Abstract

Twelve dairy cows in mid to late lactation were fed iso-nitrogenous diets (161 g CP/kg DM, forage concentrate ratio 65 35) where rolled barley and coarsely ground seeds from either narrow-leafed lupin or field pea supplemented grass-clover silage Feed allowance was individually restricted and fixed (18.8 +/- 0 6 kg dry matter/day) throughout the experiment to avoid refusals The experiment was of 2 x 2 change-over design and utilized a previous change-over experiment with 3 periods as covariate. Nitrogen balance was assessed by quantitative urine sampling and fecal spot sampling in eight cows whereas rumen metabolism was studied in four cannulated cows. Production of energy corrected milk was 243 kg/day with the lupin diet and 23.2 kg/day with the pea diet (P<0.05). Daily milk fat yield was also higher (P<0.05) with the lupin diet. Proportion of feed N excreted in milk did not differ between diets. Milk urea concentration, as well as the amounts of total urinary N and urinary urea were higher (P<0.05) for the lupin diet, while urinary N proportion of feed N only tended (P = 008) to be higher with the lupin diet. N balance was lower with the lupin diet. Digestibilities of organic matter, neutral detergent fiber and crude protein did not differ between diets and neither did ruminal pools of these constituents. In addition, there were no differences between the diets with respect to the ruminal concentrations of NH(3)-N and total volatile fatty acids, and only minor differences in ruminal pH and ruminal concentrations of iso-acids and alpha-amino-N It is concluded that the higher fat content in lupins compared to peas is an advantage in typical Scandinavian home-grown rations and probably explains the higher milk yield in this experiment. Differences in protein utilization between lupins and peas are of small magnitude when fed ground without thermal processing. In practical feeding, ad libitum forage allowance may create response differences between lupin seeds and peas not observed in this experiment. (C) 2010 Elsevier B.V All rights reserved

Keywords

Dairy cow; Nitrogen balance; Protein degradation, lupins; Peas

Published in

Livestock Science
2010, Volume: 131, number: 1, pages: 39-44
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Eriksson, Torsten

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

UKÄ Subject classification

Animal and Dairy Science
Veterinary Science


Publication identifier

DOI: https://doi.org/10.1016/j.livsci.2010.02.021

Permanent link to this page (URI)

https://res.slu.se/id/publ/60477