| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Kungsängen Research Centre, S-753 23 Uppsala, Sweden
Sixteen multiparous cows, including eight rumen fistulated cows, were used in a 4 x 4 Latin square experiment designed to study dietary effects on rumen and blood parameters and milk production in cows differing in genetic capacity for milk fat content. Diets contained forage to concentrate ratios of 50:50 or 30:70 with either grass hay or silage as the forage. Ruminal fermentation was characterized by a high molar percentage of buty-rate, 14 to 17%. Forage to concentrate ratio affected most rumen parameters, with the exception of the molar percentage of propionate (18 to 19%). The silage had a higher fiber degradation rate compared with hay. Compared to hay diets, silage diets had higher ruminal out-flow rates, lower acetate:propionate ratios, and greater milk production with no differences in milk composition. Cows selected for low milk fat had higher molar percentages of propionate in the rumen. The low milk fat cows had higher milk production than cows selected for high milk fat but did not differ in milk fat yield. Cows fed the 30:70 diets had higher plasma insulin concentrations in response to a glucose challenge. The low milk fat cows had lower basal concentrations of insulin and lower insulin responses to a glucose challenge. Small changes in nutrient metabolism and supply were sufficient to influence milk production.
Key Words: rumen fermentation • selection lines • milk fat • glucose challenge
Submitted on May 10, 1999
Accepted on October 20, 1999
This article has been cited by other articles:
|
|
 |
|
  E. Vargas-Bello-Perez, A. F. Mustafa, and P. Seguin Effects of Feeding Forage Soybean Silage on Milk Production, Nutrient Digestion, and Ruminal Fermentation of Lactating Dairy Cows J Dairy Sci, January 1, 2008; 91(1): 229 - 235. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. B. Kristensen, J. Sehested, S. K. Jensen, and M. Vestergaard Effect of Milk Allowance on Concentrate Intake, Ruminal Environment, and Ruminal Development in Milk-Fed Holstein Calves J Dairy Sci, September 1, 2007; 90(9): 4346 - 4355. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Moorby, R. J. Dewhurst, R. T. Evans, and J. L. Danelon Effects of dairy cow diet forage proportion on duodenal nutrient supply and urinary purine derivative excretion. J Dairy Sci, September 1, 2006; 89(9): 3552 - 3562. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. O. Odensten, Y. Chilliard, and K. Holtenius Effects of Two Different Feeding Strategies During Dry-Off on Metabolism in High-Yielding Dairy Cows J Dairy Sci, June 1, 2005; 88(6): 2072 - 2082. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Eriksson, M. Murphy, P. Ciszuk, and E. Burstedt Nitrogen Balance, Microbial Protein Production, and Milk Production in Dairy Cows Fed Fodder Beets and Potatoes, or Barley J Dairy Sci, April 1, 2004; 87(4): 1057 - 1070. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
