Effects of oestrous synchronization with altrenogest in gilts on endometrial and embryonic characteristics
G.M. Ravagnani,
C.H.G. Martinez,
R.F. Carnevale,
B.B.D. Muro,
M.V. Mendonça,
A.P.P. Pavaneli,
M.S. Passareli,
D.H. Nakasone,
R.F. Strefezzi,
S.M.M.K. Martins,
A.F.C. Andrade
Affiliations
G.M. Ravagnani
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
C.H.G. Martinez
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
R.F. Carnevale
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
B.B.D. Muro
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
M.V. Mendonça
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
A.P.P. Pavaneli
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
M.S. Passareli
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
D.H. Nakasone
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
R.F. Strefezzi
Faculty of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
S.M.M.K. Martins
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil; Faculty of Animal Science and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
A.F.C. Andrade
Swine Research Center, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Duque de Caxias Norte, 225, Pirassununga 13635-900, Brazil
The use of altrenogest (ALT) supplementation for oestrous synchronization improves subsequent reproductive performance of gilts and sows. However, the causes of this improvement in reproductive performance after ALT treatment are not fully/clearly understood. The objective of this study was to evaluate the effects of ALT supplementation for oestrous synchronization in gilts on the endometrial glands and embryonic development characteristics at 28 days of pregnancy. Pregnant gilts were divided into two experimental treatments: Control (did not receive ALT; n = 9 gilts) and ALT (ALT feeding at 20 mg/day for 18 days; n = 9 gilts). At 28 days of pregnancy, six gilts from each treatment were slaughtered, and reproductive tracts were immediately evaluated. There was no statistical difference (P > 0.05) between treatments regarding ovulation rate, number of embryos, number of vital embryos and number of non-vital embryos. Embryo weight, length and embryonic vesicle weight were lower in ALT treatment compared with Control (P < 0.01), and it was lower in the cervical uterine region compared with apex uterine region, respectively (P < 0.05). Higher values of gland duct area, gland duct perimeter, percentage of the glandular area and total endometrial area were observed in ALT treatment compared with Control (P < 0.05). The use of ALT during 18 days for oestrous synchronization in gilts increased the gland duct area, perimeter and total endometrial area but did not increase the embryo number and embryo size at day 28 of pregnancy.
