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Effect of reduced energy density of close-up diet on ruminal fermentation parameters in multiparous Holstein cows

Wednesday, July 23, 2014: 10:30 AM
2103A (Kansas City Convention Center)
Wen-Ming Huang , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Amina Simayi , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Amingul Yasheng , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Zhao-Hai Wu , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Zhi-Jun Cao , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Sheng-Li Li , State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
Abstract Text:

The objective of this study was to determine the effect of reduced energy density of close-up diet on ruminal fermentation parameters in multiparous Holstein cows. Fourteen dry cows were utilized in a randomized block design. Cows were blocked by their milk production in the first 3 months of the previous parity, BW and expected calving date and assigned randomly into 1 of 3 energy levels (6.8, 6.2, 5.4 MJ of NEL/kg; 14.0 % CP) diets to meet 100% (100NRC; n = 4), 90% (90NRC; n = 5), 80% (80NRC; n = 5) of the NRC (2001) dietary NEL recommendation, respectively, from 21 d before expected day of calving. After parturition, all cows were fed the same lactation diet to 28 d in milk (DIM). Intake of DM (DMI) of individual cows was determined every day. Ruminal fluid was obtained at 1030 h on -21, -14, -7, 1, 3, 5, 7, 14, 21 and 28 d relative to parturition, and at 0830, 1030, 1230, 1430, 1630, 1830 h on 7 DIM, at 0930, 1130, 1330, 1530, 1730, 1930 h on 8 DIM. Data were analyzed by SPSS with repeated measures procedure. The reduced energy density diet decreased the average DMI prepartum (P < 0.05) and tended to increase the DMI postpartum (P = 0.08). The average ruminal pH of the 80NRC group was higher prepartum (6.88, 6.35, 6.44; P < 0.05) and lower (6.05, 6.21, 6.30; P < 0.05) during the first 4 wk of lactation compared with 90NRC and 100NRC groups. The 80NRC group had 3 sampling points of pH below 5.6 on 7 and 8 DIM, none for 90NRC and 100NRC groups. The reduced energy density diet depressed the average ruminal concentration of propionate (16.7, 17.9, 19.6 mmol/L; P = 0.04), tended to decrease butyrate (7.4, 9.4, 10.4 mmol/L; P = 0.06) prepartum, and increased the average concentration of total VFA (112.6, 95.8, 92.0 mmol/L; P < 0.001), and decreased the ratio of acetate to propionate (2.4, 2.3, 2.7; P= 0.03) during the first 4 wk of lactation. In conclusion, the cows fed reduced energy density diet prepartum had higher VFA concentration for energy metabolism but were more susceptible to subacute ruminal acidosis postpartum.

Keywords:

Holstein cow, dietary energy density, ruminal parameters

See more of: Ruminant Nutrition VII: Dairy Metabolism
See more of: Ruminant Nutrition
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