Efecto del destete precoz de terneras sobre su fertilidad, en sistemas de carne con entore a los dos años
The reproductive performance of crossbred heifers at first mating wether they were early weaned at calves (DP, 60-90 days, n=706) or grown with their mothers and weaned normally at 5-7 months old (DT, n=35) was evaluated. The research was conducted in three farms in the north of Córdoba province (Ar...
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Published in | Archivos latinoamericanos de producción animal Vol. 16; no. 1; pp. 13 - 17 |
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Main Authors | , , , |
Format | Journal Article |
Language | Spanish |
Published |
Asociación Latinoamericana de Producción Animal
2008
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Subjects | |
Online Access | Get full text |
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Summary: | The reproductive performance of crossbred heifers at first mating wether they were early
weaned at calves (DP, 60-90 days, n=706) or grown with their mothers and weaned normally at 5-7 months old
(DT, n=35) was evaluated. The research was conducted in three farms in the north of Córdoba province
(Argentina). Calves heifers with DP were fed in a pen with a commercial concentrate (18% PB) and hay of
Panicum maximun (9% PB) until day 60. They grazed in a pasture either of Panicum maximun ( cv.Gatton) and
Cloris gayana (grama rodes), or Cencrhus ciliaris (cv.Texas) depending on the farm, until the moment of the
conventional weaning in the control group. Age and initial weight was taken (ranges 63-97 days, and 59,0-
99,0 kg respectivelly) and weight at 180 days (ranges 128-195k y 143-191k en DP y DT respectivelly). Heifer
rearing continued grazing deferred C4 grasses trough winter and spring; they stayed at the same pastures
during graze regrowth in summer and again on deferred material until next spring, with ureic-mineral suplement.
Prior to maiting (24-26mo.) heifers were reproductivelly scored. Those with score ³3 were mated during 75 days
(3.5% bulls) (78.4% group DP and 74.3% of DT). No relationship were found between reproductive scoring
(p=0.558) or pregnancy rate (p=0.863) and weaning treatment. Neither were found any association between
weaning groups and reproductive scoring or pregnancy rates when actual DP and DTPr (DT of previous
breeding year) were compared (p=0.432 and p=0.854 respectivelly). In conclusion the DP do not affect the
reproductive maturity Se evaluó la eficiencia reproductiva del primer servicio de vaquillonas cruzas Bos indicus
destetadas precozmente (DP, 60-90 días, n=706) o a los 6 meses de edad (DT, n=35). Se trabajó en tres establecimientos
del norte de la Provincia de Córdoba (Argentina). Las terneras con DP permanecieron en corral con
un concentrado comercial (18%PB) y heno de Panicum maximun (9%PB) hasta día 60. Luego fueron a pastoreo
de Panicum maximun (cv.Gatton) y Cloris gayana (grama rodes), o Cencrhus ciliaris (cv.Texas) según establecimiento,
hasta el momento del destete tradicional del lote testigo. Se controló edad (rango: 63-97 días) y peso
inicial (rango 59-99 kg) de todas las terneras, y peso a los 180 días (rango 128-195 y 143-191 kg en DP y DT
respectivamente). La recría continuó en pastoreo sobre megatérmicas diferidas, hasta inicio de primavera;
rebrotes de las mismas con las precipitaciones primavero-estivales y nuevamente material diferido hasta la
primavera siguiente, con mezcla mineral ureica. Previo al entore (24-26meses de edad) se calificaron
reproductivamente, dándose servicio natural durante 75 días sólo a las hembras con calificación ³3 (78.4% del grupo DP y 74,3% de DT). No hubo asociación entre calificaciones reproductivas (p=.558) o resultados de
preñez (p=.863) y tipo de destete. Tampoco se observó asociación entre tipo de destete y calificaciones
reproductivas o porcentajes de preñez, analizando DTPr (DT del servicio del año anterior) y DP actual (p=.432
y p=.854 respectivamente). Se concluye que el DP no afecta la performance reproductiva de hembras cruzas
índicas, criadas en condiciones semi-extensivas y entoradas a los dos años de edad. |
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ISSN: | 1022-1301 |