摘要
本文研究了添加米曲霉培养物和蛋氨酸羟基类似物对不同粗料底物瘤胃发酵和奶牛泌乳性能的影响。研究内容包括：1)分别以羊草、苜蓿、青贮玉米和玉米秸为底物,添加米曲霉培养物(AOC)和蛋氨酸羟基类似物(HMB),研究其对体外产气量和瘤胃发酵的影响；2)不同粗料底物添加AOC与HMB对羊草、苜蓿和青贮玉米瘤胃微生物及其酶活的影响；3)通过奶牛饲养试验,研究添加AOC与HMB对泌乳奶牛泌乳性能、瘤胃发酵和微生物菌群的影响。
试验一通过体外产气试验,研究不同粗料底物添加AOC与HMB对体外瘤胃产气特性和瘤胃发酵的影响。试验底物精粗比为50：50,其中精料是玉米,粗料分别是羊草、苜蓿、青贮玉米和玉米秸之一,每种底物按照2×3因子设计，添加不同水平的AOC (0、3、6mg)和HMB (0、15mg)作为主因子。记录2,4,8,12和24h瘤胃产气量,测定培养24h的瘤胃液pH、氨态氮、挥发性脂肪酸(VFA)和微生物蛋白(MCP)含量。添加AOC与HMB显著提高底物羊草、首蓿和青贮玉米体外发酵24h的产气量、潜在产气量和有机物消化率(P<0.05),对底物青贮玉米的瘤胃发酵指标有显著的交互作用。AOC与HMB显著降低底物青贮玉米的瘤胃氨态氮浓度(P<0.05),两者有显著的交互作用(P=0.03)。MCP浓度随AOC与HMB的添加显著提高(P＜0.01),两者对底物羊草和青贮玉米有交互作用。AOC和HMB显著增加底物羊草、苜蓿和青贮玉米瘤胃内总VFA浓度(P<0.01),对羊草和苜蓿瘤胃内各个VFA的摩尔比没有显著影响,显著增加底物青贮玉米乙酸摩尔比(P=0.02),显著降低丁酸摩尔比(P<0.01),对青贮玉米的乙丙比没有影响(P-=-0.06),但有交互作用(P<0.01)。AOC与HMB不影响底物玉米秸瘤胃内总VFA,但显著增加其丙酸摩尔比,降低乙丙比(P<0.01),对其他指标没有影响(P>0.05)。结果提示,AOC与HMB可以促进底物羊草、首蓿和青贮玉米的瘤胃发酵,对玉米秸没有显著影响,且对青贮玉米有交互作用。
试验二根据试验一的结果,AOC与HMB对底物羊草、苜蓿和青贮玉米的体外瘤胃发酵有促进作用,因此本试验选取三种粗料发酵瘤胃液提取DNA,采用real-time PCR技术测定瘤胃内不同微生物的相对数量并测定微生物酶活。结果表明：添加AOC与HMB显著增加底物羊草和苜蓿的瘤胃真菌数(P<0.01)、底物青贮玉米瘤胃液产琥珀酸丝状杆菌(F. succinogenes)(P=0.02)、底物羊草和青贮玉米瘤胃反刍兽新月形单胞菌(S. ruminatium)(P<0.01)。添加AOC还可以增加底物羊草瘤胃发酵液的F. succinogenes (P<0.01)、黄色瘤胃球菌(Rflavefaciens)(P<0.01)和白色瘤胃球菌(R. albus)、苜蓿瘤胃发酵液R. albus数(P<0.01)。添加HMB可以显著增加青贮玉米瘤胃发酵液的R. albus (P<0.01),苜蓿底物的S. ruminatium且与AOC有交互作用(P=0.03). AOC提高羊草底物羧甲基纤维素酶(CMCase)和淀粉酶活性、苜蓿底物的木聚糖酶活性(P<0.01); HMB显著提高了苜蓿底物瘤胃内CMCase活性(P<0.01)和羊草、苜蓿底物的木聚糖酶活性(P<0.05)。AOC与HMB对羊草、苜蓿底物的CMCase和淀粉酶活性有交互作用,对三种粗料的木聚糖酶活性有交互作用。添加AOC与HMB可以显著增加羊草、苜蓿和青贮玉米底物瘤胃内纤维分解菌、反刍兽新月形单胞菌以及纤维素分解酶活性。
试验三研究添加AOC与HMB对泌乳奶牛产奶性能的影响。试验选择64头经产奶牛(体重520kg,泌乳136天,日产奶31kg),按产奶量一致,泌乳天数相近原则随机分入4个组中,每组16头。4组奶牛接受不同的日粮处理：对照组Control、处理AOC(添加AOC5g/d)、处理HMB(添加HMB25g/d)和处理AM(同时添加AOC与HMB分别为5g/d和25g/d)。试验结果表明：1)各处理组干物质采食量(DMI)和产奶量没有显著差异(P>0.05)。HMB可以显著提高乳蛋白、乳脂产量和乳中总固体物(TS)含量(P=0.02),有提高3.5%FCM产量、乳蛋白率和乳脂率的趋势(P=0.07), AOC显著提高了乳糖含量(P=-0.04)；2)AOC显著降低了血浆游离脂肪酸(NEFA)的浓度,HMB显著降低了血糖浓度(P=0.03)；3)HMB有增加血浆Cys的趋势(P=0.07)。上述结果表明,泌乳奶牛日粮添加AOC显著降低血液NEFA含量,添加HMB增加乳蛋白、乳脂含量和产量,显著增加乳糖和TS含量,。
试验四研究添加AOC与HMB对泌乳奶牛瘤胃发酵、微生物菌群的影响。试验设计同试验三,在试验的中期和末期,每组随机选取6头,采用口腔取瘤胃液的方法收集瘤胃液,测定AOC与HMB对瘤胃发酵参数、瘤胃微生物相对数量和酶活的影响。添加AOC与HMB可以显著增加瘤胃总VFA.MCP浓度(P<0.05)。添加HMB显著增加乙酸摩尔比、降低丙酸摩尔比(P<0.01),。添加AOC与HMB可以显著增加真菌、F. succinogenes和R. flavefaciens的数量,(P≤0.03),而且添加AOC与HMB显著提高了CMCase的活性(P<0.05)。结果表明,AOC与HMB可以通过增加瘤胃微生物的数量和CMCase的活性促进瘤胃发酵和提高奶牛泌乳性能。
综上所述,AOC与HMB对不同粗料的体外瘤胃发酵不同,可以显著提高羊草、苜蓿和青贮玉米底物的瘤胃发酵,但是对玉米秸的瘤胃发酵没有显著影响；AOC与HMB可能主要是通过对瘤胃纤维分解菌和CMCase的影响而促进瘤胃发酵。泌乳中期奶牛日粮添加AOC与HMB对干物质采食量和产奶量没有显著影响,但是添加AOC可以促进瘤胃总VFA生成,降低血浆NEFA浓度,从而改善了奶牛能量代谢；添加HMB可提高乳蛋白和乳脂含量、产量及4%脂肪校正乳产量；添加HMB促进总挥发性脂肪酸和乙酸生成以及瘤胃微生物蛋白合成。AOC与HMB的作用推测是通过促进纤维分解菌的生长,提高CMCase的活性,改善奶牛瘤胃发酵和泌乳性能。
This study was conducted to investigate the effects of Aspergillus oryzae culture (AOC) and2-hydroxy-4-(methylthio) butanoic acid (HMB) on rumen fermentation with different forages as substrates and lactation performance of diary cows. In vitro gas incubation system was used to estimate the effects of AOC and HMB on gas production and rumen fermentation with substrates of Chinese wild rye (CWR), alfalfa hay (AH), corn silage (CS) and corn straw (CST). On this basis, the effects of AOC and HMB on rumen microbial populations and microbial enzyme activities were studied. The effect of AOC and HMB on the lactation performance, rumen fermentation and populations of microbes was also studied.
Experiment1. Using in vitro gas production test, the effects of AOC and HMB on rumen gas production characteristics and rumen fermentation was investigated. The ratio was concentrate (corn meal) and forage (CWR, AH, CS or CST) was50:50. Each forage substrate was assigned to all6treatments in a2×3factorial arrangement with AOC (0,3or6mg) and HMB (0or15mg) as main effects. The determination of rumen fermentation was made with in vitro gas test procedure for Chinese wild rye (CWR), alfalfa hay (AH) and corn silage (CS). Gas production (GP) was recorded at2,4.8,12and24h. Ammonia-N, pH, volatile fatty acids (VFA), microbial protein (MCP) were determined at24h. The GP, potential GP and in vitro organic matter digestibility (IVOMD) significantly increased (P<0.05) when AOC and HMB was added in substrates of CWR, AH and CS substrates, and the interactive effect occurred between AOC and HMB with CS substrate (P<0.05). No effect of AOC and HMB on rumen fermentation with CST was observed (P>0.05). Adding AOC and HMB significantly increased ammonia-N concentration of CS (P<0.05). MCP concentration with substrates of CWR, AH and CS was increased with addition of AOC and HMB. And there was an interaction with MCP between AOC and HMB. Supplemental AOC and HMB increased total VFA with substrates of CWR, AH and CS except CST (P<0.01). Either AOC or HMB had little effect on molar proportions of individual VFA in CWR and AH. However, inclusion of AOC and HMB in CS substrate significantly increased molar proportion of acetate (P=0.02), and decreased proportion of butyrate (P<0.01). In addition, molar proportion of propionate increased with supplementing AOC to CS substrate (P<0.01). There was the interaction between AOC and HMB in proportion of propionate (P<0.01), butyrate (P=0.04) and ratio of acetate to propionate (A:P)(P<0.01) with CS substrate. Adding AOC and HMB had no response to the total VFA of CST, but increased molar proportion of propionate and decreased the ratio of A:P. It was inferred adding AOC and HMB could improve the rumen fermentation of substrates of CWR, AH and CS except CST and there was an interaction of CS.
Experiment2. The objective of this study was to evaluate the effects of AOC and HMB on rumen microbial population using real-time PCR and enzyme activities with CWR, AH and CS on the basis of Experiment1. The effect of adding of AOC and HMB on rumen microbes was the increased fungi population for substrates of CWR and AH (P<0.01), F. succinogenes for CS (P=0.02), and S. ruminatium population for CWR and CS (P<0.01). Addition of AOC also significantly increased populations of F. succinogenes, R. flavefaciens and R. albus for CWR (P<0.01), and R. albus for AH (P<0.01). Adding HMB significantly increased populations of R. albus for CS and R. flavefaciens and S. ruminatium population for AH (P<0.01),with significant interaction with AOC (P<0.01). Besides, activities of CMCase and amylase of CWR and xylanase of AH were increased with the addition of AOC (P<0.05). Inclusion of HMB significantly increased CMCase for AH and xylanase for substrates of CWR and AH (P<0.05). There was an interaction of AOC and HMB with activities of CMCase and amylase for substrates of CWR and AH, and xylanase with CWR, AH and CS. It suggested that adding AOC and HMB could stimulate rumen fibrolytic bacteria and cellulolytic enzyme activities with substrates of CWR, AH and CS.
Experiment3. The effects of adding AOC and HMB on lactation performance of dairy cows were investigated. Sixty-four multiparous Chinese Holstein cows (body weight=520kg, average days in milk=136, milk yield=31kg) were randomly allocated to4dietary treatments. A2×2factorial arrangement of treatment was adopted to provide2levels of supplemental AOC (0or5g/d per cow) and2levels of HMB (0or 25g/d per cow). HMB inclusion improved yield of milk protein and fat, percentage of milk total solid ((P<0.05)). Besides, there was a trend to increase the yield of4%FCM and the percentage of milk protein and fat (P=0.1), while addition of AOC significantly increased the percentage of milk lactose (P<0.05). Supplementation of AOC significantly decreased serum NEFA concentration and HMB significantly decreased serum lactose concentration (P<0.05). And there was a trend of HMB to increase serum Cys (P<0.1). It was included addition of AOC significantly decreased blood NEFA concentration, adding HMB increased the percentage of milk protein and fat, lactose and TS and the yield of milk protein and fat of Chinese Holstein cows in mid-lactation.
Experiment4. The effects of AOC and HMB on rumen fermentation and microbial populations of dairy cows were investigated. The experiment design was the same with Experiment3. Six cows of each treatment were chosen to collect ruminal liquid by an oral stomach tube in the middle and late period of the experiment. Supplementation of AOC and HMB significantly increased concentrations of rumen microbial protein and total volatile fatty acids. Adding HMB significantly increased molar proportion of acetate, but decreased molar proportion of propionate so increased the acetate to propionate ratio. Populations of rumen fungi, F. succinogenes and R. flavefaciens relative total bacteruak16S rDNA were increased with supplementing AOC and HBM. Activity of carboxymethl cellulase (CMCase) was significantly higher by adding AOC and HMB and there was an interaction between AOC and HMB. From this study, it is inferred supplementation of AOC and HMB improved rumen fermentation and lactation performance.by stimulating rumen microbes and CMCase activity.
In summary, the effects of AOC and HMB on different forages were different. Inclusion of AOC and HMB significantly improved rumen fermentation of CWR, AH and CS, while had no effect on CST. It was indicated that the effect of AOC and HMB on rumen fermentation was concerned with the effect of rumen fibrolytic bacteria population and rumen CMCase activity. Addition of AOC and HMB to the diets of Chinese Holstein dairy cows in mid-lactation had no effect on DMI and milk yield. However, adding AOC significantly decreased plasma NEFA concentration by stimulating rumen total VFA and improved energy metabolism in dairy cows. Adding HMB significantly increased concentrate and yield of milk protein and fat and yield of4%FCM by stimulating total VFA, acetate proportion and MCP. It was inferred the effect of AOC and HMB on dairy cows probably resulted from the stimulation of fungi, fibrolytic bacteria and CMCase activity.
引文
Arambel, M J., Wiedmeier R D and Walters J L.1987. Influence of donor animal adaptation to added yeast culture and/or Aspergillus oryzae fermentation extract on in vitro rumen fermentation. Nutr. Rep. Inter.,35:433.
AOAC.1990. Official Methods of Analysis. Vol.1.15th ed. Assoc. Offic. Anal. Chem., Arlington, VA.
Ayala J O, Gonzalez S S, Herrera R, Mendoza, G D.1992. Effect of a probiotic and a molasses-urea supplement on fiber digestibility of sesame straw. J. Anim. Sci., 70(Suppl.1):307.
Barbesgaard P, Heldt-Hansen H P and Diderichsen B.1992. On the safety of Aspergillus oryzae:a review. Appl. Microbiol. Biotechnol,36:569-572.
Beharka A A, Nagaraja T G, Morrill J L.1990. Performance and ruminal function development of young calves fed diets with Aspergillus oryzae fermentation extract. J. Dairy Sci.,74:4326-4336.
Beharka A A and Nagaraja T G.1993. Effect of Aspergillus oryzae fermentation extract (Amaferm) on in vitro fiber degradation. J. Dairy Sci.,76:812-818.
Beharka A A and Nagaraja T G.1998. Effect of Aspergillus oryzae extract alone or in combination with antimicrobial compounds on ruminal bacteria. J. Dariy Sci.,81: 1591-1598.
Belasco I J.1972. Stability of methionine hydroxyl analog in rumen liquid and its conversion in vitro to methionine by calf liver and kidney. J. Dairy Sci.,55: 353-357.
Belasco I J.1980. Fate of carbon-14 labeled methionine hydroxyl analog and methionine in the lactating cow. J. Dairy Sci.,63:775-784.
Belasco I J.1997. Stability of methionine hydroxy analog in rumen fluid and its conversion in vitro to methionine by calf liver and kidney. J. Dairy Sci.,80: 2513-2522.
Benefield B C, Patton R A, Stevenson M J, and Overton T R.2009. Evaluation of rumen-protected methionine sources and period length on performance of lactating dairy cows within Latin squares. J. Dairy Sci.,92:4448-4455.
Blake W L, Stern M D, and Hannah S M.1986. Effect of supplementing methionine in various forms on bacterial degradation of methionine in continuous culture. Nutr. Rep. Int.,33:729-738.
Blum J W, Bruckmaier R M and Jans J.1999. Rumen-protected methionine fed to dairy cows:Bioavailability and effects on plasma amino acid pattern and plasma metabolite and insulin concentrations. J. Dairy Sci.,82:1991-1998.
Benefield B C, Patton R A, Stevenson M J and Overton T R.2009. Evaluation of rumen-protected methionine sources and period length on performance of lactating dairy cows within Latin squares. J. Dairy Sci,92:4448-4455.
Campos-Montiel R, Herrara-Saldand, R, Viniegas, G G. and Diaz C M.1990. The effect of Aspergillus niger and Aspergillus oryzae (Amaferm) as probiotics on in situ digestibility of a high fiber diet. J. Dairy Sci.,73 (Suppl.1):133.
Caton J S, Erickson D O, Carey D A and Ulmer D L.1993. Influence of Aspergillus oryzae fermentation extract on forage intake, site of digestion, in situ degradability, and duodenal amino acid flow in steers grazing cool-season pasture. J.Anim. Sci.,71:779-787.
Chalupa W.1976. Degradation of amino acids by mixed rumen microbial population. J.Anim Sci.,43:829-834.
Chang J S, Harper E M and Calza R E.1999. Fermentation extract effects on the morphology and metabolism of the rumen fungus Neocallimastix frontalis EB 188. Journal of Applied Microbiology,86:389-398.
Chen C R, Yu B and Chiou P W S.2004. Roughage energy and degradability estimation with Aspergillus oryzae inclusion using Daisy in vitro fermentation. Asian-Aust J. Anim. Sci.,17(1):53-62.
Chiou P W S, Chen C R and Yu B.2000. Effects of Aspergillus oryzae fermentation extract on in situ degradation of feedstuffs. Asian-Aust J. Anim. Sci., 13:1076-1083.
Christensen T, Woeldike H, Boel E, Mortensen Steen B, Hjortshoej Kristen, Thim Lars and Hansen Mongens T.1988. High level expression of recombinant genes in Aspergillus oryzae. Nat. Bioechnol.,6:1419-1422.
Colin-Schoellen O, Laurent F, Vignon B, Robert J C, and Sloan B.1995. Interaction of ruminally protected methionine and lysine with protein source or energy level in the diets of cows. J. Dairy Sci.,78:2807-2818.
Denigan M E, Huber J T, Alhadhrami G and al-Dehneh A.1992. Influence of feeding varying levels of Amaferm on performance of lactating dairy cows. J. Dairy Sci.,75:1616-1621.
Denman S E, Mcs weeney C S.2006. Development of a real-time PCR assay for monitoring anaerobic fungal and cellulolytic bacterial populations within the rumen. FEMS Microb. Ecol.,58:572-582.
Dibner J J and Knight C D.1984. Conversion of 2-hydroxy-4-(methylthio) butanoic acid to L-methionine in the chick:A stereospecific pathway. J. Nutr.,114: 1716-1723.
Dibner J J and Ivey F J.1990. Hepatic protein and amino-acid metabolism in poultry. Poult. Sci.,69:1188-1194.
Erasmus L J, Botha P M and Kistner A.1992. Effect of yeast culture supplement on production, rumen fermentation, and duodenal nitrogen flow in dairy cows. J. Dairy Sci.,75:3056-3065.
Fahey J J, Mee F, Callaghan O D, Murphy J J.2002a. Effects of calcium salts of fatty acids and calcium salt of methionine hydroxyl analogue on reproductive response and milk production in Holstein-Friesian cows. J. Anim Sci.,74: 145-154.
Fahey J J, Mee F, Murphy J J and O'Callaghan D.2002b. Effects of calcium salts of fatty acids and calcium salt of methionine hydroxyl analogue on plasma prostaglandin F2alpha metabolite and milk fatty acid profiles in late lactation Holstein-Friesian cows. Theriogenology,58:1471-1482.
Fondevila M, Newbold C J, Hotten P M and (?)rskov E R.1990. A note on the effect of Aspergillus oiyzae fermentation extract on the rumen fermentation of sheep given straw. Anim. Prod.,51:423-425.
Foroozandeh A D, Rezaeian M, Balaly G R and Alikhani M.2009. Relative contributions of ruminal bacteria, protozoa and fungi to degradation of forage fiber fractions. Journal of Animal and Veterinary Advances,8 (3):603-607.
Francia A Di, Masucci F, Rosa G De, Varricchio M L and Proto V.2008. Effects of Aspergillus oryzae extract and a Saccharomyces cerevisiae fermentation product on intake, body weight gain and digestibility in buffalo calves. Anim Feed Sci. Technol., 140:67-77.
Frumholtz P P, Newbold C J and Wallace R J.1989. Influence of Aspergillus oryzae fermentation extract on the fermentation of a basal ration in the rumen simulation technique (Rusitec). J. Agric. Sci. (Camb.),113:169-172.
Gil L A, Shirley R L and Moore J E.1972. Effect of methionine hydroxy analog on growth, amino acid content, and catabolic products of glucolytic rumen bacteria in vitro. J. Dairy Sci.,56:757-762.
Gil L A, Shirley R L, and Moore J E.1973a. Effect of methionine hydroxy analog on bacterial protein synthesis from urea and glucose, starch or cellulose by rumen microbes in vitro. J. Anim. Sci.,37:159-163.
Gil L A, Shirley R L and Moore J E.1973b. Effect of methionine hydroxy analog on growth, amino acid content, and catabolic products of glucolytic rumen bacteria in vitro. J. Dairy Sci.,56:757-762.
Gill M and Powell C.1993. Prediction of associative effect of mixing feed. FAO: International conference on animal production with local resources. pp.393-405.
Giri S S, Jaggi S and Pathak N N.2005. Feeding of grainless diets containing different nitrogen sources to crossbred growing bulls:effects on rumen fermentation pattern, microbial enzyme activity and ciliate protozoa population. Anim Feed Sci. Technol.,118:187-2000.
Gomez-Alarcon, R A, Dudas C and Huber J T.1987. Effect of Aspergillus oryzae (Amaferm) and yeast on feed utilization by Holstein cows. J. Dairy Sci.,70 (Suppl.):218.
Gomez-Alarcon, R A, Dudas C and Huber J T.1990. Influence of culture of Aspergillus oryzae on rumen and total tract digestibility of dietary components. J. Dairy Sci.,73:703-710
Gomez-Alarcon R A, Huber J T, Higginbotham G E and Wanderiey R.1986. Effect of feeding a culture of A. oryzae on rumen and total tract digestion in dairy cows. J. Dairy Sci.,69 (Suppl.):188.
Gomez-Alarcon R A, Huber J T, Higginbotham G E, Wiersma F, Ammon D, and Taylor B.1991. Influence of feeding Aspergillus oryzae fermentation extract on the milk yields, eating patterns, and body temperatures of lactating cows. J. Anim. Sci.,69:1733-1740.
Hansen W P, Otterby D E, Linn J G and Donker J D.1991. Influence of forage type, ratio of forage to concentrate, and methionine hydroxy analog on performance of dairy cows. J. Dairy Sci.,74:1361-1369.
Harper E G, Welch R P, Contreras Lara, D, Chang, J S, Calza, R E.1996. The effect of Aspergillus oryzae fermentation extract on the anaerobic fungi Neocallimastix frontalis EB 188, Piromyces communis DC 193 and Orpinomyces ssp. RW 206: generalized effects and component analysis. Appl. Microbiol. Biotechnol.,45, 817-821.
Harris B Jr, Van Horn H H, Manookian K E, Marshall S P, Taylor M J and Wilcox C J. 1983. Sugarcane silage, sodium hydroxide and steam pressure-treated sugarcane bagasse, com silage, cottonseed hulls, sodium bicarbonate, and Aspergillus oiyzae production complete rations for lactating cows. J. Dariy Sci.,66: 1474-1485.
Harrison C A, Tricarico J M.2007. Effects of an Aspergillus oryzae extract containing a-amylase activity on lactational performance in commercial dairy herds. The Professional Animal Scientist,23:291-294.
Hemandez-Diaz R, Pimentel-Gonzalez D J, Figueira A C, Viniegra-Gonzalez G, Campos-Montiel R G,2010. Influence of an aerobic fungus grown on solid culture on ruminal degradability and on a mixture culture of anaerobic cellulolytic bacteria. J. Anim. Physiol. An. N.,94,330-337.
Higginbotham G E, Bath D L and Butler L J.1993. Effect of feeding an Aspergillus oryzae extract on milk production and related response in a commercial dairy herd. J. Dairy Sci.,76:1484-1489.
Higginbotham G E, Santos J E P, Juchem S O and DePeters E J.2004. Effect of feeding Aspergillus oryzae extract on milk production and rumen parameters. Livestock Produciton Science.86:55-59.
Holter J B, Kim C W and Colovos N F.1972. Methionine hydroxyl analog for lactating dairy cows. J. Dairy Sci.,55:460-465.
Huber J T, Emery R S, Bergen W G, Liesman J S, Kung L Jr, King K J, Gardner R W, Checketts M.1984. Influences of methionine hydroxy analog on milk and milk fat production, blood serum lipids, and plasma amino acids. J. Dairy Sci.,67: 2525-2531.
Iriki T, Hosogai A, Yamanoguchi K and Abe M.1989. Administration of methionine hydroxy analog to ruminants:effects on rumen fermentation and plasma methionine concentration. Bulletin of Azabu University Veterinary Medicine,10: 1-2,5-11.
Janovick Guretzky N A, Carlson D B, Garrett J E and Drackley J K.2006. Lipid metabolite profiles and milk production for Holstein and Jersey cows fed rumen-protected choline during the periparturient period. J. Dairy Sci.,89: 188-200.
Jung H G.1989. Forage lignins and their effect on fiber digestibility. Agron. J., 81:33-38.
Jung H G, Ralph J, and Hatfield R D.1991. Degradability of phenolic acid-hemicellulose esters:A model system. J. Sci. Food Agnc.,56:469-478.
Kanegasaki S and Takahashi H.1967. Function of growth factors for rumen microorganisms. Ⅰ. Nutritional characteristics of Selenomonas ruminantium. J. Bacterio.,93:456-463.
Kellems R O, Johnston N P, Wallentine M V, Largerstedt A, Andrus D, Jones R and Huber J T.1987. Effect of feeding Aspergillus oryzae on performance of cows during early lactation. J. Dairy Sci.,70(Suppl.1):219.
Kellems R O, Lagerstedt A and Wallentine M V.1990. Effect of feeding Aspergillus oiyzae fermentation extract or Aspeigillus oryzae plus yeast culture plus mineral and vitamin supplement on performance of Holstein cows during a complete lactation. J. Dairy Sci.,73:2922-2928.
Kim S W, Knabe D A,Hong K J and Easter R A.2003. Use of carbohydrases in corn-soybean meal-based nursery diets. J. Anim Sci.,81:2496-2504.
Kim H S, Ahn B S, Chung S G, Moon Y H, Ha J K, Seo I J, Ahn B H and Lee S S. 2006. Effect of yeast culture, fungal fermentation extract and non-ionic surfactant on performance of Holstein cows during transition period. Animal Feed Science and Technology,126:23-29.
Koenig K M, Rode L M, Knight C D and McCullough P R.1999. Ruminal escape, gastrointestinal absorption, and response of serum methionine to supplementation of liquid methionine hydroxy analog in dairy cow. J. Dairy Sci., 82:355-361.
Koenig K M, Rode L M, Knight C D and Vazquez-Anon M.2002. Rumen degradation and availability of various amounts of liquid methionine hydroxy analog in lactating dairy cows. J. Dairy Sci.,85:930-938.
Koike S and Kobayashi Y.2001. Development and use of competitive PCR assays for the rumen cellulolytic bacteria:Fibrobacter succinogenes, Ruminococcus albus and Ruminococccus flavefacies. FEMS Microbiol. Lett.,204:361-366.
Koike S and Kobayashi Y.2009. Fibrolytic rumen bacteria:their ecology and function. Asiar-Australasian J. Anim. Sci.,22 (1):131-138.
Kung L.1998. The effect of preservatives based on propionic acid on fermentation and aerobic stability of corn silage and a total mixed ration. J. Dairy Sci.,81: 1322-1330.
Lawson C Q, Iver F J.1986. Hydrolysis of 2-hydroxy-4-(methylthio) butanoic acid in two molde systems. Poul. Sci.,65:1749-1753.
Lee S S, Ha J K, Cheng K J.2000. Influence of an anaerobic fungal culture administration on in vitro ruminal fermentation and nutrient digestion. Anim Feed Sci. Technol.,88:201-217.
Lee S S, Choi C K, Ahn B H, Moon Y H, Kim C H and Ha J K.2004. In vitro stimulation of rumen microbial fermentation by a rumen anaerobic fungal culture. Anim Feed Sci. Technol.,115:215-226.
Leonardi C, Stevenson M and Armentano L E.2003. Effect of two levels of crude protein and mehionine supplementation on performance of dairy cows. J. Dairy Sci.,86:4033-4042.
Linehan B, Scheifinger C C and Wolin M J.1978. Nutritional requirements of Selenomonas ruminantium for growth on lactae, glycerol, or glucose. Appl. Environ. Microbiol.,35:317-322.
Loerch S G and Oke B O.1989. Rumen protected amino acids in ruminant nutrition. Page 187-200 in Absorption and Utilization of Amino Acids. Vol.3. M. Friedman, ed. CRC Press, Boca Raton, FL.
Lubis D, Wina E, Haryanto B and Suhargiantatmo T.2002. Effectiveness of Aspergillus oryzae fermentation culture to improve digestion of fibrous feeds:In vitro. JITV 7(2):90-98.
Lundquist R G, Linn J G and Otterby D E.1983. Influence of dietary energy and protein on yield and composition of milk from cows fed methionine hydroxy analog. J. Dairy Sci.,66:475-491.
Lundquist R G, Otterby D E and Linn G G.1985. Influence of three concentrations of DL-methionine or methionine hydroxy analog on milk yield and composition. J. Dairy Sci.,68:3350-3354.
Machida M.2002. Progress of Aspergillus oryzae genomics. Adv. Appl. Microbiol., 25(3):47-51.
Martin S A and Nisbet D J.1990. Effects of Aspergillus oryzae fermentation extract on fermentation of amino acids, bermudagrass and starch by mixed ruminal microorganisms in vitro. J. Anim Sci.,68:2142-2149.
Martin S A and Nisbet D J.1992. Effect of direct-fed microbials on rumen microbial fermentation. J. Dairy Sci.,75:1736-1744.
Martin S A and Streeter M N.1994. Effect of malate on the in vitro ruminal microorganism fermentation. J. Anim Sci.,72(Suppl.1):384.
Mbanzamihigo L, Vandycke E and Demeyer D I.1997. Degradation of methionine by rumen contents in vitro and efficiency of its protection. Anim. Feed Sci.,67: 339-347.
McCollum M Q, Vazquez-A M, Dibne J J and Webb K E Jr.2000. Absorption of 2-hydroxy-4-(methylthio) butanoic acid by isolated sheep ruminal and omasal epithelia. J. Anim. Sci.,78:1078-1083.
McDonald P, Edwards R A, Greenhalgh J F D. Animal Nutrition 5th Edition. Essex, UK:Longman Scientific & Technical. pp.607.
McKain N, Newbold C and Wallace R J.1991. Combined effects of Aspergillus oryzae fermentation extract (Amaferm) and monensin on fermentation in the rumen simulation technique (Rusitec). Anim. Prod.,52:593 (Abstr.).
Menke K H, Steingass H.1988. Estimation of the energetic feed value obtained from chemical analysis and in vitro rumen fluid. Anim. Res. Dev.,28:7-55.
Miranda R L A, Mendoza M G D, Barcena-Gama J R, Gonzalez M S S, Ferrara R, Ortega C M E and Cobos P M A.1996. Effect of Saccharomyces cerevisiae or Aspergillus oryzae cultures and NDF level on parameters of ruminal fermentation. Anim. Feed Sci.,63:289-296.
Mounfort D O, Asher R A and Baushop T.1982. Fermentation of cellulose to methane and carbon dioxide by a rumen anaerobic fungus in a triculture with Methanobrevibacter sp. Strain RA1 and Methanosarcina barkeri. Appl. Environ.Microbiol.,44(1):128-134.
Newbold C J, Brock R. and Wallace R J.1991 Influence of autoclaved or irradiated Aspergillus oryzae fermentation extract on fermentation in the rumen simulation technique (Rusitec). Journal of Agricultural Science,116:159-162.
Newbold C J, Brock R and Wallace R J.1992a. The effect of Aspergillus oryzae fermentation extract on the growth of fungi and ciliate protozoa in the rumen. Letters in Applied Microbiology,15:109-112.
Newbold C J, Frumholtz P P and Wallace R J.1992b. Influence of Aspergillus oryzae fermentation extract on rumen fermentation and blood constituents in sheep given diets of grass hay and barely. J. Agric. Sci (Camb.).,119:423-427
Newbold, J.,1997. Proposed mechanisms for enzymes as modifiers of ruminal fermentation. In Processing of the 8th Annual Ruminant Nutrition Symposium, Gainesville, Florida, USA, pp.146-159.
Nichols J R, Schingoethe D J, Maiga H A, Brouk M J, Piepenbrink M S.1998. Evaluation of corn distillers grains and ruminally protected lysine and methionine for lactating dairy cows. J. Dairy Sci.,81:482-491.
Nisbet D J and Martin S A.1989. Factors affecting lactate uptake by Selenomonas ruminantium HD4. In 20th Biennial Conference on rumen function, abstract No. 8. Chicago, Illinois.
Nisbet D J and Martin S A.1990. Effect of dicarboxylic acids and Aspergillus oryzae fermentation extract on lactate uptake by the ruminal bacterium Selenomonas ruminantium. Appl. Environ. Microbiol.,56:3515-3518.
Noel R J.2000. Official feed term. Association of American Feed Control Officials. Officail Publication,187-200.
Noftsger S M, St-Pierre N R, Karnati S K and Firkins J L.2003. Effects of 2-hydroxy-4-(methylthio) butanoic acid (HMB) on microbial growth in continuous culture. J. Dairy Sci.,86:2629-2636.
Noftsger S, St-Pierre N R and Sylvester J T.2005. Determination of rumen degradability and ruminal effects of three sources of methionine in lactating cows. J. Dairy Sci.,88:223-237.
Oellermann S 0, Arambel M J, Kent B A and Walters J L.1990. Effect of graded amounts of Aspergillus oryzae fermentation extract on ruminal characteristics and nutrient digestibility in cattle. J. Dairy Sci.,73:2413-2416.
Onodera R.1993. Methionine and lysine metabolism in the rumen and the possible effects of their metabolites on the nutrition and physiology of ruminants. Amino Acids,5:217-232.
Ouwerkerk D, Klieve A V and Forster R J.2002. Enumeration of Megasphaera elsdenii in rumen contents by real-time Taq nuclease assay. Journal of Applied Microbiology,92:753-758.
Patterson J A and Kung L.1988. Metabolism of dl-methionine and methionine analogs by rumen microorganisms. J. Dairy Sci.,71:3292-3301.
Patton R A, Mccarthy R D and Griel L C Jr.1970a. Liquid synthesis by rumen microorganisms. Ⅱ. Further characterization of the effects of methionine. J. Dairy Sci.,53:460-465.
Patton R A, Mccarthy R D and Griel L C Jr.1970b. Observations on rumen fluid, blood serum, and milk lipids of cows fed methionine hydroxyl analog. J. Dairy Sci.,53:776-780.
Patton R A, Mccarthy R D, Keske L C, Baumgardt B R.1970c. Effect of feeding methionine hydroxyl analog on the concentration of protozoa in rumen of sheep. J. Dairy Sci.,53:933-935.
Piepenbrink M S, Marr A L, Waldron M R, Butler W R, Overton T R, Vazquez-Anon M and Holt M D.2004. Feeding 2-hydroxy-4-(methylthio)-butanoic acid to preparturient dairy cows improves milk production but not hepatic metabolism. J. Dairy Sci.,87:1071-1084.
Pinotti L, Baldi A and Dell Orto V.2002. Comparative mammalian choline metabolism with emphasis on the high-yielding dairy cow. Nutr. Res. Rev.,15: 315-332.
Pisulewski P M, Rulquin H, Peyraud J L and Verite R.1996. Lactational and systemic responses of dairy cows to postruminal infusions of increasing amounts of methionine. J. Dairy Sci.,79:1781-1791.
Polan C E, Chandler P T and Miller C N.1970. Methionine hydroxy analog:Varying levels for lactating cows. J. Dairy Sci.,53:607-610.
Robert J C, Williams P E V and Bouza B.1997. Influence of source of methionine and protection technology on the post ruminal delivery and supply to the blood of dairy cows of an oral supply of methionine. J. Dairy Sci.,80(1):248.
Robert J C, Ferragu V, Bouza B and Williams P E V.1998. Influence of liquid methionine hydroxy analogue on digestibility of organic matter of corn-silage and/or concentrate measured in rumen in vitro. J. Dairy Sci.,81(Suppl. 1):350. (Abstr.)
Rode L M, Knight C D, Andrews K A and Koenig K M.1998. Effects of pre- and post-partum Alimet supplementation on milk production of dairy cows. J. Dairy Sci.81(Suppl.1):294. (Abstr.)
Rulquin H, Pisulewski P M, Verite R and Quinard J.1993. Milk production and composition as a function of postruminal lysine and methionine supply:a nutrient-response approach. Livest. Prod. Sci.,37(1):69-90.
Rulquin H, Grauiet B, Deiaby L and Robert J C.2006. Effect of different forms of methionine on lactational performance of dairy cows. J. Dairy Sci.,89: 4387-4394.
Salsbury R L, Marvil D K, Woodmansee C W and Haenlein F W.1971. Utilization of methionine and methionine hydroxy analof by rumen microorganisms in vitro. J. Dairy Sci.,54(3):390-396.
Salter D N.1979. The origin of nitrogen incorporated into compounds in the bacteria of steers given protein and urea-containing diets. Br. Nutr.,41:197.
Samuelson D J, Denise S K, Roffler R, Ax R L, Armstrong D V and Romagnolo D F. 2001. Response of Holstein and Brown Swiss cows fed alfalfa hay-based diets to supplemental methionine at two stages of lactation. J. Dairy Sci.,84:917-928.
Sandev S, Stojanov A, Dardionov T.1976. Formalin treated sunflower oilmeal and methionine hydroxyl analogue in feeds highly productive sheep. Archiv. Fur. Tierernahrung,26:637-642.
SAS. User's Guide:Statistics, version 8.01.2000. SAS Inst., Inc., Cary, NC.
Schmidt J A, Albright S, Calza G M, Calza R E.2004. Characterization of Aspergillus oryzae fermentation extract effects on the rumen fungus Neocallimastix frontalis EB 188. Part 2. Carbon source utilization and effects on zoospore production.63, 431-437.
Schwab C G, Bozak C K, Whitehouse N L.1992. Amino acid limitation and flow to duodenum at four stages of lactation.1. Sequence of lysine and methionine limitation. J. Dairy Sci.,75(12):3486-3502.
Shen J S, Chai Z, Song L J, Liu J X and Wu Y M. Insertion depth of oral stomach tubes may affect the fermentation parameters of ruminal fluid collected in dairy cows. J. Dairy Sci.,(in press).
Socha M T.1994. Determining the metionine requirements of lactating dairy cows. Ph. D. thesis. University of New Hampshire, Durham.
Stokes M R, Clark J H, and Steinmetz L M.1981. Performance of lactating dairy cows fed methionine or methionine analog at two concentrations of dietary crude protein. J. Dairy Sci.,64:1686-1694.
St-Pierre N R, Sylvester J T.2005. Effects of 2-hydroxy-4-(Methylthio) butanoic acid (HMB) and its isopropyl ester on milk production and composition by Holstein cows. J. Dairy Sci.,88:2487-2497.
Sylvester, J T, Karnati S K R, Morrison Z Yu and Firkins J L.2004. Development of an assay to quantify rumen ciliate protozoal biomass in cows using real-time PCR.J.Nutr.3378-3384.
Tajima K, Aminov R I, Nagamine T, Matsui H, Nakamura M and Benno Y.2001. Diet-dependent shifts in the bacterial population of the rumen revealed with real-time PCR. Applied and Environmental Microbiology,67(6):2766-2774.
Tricarico J M, Johnston J D, Dawson K A, Hanson K C, McLeod K R and Harmon D L.2005. The effects of an Aspergillus oryzae extract containing alpha-amylase activity on ruminal fermentation and milk production in lactating Holstein cows. Anim. Sci,.81:365-374.
Tricarico J M, Abney M D, Galyean M L.2007. Effects of a dietary Aspergillus oryzae extract containing a-amylase activity on performance and carcass characteristics of finishing beef cattle. J.Anim. Sci.,85:802-811.
Valkeners D, Thewis A, Piron F and Bechers Y.2004. 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.,82: 1818-1825.
Van Horn P J, Bobertson J B and Lewis B A.1991. Methods of dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci.,74:3583-3597.
Van Horn H H, Wikie A C, Powers W J and Nordstedt R A.1994. Components of dairy manure management systems. Symposium in Diary Manure and Waste Management. J. Dairy Sci..77:2008-2030.
Varel V H, Kreikemeier K K, Jung HJ G and Hatfield R D.1993. In vitro stimulation of forage fiber degradation by rumina microorganisms with Aspergillus orzyae fermentation extract. Appl. Environ. Microbiol.,59:3171-3176.
Varel V H. Kreikemeier K K.1994. Response to various amounts of Aspergillus oryzae fermentation extract on ruminal metabolism in cattle. J. Dairy Sci.,77: 3081-3086.
Varga G A, Kolver E S.1997. Microbial and animal limitations to fiber digestion and utilization. Journal of Nutrition,127:819-823.
Vazquez-Anon M, Cassidy T, McCullough P and Varga G A.2001. Effects of Alimet on nutrient digestibility, bacterial protein synthesis and ruminal disappearance during continuous culture. J. Dairy Sci.,84:159-166.
Waldrip H M and Martin S A.1993. Effects of an Aspergillus oryzae fermentation extract and other factors on lactate utilization by the ruminal bacterium Megasphaera elsdenii. J. Anim. Sci.,71:2770-2776.
Wang C, Liu H Y, Wang Y M, Yang Z Q, Liu J X, Wu Y M, Yan T and Ye H W.2010. Effects of dietary supplementation of methionine and lysine on milk production and nitrogen utilization in dairy cows. J. Dairy Sci.,93:3661-3670.
Windschitl P M and Stern M D.1988. Influence of methionine derivatives on effluent flow of methionine from continuous culture of ruminal bacteria. J. Anim Sci.,66: 2937-2947.
Wiedmeier R D, Arambel M J and Walters J L.1987. Effect of yeast culture and Aspergillus oryzae fermentation extract on ruminal characteristics and nutrient digestibility. J. Dairy Sci.,70:2063-2068
Williams A G and Coleman G S.1991.The rumen protozoa. Springer-verlag New York Inc.
Wiiiiams P E V, Tait C A G, Innes G M and Newbold C J.1991. Effects of the inclusion of yeast culture (Saccharomyces cerevisiae plus growth medium) in the diet of dairy cows on milk yield and forage degradation and fermentation patterns in the rumen of steers. J. Anim Sci.,69:3016-3026.
Yu Z T and Morrison M.2004. Improved extraction of PCR-quality community DNA from digesta and fecal samples. Bio Techniques,36:808-812.
陈力力.2003.血粉发酵生产中的微生物.肉类工业,,(7)：43.
刁其玉,张乃峰.粗纤维对动物的营养价值及其调控因素.中国畜牧报.
段得贤,贺信恒,曹光荣.1981.奶山羊过食谷物中毒的研究.西北农科院学报,3：21-33
冯仰廉.2004.反刍动物营养学.北京：科学出版社.
高红建.2000.氮-羟甲基蛋氨酸钙对绵羊瘤胃代谢及营养物质消化代谢的影响.中国农业科学院研究生院兰州序幕与兽药研究所硕士论文.
胡伟莲.2005.皂甙对瘤胃发酵与甲烷产量及动物生产性能影响的研究.浙江大学博士论文.
黄帅.2010.米曲霉对奶牛瘤胃降解率及日粮表观消化率的影响.中国牛业科学,36：23-26,50
黄帅.2011.米曲霉和酿酒酵母对奶牛瘤胃发酵及血液生化指标的影响.黑龙江八一农垦大学硕士论文.
姜淑贞.2000.肉牛十二指肠蛋氨酸灌注及过瘤胃蛋氨酸代谢规律的研究.山东农业大学硕士论文.
李成会,朱莲英.2003.羟基蛋氨酸钙对奶牛生产性能的影响.黑龙江畜牧兽医,(12)：24-25.
李改英,刘得稳,高腾云,廉红霞.2011.苜蓿的营养特点及对反刍动物作用机理的研究.江西农业学报,23(1)：172-175.
李华.2008.粗饲料中纤维素、半纤维素酶解测定方法的研究与评价.新疆农业大学硕士论文.
刘欣,冯杰,刘媛媛.2007.Aspergillus oryzae发酵豆粕对肉仔鸡生长性能及免疫功能的影响.中国畜牧杂志,43：25-27.
刘艳丰,潘晓亮,蒋慧,寇焕起,赵海丰.2007.糊化羟甲基蛋氨酸钙对泌乳中期奶牛产奶量及乳成分的影响.中国畜牧兽医,34(1)：20-23.
刘晓牧,王中华,李福昌,于志勇.奶牛过瘤胃氨基酸的研究进展.饲料工业.21 (4)：16-17.
卢德勋.2004.系统动物学营养导论.北京：中国农业出版社.
鲁海军,单安山.2005.蛋氨酸及其类似物的作用及应用,(3)：14-17.
马文强,冯杰,刘媛媛.2006. Aspergillus oyzae发酵豆粕对肉仔鸡相关消化酶活性的影响.饲料工业,27：23-25.
庞伟英,阎宏.2007.反刍动物对纤维素的消化利用及调控.草食家畜,(1)：46-47.
庞伟英,阎宏.2007.反刍动物对纤维素的消化利用及调控.草食家畜(1)：46-47.荣辉,余成群,孙维,下调雅敬,邵涛.2010.瘤胃微生物对结构性碳水化合物的降解机制研究进展.草业科学,2010,27(9)：134-143.
沈美英.2006.日粮内不同粗饲料品质对绵羊瘤胃发酵功能和微生物区系的影响.内蒙古农业大学硕士论文.
宋金昌,范莉.2002.利用微生物提高秸秆粗蛋白质的试验.动物科学与动物医学,19(1)：46-49.
孙安权,沙海锋,王光文.2006.米曲霉提取物对瘤胃生态及奶牛生产性能的影响.中国奶牛,(11)：11-12.
孙春华,王应文,简政,常维山.2009.米曲霉发酵粗酶制剂对肉鸡生产性能和食糜黏度的影响.畜牧与兽医,41(1)：32-35.
孙国强,王世成,吕永艳.2002.精料中添加金属蛋氨酸锌螯合物对奶牛产奶量的影响的研究.中国奶牛,(6)：5-16.
孙宏选.2006.不同来源的蛋白质和非结构性碳水化合物对泌乳奶牛瘤胃微生物酶活性的影响.中国农业科学院硕士论文.
唐海翠,庞学东,装苏,等.2006.直接饲喂微生物在反刍动物生产上的应用中国草食动物,26(4)：41-43.
王洪荣,邵凯,荣威恒,徐桂梅,张海鹰,珊丹,包赛娜.1998.蛋氨酸锌螯合物在绵羊体内消化代谢规律的研究.畜牧兽医学报,29(4)：322-331.
王洪荣,卢德勋.1999.饲喂豆饼、亚麻饼和血粉氮源日粮的生长绵羊限制性氨基酸研究.动物营养学报,(11)：106--122.
王建华.2004.瘤胃保护性氨基酸的研制及其对内蒙古白绒山羊消化代谢影响的研究.内蒙古农业大学硕士学位论文.
王晓佳.2012.不同粗饲料对奶牛能量代谢的影响.现代畜牧兽医,(7)：51-54.
王小林.2011.直接饲喂微生物在奶牛生产中的研究进展.中国奶牛,(9)：43-45
魏时来.2000.益康XP酵母培养物提高奶牛产乳量的试验.甘肃牧畜兽医,30(5)：23-24.
夏中生,李致宝,王振权.梁辛,杨炳壮,邹彩霞,梁贤威.2005.半胱胺、有机铬和蛋氨酸羟基类似物对水牛泌乳性能及血清生理生化指标的影响.畜牧与兽医,31(3)：4-7.
谢实勇.2002.不同形式蛋氨酸对绒山羊消化代谢及生产性能影响研究.中国农业大学硕士学位论文.
熊香梅.2004.氮-羟甲基蛋氨酸钙对中国荷斯坦奶牛瘤胃代谢及生产性能的影响.甘肃农业大学硕士论文.
杨文艳,刘国文.2008.直接饲喂微生物对反刍动物的影响饲料工业,29(23)：39-41.
袁慧.1998.湖南省没变饲料中青霉毒素的实验调查.湖南饲料,(5)：22-23.
张海,冯成利,刘成更,刘涛.1996.利用米曲霉诱变株发酵生产奶牛新型饲料添加剂的研究.中国奶牛,(1)：22.
张吉鹏,李龙瑞.2003.粗饲料在反刍动物营养中的作用及影响粗饲料营养价值的因素.中国乳业,(12)：25-29.
张乐颖.2008.反刍动物蛋白质代谢研究进展.乳业科学与技术,(1)：47-50.
张丽英.2007.饲料分析及饲料质量检测技术.3版.北京：中国农业大学出版社.
张倩摘译.1998.饲喂非降解氨基酸可提高牛奶产量.国外畜牧科技,2：8-9.
张芹,毛胜勇,朱伟云.2007.外源酶在反刍动物生产中的应用及作用机制.畜牧与兽医,39(5)：55-58.
张伟,陈志虹.2001.氨基酸螯合锌的营养及应用研究进展.饲料博览,11：11-12.
周学辉,张力,熊春梅,蒋学勤,穆林,郭爱伟,苗小林.2004.保护性蛋氨酸对高产奶牛泌乳前期生产性能的影响.中国草食动物,4(6)：38-39.
邹阿玲,孙国军,李明强,付丰收.过瘤胃蛋氨酸对泌乳早期奶牛生产性能的影响.中国奶牛,(2)：27-29.
朱宇旌,张勇.2003.反刍动物粗饲料利用的营养调控.草业科学,20(6)：36-39.