Individual data for each operation can be found in Table 1. One farm utilized a two-year old and mature cow grouping strategy. The herd housed in freestalls had four groups of lactating cows, each being treated the same and containing cows of all ages. All herds used bST as a management tool. The average dry period for the six farms was 57 days with a range of 51 to 68.
Reproductive efficiency is always a challenge in high producing herds.
Average days to first AI was 84 days and ranged from 55 to 100. See Table 2. As indicated earlier, five of the six farms housed their lactating cows in tie stalls. Research indicates that the blood flow through a cow s udder increases by 25 to 50 percent while she is lying down as compared to standing. This increased blood flow results in increased milk production.