Physical and chemical properties, gas fermentation parameters, starch digestibility and starch granules structure in Iranian corn grain Single cross 702 in comparison with different kind of imported corn grain

Document Type : Ruminant Nutrition


1 Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.

2 Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

3 Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran


Introduction[1] Corn grain represents the most important energy source in ruminant diets. In high-producing dairy cows, the diets contain high levels of corn in order to meet their energy requirements. Corn has a complex structure where a range of nutrients interact with each other or physically associations. Ultimately, the quantity and availability of these nutrients determines the nutritional value of this grain. In corn nutrients and energy utilization is influenced by both intrinsic (e.g. starch granules and protein matrix structure) and extrinsic (e.g. growing and storage conditions, climate and agronomy conditions and grain drying process) factors. Corn endosperm represents more than 80% of total grain and is composed of starch granules that are imbedded in a protein matrix and surrounded by plant cell walls. Starch granules size, starch composition (amylose/amylopectin ratio), starch encapsulation (by endosperm cell walls and protein bodies) are among the factors with the most influence on digestion of starch. The structure and distribution of starch and protein matrix network of grains vary in different corn varieties. The Objectives of this study were to evaluate physical and chemical properties, gas fermentation parameters, starch digestibility and starch granules structure in Iranian corn grain Single cross 702 in comparison with different kind of imported corn grains (Russia, Ukraine and Brazil).  
Materials and methods Corn grain samples (Single cross 702, Russia, Ukraine and Brazil) were obtained from Khorasan Razavi Agricultural and Natural Resources Research Center, Mashhad, Iran. The apparent density was measured and the samples were analyzed for DM, OM, CP, EE, NDF, ADF, starch. Gas production was conducted in a 125 ml amber flask with three series of incubation. Gas production parameters were calculated. Also, rumen, intestine and total tract digestibility of DM, starch and CP were determined by using the in situ mobile bag procedure. Different parameters of damaged starch (the absorption of iodine, Ai%; damaged starch content in UCD, Chopin units; UCDc, Chopin units on protein basis matter) were determined using the amperometry method (Chopin, ZI Val de Sein, 92390 VLG, France). Starch gelatinization was determined according to the enzymatic procedure (AACC Method 76-31.01; K-SDAM, 09/2018). Scanning electron microscope (LEO 1450 VP, USA), at an accelerating voltage of 25 kV, and under 2500x magnification to study the grain structure was done. Data were analyzed by GLM procedure of SAS with a completely randomized design.
Results and discussion Apparent shape of Single cross 702 was smaller than other corn varieties. Apparent density was higher in Brazil corn than other corn varieties. DM, OM and EE were not shown significantly difference between corn varieties; however, CP, ADF, NDF, starch, NFC, TDN, NEg and NEl were significantly affected by different corn varieties. Starch in Single cross 702 corn (69.03%) was significantly lower than Russia (71.04%), Ukraine (70.36%) and Brazil (71.49%) corns. Asymptote gas production (A) was not influenced by different corn varieties; however, the real gas production in time 24 and 48 h incubation in Brazil, Russia and Single cross 702 corns was greater than Ukraine corn. The instant rate of gas production until 8 h incubation in Single cross 702 and Russia corns was greater than Ukraine and Brazil corns. The time for fermentation of 25 and 75% of substrate in Single cross 702 and Russia corns were significantly reduced than other corn varieties. The PH, NH3-N and total VFA of bath culture in 24 h didn’t influence by corn varieties, however acetate to propionate ratio in Brazil corn was greater than other corns. In spite of that the rumen starch digestibility of Single cross 702 (61.59%) and Russia (59.51%) was increased than Ukraine (45.31%) and Brazil (40.51%) corns; however, Ukraine (97/.06%) and Brazil (98.39%) corns showed the intestine starch digestibility greater than Single cross 702 (93.79%) and Russia (93.87 %) corns. The starch gelatinization in both of Single cross 702 (4.24%) and Russia (4.17%) was greater than Ukraine (3.78%) and Brazil (3.32%) corns. The scanning electron microscopy showed that the starch granules size was not uniform in the Single cross 702 corn and the number of small starch granules was greater than other corn varieties. Also, the thin protein matrix was observed in the Single cross 702 corn. In contrast, the starch granules size in the Russia and Ukraine corns were larger and uniform. In Brazil corn, the starch granules were arranged with greater density and a non-smooth surface was observed on the granules. Many studies were done on nutrient value of different corn varieties. Numerous factors can affect the grain chemical composition, physical properties and starch availability on corn grain that include cell wall structure, type of endosperm (floury or vitreous), starch granules and protein matrix, genetic and environment. Corns contain higher floury to horny starch ratio showed greater starch gelatinization and greater starch digestibility in the rumen and total tract. Findings of this study represent the Single cross 702 and Russia corns showed higher gas production, rate of gas production, starch gelatinization and rumen digestibility of starch than Brazil corn.
Conclusion It is concluded that the Single cross 702 corn in terms of flurry endosperm, gas production, gas production rate, starch gelatinization and rumen digestibility of starch was similar to Russia corn, although the structure of starch granules was different. Brazil corn had a horny endosperm and showed lower rate of gas production in initial hours of incubation, lower starch gelatinization and higher intestine digestibility of starch than other corns. It generally seems that the result of this study and similar studies can offer useful information about corn grain for farmers and the animal feed manufactures for processing of corn.  


1-         Abdelrahman, A. A., and R. C. Hoseney. 1984. Basics for hardness in pearl millet, grain sorghum and corn. Cereal Chemistry, 61:232–235.
2-         Allen, M. S., R. A. Longuski., and Y. Ying. 2008. Endosperm type of dry ground corn affects ruminal and total tract digestion of starch in lactating dairy cows. Journal of Dairy Science, 91 (E-Suppl. 1): 529. (Abstract)
3-         AOAC, 2012. Official Methods of Analysis, 19th ed. Association of Official Analytical Chemists, Washington, DC, 121-130.
4-         Bechtel, D. B., I. Zeyas., L. Kaleikau., and Y. Pomeranz. 1990. Size-distribution of wheat starch granules during endosperm development. Cereal Chemistry, 67: 59–63.
5-         Bechtel, D. B., I. Zeyas., R. Dempster., and J. D. Wilson. 1993. Size-distribution of starch granules isolated from hard red winter and soft winter wheat. Cereal Chemistry, 70: 238–240.
6-         Chai, W. Z., A. H. van Gelder., and J. W. Cone. 2004. Relationship between gas production and starch degradation in feed samples. Aminal Feed Science and Technology, 114: 195-204.
7-         Chen, K. H., J. T. Huber., J. Simas., C. B. Theurer., P. Yu., S. C. Chan., F. Santos., Z. Wu., and R. S. Swingle. 1994. Effect of enzyme treatment or steam flaking of sorghum grain on lactation and digestion in dairy cows. Journal of Dairy Science, 78: 1721-1727.
8-         Cone, J. W. 1998a. The development, use and application of the gas production technique at the DLO Institute for Animal Science and Health (AD-DLO), Lelystad, The Netherlands. In: Deaville, E. R., Owen, E., Adesogan, A. T., Rymer, C., Huntington, J. A., Lawrence, T. L. J. (Eds.), In vitro Techniques for Measuring Nutrient Supply to Ruminants. Occasional publication No. 22 British Society of Animal Science, pp. 65-78.
9-         Correa, C. E. S., R. D. Shaver., M. N. Pereira., J. G. Lauer., and K. Kohn. 2002. Relationship between corn vitreousness and ruminal in situ starch degradability. Journal of Dairy Science, 85: 3008-3012.
10-     Cromwell, G. L., M. J. Bitzer., T. S. Stahly., and T. H. Johnson. 1983. Effects of soil nitrogen fertility on the protein and lysine content and nutritional value of normal and opaque-2 corn. Journal of Animal Science, 57:1345-1351.
11-     Cui, L., S. Dong., J. Zhang., and P. Liu. 2014. Starch granule size distributionandmorphogenesisin maize (Zea mays L.) grains with different endosperm types. Australian journal of crop science, 8 (11): 1560-1565.
12-     D’Alfonso, T. H. 2005. Sources of variance of energy digestibilityin corn-soy poultry diets and the effect on performance: Starch, protein, oil and fiber. Agris Science, 47:83–86.
13-     D’Alfonso, T. H., and K. McCracken. 2002. Global corn quality variability. Proceedings of the Multistate Poultry Meeting, Indianapolis, Indiana, May14-16.
14-     Dunshea, F. R., S. A. Pate., V. M. Russo., and B. J. Leary. 2012b. A starch binding agent decreases the rate of fermentation of wheat in a dose-dependent manner. Accessed March 21. The university of Melbourne.
15-     Dunshea, F. R., V. M. Russo., I. Sawyer., and B. J. Leary. 2012a. A starch-binding agent decreases the in vitro rate of fermentation of wheat. Journal of Dairy Science, 95 (Suppl 2): 199. (Abstract).
16-     Fanning, K. C., R. A. Longuski., R. J. Grant., M. S. Allen., and J. F. Beck. 2002. Endosperm type and kernel processing of corn silage: Effect on starch and fiber digestion and ruminal turnover in lactating cows. Journal of Dairy Science, 85 (Suppl. 1): 204. (Abstract).
17-     Firkins, J. L., M. L. Eastridge., N. R. St-Pierre., and S. M. Noftsger. 2001. Effects of grain variability and processing on starch utilization by lactating dairy cattle. Journal of Animal Science, 79 (E Suppl.): E218-E238.
18-     France, J., J. Dijkstra., M. S. Dhanoa., S. Lopez., and A. Bannink. 2000. Estimating the extent of degradation of ruminant feeds from a description of their gas production profiles observed in vitro: derivation of models and other mathematical considerations. British Journal of Nutrition, 83: 143–150.
19-     Genter, C. F., J. F. Eheart., and W. N. Linkous. 1956. Effects of location, hybrid, fertilizer, and rate of planting on the oil and protein contents of corn grain. Agronomy Journal, 48: 63-67.
20-     Giuberti, G., A. Gallo., F. Masoero., L. F. Ferraretto., P. C. Hoffman., and R. D. Shaver. 2014. Factors affecting starch utilization in large animal food production system: A review. Starch, 66: 72–90.
21-     Gozho, G. N., and T. Mutsvangwa. 2008. Influence of carbohydrate source on ruminal fermentation characteristics, performance, and microbial protein synthesis in dairy cows. Journal of Dairy Science, 91: 2726– 2735.
22-     Groot, J. C. J., J. W. Cone., B. A. Williams., F. M. Debersaques., and E. A. Lantinga. 1996. Multiphasic analysis of gas production kinetics for in vitro fermentation of ruminant feeds. Animal Feed Science and Technology, 64: 77–89.
23-     Hoffman, P. C., and R. D. Shaver. 2009. Corn Biochemistry: Factors relating to starch digestibility in lactating cows. Dairy Health and Nutrition Conference. New York, USA.
24-     Hoffman, P. C., D. Ngonyamo-Majee., and R. D. Shaver. 2010. Technical note: Determination of corn hardness in diverse corn germplasm using near-infrared reflectance baseline shift as a measure of grinding resistance. Journal of Dairy Science, 93: 1685-1689.
25-     Hurkman, W. J., K. F. McCue., S. B. Altenbach., A. Korn., C. K. Tanaka., K. M. Kothari., E. L. Johnson., D. B. Bechtel., J. D. Wilson., O. D. Anderson., and F. M. Dupont. 2003. Effect of temperature on expression of genes encoding enzymes for starch biosynthesis in developing wheat endosperm. Plant Science, 164: 873–881
26-     Hutjens, M., and H. Dann. 2000. Grain processing: is too coarse or too fine? Department of Animal Sciences, University of Illinois.
27-     Iji, P. A., K. Khumalo., S. Slippers., and R. M. Gous. 2003. Intestinal function and body growth of broiler chickens on diets based on maize dried at different temperatures and supplemented with a microbial enzyme. Reproduction Nutrition Development, 43:77-90.
28-     Jaeger, S. L., C. N. Macken., G. E. Erickson., T. J. Klopfenstein., W. A. Fithian., and D. S. Jackson. 2004. The influence of corn kernel traits on feedlot cattle performance. Nebraska Beef Report, 54-57.
29-     Ji, Y., K. Seetharaman., K. Wong., J. Hasjim., L. M. Pollak., S. Duvick., J. Jane., and P. J. White. 2003a. Thermal and structure properties of unusual starches from developmental corn lines. Carbohydrate Polymer, 51: 439–450.
30-     Ji, Y., K. Wong., J. Hasjim., L. M. Pollak., S. Duvick., J. Jane., and P. J. White. 2003b. Structure and function of starch from advanced generation of new corn lines. Carbohydrate Polymer, 54: 305–319.
31-     Kaczmarek, S., A. Cowieson., D. Jozefiak., and M. Bochenek. 2007. The effect of drying temperature and exogenous enzymes supplementation on the nutritional value of maize for broiler chickens. In: Proceedings of the 16th European Symposium on poultry nutrition, August 26-30, 2007, Strasbourg, France, 555-558.
32-     Kaur, A., N. Singh., R. Ezekiel., and H. S. Guraya. 2007. Physicochemical, thermal and pasting properties of starches separated from different potato cultivars grown at different locations. Food Chemistry, 101: 643–651.
33-     Kniep, K. R., and S. C. Mason. 1991. Lysine and protein content of normal and opaque-2 maize grain as influenced by irrigation and nitrogen. Crop Science, 31: 177-181.
34-     Knutson, C. A. 1990. Annealing of maize starches at evevated temperatures. Cereal Chemistry, 67: 376-384.
35-     Kotara, D., and B. Fuchs. 2001. The effect of gelatinization degree and source of starch on the ileal and faecal digestibility of nutrients and growth performance of early-weaned piglets. Animal Feed Science and Technology, 10:163-70.
36-     Leeson, S., A. Yersin., and L. Volker. 1993. Nutritive value of the 1992 corn crop. Journal of Applied Poultry Research, 2: 208-213.
37-     Leeson, S., and J. D. Summers. 1976. Effect of adverse growing conditions on corn maturity and feeding value for poultry. Poultry Science, 55: 588-593.
38-     Leeson, S., J. D. Summers, and T. B. Daynard. 1977. The effect of kernel maturity at harvest as measured by moisture content, on the metabolizable energy value of corn. Poult. Sci. 56:154-156.
39-     Leeson, S., J. D. Summers., and T. R. Daynard. 2003. The effect of kernel maturity at harvest as measured by moisture content, on the metabolizable energy value of corn. Poultry Science, 56: 154–156.
40-     Li, Q. F., M. Shi., and C. X. Shi. 2014. Effect of variety and drying method on the nutritive value of corn for growing pigs. Journal of Animal Science Biotechnology, 5:18-28.
41-     Li, Y. L. 1999. Effect of normal corn pollen burst of maize grain and burst characteristics. Chinese Agricultural Science Bulletin, 15 (6): 24–26.
42-     Liu, P., C. H. Hu., S. T. Dong., K. J. Wang., J. W. Zhang., and B. R. Zhang. 2005. Comparison of enzymes activity associated with sucrose metabolism in the developing grains between sweet corn and normal corns. Scientia Agricola, 38 (1): 52–58.
43-     Longuski, R. A., K. C. Fanning., M. S. Allen., R. J. Grant., M. S. Allen., and J. F. Beck. 2002. Endosperm type and kernel processing of corn silage: Effect on short-term lactational performance in dairy cows. Journal of Dairy Science, 85 (Suppl. 1): 204.
44-     Lopes, J. C., R. D. Shaver, P. C. Hoffman, M. S. Akins, S. J. Bertics, H. Gencoglu, and J. G. Coors. 2009. Type of corn endosperm influences nutrient digestibility in lactating dairy cows. Journal of Dairy Science, 92: 4541-4548.
45-     Lopes, J. C., R. D. Shaver., P. C. Hoffman., M. S. Akins., S. J. Bertics., H. Gencoglu., and J. G. Coors. 2009. Type of corn endosperm influences nutrient digestibility in lactating dairy cows. Journal of Dairy Science, 92: 4541-4548.
46-     Lu, D. L., H. F. Guo., and W. P. Lu. 2011. Effects of sowing date, variety and nitrogen top-dressing at jointing stage on starch granule size distribution of waxy maize. Scientia Agricola, 44 (2): 263–270.
47-     Ma, D., J. Li., C. Huang., F. Yang., Y. Wu., L. Liu., W. Jiang., Z. Jia., P. Zhang., X. Liu., and S. Zhang. 2019. Determination of the energy contents and nutrient digestibility of corn, waxy corn and steam-flaked corn fed to growing pigs. Asian-Australian Journal of Animal Science, 32 (10): 1573-1579.
48-     McAllister, T. A., L. M. Rode., K. J. Cheng., and C. W. Forsberg. 1991. Selection of a sterilization method for the study of cereal grain digestion. Journal of Animal Science, 69: 3039-3043.
49-     McAllister, T. A., R. Phillippe., L. M. Rode., and K. J. Cheng. 1993. Effect of the protein matrix on the digestion of cereal grains by ruminal microorganisms. Journal of Animal Science, 71: 205-212.
50-     McDonough, C. M., B. J. Anderson., and L. W. Rooney. 1997. Structural Characteristics of Steam-Flaked Sorghum. Cereal Chemistry, 74: 542–547.
51-     Medcalf, D., and K. Gilles. 1965. Effect of a Lyotropic Ion Series on the Pasting Characteristics of Wheat and Corn Starches. Starch, 18, 101-105.
52-     Menke, H. H., and H. Steingass. 1988. Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research Development, 28: 7–55. 
53-     Mohd, B. M. N., and M. Wootton. 1984. In vitro digestibility of hydroxypropyl maize, waxy maize and high amylose maize starches. Starch, 36: 273-275.
54-     National Research Council (NRC) (2001). Nutrient requirements of dairy cattle. 7th Edn., Washington, D.C., National Academy Press. P: 450.
55-     Ngonyamo-Majee, D., R. D. Shaver., J. G. Coors., D. Sapienza., and J. G. Lauer. 2008b. Relationships between kernel vitreousness and dry matter degradability for diverse corn germ plasm. II. Ruminal and post-ruminal degradabilities. Animal Feed Science and Technology, 142: 259-274.
56-     Ngonyamo-Majee, D., R. D. Shaver., J. G. Coors., D. Sapienza., D. E. S. Correa., J. G. Lauer., and P. Berzaghi. 2008a. Relationships between kernel vitreousness and dry matter degradability for diverse corn germplasm. I. Development of near-infrared reflectance spectroscopy calibrations. Animal Feed Science and Technology, 142: 247-258.
57-     Ngonyamo-Majee, D., R. D. Shaver., J. G. Coors., D. Sapienza., J. G. Lauer. 2009. Influence of single-gene mutations, harvest maturity and sample processing on ruminal in situ and post-ruminal in vitro dry matter and starch degradability of corn grain by ruminants. Animal Feed Science and Technology, 151, 240–250.
58-     Office of Business Planning, Statistics and Research (OBPSR). 2016. Iran Foreign Trade Performance Report. www. Page 11. (In Persian)
59-     Owens, F. 2007. Corn genetics and animal feeding value. Pioneer Hi-Bred International, Inc., Johnston, I A.
60-     Owens, F. N., D. S. Secrist., W. J. Hill., D. R. Gill. 1997. The effect of grain source and grain processing on performance of feedlot cattle: a review. Journal of Animal Science, 75: 868-79.
61-     Panozzo, J. F., and H. A. Eagles. 1998. Cultivar and environmental effects on quality characters in wheat: I. Starch. Australian Journal of Agriculture Research, 49: 757–766
62-     Pashaei, S., V. Razmazar., and R. Mirshekar. 2010. Gas production: A proposed in vitro method to estimate the extent of digestion of a feedstuff in the rumen. Journal of Biology Science, 10: 573-580.
63-     Paterson. J. L., A. Hardacre., P. Li., and M. A. Rao. 2001. Rheology and granule size distribution of corn starch dispersions from two genotypes and grown in four regions. Food Hydrocolloids, 15: 453–459.
64-     Peron, A., and C. E. Gilbert. 2011. Differences between corn: a study of origin and harvests. Asian feed technical. Poultry feed quality conference. Kuala Lumpur.
65-     Philippeau, C., and B. Michalet-Doreeau. 1997. Influence of genotype and stage of maturity of maize on rate of ruminal starch degradation. Animal Feed Science and Technology, 68: 25-35.
66-     Philippeau, C., C. Martin., and B. Michalet-Doreau. 1999b. Influence of grain source on ruminal characteristics and rate, site, and extent of digestion in beef steers. Journal of Animal Science, 77: 1587–1596.
67-     Philippeau, C., F. Le Deschault de Monredon., and B. Michalet-Doreau. 1999a. Relationship between ruminal starch degradation and the physical characteristics of corn grain. Journal of Animal Science, 77: 238–243.
68-     Ramos, B. M. O., M. Championb., C. Poncet., I. Y. Mizubuti., and P. Nozi`ere. 2009. Effects of vitreousness and particle size of maize grain on ruminal and intestinal in sacco degradation of dry matter, starch and nitrogen. Animal Feed Science and Technology, 148: 253–266.
69-     Rehman, Z. U., F. Habib., and S. I. Zafar. 2002. Nutritional changes in maize (Zea mays) during storage at three temperatures. Food Chemistry, 77: 197-201.
70-     Rooney, L. W., and R. I. Pflugfelder. 1986. Factors affecting starch digestibility with special emphasis on sorghum and corn. Journal of Animal Science, 63: 1607-1623.
71-     Sangeeta, G., and R. B. Grewal. 2018. Physical and chemical properties of corn varieties (HQPM-1 and HQPM-7). International Journal of Chemical Studies, 6 (3): 3380-3382.
72-     SAS Institute. 2009. SAS/STAT Users Guide. SAS Inst., Inc., Cary, NC.
73-     Shiri. M. R., F. Azizi., M. Abaspour., H. Fakhimi., A. Badali., M. Jalil., and A. Kasraei. 2016. Comparison of the performance of the new Single Cross 704 hybrid with the Single Cross 702. Agricultural Research, Education and Promotion Organization, R 43978: 6-7. (In Persian)
74-     Simmonds, D. H., K. K. Barlow., and C. W. Wrigley. 1973. The biochemical basis of grain hardness in wheat. Cereal Chemistry, 50: 553–562.
75-     Song, G. L., D. F. Li., X. S. Piao., F. Chi., and W. J. Yang. 2003. Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of high-oil corn varieties and its effects on growth performance of pigs. Archive of Animal Nutrition, 57: 297-306.
76-     Soulski, F. W., and A. M. Cadden. 1982. Composition and physiological properties of several sources of dietary fiber. Journal of Food Science, 47: 1472-1477.
77-     Subuh, A. M. H., T. G. Rowan., T. L. J. Lawrence. 1996. Effect of heat or formaldehyde treatment on the rumen degradability and intestinal tract apparent digestibility of protein in soya-bean meal and in rapeseed meals of different glucosinolate content. Animal Feed Science and Technology, 57: 139-152.
78-     Taylor, C. C., and M. S. Allen. 2005. Corn grain endosperm type and brown midrib 3 corn silage: Feeding behavior and milk yield of lactating cows. Journal of Dairy Science, 88: 1425-1433.
79-     Theodorou, M. K., B. A. Williams., M. S. Dhanoa., A. B. McAllan., and J. France. 1994. A simple gas production method using a pressure transducer to determine the fermentation kinetics ofruminant feeds. Animal Feed Science and Technology, 48: 185–197.
80-     Theurer, C. B. 1986. Grain processing effects on starch utilization by ruminants. Journal of Animal Science, 63: 1649-1662.
81-     Thompson, D. L., M. D. Jellum., and C. T. Young. 1973. Effect of controlled temperature environments on oil content and on fatty acid composition of corn oil. Journal of American Oil Chemists Society, 50: 540-542.
82-     Van zyl. J. H. C. 2017. The effect of maize vitreousness and a starch binder on in vitro fermentation parameters and starch digestibility in dairy cows. PhD thesis. Stellenbosch University. Department of Animal Sciences. Faculty of AgriScience.
83-     Weatherburn, W. M. 1967. Phenol-hypochlorite reaction for determination of ammonia. Annual Chemistry, 39: 971–975.
84-     Wilson, J. D., D. B. Bechtel., T. C. Todd., and P. A. Seib. 2006. Measurement of wheat starch granule size distribution using image analysis and laser diffraction technology. Cereal Chemistry, 83: 259–268.
85-     Zhang, H. Y., R. Q. Gao., and S. T. Dong. 2011. Anatomical and physiological characteristicsassociated with corn endosperm texture. Agronomy Journal, 103: 1-7.
86-     Zhang, L., J. W. Zhang., P. Liu., and S. T. Dong. 2011. Starch granule size distribution in grains of maize with different starch contents. Scientia Agricola, 44 (8): 1596–1602.
87-     Zhang, L., Y. K. Li., Z. C. Li., Q. F. Li., M. B. Lyu., D. F. Li., and C. H. Lai. 2016. The Nutritive Values in Different Varieties of Corn Planted in One Location Fed to Growing Pigs over Three Consecutive Years. Asian Australas. Journal of Animal Science, 29 (12): 1768-1773.
88-     Zhirkovaa, E. V., M. V. Skorokhodovaa., V. V. Martirosyanb., E. F. Sotchenkob., V. D. Malkinac., and T. A. Shatalovad. 2016. Chemical composition and antioxidant activity of corn hybrids grain of different pigmentation. Foods and Raw Materials, 4 (2): 85–91.
89-     Zilic, S., M. Milasinovic., D. Terzic., M. Barac., and D. Ignjatovic-Micic. 2011. Grain characteristics and composition of maize specialty hybrids. Spanish Journal of Agricultural Research, 9(1): 230-241.
90-     Zinn. R., F. Owens., and R. Ware. 2002. Flaking corn: processing mechanics, quality standards, and impacts on energy availability and performance of feedlot cattle. Journal of Animal Science, 80: 1145-56.
  • Receive Date: 10 January 2020
  • Revise Date: 22 February 2020
  • Accept Date: 11 April 2020
  • First Publish Date: 27 November 2020