Reproductive performance of postpartum ewes treated with insulin or progesterone hormones in association with ram effect.
The reproductive performance of postpartum Santa Inês (SI) and Morada Nova (MN) ewes treated with insulin or progesterone hormones in association with ram effect was evaluated. Ewes from SI (n = 69) and MN (n = 69) breeds were randomly allocated to three groups of each breed (T1-ram effect only; T2-ram effect + insulin; T3-ram effect + progesterone). Progesterone concentrations (ηg/ml; mean ± SD) before and after introduction of rams (n = 6) were 0.51 ± 0.22 and 3.78 ± 0.68 (T1), 0.65 ± 0.21 and 3.77 ± 0.78 (T2) and 0.52 ± 0.21 and 3.84 ± 0.84 (T3) in SI ewes and 0.74 ± 0.19 and 3.71 ± 0.56 (T1), 0.70 ± 0.21 and 3.79 ± 0.75 (T2) and 0.81 ± 0.14 and 3.87 ± 0.80 (T3) in MN ewes, respectively. Thus, lower progesterone concentrations were found before the introduction of rams (p < .05). After the introduction of rams, preovulatory peaks of LH (ηg/ml) occurred at 28 (T1), 44 (T2) and 48 (T3) hr in SI ewes and at 64 (T1), 40 (T2) and 44 (T3) hr in MN ewes. The mean number of ovulations was similar between groups (p > .05), was 1.3 ± 0.51 (T1), 1.5 ± 0.54 (T2) and 1.6 ± 0.51 (T3) in SI ewes and 1.3 ± 0.51 (T1), 1.6 ± 0.51 (T2) and 1.6 ± 0.51 (T3) in MN ewes. In conclusion, the ram effect alone is effective at inducing and synchronizing oestrus in sheep under postpartum anoestrus, irrespective of hormone treatments.
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
J C
http://orcid.org/0000-0003-3544-3859
JC
Ferreira-Silva
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
Srl
S
Basto
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
F
F
Tenório Filho
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
M T
MT
Moura
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
M L
ML
Silva Filho
Laboratory of Reproductive Biotechniques, Department of Veterinary Medicine, University Federal Rural de Pernambuco, Recife, Brazil.
Mal
M
Oliveira
D000780:Anestrus / Q000187:drug effects; D000818:Animals; D004973:Estrus Synchronization / Q000187:drug effects / Q000502:physiology; D005260:Female; D007328:Insulin / Q000627:therapeutic use*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D049590:Postpartum Period / Q000187:drug effects; D011247:Pregnancy; D011374:Progesterone / Q000627:therapeutic use*; D012756:Sheep
D007328:Insulin; D011374:Progesterone; D007986:Luteinizing Hormone

LH
; P4; insulin; male effect; ovulation; pregnancy; prolificacy