| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Dairy Science, University of Wisconsin, Madison 53706-1284
Corresponding author: R. R. Grummer; e-mail: rgrummer{at}facstaff.wisc.edu.
The objective of this study was to determine if the length of chop of processed corn silage influences the impact of supplemental fat on rumen fermentation and performance of dairy cows. We hypothesized that increasing forage particle length may alleviate the interference of fat on rumen fermentation. Sixteen Holstein cows averaging 120 d in milk were used in a replicated 4 x 4 Latin square design with 21-d periods. Treatments were arranged as a 2 x 2 factorial with 0 or 2% tallow (dry matter basis), and corn silage harvested at either 19 or 32 mm theoretical length of cut. The forage:concentrate ratio was 50:50, and diets were formulated to contain 18% crude protein and 32% neutral detergent fiber (dry matter basis). Cows were allowed ad libitum consumption of diets that were fed twice daily as a total mixed ration. Fat supplemented cows had lower dry matter intake and produced less milk fat relative to nonsupplemented cows. No effect of corn silage particle length was observed for dry matter intake and milk fat production. Proportion of trans-10 C18:1 and of trans-10, cis-12 conjugated linoleic acid was highest in milk fat of cows fed 2% supplemental tallow. Rumen pH was not affected by feeding tallow, and tended to be highest for cows eating the 32-mm theoretical length of chop corn silage diets. No effect of treatments was observed for rumen acetate-to-propionate ratio or rumen ammonia concentration. In this study, tallow supplementation had a negative impact on performance of dairy cows regardless of the corn silage particle length. Feeding tallow increased formation of trans-fatty acids in the rumen in the absence of significant changes in the rumen environment.
Key Words: corn silage • milk fat • particle size • tallow
Abbreviation key: CLA = conjugated linoleic acid, FA = fatty acid, MFD = milk fat depression, TLC = theoretical length of chop
This article has been cited by other articles:
|
|
 |
|
  Q. Zebeli, J. Dijkstra, M. Tafaj, H. Steingass, B. N. Ametaj, and W. Drochner Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet J Dairy Sci, May 1, 2008; 91(5): 2046 - 2066. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Z. Yang and K. A. Beauchemin Physically effective fiber: method of determination and effects on chewing, ruminal acidosis, and digestion by dairy cows. J Dairy Sci, July 1, 2006; 89(7): 2618 - 2633. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Zebeli, M. Tafaj, H. Steingass, B. Metzler, and W. Drochner Effects of Physically Effective Fiber on Digestive Processes and Milk Fat Content in Early Lactating Dairy Cows Fed Total Mixed Rations J Dairy Sci, February 1, 2006; 89(2): 651 - 668. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. W. Soita, M. Fehr, D. A Christensen, and T. Mutsvangwa Effects of Corn Silage Particle Length and Forage:Concentrate Ratio on Milk Fatty Acid Composition in Dairy Cows Fed Supplemental Flaxseed J Dairy Sci, August 1, 2005; 88(8): 2813 - 2819. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. L. Palmquist, N. St-Pierre, and K. E. McClure Tissue Fatty Acid Profiles Can Be Used to Quantify Endogenous Rumenic Acid Synthesis in Lambs J. Nutr., September 1, 2004; 134(9): 2407 - 2414. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. G. Onetti, S. M. Reynal, and R. R. Grummer Effect of Alfalfa Forage Preservation Method and Particle Length on Performance of Dairy Cows Fed Corn Silage-Based Diets and Tallow J Dairy Sci, March 1, 2004; 87(3): 652 - 664. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
