Estimation of heterotic components for lactation traits and reproductive performance in three crossbreeding trials of Holstein cattle with German Friesian raised under hot climatic conditions

Abstract

Lactation traits and reproductive performance of three trials of crossing Holstein cattle (H) and German Friesians (F) raised in a hot climatic were evaluated. The first 90-day (M90), 305-day (M305) and total milk yield (TMY), 305-day milk yield per day of calving interval (MCI1), total milk yield per day of calving interval (MCI2) along with length of lactation period (LP), age at first calving (AC1) and calving interval (CI) were used. For these traits, a genetic model was applied for each trial separately to obtain estimates of individual (G I ) and maternal (G M ) additive effects, individual (H I ) and maternal (H M ) heterosis and individual recombination effect (R I ). Data of 8045 normal lactations from the three trials were analysed. Among the crossbreds obtained in the three trials, cows of 3 / 4 H 1 / 4 F ranked first in their lactational performance. Estimates of G I and G M were generally large and in favour of H cows (daughters) and dams for most milk-yield traits, CI and AC1 in the three trials. Estimates of H I in crossbred cows for milk traits, CI and AC1 were mostly negative and reveal that crossing F with H was associated with a reduction in milk-yield traits, shorter CI and earlier AC1 along with longer LP in the three trials. Estimates of H M for milk yields, LP, AC1 and CI in daughters of crossbred dams were mostly negative. Recombination losses in crossbred cows were negative for milk-yield traits, AC1 and CI in most cases. Zusammenfassung Schä tzung von Heterosiswirkungen in Merkmalen der Laktation und Fruchtbarkeit in 3 Kreuzungsversuchen zwischen Holstein Friesian und Dt. Schwarzbunten unter heißen klimatischen BedingungenEs wurden drei Versuche mit Kreuzungen zwischen Holstein (H) und deutschen Schwarzbunten (F) in heißem klima ausgewertet, wo 90 Tage (M90), 305 Tage (M305) und Gesamtmilchleistung (TMY), Tagesmilchleistung während des 303 Tage Intervalls (MCI1) und während der Zwischenkalbezeit, Länge der Laktationsperiode (LP), Erstkalbealter (AC1) und Zwischenkalbezeit (CI) untersucht worden sind. Es wurden geschätzt, fü r jeden Versuch separat, individuelle (G I ) und matennale (G M ) additive Wirkungen, individuelle (H I ) und maternale Heterosiswirkungen sowie individuelle Rekombinationswirkung (R I ). Daten von 8045 normalen Laktationen konnten analysiert werden. Rü ckkreuzungen zu H ( 3 / 4 H 1 / 4 F) zeigten unterKreuzungen die hö chsten Leistungen. Additive Wirkungen, individuelle und maternale, ware groß und zugunsten H fü r die meisten Leistungseigenschaften, individuelle Heterosis fü r diese und CI sowie AC1 meistens negativ, sodaß Kreuzungen von H und F nicht empfohlen werden. Dies resultierte in weniger Milch, kü rzeres CI und frü here AC1 mit längerem LP. Rekombinationsverlust war negativ fü r Milchleistung, AC1 und CI in den meisten Fällen. U.S.

Fit of Wood's function to daily milk records and estimation of environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crossbred dual purpose cattle

“…The estimate of recombination effects for TM for the H × BS cross was positive. This is consistent with several studies in the temperate (Grosshans et al, 1994;Wolf et al, 1995) and tropical regions (Khalil et al, 2000;Demeke et al, 2003) for B. taurus ×B. taurus crosses.…”

Estimates of genetic parameters for Boran, Friesian and crosses of Friesian and Jersey with the Boran cattle in the tropical highlands of Ethiopia: reproduction traits

“…Mackinnon et al 1996;Kahi et al 2000;Khalil et al 2000;Rutledge 2001). In most studies recombination losses were non-important as genetic factor for CI (e.g.…”

“…In most studies recombination losses were non-important as genetic factor for CI (e.g. Mackinnon et al 1996;Kahi et al 2000;Khalil et al 2000;Rutledge 2001). In the present study the results indicate that for F · B crosses about 2.9 ± 1.0 months delay in AFC could be attributed to the recombination losses.…”