990,60:853-860.
    217. Preston T. R. Tropical animal feeding (a manual for research workers). FAO Animal Production and Health 1995, Paper 126, Rome.
    218. Priolo A., Mikol D., Agabaiel J:Effects of grass feeding systems on ruminant meat colour and flavour. A review. Anim. Res.2001,50:185-200.
    219. Puga D. C., Galina H. M., P6rez-Gil R. F., Sangines G L., Aguilera B. A., and Haenlein G. F. W. Effect of a controlled-release urea supplement on rumen fermentation in sheep fed a diet of sugar cane tops (Saccharum officinarum), corn stubble (Zea mays) and King grass (Pennisetum purpureum). Small Ruminant Research 2001,39:269-276.
    220. Rahal A., Singh A., and Singh M. Effect of urea treatment and diet composition on, and prediction of nutritive value of rice straw of different cultivars. Anim. Feed Sci. Technol.1997,68:165-182.
    221. Reid J.T. Urea as a protein replacement for ruminants:a review. J. Dairy Sci.1953,36:955-996. Replacement for Ruminants. A Review. J. Anim. Sci.1975,40:1150-1184.
    222. Reynolds C.K., Kristensen N.B. Nitrogen recycling through the gut and the nitrogen economy of ruminants:an asynchronous symbiosis. J. Anim. Sci.2008,86:293-305.
    223. Rezende L. H. G. S., Albertini T.Z., Detmann E., Tomich T.R., Franco GL., Lempp B., and Morais M.G.Intake and digestibility of palisade grass hay by beef cattle supplemented with a mixture containing ammonium sulphate, casein and urea. Rev. Bras. Zoo.2008,37:717-723. (Eng abstr.).
    224. Ribeiroa S.S.,Vasconcelosb J.T.,Moraisa M.G.,itavoa C.B.C.F.,and Francoa G.L., Effects of ruminal infusion of a slow-release polymer-coated urea or conventional urea on apparent nutrient digestibility, in situ degradability, and rumen parameters in cattle fed low-quality hay, Anim. Feed Sci. and Tech.2011,164:53-61.
    225. Richardson J. M., Wilkison R. G., and Sinclair L. A. Synchrony of nutrient supply to the rumen and dietary energy source and their effects on the growth and metabolism of lambs. J. Anim. Sci.2003, 81:1332-1347.
    226. Rodrigues M. A. M., Pinto P., Bezerra R. M. F., Dias A. A., Guedes C. V. M., Gardoso, J. W. Cone V. M. G., Ferreira L. M. M., Colaco J. and Sequeira C. A. Effect of enzyme extracts isolated from white-rot fungi on chemical composition and in vitro digestibility of wheat straw. Anim. Feed Sci. Technol.2008,141:326-338.
    227. Rupel I.W., Bohstedt G.and Hart E.B. The comparative value of urea and linseed meal for milk production. J. Dairy Sci.1943,26:647-664.
    228. Russell J.B., Muck R. E., and Weimer P. J., Quantitative analysis of cellulose degradationand growth of cellulolytic bacteria in therumen. FEMS Microbiol. Ecol.2009,67:183-197.
    229. Russell J.B., O'Connor J. D., Fox D. G., Van Soest P. J., and Sniffen C. J. A net carbohydrate and protein system for evaluating cattle diets.1. Ruminal fermentation. J. Anim. Sci.1992,70:3551-3561.
    230. Saenger P.F., Lemenager R.P., and Hendrix K.S.Anhydrous ammonia treatment of corn Stover and its effect on digestibility, intake and performance of beef cattle. J. Anim. Sci.1982,54:419-424.
    231. Sal Juan Domingo.Increasing the Role of Ruminant Animals in the World Food System.2011. Dpt. of Applied Economics-St. Paul Campus-University of Minnesota. http://www.inta.gov.ar/leales/info/pdf/sal4.pdf
    232. Saleh M. S. Using of feed additives for feeding farm animals. PhD Diss. Fac. of Agric. Kafr El-Sheikh, Tanta University, Egypt 1994.
    233. Salem F.A.F., El-Amary H., and Hassanin S.H., Effect of bentonite supplementation on nutrients digestibility, rumen fermentation, some blood physiological parameters and perfromance of growing lambs. Egypt J.of Nutr. and Feeds 2001,4:179-191.
    234. Santurio J.M., Mallmann C.A, Rosa A.P, Appel G., Heer A., Dageforde S., Bottcher M. Effect of sodium bentonite on the performace and blood variables of broiler chickens intoxicated with aflatoxins. Brit. Poult. Sci.1999,40:115-119.
    235. Sarnklong C., Cone J.W., Pellikaan W., Hendriks W.H. Utilization of rice straw and different treatments to improve its feed value for ruminants:a review. Australasian Journal of Animal Sciences Publisher:Asian-Australasian Association of Animal Production Societies 2010.
    236. SAS. SAS(?) User's Guide:Statistics. Version 8.2, SAS Inst. Inc., Cary, NC.USA 1999.
    237. Satter L. D., and Roffler R. E. Nitrogen requirement and utilization in dairy cattle. J. Dairy Sci. 1975,58:1219-1237.
    238. Satter L. D., and Roffler R. E. Influence of nitrogen and carbohydrate inputs on rumen fermentation in:Recent Acvances in animal nutrition. Butterworth Inc., Boston, MA.1977.
    239. Satter L. D., and Slyter L.L.Effect of ammonia concentration on rumen microbial protein production in vitro. Brit. J. Nutr.1974,32:199-208.
    240. Schell T.C., Lindemann M.D., Kornegay E.T., Blodge D.J.., Doerr J.A. Effectiveness of different types of clay for reducing the detrimental effects of aflatoxin contaminated diets on performance and serum profiles of weanling pigs. J. Anim. Sci.1993,71:1226-1231.
    241. Schiere J. B., and Ibrahim M. N. M. Feeding of urea-ammonia treated rice straw:A compilation of miscellaneous reports produced by the Straw Utilization Project (Sri Lanka). Pudoc, Wageningen. Second ed. Comstock Pub., Ithaca, NY, USA 1989.
    242. Scott P. Greiner. State Fair of Virginia Lamb Carcass Evaluation Summary,2004 Extension Animal Scientist, Sheep, VA Tech. http://www.sites.ext.vt.edu/newsletter-archive/livestock/aps-04_06/aps-348.html.
    243. Selim A. S. M., Pan J., Takano T., Suzuki T., Koike S., Kobayashi Y., and Tanaka K. Effect of ammonia treatment on physical strength of rice straw, distribution of straw particles and particle-associated bacteria in sheep rumen. Anim. Feed Sci. Technol.2004.115:117-128.
    244. Seo J.K., Kim M.H, Yang J.Y., Kim H.J., Lee C.H., Kim K.H., Ha Jong K. Effects of synchronization of carbohydrate and protein supply on ruminal fermentation, nitrogen metabolism and microbial protein synthesis in Holstein steers. Asian-Aust. J. Anim. Sci.2010,23:1455-1461
    245. Sinclair L. A., Garnsworthy P. C., Newbold J. R., and Buttery P. J. Effect of synchronizing the rate of dietary energy and nitrogen release on rumen fermentation and microbial protein synthesis in the sheep. J. Agric. Sci.1993,120:251-263.
    246. Sinclair L.A., Blake C.W., Griffin P., Jones G.H. The partial replacement of soyabean meal and rapeseed meal with feed grade urea or a slow-release urea and its effect on the performance, metabolism and digestibility in dairy cows. Animal.2012 Jun;6(6):920-927.
    247. Smith C.G, and Carpenter Z. L. Postmortem Shrinkage of Lamb Carcasses J. Anim. Sci.1973, 36:862-867.
    248. Smith G.S., Dunbar R.S., McLaren C A., Anderson C C., and Welsh J.A. Measurement of the adaptation response to urea-nitrogen utilization in ruminants. J. Nutr.1960,71:20.
    249. Smith R. H. Utilization of NPN-supplements, other than urea, by ruminants. Arch. Anim. Nutr. 1986,36:175-182.
    250. Smulders F.J.M., Toldra F., Flores J., Prieto M. New technologies for meat and meat products. Audet Tijdschriften, Utrecht, The Netherlands 1992,182:186-188.
    251. Steel R.G D., and Torrie J. H. Principles and procedures of statistics:a biometrical approach,1980, 2nd ed. New York:McGraw-Hill.
    252. Stensig T., Weisbjerg M. R., Madsen J. and Hvelplund T. Estimation of voluntary feed intake from in sacco degradation and rate of passage of DM or NDF. Livest. Prod. Sci.1994,39:49-52.
    253. Stern M.D., Calsamiglia S., Endres M.I. Dynamics of ruminal nitrogen metabolism and their impact on intestinal protein supply. In:Proc. Cornell Nutr. Conf. Feed Manuf, Rochester, NY. Cornell Univ., Ithaca, NY.1994, p.105.
    254. Sundstol F. Improvement of poor quality forages and roughage. In:Feed Science (Editor:E R Orskov), Elsevier Science Publishers 1988,257-276.
    255. Sundstol F. and Coxworth E. M. Ammonia treatment. In:Straw and Other Fibrous By-products as Feed (Ed. F. Sundst(?)l and E. Owen). Developments in Animal Veterinary Sciences,14. Elsevier, Amsterdam 1984,196-247.
    256. Sundstol F., and Owen E. Straw and Other Fibrous By-products as Feed. Amsterdam, the Netherlands:Elsevier 1984.
    257. Taylor-Edwards C. C., Elam N. A., Kitts S. E., McLeod K. R., Axe D. E., Vanzant E. S., Kristensen N. B., and Harmon D. L. Influence of slow-release urea on nitrogen balance and portal-drained visceral nutrient flux in beef steers. J. Anim. Sci.2009a,87:209-221.
    258. Taylor-Edwards C. C., Hibberd G, Kitts S. E., Mcleod K, R., AxeD. E., Vanzant E. S., Kristensen N. B., and Harmon D. L. Effects of slow-release urea on ruminal digesta characteristics and growth performance in beef steers. J. Anim. Sci.2009b,87:200-208.
    259. Tedeschi L. O., Baker M. J., Ketchen D. J., and Fox D. G Performance of growing and finishing cattle supplemented with a slow-release urea product and urea. Can. J. Anim. Sci.2002,82:567-573.
    260. Tedeschi L. O., Fox D. G., and Russell J. B. Accounting for the effects of a ruminal nitrogen deficiency within the structure of the Cornell net carbohydrate and protein system. J. Anim. Sci. 2000,78:1648-1658.
    261. Theander O., and Aman P. Anatomical and chemical characteristics. In:Straw and Other Fibrous By-products as Feed. (Ed. F. Sundstel and E. Own). Developments in Animal Veterinary Sciences, 14. Elsevier, Amsterdam,1984, pp.45-78.
    262. Tikofsky J. and Harrison G.A.Optigen(?) II. Improving the efficiency of nitrogen in the dairy cow. In:Nutritional Biotechnology in the Feed and Food Industries, Proceedings of Alltech's 22nd Annual Symposium (T.P. Lyons, K.A. Jacques and J.M. Hower, eds). Nottingham University Press, UK 2006,65-73.
    263. Tovar-Gomez M. R., Emile J. C., Michalet-Doreau B., and Barrier Y. In situ degradation kinetics of maize hybrid stalks. Anim. Feed Sci. Technol.1997,68:77-88.
    264. Trach N.X., Magne Mo and Cu Xuan Dan. Effects of treatment of rice straw with lime and/or urea on its intake, digestibility and rumen liquor characteristics in cattle. J. Livestock Research and Development,2001 Vol.13 No.4.
    265. Uden P. The effect of grinding and pelleting hay on digestibility, fermentation rate, digesta passage and rumen and fecal particle size in cows. Anim. Feed Sci. Technol.1988,19:145-157.
    266. Undi M., and Wittenberg K. M.Intake, rumen fermentation characteristics, and feed stuff in situ digestion kinetics as influenced by fungal biomass in alfalfa hay fed to cattle. Anim. Feed Sci. Technol.1996,61:291-303.
    267. USDA. Official United States Standards for grades of lamb, yearling mutton and mutton carcasses. USDA, Agric. Mark. Serv., Washington, DC.1992.
    268. Valkeners D., Thewis A., Piron F., and Beekers Y. Effect of imbalance between energy and nitrogen supplies on microbial protein synthesis and nitrogen metabolism in growing double muscled Belgian blue bulls. J. Anim. Sci.2004,82:1818-1825.
    269. Van Soest P. J. Nutritional ecology of the ruminant 2nd ed. Cornell University Press. Ithaca, NY. 1994.
    270. Van Soest P. J., Robertson J. B., and Lewis B. A. Methods for dietary fiber, neutral detergent fiber, and non starch polysaccharides in relation to animal nutrition. J. Dairy Sci.1991,74:3583-3597.
    271. Verma M L.Chemical treatment of straw. Paper presented at the seminar on maximum livestock production on minimum land. Bangladesh Agricultural University 2-5 February 1981.
    272. Vetter R. L. Evaluation of chemical and nutritional properties of crop residues. In Crop Residue Symposium. Lincoln:University of Nebraska 1973.
    273. Virk A. S., Steingass H., and Menke K. H. Studies on in vitro degradation and in vivo digestion of a slow ammonia releasing urea product. Arch. Anim. Nutr.1989,39:167-176.
    274. Voisey P.W. Engineering assessment and critique of instruments used for meat tenderness evaluation. J.Textural Studies 1976,7:11-48.
    275. Waghorn G. C., Black H., and Horsbrugh T. The effect of salt and bentonite supplementation on feed and water intake, fecal characteristics and urine output in sheep. New Zealand Vet. J.199442: 24-29
    276. Wahrmund J., Araujo D.B., Hersom M., and Arthington J.D. Evaluation of Optigen II(?)as a source of rumen degradable protein for mature beef cows. J. Anim. Sci.2007,85(Suppl.1):26.
    277. Wallace R. J. and Newbold C. J. Effect of bentonite on fermentation in the rumen simulation technique (Rusitec) and rumen ciliate protozoa. J. of Agri. Sci. Camb.1991,116:163-168.
    278. Wallace R.J. and Cotta M.A. Metabolism of nitrogen-containing compounds. In:The rumen microbial ecosystem (P.N. Hobson, ed.), Elsevier Applied Science, London and New York 1988, 217-249.
    279. Walz L. S., White T. W., Fernandez J. M., Gentry L. R., Blouin D. C., Froetschel M. A., Lupton C. J., and Chapa A. M. Effects of Fish Meal and Sodium Bentonite on Performance, and Ruminal and Blood Characteristics of Kids Fed Concentrate or Forage Diets, Professional Anim. Sci. 1998,14:159-164.
    280. Walz L.S., White T.W., Fernandez J.M., Gentry L.R., Blouin D.C., Froetschel M.A., Brown T.F., Lupton C.J., and Chapa A.M. Effects of fish meal and sodium bentonite on daily gain, wool growth, carcass characteristics, and ruminal and blood characteristics of lambs fed concentrate diets. J. Anim. Sci.1998,76:2025-2031.
    281. Wang A. Studies on dietary application of cellulose complex in monogastric and ruminant animals.J.Northeast Agric.Univ.1998.29:236-251.
    282. Wang Y., Spratling B. M., ZoBell D. R., Wiedmeier R. D., and McAllister T. A. Effect of alkali pretreatment of wheat straw on the efficacy of exogenous fibrolytic enzymes. J. Anim. Sci.2004. 82:198-208.
    283. Warner A. C. I. Enumeration of rumen Micro-organisms. J. Gen. Microbiology 1962,28,119-128.
    284. Weisbjerg M., Hvelplund T., Hellberg S., Olsson S., Same S. Effective rumen degradability and intestinal digestibility of individual amino acids in different concentrates determined in situ Anim. Feed Sci. Technol.1996,62:179-188.
    285. Welch J.A., Anderson G.C., McLaren C. A., Cambell C. P., and Smith G.S. Time, diethylstibesterol and vitamin B.Λin the adaption of lambs to NPN utilization. J. Anim. Sci.1957,16:1634. (Abstr.).
    286. Whittier J.C. Urea and NPN for Cattle and Sheep, Colorado State University professor, department of animal sciences.6/98. Revised 6/11,1998. http://www.ext.colostate.edU/pubs/livestk/01608.html#top
    287. Witt M. W., Sinclair L. A., Wilkinson R. G, and Buttery P. J. The effects of synchronizing the rate of dietary energy and nitrogen supply to the rumen on the production and metabolism of sheep: food characterization and growth and metabolism of ewe lambs given food ad libitum. Anim. Sci. 1999,69:223-235.
    288. Xin H.S., Schaefer D.M., Liu Q. P., Axe D.E., and Meng Q.X. Effects of polyurethane coated urea supplement on in vitro ruminal fermentation, ammonia release dynamics and lactating performance of Holstein dairy cows fed a steam-flaked corn-based diet. Asian-Aust. J. Anim. Sci.2010,23: 491-500.
    289. Yahya M., Mahyuddin M., Alimon A.R., Abdullah N., Ivan M. Sago pith meal based diets in sheep containing different sources of nitrogen:Feed preparation, growth performance, digestibility and carcass quality. Anim. Feed Sci. Technol.2011,170:45-52.
    290. Yamakava M. and Okamnto H. A. Effect of incubation with edible mushroom, Pleurotus ostreatus, on voluntary intake and digestibility or rice bran by sheep. Anim. Feed Sci. Technol.1992,63:133-138.
    291. Yang X.Y., Cao Q., and Zhu M.Z. Substrate residues from mushroom culture as feed ingredient for pigs. (Abstract) p.98-99, in:Proceedings of 4th Conference of National Society of Animal Nutrition, CAASV.1986.
    292. Zhu S., Wu Y., Yu Z., Liao J., and Zhang Y. Pretreatment by microwave/alkali of rice straw and its enzymic hydrolysis. Process Biochem.2005,40:3082-3086.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700