One Group Versus Two Group System for Lactating Cows Fed Complete Rations

Allocation of feed based on individual dairy cow live weight changes

“…Compared to the present experiment, there was no indication that ration energy concentration was reduced to a markedly higher extent or that milk yield of the cows was higher in the experiments of Everson et al (1976), Smith et al (1978) and Spahr et al (1993). The different response in milk yield to reduction of ration energy concentration in their experiments compared to the present experiment is therefore likely to be related to differences in lactation stage at the time of reducing ration energy concentration.…”

“…The different response in milk yield to reduction of ration energy concentration in their experiments compared to the present experiment is therefore likely to be related to differences in lactation stage at the time of reducing ration energy concentration. In the present experiment ration energy concentration was reduced 87± 19, and 114 ± 38 days after parturition for primiparous cows and 75± 5 and 109 ± 43 day after parturition for multiparous cows, when offered the MR2-E and MR2-L strategy, respectively (Bossen et al, 2009), and it was earlier than in the experiments of Everson et al (1976), Smith et al (1978) and Spahr et al (1993). In the experiment of Everson et al (1976) cows entered positive energy balance (deposition period) approximately 7 weeks after parturition, and had an average weight gain of more than 20 kg when ration energy concentration was reduced during lactation week 21.…”

“…The results obtained for the DH suggest that this way of reducing ration energy concentration can be accomplished without the long-term damaging effect on daily milk yield observed in several other experiments (e.g. Everson et al, 1976;Smith et al, 1978;Spahr et al, 1993).…”

“…However, several experiments were found where a specific time relative to parturition or milk yield were used to assess the time for reducing ration energy concentration (e.g. Smith et al, 1978;Cassel et al, 1984;Kroll et al, 1986). Results from these experiments indicate, that the positive effect of high energy rations in early lactation was counterbalanced by reduced milk yield persistency when ration energy concentration was reduced.…”

Protein Levels in Grass Silage-Based Total Mixed Rations for Dairy Cows in Midlactation

“…This aspect has presented practical problems for many of the smaller dairy herds in Eastern Canada. In meeting the protein requirements of a specific production group, the level ofprotein in the ration as well as the level of intake under ad libitum feeding conditions must be established (Smith et al 1978). Underfeeding of protein will reduce milk yields while overfeeding reduces production efficiency and increases costs (Keys et al 1983;Lamb et al 1974).…”