Crop Processing and Chop Length of Corn Silage: Effects on Intake, Digestion, and Milk Production by Dairy Cows

Abstract

Effects of corn silage crop processing and chop length on intake, digestion, and milk production were evaluated. Corn silage treatments were harvested at one-half milkline stage of maturity (65% whole-plant moisture content) and at 0.95-cm theoretical length of cut without processing (control) or 0.95-, 1.45-, or 1.90-cm theoretical length of cut with processing at a 1-mm roll clearance. Twenty-four multiparous Holstein cows averaging 71 d in milk at trial initiation were in a replicated 4 x 4 Latin square design with 28-d periods; one square was comprised of ruminally cannulated cows for rumen measurements. Corn silage treatments were fed in total mixed rations containing 50% forage (67% corn silage and 33% alfalfa silage) and 50% corn and soybean meal based concentrate (dry matter basis). Dry matter intake (25.9 vs. 25.3 kg/d) and milk (46.0 vs. 44.8 kg/ d) and fat (1.42 vs. 1.35 kg/d) yields were higher for the processed corn silage treatments compared with the control corn silage. Within the processed corn silage treatments, there were no chop length effects on intake, milk production, or milk composition. Chewing activity was not different among the four corn silage treatments averaging 12 h/d. Total tract digestion of dietary starch was lower for control corn silage (95.1%) compared with fine, medium, and coarse processed corn silage treatments, which averaged 99.3%. Total tract digestion of dietary NDF was reduced for fine-processed corn silage compared with control corn silage and coarse-processed corn silage (28.4% vs. 33.9 and 33.7%, respectively). Processing corn silage improved dry matter intake, starch digestion, and lactation performance. Under the conditions of this study and with theoretical lengths of cut ranging from 0.95 to 1.90 cm, length of chop effects were minimal in processed corn silage.

The effects of lucerne hay particle size on chewing activity and rumen fermentation in dry cows

“…This result was similar to previous study (Kononoff and Heinrichs, 2003) which suggested increasing the proportion of particles >19.0 mm may be a primary factor affecting chewing activity of dairy cattle. In the current study, reducing lucerne hay particle size did not signifi cantly affect total ruminating time, but signifi cantly reduced eating time, which was different from other reports (Bal and Shaver, 2000;Schwab and Shaver, 2002), it was possibly due to the greater differences of lucerne hay length. Present diets had the same sources and amount of NDF, and ingredients were same among different treatments.…”

Quantitative analysis of ruminal bacterial populations involved in lipid metabolism in dairy cows fed different vegetable oils

“…A quantity of 10 ml of residual ruminal fluid was immediately used to determine pH by using a pH meter (PP-201; GOnDO Electronic, Taipei, Taiwan), 10 ml were kept for NH 3 -N analysis (Bal et al, 2000) and another 10 ml were preserved for VFA determination by adding 1 ml of 25% metaphosphoric acid. Samples were frozen (−20°C) for later analysis.…”

The Effect of Corn Silage Particle Size and Cottonseed Hulls on Cows in Early Lactation

“…Positive effects on DMI with reduced particle size have been reported in some studies (Weigand et al, 1993;Stockdale and Beavis, 1994) but have not been observed in others (Schwab et al, 2002). In contrast, total-tract NDF digestibility has been observed to increase with increasing chop length (Bal et al, 2000), and as a result, interactive effects between fiber digestion and chop length may exist.…”