Lupin-Pea-Cereal Mixture or Cereals as Supplements for Organic Dairy Cows

Abstract

ABSTRACT The present study was conducted to examine whether organic cows fed a concentrate mixture based on cereal grains (treatment C) could maintain the same feed intake and performance as cows fed a concentrate mixture rich in protein and energy (lupins and peas) (treatment P). Forage consisted of grass-clover silage, maize silage and hay and was offered on an ad libitum basis. The trial was carried out as a change-over design and lasted for 16 weeks. Intake of concentrates, dry matter (DM), neutral detergent fibre (NDF), energy and utilizable crude protein in the duodenum (uCP) were similar in both treatments. However, significant differences between treatments were found for daily forage dry matter intake (DMI) (13.4 vs. 13.1 kg in treatment C and P, respectively), daily crude protein (CP) intake (2454 vs. 2681 g) and the daily ruminai nitrogen balance (RNB) (4 vs. 35 g). Milk yield was not affected by treatment, but in treatment C, milk protein content was significantly higher at 29.1 g kg−1, and milk urea concentration significantly lower at 17 mg 100 ml−1 than with treatment P. Efficiency of N use (N in milk as % of N intake) was improved in treatment C as compared to treatment P (28 vs. 26%). Balances of energy and uCP (intake as a percentage of estimated requirements) tended to be closer to zero in treatment C than in treatment P.