Abstract

A total of 44 dairy cows of the Swedish Red and White dual-purpose breed were divided into 4 equal groups. Two groups were fed concentrate containing approximately 19% crude protein (high level), while two groups were fed concentrate containing 14.3% crude protein (low level). The differences were obtained by mixing either 25 or 8% 00-rapeseed meal into a basic grain-dominated mixture. Within each protein level, one half of the cows were allotted untreated rapeseed meal and the other half heat-treated rapeseed meal. The heat treatment decreased the effective protein degradability of the rapeseed meal by 20 units from 72 to 52%.The experiment was commenced as a continuous experiment, where weeks 1-3 of the lactation were a preliminary period in which all cows received the same feeding. The experimental period covered lactation weeks 4-20. When the experiment was analysed, the results from the preliminary period were used as covariates.Significant treatment effects were reached both for level and degradability. This was mainly due to a significantly lower milk and protein production on the treatment URM - low protein level. This treatment also reached a significantly lower feed energy utilization and a higher fat percentage in milk. It was concluded that evaluating the protein according to the new Nordic AAT/PBV system correlated better to milk production than did crude protein or digestible crude protein.By using the AAT-PBV system it was possible to minimize the crude protein content in the concentrate without impairing milk production. A general conclusion is that there are benefits in the form of higher milk production and better feed utilization from decreasing protein degradability in rapeseed meal.

Keywords

AAT; PBV; NITROGEN; MILK PRODUCTION; FERTILITY; PROTEIN LEVEL

Published in

Acta Agriculturae Scandinavica, Section A - Animal Science
1994, Volume: 44, number: 4, pages: 222-229

SLU Authors

• Bertilsson, Jan

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

• Gonda, Horacio

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

• Lindberg, Jan Erik

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Animal and Dairy Science


Publication identifier

DOI: https://doi.org/10.1080/09064709409410902

Permanent link to this page (URI)

https://res.slu.se/id/publ/96527