[1] TAMATE H,MCGILLIARD A D,JACOBSON N L,et al.Effect of various dietaries on the anatomical development of the stomach in the calf[J].Journal of Dairy Science,1962,45(3):408-420.

[2] SMITH R H.The development and function of the rumen in milk-fed calves Ⅱ.Effect of wood shavings in the diet[J].The Journal of Agricultural Science,1961,56(1):105-111.

[3] WARNER R G,FLATT W P,LOOSLI J K.Ruminant nutrition,dietary factors influencing development of ruminant stomach[J].Journal of Agricultural and Food Chemistry,1956,4(9):788-792.

[4] GÓRKA P,KOWALSKI Z M,ZABIELSKI R,et al.Invited review:use of butyrate to promote gastrointestinal tract development in calves[J].Journal of Dairy Science,2018,101(6):4785-4800.

[5] GREENWOOD R H,MORRILL J L,TITGEMEYER E C,et al.A new method of measuring diet abrasion and its effect on the development of the forestomach[J].Journal of Dairy Science,1997,80(10):2534-2541.

[6] CASTELLS L,BACH A,ARAUJO G,et al.Effect of different forage sources on performance and feeding behavior of Holstein calves[J].Journal of Dairy Science,2012,95(1):286-293.

[7] SUÁREZ B J,VAN REENEN C G,BELDMAN G,et al.Effects of supplementing concentrates differing in carbohydrate composition in veal calf diets:Ⅰ.Animal performance and rumen fermentation characteristics[J].Journal of Dairy Science,2006,89(11):4365-4375.

[8] 解彪.不同NDF水平饲粮对羔羊生长性能和瘤胃发育的影响[D].硕士学位论文.太谷:山西农业大学,2018. XIE B.Effects of diets with different NDF levels on growth performance and rumen development of lambs[D].Master's Thesis.Taigu:Shanxi Agricultural University,2018.(in Chinese)
[9] DANESHVAR D,KHORVASH M,GHASEMI E,et al.The effect of restricted milk feeding through conventional or step-down methods with or without forage provision in starter feed on performance of Holstein bull calves[J].Journal of Animal Science,2015,93(8):3979-3989.

[10] MOJAHEDI S,KHORVASH M,GHORBANI G R,et al.Performance,nutritional behavior,and metabolic responses of calves supplemented with forage depend on starch fermentability[J].Journal of Dairy Science,2018,101(8):7061-7072.

[11] HAMADA T,MAEDA S,KAMEOKA K.Factors influencing growth of rumen,liver,and other organs in kids weaned from milk replacers to solid foods[J].Journal of Dairy Science,1976,59(6):1110-1118.

[12] HOSSEINI S H,MIRZAEI-ALAMOUTI H,VAZIRIGOHAR M,et al.Effects of whole milk feeding rate and straw level of starter feed on performance,rumen fermentation,blood metabolites,structural growth,and feeding behavior of Holstein calves[J].Animal Feed Science and Technology,2019,255:114238.
[13] SUÁREZ B J,VAN REENEN C G,STOCKHOFE N,et al.Effect of roughage source and roughage to concentrate ratio on animal performance and rumen development in veal calves[J].Journal of Dairy Science,2007,90(5):2390-2403.

[14] NOCEK J E,HEALD C W,POLAN C E.Influence of ration physical form and nitrogen availability on ruminal morphology of growing bull calves[J].Journal of Dairy Science,1984,67(2):334-343.

[15] 王斯琴塔娜.探讨粗饲料品质对犊牛消化道组织形态及内脏器官发育的影响[D].硕士学位论文.呼和浩特:内蒙古农业大学,2007. WANG S.The effects of forage quality on morphology of gastrointestinal tract and visceral tissues growth in Holstein calves[D].Master's Thesis.Hohhot:Inner Mongolia Agricultural University,2007.(in Chinese)
[16] 云强.蛋白水平及Lys/Met对断奶犊牛生长、消化代谢及瘤胃发育的影响[D].硕士学位论文.北京:中国农业科学院,2010. YU Q.Effects of protein level and Lys/Met on performance,nutrition digestibility and rumen development for weaned calves[D].Master's Thesis.Beijing:Chinese Academy of Agricultural Science,2010.(in Chinese)
[17] CASTELLS L,BACH A,ARIS A,et al.Effects of forage provision to young calves on rumen fermentation and development of the gastrointestinal tract[J].Journal of Dairy Science,2013,96(8):5226-5236.

[18] MAKTABI H,GHASEMI E,KHORVASH M.Effects of substituting grain with forage or nonforage fiber source on growth performance,rumen fermentation,and chewing activity of dairy calves[J].Animal Feed Science and Technology,2016,221:70-78.
[19] DRACKLEY J K.Calf nutrition from birth to breeding[J].Veterinary Clinics of North America:Food Animal Practice,2008,24(1):55-86.

[20] YU P Q,MCKINNON J J,CHRISTENSEN C R,et al.Using synchrotron-based FTIR microspectroscopy to reveal chemical features of feather protein secondary structure:comparison with other feed protein sources[J].Journal of Agricultural and Food Chemistry,2004,52(24):7353-7361.

[21] YU P Q.Protein secondary structures (α-helix and β-sheet) at a cellular level and protein fractions in relation to rumen degradation behaviours of protein:a new approach[J].British Journal of Nutrition,2005,94(5):655-665.

[22] 郑娟善,张剑搏,梁泽毅,等.瘤胃微生物对木质纤维素降解的研究进展[J].动物营养学报,2020,32(5):2010-2019. ZHENG J S,ZHANG J B,LIANG Z Y,et al.Research progress on degradation of lignocellulose by rumen microorganisms[J].Chinese Journal of Animal Nutrition,2020,32(5):2010-2019.(in Chinese)
[23] 陈连民,沈宜钊,王洪荣.牛链球菌在瘤胃中产酸的代谢机制及调控[J].动物营养学报,2016,28(3):665-673. CHEN L M,SHEN Y Z,WANG H R.Metabolic mechanism of acid production by
Streptococcus bovis in rumen and its regulation[J].Chinese Journal of Animal Nutrition,2016,28(3):665-673.(in Chinese)
[24] KIM Y H,NAGATA R,OHTANI N,et al.Effects of dietary forage and calf starter diet on ruminal pH and bacteria in Holstein calves during weaning transition[J].Frontiers in Microbiology,2016,7:1575.
[25] GUZMAN C E,BEREZA-MALCOLM L,DE GROEF B,et al.Uptake of milk with and without solid feed during the monogastric phase:effect on fibrolytic and methanogenic microorganisms in the gastrointestinal tract of calves[J].Animal Science Journal,2016,87(3):378-388.

[26] 李岚捷,成述儒,刁其玉,等.不同NFC/NDF水平饲粮对犊牛瘤胃发酵参数和微生物区系多样性的影响[J].畜牧兽医学报,2017,48(12):2347-2357. LI L J,CHENG S R,DIAO Q Y,et al.Effects of diets with different NFC/NDF levels on the rumen fermentation parameters and bacterial community in male calves[J].Chinese Journal of Animal and Veterinary Sciences,2017,48(12):2347-2357.(in Chinese)
[27] 马满鹏,王炳,屠焰,等.日粮纤维水平和来源影响犊牛生长和胃肠道发育的研究[J].家畜生态学报,2019,40(5):7-12. MA M P,WANG B,TU Y,et al.Effects of dietary fiber levels and sources on calf growth and gastrointestinal development[J].Journal of Domestic Animal Ecology,2019,40(5):7-12.(in Chinese)
[28] 张双奇,昝林森,梁大勇,等.日粮精粗比对荷斯坦公犊瘤胃组织结构的影响[J].西北农林科技大学学报(自然科学版),2009,37(9):59-64. ZHANG S Q,ZAN L S,LIANG D Y,et al.Effect of different dietary concentrate to forage ratio on rumen morphological structure of Chinese Hostein bull[J].Journal of Northwest A&F University (Natural Science Edition),2009,37(9):59-64.(in Chinese)
[29] KEHOE S I,DILL-MCFARLAND K A,BREAKER J D,et al.Effects of corn silage inclusion in preweaning calf diets[J].Journal of Dairy Science,2019,102(5):4131-4137.

[30] MIRZAEI M,KHORVASH M,GHORBANI G R,et al.Effects of supplementation level and particle size of alfalfa hay on growth characteristics and rumen development in dairy calves[J].Journal of Animal Physiology and Animal Nutrition,2015,99(3):553-564.

[31] 王安思.不同精粗比日粮对肉公犊牛生长性能及瘤胃发育的影响[D].硕士学位论文.郑州:河南农业大学,2017. WANG A S.Effects of different diets on growth performance and rumen development of meat calves[D].Master's Thesis.Zhengzhou:Henan Agricultural University,2017.(in Chinese)
[32] 杨宏波,刘红,占今舜,等.不同精粗比颗粒饲料对断奶公犊牛瘤胃发酵参数和微生物的影响[J].草业学报,2015,24(12):131-138. YANG H B,LIU H,ZHAN J S,et al.Effects of diet pellets with different concentrate-roughage ratios on rumen fermentation parameters and microorganism abundance in weaned bull calves[J].Acta Prataculturae Sinica,2015,24(12):131-138.(in Chinese)
[33] XIA C Q,MUHAMMAD A U R,NIU W J,et al.Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake,digestibility,plasma metabolites,ruminal fermentation and fecal microflora of male Chinese Holstein calves[J].Journal of Integrative Agriculture,2018,17(2):415-427.

[34] BEIRANVAND H,GHORBANI G R,KHORVASH M,et al.Interactions of alfalfa hay and sodium propionate on dairy calf performance and rumen development[J].Journal of Dairy Science,2014,97(4):2270-2280.

[35] COVERDALE J A,TYLER H D,QUIGLEY Ⅲ J D,et al.Effect of various levels of forage and form of diet on rumen development and growth in calves[J].Journal of Dairy Science,2004,87(8):2554-2562.

[36] BULL L S,BUSH L J,FRIEND J D,et al.Incidence of ruminal parakeratosis in calves fed different rations and its relation to volatile fatty acid absorption[J].Journal of Dairy Science,1965,48(11):1459-1466.

[37] HIBBS J W,CONRAD H R,POUNDEN W D,et al.A high roughage system for raising calves based on early development of rumen function.Ⅵ.Influence of hay to grain ratio on calf performance,rumen development,and certain blood changes[J].Journal of Dairy Science,1956,39(2):171-179.

[38] KELLAWAY R C,THOMSON D J,BEEVER D E,et al.Effects of NaCl and NaHCO
3 on food intake,growth rate and acid-base balance in calves[J].The Journal of Agricultural Science,1977,88(1):1-9.

[39] SANTINI F J,HARDIE A R,JORGENSEN N A,et al.Proposed use of adjusted intake based on forage particle length for calculation of roughage indexes[J].Journal of Dairy Science,1983,66(4):811-820.

[40] NEMATI M,AMANLOU H,KHORVASH M,et al.Rumen fermentation,blood metabolites,and growth performance of calves during transition from liquid to solid feed:effects of dietary level and particle size of alfalfa hay[J].Journal of Dairy Science,2015,98(10):7131-7141.

[41] 陈宁,尹君亮,刘福元,等.不同日粮组成对断奶初期奶公犊瘤胃内环境指标的影响[J].家畜生态学报,2006,27(6):124-128. CHEN N,YIN J L,LIU F Y,et al.Effect of metabolic parameters of rumen fluid with different diets at the initial stage of weaning calf[J].Journal of Domestic Animal Ecology,2006,27(6):124-128.(in Chinese)
[42] 刘春龙,李忠秋,孙海霞,等.纤毛虫对反刍动物瘤胃内环境指标、营养物质代谢的影响的研究[J].家畜生态,2004,25(3):57-60. LIU C L,LI Z Q,SUN H X,et al.Effects of ciliate on rumen inner circumstance and metabolism of nutriment[J].Ecology of Domestic Animal,2004,25(3):57-60.(in Chinese)
[43] 苑文珠,叶均安,刘建新.瘤胃原虫对反刍动物的影响[J].饲料博览,2002(1):17-18. YUAN W S,YE J A,LIU J X.Effects of rumen protozoa on ruminants[J].Feed Review,2002(1):17-18.(in Chinese)
[44] DILL-MCFARLAND K A,WEIMER P J,BREAKER J D,et al.Diet influences early microbiota development in dairy calves without long-term impacts on milk production[J].Applied and Environmental Microbiology,2019,85(2):e02141-18.
[45] VAN ACKEREN C,STEINGAB H,HARTUNG K,et al.Effect of roughage level in a total mixed ration on feed intake,ruminal fermentation patterns and chewing activity of early-weaned calves with
ad libitum access to grass hay[J].Animal Feed Science and Technology,2009,153(1/2):48-59.
[46] KHAN M A,WEARY D M,VON KEYSERLINGK M A G.Hay intake improves performance and rumen development of calves fed higher quantities of milk[J].Journal of Dairy Science,2011,94(7):3547-3553.

[47] SUAREZ-MENA F X,HEINRICHS A J,JONES C M,et al.Straw particle size in calf starters:effects on digestive system development and rumen fermentation[J].Journal of Dairy Science,2016,99(1):341-353.

[48] 曾银,贺鸣,曹志军,等.全混合日粮中粗饲料长度对奶牛咀嚼行为和瘤胃发酵的影响[J].动物营养学报,2010,22(6):1571-1578. ZENG Y,HE M,CAO Z J,et al.Effects of roughage particle size of TMR on chewing activity and rumen fermentation in dairy cows[J].Chinese Journal of Animal Nutrition,2010,22(6):1571-1578.(in Chinese)
[49] OMIDI-MIRZAEI H,AZARFAR A,MIRZAEI M,et al.Effects of forage source and forage particle size as a free-choice provision on growth performance,rumen fermentation,and behavior of dairy calves fed texturized starters[J].Journal of Dairy Science,2018,101(5):4143-4157.

[50] SUAREZ-MENA F X,HEINRICHS A J,JONES C M,et al.Digestive development in neonatal dairy calves with either whole or ground oats in the calf starter[J].Journal of Dairy Science,2015,98(5):3417-3431.

[51] KONONOFF P J,HEINRICHS A J,LEHMAN H A,et al.The Effect of corn silage particle size on eating behavior,chewing activities,and rumen fermentation in lactating dairy cows[J].Journal of Dairy Science,2003,86(10):3343-3353.

[52] BEHARKA A A,NAGARAJA T G,MORRILL J L,et al.Effects of form of the diet on anatomical,microbial,and fermentative development of the rumen of neonatal calves[J].Journal of Dairy Science,1998,81(7):1946-1955.

[53] BOLT S L,BOYLAND N K,MLYNSKI D T,et al.Pair housing of dairy calves and age at pairing:effects on weaning stress,health,production and social networks[J].PLoS One,2017,12(1):e0166926.
[54] OVERVEST M A,CROSSLEY R E,MILLER-CUSHON E K,et al.Social housing influences the behavior and feed intake of dairy calves during weaning[J].Journal of Dairy Science,2018,101(9):8123-8134.

[55] BALDWIN R L,MCLEOD K R,KLOTZ J L,et al.Rumen development,intestinal growth and hepatic metabolism in the pre- and postweaning ruminant[J].Journal of Dairy Science,2004,87:E55-E65.
[56] HOSSEINI S M,GHORBANI G R,REZAMAND P,et al.Determining optimum age of Holstein dairy calves when adding chopped alfalfa hay to meal starter diets based on measures of growth and performance[J].Animal,2016,10(4):607-615.

[57] LIN X Y,WANG J,HOU Q L,et al.Effect of hay supplementation timing on rumen microbiota in suckling calves[J].Microbiology Open,2018,7(1):e00430.