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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #79223
Title: EFFECT OF CORN SILAGE CHOP LENGTH ON INTAKE, MILK PRODUCTION, AND MILK COMPOSITION OF LACTATING DAIRY COWS

Author
item KUEHN, CARLA - UNIVERSITY OF MINNESOTA
item LINN, J - UNIVERSITY OF MINNESOTA
item Jung, Hans Joachim

Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Corn was harvested for silage with a theoretical chop length of .87 cm (L) or .32 cm (S). Approximately 6 tons of each was packed into a 25 cu m steel refuse container lined with plastic and allowed to ferment for 28 days. Average pH and temperature of the L and S silage during the feeding period was 4.36 and 4.14, and 35.7 and 31.1 degrees C, respectively. Experimental design was a 2 x 2 latin square (2 periods and 2 treatments) replicated across 4 blocks. Eight mid-lactation Holstein cows were assigned to blocks according to DIM and milk production. Prior to the start of the experiment, all cows received a diet consisting of 40% of the DM from a standard corn silage. A 7 d adjustment to treatment silage preceded a 4 d collection period for period 1 and a 5 d adjustment period preceded the 4 d collection for period 2. Treatment diets consisted of 40% of the DM as either L or S silage. Remaining dietary ingredients were constant across diets. Diets averaged, DM basis, 34.2% NDF, 15.7% ADF, and 16.0% CP and 34.7% NDF, 15.9% ADF, and 15.8% CP for L and S treatments, respectively. Data collection included DMI, milk production, and milk composition. Chewing activity was monitored at 5 min intervals for 24 h in each period. Intakes for the L or S did not differ for DM (25.4 vs. 26.3 kg/d, P=0.14) or NDF (8.7 vs. 9.1 kg/d, P=0.07). Milk production (29.6 vs. 29.1 kg/d), fat (1.2 vs. 1.2 kg/d), protein (1.0 vs. 1.0 kg/d), time spent chewing (431.3 vs. 426.9 min/d), and eating (272.5 vs. 275.6 min/d) did not differ for L and S diets. Rumen pH pre-feeding averaged 6.7 for both periods and dropped to 6.4 and 5.6 at 4-hr post-feeding for L and S, respectively. The shorter chopped corn silage tended to promote higher NDF intake but caused a greater drop in rumen pH.