Effect of an energy supplementation, weaning and oestrous synchronisation on ovarian activity and ovulation in early postpartum primiparous Bos indicus cows raised in the tropics of Costa Rica
Por:
Galindo, J., Estrada, S., Galina, C. S., Molina, R., Contreras, D. A., Maquivar, M.
Publicada:
1 ene 2016
Resumen:
To evaluate the effect of an energy supplementation, 26 postpartum Bos
indicus cows were assigned either to receive an energy diet
supplementation (n = 11, SSD) or no supplementation (n = 15, NSSD). Cows
in the SSD treatment received a diet consisting of 5.5% crude protein,
2.85 Mcal digestible energy per head per day, at 1% ratio of the
average bodyweight, started 23.5 +/- 3.4 days after calving and
continued for 44 days. In contrast, NSSD cows were grazing only native
pastures during the experiment. All cows were synchronised at 65 days
postpartum with a subcutaneous progestin ear implant (Norgestomet) for 9
days and an injection of oestradiol valerate and Norgestomet at the same
time as implant placement. A random sample of six animals from each
treatment was scanned with ultrasound every 6 h and the dominant
follicle (s) was measured until ovulation occurred or after 114 h. The
nadir of body condition score for the NSSD was observed at 37.5 +/- 3.4
days postpartum, while SSD was at 22.3 +/- 7.9 days (P < 0.01); no
differences (P > 0.05) in dorsal backfat thickness or average bodyweight
between treatments were observed. During the ultrasound-scanning period,
four of six cows ovulated in the SSD treatment and five of six in the
NSSD. No difference (P > 0.05) was observed at the time of ovulation
after progestin implant withdrawal (55.8 +/- 7.8 h in NSSD vs 94.5 +/-
21.7 h in SSD). The largest follicle diameter at the beginning of the
scanning was in SSD treatment (7.25 +/- 1.4 mm in SSD vs 5.0 +/- 0.8 mm
in NSSD), whereas at the time of ovulation, it was similar (15.2 +/- 1.8
mm in SSD vs 11.0 +/- 1.4 mm in NSSD) between the treatments (P > 0.05).
The resumption of ovarian activity was similar between SSD (69 +/- 20.7
days, ranging from 42 to 83 days) and NSSD (69.8 +/- 6.4 days, ranging
from 59 to 73 days). The length of postpartum anoestrus was influenced
by the onset of the nadir of body condition score. Energy diet
supplementation did not influence the onset of ovarian activity.
Filiaciones:
Galindo, J.:
Inst Tecnol Costa Rica, Escuela Agron, San Carlos 21001, Alajuela, Costa Rica
Estrada, S.:
Univ Nacl, Programa Prod Anim Sostenible, Postgrad Reg Ciencias Vet Trop, Salud Hato,Escuela Med Vet, Heredia, Costa Rica
Galina, C. S.:
Univ Nacl Autonoma Mexico, Fac Med Vet & Zootecnia, Dept Reprod, Mexico City 04510, DF, Mexico
Molina, R.:
Inst Tecnol Costa Rica, Escuela Agron, San Carlos 21001, Alajuela, Costa Rica
Contreras, D. A.:
Univ Nacl Autonoma Mexico, Fac Med Vet & Zootecnia, Dept Reprod, Mexico City 04510, DF, Mexico
Maquivar, M.:
Washington State Univ, Dept Anim Sci, Pullman, WA 99164 USA
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