RT Journal Article T1 The use of crossbreeding with beef bulls in dairy herds: effects on calving difficulty and gestation length A1 Fouz Dopacio, Ramiro A1 Gandoy, Fernando A1 Sanjuán Hernán-Pérez, María Luisa A1 Yus Respaldiza, Eduardo A1 Diéguez Casalta, Javier K1 Crossbreeding K1 Dairy K1 Calving difficulty K1 Gestation length K1 Stillbirths AB This study was designed to analyse the evolution in the use of beef bull semen for dairy cattle insemination and, mainly, to assess calving difficulty, gestation length and proportion of stillbirths after breeding pure Holsteins or crossbreeding. Data were collected during 2004 to 2011 for 552 571 Holstein calvings (457 070 Holstein × Holstein, 43 384 Holstein × Limousine, 32 174 Holstein × Belgian Blue and 19 943 Holstein × Galician Blonde). The highest calving difficulty, compared with pure Holsteins was for crosses with Belgian Blue followed by Limousine and Galician Blonde. The Holstein × Limousine and Holstein × Galician Blonde crossbred calves had significantly longer gestation lengths than Holstein × Holstein and Holstein × Belgian Blue calves. Between the latter two, pure Holstein had the shortest gestation length. Calving difficulty and gestation length decreased as the age of the dam advanced. The most difficult calvings were observed in twin calvings, followed by the calvings of male calves and female calves. The gestations leading to the birth of male calves were longer than those leading to female calves and twin calves. Stillbirths were not related to the breed used for mating. Through examining these parameters, sire breed should be considered when selecting a beef breed for the insemination of milk-producing dams PB Elsevier SN 1751-7311 YR 2013 FD 2013 LK http://hdl.handle.net/10347/24278 UL http://hdl.handle.net/10347/24278 LA eng NO Animal, Volume 7, Issue 2, 2013, Pages 211-215 DS Minerva RD 24 abr 2026