The effects of low vs. high concentrate level in the diet on performance in cows milked two or three times daily in early lactation

The effect of concentrate:forage ratio in the diet and milking frequency on performance was investigated in a 2 X 2 factorial block design comprising 40 Danish-Holstein dairy cows from parturition to week 16 of lactation. One factor was concentrate level, either low (L 25% concentrate) or high (H: 75% concentrate), in an ad libitum fed total mixed ration. The second factor was milking frequency, either two or three times daily milking during the first 8 weeks of lactation. From weeks 9 to 16 of lactation, all cows were milked twice daily. During weeks 0 to 8, the cows receiving diet H had a 4.2 units higher net energy intake (Scandinavian feed units), and a 15% higher milk yield compared with the cows receiving diet L. The cows being milked three times a day had an 8% higher daily milk yield, without an increase in DMI, than the cows milked twice a day. In the period from weeks 0 to 8 of lactation, the cows that were fed diet L and milked three times daily mobilised 70 kg, which was I I to 18 kg more than in the other experimental groups. During weeks 9 to 16 of lactation, the cows receiving diet H maintained a higher feed intake and milk yield similar to that observed in the first 8 weeks of lactation. No positive carry-over effect was seen by changing from three to two milkings a day in early lactation. In conclusion, it seems that cows with high milk yield, achieved by increasing the milking frequency, will benefit from a high concentrate level in the diet. (C) 2002 Elsevier Science B.V. All rights reserved.