That's what new research using data from the USDA National Dairy Database is showing. Since 1995, the database has collected a multitude of reproductive statistics on Holstein and Jersey herds throughout the United States. This information allows trends to be seen over time relating to reproductive performance.
    
The following parameters have been measured over nearly 200 million breedings in more than eight million lactations of more than five million cows in 23,000 herds:

  • Days to first breeding after calving
  • 70-day nonreturn rate
  • Conception rate
  • Number of breedings per lactation
  • Interval between first and last breeding during the lactation
  • Days to last breeding after calving
  • Pregnancy Rate
  • Calving interval
  • Interval between consecutive breedings

Research published in the July 2009 Journal of Dairy Science compared reproductive figures today with those from 10 years ago. A few statistics to highlight include:

  • Days to first breeding declined from 92 days to 85 days in Holsteins from 1996 to 2007.
  • First- and all-breeding 70-day nonreturn rate declined five to nine percentage units.
  • The number of breedings increased slightly over time but remained constant across parities for Holsteins; this figure increased for Jerseys.
  • Average pregnancy rate was highest in the Southwest at 28.3 percent; the lowest was in the Midwest and Southeast at 22.2 percent.

Researchers concluded the use of Timed Artificial Insemination has reduced days to first breeding, lowered conception rate and increased the number of breedings while reducing days to last breeding and calving interval. Since 2002, performance in multiple reproductive areas has improved, reversing the historical decline.
     
Read more.