title: Crossbreds of Jersey x Holstein compared with pure Holsteins for body weight, body condition score, dry matter intake, and feed efficiency during the first one hundred fifty days of first lactation.
abstract: Jersey x Holstein crossbred (JxH) cows (n = 24) were compared with pure Holstein cows (n = 17) for body weight, body condition score, dry matter intake (DMI), and feed efficiency during the first 150 d of first lactation. Cows were housed in the University of Minnesota dairy facility at the St. Paul campus and calved from September 2004 to January 2005. The JxH cows were mated by artificial insemination with Montbeliarde bulls, and Holstein cows were mated by artificial insemination with Holstein bulls. Cows were weighed and body condition was scored every other week. Cows were individually fed a TMR twice daily, and feed refusals were measured once daily. The DMI of cows was measured daily and averaged across 7-d periods. Milk production and milk composition were from monthly Dairy Herd Improvement records. Best Prediction was used to calculate actual production (milk, fat, protein) for each cow from the 4th to 150th day of first lactation. The JxH cows had significantly less body weight (467 vs. 500 kg) and significantly higher body condition scores (2.90 vs. 2.76) than pure Holstein cows. The JxH cows had significantly less milk production (4,388 vs. 4,644 kg) during the 4th to 150th day of lactation than did pure Holstein cows. However, fat plus protein production during the first 150 d of lactation was not significantly different for JxH (302 kg) and Holstein (309 kg) cows. The JxH and pure Holstein cows did not differ significantly for daily DMI (22.0 vs. 22.7 kg, respectively), and the JxH (4.7%) and pure Holstein (4.5%) cows consumed similar DMI based on percentage of body weight. Consequently, feed efficiency for the 4th to 150th day of lactation did not differ for JxH and pure Holstein cows.
authors.affiliation: Department of Animal Science, University of Minnesota, St. Paul 55108, USA. hein0106@umn.edu
authors.forename: B J
authors.initials: BJ
authors.lastname: Heins
authors.forename: L B
authors.initials: LB
authors.lastname: Hansen
authors.forename: A J
authors.initials: AJ
authors.lastname: Seykora
authors.forename: A R
authors.initials: AR
authors.lastname: Hazel
authors.forename: D G
authors.initials: DG
authors.lastname: Johnson
authors.forename: J G
authors.initials: JG
authors.lastname: Linn