Response of Dairy Cows in Early Lactation to Additions of Cottonseed Meal in Alfalfa-Based Diets

¹ Department of Animal Science, University of Idaho, Moscow 83843

The effect of increasing CP levels by additions of cottonseed meal to diets for early lactation was studied in 24 multiparous Holstein cows. Diets containing 13.8, 17.5, 20.4, and 23.9% CP were fed during three 3-wk periods beginning at wk 4 postpartum. Each cow received three of the four dietary treatments giving 18 observations per treatment in a randomized complete block design. Undegraded intake protein as a fraction of total protein for the diets was .25, .32, .36, and .39. Dry matter intake increased linearly with increasing dietary CP concentrations. Daily milk yield increased as dietary CP increased from 13.8 to 17.5%. Increased milk yield was accompanied by increased daily yields of milk fat and protein, but the concentration of these components in milk was not altered. The proportion of total milk N that was NPN increased linearly with increasing dietary CP level. Plasma amino acids and urea N were increased by increasing the dietary CP level. The conclusions of the study were that increasing dietary CP levels from 13.8 to 17.5% by the use of cottonseed meal was beneficial to cows consuming alfalfa-based diets in early lactation. Increasing dietary CP above 17.5% showed little benefit in milk yield. Increasing dietary protein caused an increase in blood urea N and milk NPN, indicating N wastage by the animal.

Key Words: cottonseed meal • protein • dairy cows

Submitted on November 19, 1990
Accepted on February 19, 1991

This article has been cited by other articles:

				S. I. Borucki Castro, L. E. Phillip, H. Lapierre, P. W. Jardon, and R. Berthiaume The Relative Merit of Ruminal Undegradable Protein from Soybean Meal or Soluble Fiber from Beet Pulp to Improve Nitrogen Utilization in Dairy Cows J Dairy Sci, October 1, 2008; 91(10): 3947 - 3957. [Abstract] [Full Text] [PDF]