Starch Properties, Nutrients Profiles, In Vitro Ruminal Fermentation and Molecular Structure of Corn Processed in Different Ways

Abstract

Processing will improve the digestion of corn by ruminant animals. The objectives of this study were to investigate the effects of processing methods (grinding, G; steam flaking, SF; extrusion, E) on the starch properties, nutrient profiles, in vitro ruminal fermentation and molecular structure of corn. Compared with G, SF and E increased (p < 0.05) the starch content, starch gelatinization, ruminal gas production (GP, 0.5–32 h), propionic acid, starch degradability (SD), the area and height of carbohydrate peaks, and decreased (p < 0.05) starch crystallinity, content of crude protein, neutral detergent fiber and acid detergent fiber, ruminal NH3-N, the area and height of amide I and II, α-helix, and β-sheet. The total VFA (24 h, 48 h) tended to be increased by SF and E (p < 0.10). The carbohydrate peak area and height were positively (p < 0.05) correlated with GP (1–24 h) and SD. The protein molecular absorption intensity was negatively correlated with SD (p < 0.05). The change in starch properties, GP (1–24 h) and molecular structure caused by E was greater than SF (p < 0.05). These results indicated that the higher starch gelatinization and lower starch crystallinity of E corn, induced by the high temperature and pressure, enabled more fermentation and digestion in the artificial rumen. The carbohydrate and protein molecular structures were correlated with the nutritional characteristics of corn.

Effect of waste mango silage on the in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics in calf diets

“…The average cumulative CH 4 production of the treatments represented 24.63% of the biogas produced ( Table-4 ). This production is due to the soluble carbohydrate content available for fermentation that produces VFA, CO 2 , and H 2 [ 24 ] and the fermentation of structural carbohydrates where acetic acid, CO 2 , and H 2 are produced [ 25 ]. Therefore, CO 2 and H 2 are substrates for the metabolism of methanogenic archaea, where CH 4 is the final product [ 26 ].…”

Physicochemical Changes of Heat-Treated Corn Grain Used in Ruminant Nutrition

“…This finding was also confirmed by Qiao et al [ 42 ]. In a study by Han, Guo, Cai, and Yang [ 24 ], 67.29% of corn starch gelatinized after steaming (100–110°C) the whole grain for 50 min, after which the moisture level was 21–23%. A smaller DG of sample SFC obtained in this study in comparison to available literature data was probably the result of a shorter grain conditioning time and lower temperature.…”

“…During extrusion, DG depends to a great extent on the given conditions, and according to Svihus et al [ 46 ], it is possible to achieve a gelatinization of only 40% of the starch by adjusting this treatment condition. In a study by Han, Guo, Cai, and Yang [ 24 ] and another by Moritz, Parsons, Buchanan, Calvalcanti, Cramer, and Beyer [ 44 ], the DG of extruded corn was 92%, while Medel, Salado, De Blas, and Mateos [ 43 ] recorded a slightly lower value of 76%. The complete gelatinization of the starch in sample EC is probably due to the larger shear forces and longer retention time of the material inside the extruder barrel under the given extrusion conditions [ 47 ].…”

“…The various processing treatments of animal feeds influence the rumen fermentation characteristics of grain starch, which in turn affect animal performance. Based on a review of the available literature, the most commonly studied treatments of corn used in ruminant nutrition are grinding, dry rolling, steam rolling, and steam flaking [ 4 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Studies covering pelleting [ 26 , 27 ], extrusion [ 24 , 28 , 29 , 30 ], and expansion [ 31 ] are available but to a much lesser extent than the above-mentioned treatments.…”

“…Based on a review of the available literature, the most commonly studied treatments of corn used in ruminant nutrition are grinding, dry rolling, steam rolling, and steam flaking [ 4 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Studies covering pelleting [ 26 , 27 ], extrusion [ 24 , 28 , 29 , 30 ], and expansion [ 31 ] are available but to a much lesser extent than the above-mentioned treatments. On the other hand, a detailed search of available studies revealed a lack of research regarding the nutritive value of micronized corn in ruminant nutrition.…”