Estimación de las curvas de lactancia en ganado Holstein y BON x Holstein en trópico alto colombiano
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Date
2008
Journal Title
Journal ISSN
Volume Title
Publisher
Corporación Universitaria Lasallista
Abstract
Introduction. Changes in milk production in a given
time can be graphically represented by using a
lactation curve, which allows the characterization of
the different production systems. Objective. To
estimate lactation curves in Holstein and BON x
Holstein cattle by using the Incomplete Gamma model
and explain the effects of the genetic group and of
some environmental factors on the coefficients of the
lactation curve. Materials and methods. 1835 milk
production records from the first and second lactations
of 23 cows were used. The effects of the race, the
birth and the time on the different coefficients
estimated from the Incomplete Gamma model and
other production and reproduction characteristics of
interest were determined. Results. Significant
differences among the racial groups were evident for
the following characteristics: Initial production, total
production, duration of the lactation period, milk
production at the peak and in the 33rd week,
production per day, post-peak slope, number of weeks with production above 15 litters, calving interval and
the milk production per day of calving interval
(P<0.05). In the calving interval there was a significant
difference in the characteristics: Initial production,
deceleration of the curve, peak milk production,
production per day, post-peak slope, persistence,
persistence percentage and number of weeks with a
production above 15 litters (P<0.05). Conclusion:
The coefficients estimated by using the Incomplete
Gamma model are highly influenced by the genetic
group, the number of births and, in a lower measure,
by the weather.
Description
Keywords
Corporación Universitaria Lasallista, Ganado lechero, Curva de lactancia, Ganado lechero - Cría y desarrollo, Ganado Holstein, Ganado Bon, Ganado lechero - Reproducción