home    about    browse    search    latest    help 
Login | Create Account

Feed nitrogen conversion in lactating dairy cows on pasture as affected by concentrate supplementation

Steinshamn, Håvard; Höglind, Mats; Garmo, Torstein H; Thuen, Erling and Brenøe, Ulrik Tutein (2006) Feed nitrogen conversion in lactating dairy cows on pasture as affected by concentrate supplementation. Animal Feed Science and Technology, 131, pp. 25-41.

[img] PDF
Limited to [Depositor and staff only]

253Kb

Summary

The effect of concentrate supplementation on nitrogen (N) intake and excretion in grazing lactating dairy cows was determined in three herds in Norway. Grazing trials were conducted with each herd in June and August for two consecutive years. The average supplementation was 1.8 (S.D. 2.1) kg DM/day, and the concentrate was based on grain with a N content ranging from 18.7 to 24 g/kg DM. Herbage DM and N intake were reduced with increasing supplementation, but total DM and N intake increased. Milk yield and protein content increased by 1.1 kg milk and 0.28 g protein per kg milk for each kg extra concentrate. Milk N excretion increased with increasing supplementation (6.5 g N/kg DM), and N utilisation improved by 11.7 g N per kg N intake per kg extra concentrate. Excretion of urine N and its share of total excreta N decreased by 4.0 and 9.2 g/kg concentrate, respectively. The reducing effect on urine N excretion of supplementation was, however, numerically low compared with other studies, most likely due to a high crude protein content of the concentrate used.


EPrint Type:Journal paper
Keywords:Dairy cattle; Concentrate; Nitrogen excretion; Nitrogen efficiency; Grazing; Milk production
Subjects: Animal husbandry > Production systems > Dairy cattle
Environmental aspects > Air and water emissions
Animal husbandry > Feeding and growth
Research affiliation: Norway > Bioforsk - Norwegian Institute for Agriculture and Environmental Research > Bioforsk Horticulture and Urban Greening Division
Norway > UMB - Norwegian University of Life Sciences
Norway > Bioforsk - Norwegian Institute for Agriculture and Environmental Research > Bioforsk Organic Food and Farming Division
Deposited By: Steinshamn, Dr Håvard
ID Code:10651
Deposited On:03 Apr 2007
Last Modified:12 Apr 2010 07:35
Document Language:English
Status:Published
Refereed:Peer-reviewed and accepted
Additional Publishing Information:Results from one of the three herds used in this publication were from an organically managed dairy herd

Repository Staff Only: item control page