title: Effects of corn and soybean meal types on rumen fermentation, nitrogen metabolism and productivity in dairy cows.
abstract: Twelve multiparous Holstein dairy cows in mid-lactation were selected for a replicated 4×4 Latin square design with a 2 ×2 factorial arrangement to investigate the effects of corn and soybean meal (SBM) types on rumen fermentation, N metabolism and lactation performance in dairy cows. Two types of corn (dry ground [DGC] and steam-flaked corn [SFC]) and two types of SBM (solvent-extracted and heat-treated SBM) with different ruminal degradation rates and extents were used to formulate four diets with the same basal ingredients. Each period lasted for 21 days, including 14 d for adaptation and 7 d for sample collection. Cows receiving SFC had a lower dry matter (DM) and total N intake than those fed DGC. However, the milk yield and milk protein yield were not influenced by the corn type, resulting in higher feed and N utilization efficiency in SFC-fed cows than those receiving DGC. Ruminal acetate concentrations was greater and total volatile fatty acids concentrations tended to be greater for cows receiving DGC relative to cows fed SFC, but milk fat content was not influenced by corn type. The SFC-fed cows had lower ruminal ammonia-N, less urea N in their blood and milk, and lower fecal N excretion than those on DGC. Compared with solvent-extracted SBM-fed cows, cows receiving heat-treated SBM had lower microbial protein yield in the rumen, but similar total tract apparent nutrient digestibility, N metabolism measurements, and productivity. Excessive supply of metabolizable protein in all diets may have caused the lack of difference in lactation performance between SBM types. Results of the present study indicated that increasing the energy degradability in the rumen could improve feed efficiency, and reduce environmental pollution.
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China ; Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China .
authors: J S
authors: JS
authors: Shen
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors: L J
authors: LJ
authors: Song
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors: H Z
authors: HZ
authors: Sun
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors: B
authors: B
authors: Wang
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Z
authors: Z
authors: Chai
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China ; Faculty of Veterinary and Animal Sciences, Lasbela University of Agriculture, Water and Marine Sciences, Uthal Balochitan 90150, Pakistan .
authors: B
authors: B
authors: Chacher
authors: Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors: J X
authors: JX
authors: Liu
keywords: Corn; Dairy Cow; Nitrogen Metabolism; Productivity; Soybean Meal
references: Animal. 2014 Feb;8(2):262-74
references: 24290203
references: J Dairy Sci. 2002 Jan;85(1):217-26
references: 11860114
references: J Dairy Sci. 1998 Mar;81(3):777-83
references: 9565881
references: J Anim Sci. 2008 Apr;86(14 Suppl):E287-92
references: 17965333
references: J Dairy Sci. 1992 Aug;75(8):2304-23
references: 1401380
references: J Anim Sci. 2006 May;84(5):1188-96
references: 16612021
references: J Dairy Sci. 1999 Aug;82(8):1779-90
references: 10480104
references: J Anim Sci. 1986 Nov;63(5):1607-23
references: 3539904
references: J Dairy Sci. 2013 Jan;96(1):533-50
references: 23164230
references: J Exp Bot. 2003 Jul;54(388):1721-30
references: 12754268
references: J Dairy Sci. 2007 Jun;90 Suppl 1:E76-86
references: 17517754
references: J Dairy Sci. 2008 Jul;91(7):2628-40
references: 18565922
references: J Physiol Pharmacol. 2005 Dec;56(4):689-98
references: 16391424
references: J Dairy Sci. 1997 Nov;80(11):2964-71
references: 9406089
references: J Dairy Sci. 2012 Oct;95(10):5978-84
references: 22921624
references: Clin Chem. 1962 Apr;8:130-2
references: 13878063
references: J Anim Sci. 1993 Sep;71(9):2516-28
references: 8407664
references: Clin Chim Acta. 1980 Oct 23;107(1-2):3-9
references: 7428175
references: J Dairy Sci. 1999 Dec;82(12):2686-96
references: 10629816
references: J Dairy Sci. 2010 Jul;93(7):3114-27
references: 20630229
references: Analyst. 1972 Feb;97(151):142-5
references: 5037807
references: J Dairy Sci. 2004 Aug;87(8):2546-53
references: 15328278
references: J Anim Sci. 1997 Mar;75(3):852-67
references: 9078506
references: J Dairy Sci. 2008 Jan;91(1):247-59
references: 18096947
references: J Dairy Sci. 2008 Oct;91(10):3931-7
references: 18832217
references: J Dairy Sci. 2002 Jan;85(1):148-59
references: 11862966
references: J Dairy Sci. 1991 Oct;74(10):3583-97
references: 1660498
references: J Dairy Sci. 2003 Mar;86(3):835-43
references: 12703620
references: Animal. 2010 Jul;4(7):1184-96
references: 22444616
references: J Dairy Sci. 2003 Dec;86(12):3972-82
references: 14740835
references: J Dairy Sci. 2006 May;89(5):1635-43
references: 16606733
references: J Dairy Sci. 2005 May;88 Suppl 1:E9-21
references: 15876575