Short communication: Jersey × Holstein crossbreds compared with pure Holsteins for body weight, body condition score, fertility, and survival during the first three lactations.
Crossbred cows (n=80) resulting from the use of Jersey (JE) semen on their pure Holstein (HO) dams were compared with pure HO cows (n=77) for body weight, body condition score, fertility, and survival during their first 3 lactations. Cows were in 2 research herds of the University of Minnesota and calved from September 2003 to June 2008. The JE × HO crossbred cows had significantly less body weight during the first (-56 kg), second (-67 kg), and third (-82 kg) lactations than pure HO cows. However, JE × HO cows had significantly greater body condition score during the first (2.94 vs. 2.84), second (2.97 vs. 2.84), and third (2.99 vs. 2.87) lactations than pure HO cows. For fertility, JE × HO cows had fewer days to first breeding during the first (-10.6d), second (-8.4d), and third (-12.3d) lactations than pure HO cows. Crossbred cows were not significantly different from pure HO cows for number of services during first lactation; however, JE × HO cows had significantly fewer services (2.2) than pure HO cows (2.7) during the second lactation. Also, JE × HO cows had significantly fewer days open than pure HO cows in the first (-24 d), second (-42 d), and third (-42 d) lactations. For survival, JE × HO cows were not significantly different from pure HO cows for percentage of cows calving a second time; however, a tendency existed for a higher percentage of JE × HO cows (63.8%) than pure HO cows (49.4%) to calve a third time, and a higher percentage of JE × HO cows calved a third time within 28, 34, and 40 mo of first calving than pure HO cows.
Department of Animal Science, University of Minnesota, St. Paul 55108, USA. hein0106@umn.edu
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Heins
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Hansen
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Hazel
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Seykora
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Johnson
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Linn
D000818:Animals; D001824:Body Constitution / Q000235:genetics / Q000502:physiology; D001835:Body Weight / Q000235:genetics*; D002417:Cattle / Q000235:genetics* / Q000502:physiology; D005260:Female; D005298:Fertility / Q000235:genetics*; D006824:Hybridization, Genetic / Q000235:genetics / Q000502:physiology; D007774:Lactation / Q000235:genetics*; D008297:Male; D011247:Pregnancy