Doizé F, Vaillancourt D, Carabin H, Bélanger D
Department of Clinical Sciences Faculty of Veterinary Medicine, University of Montréal Saint-Hyacinthe Québec J2S 7C6, Canada.
Theriogenology. 1997 Aug;48(3):449-60. doi: 10.1016/s0093-691x(97)00254-9.
Three experiments were conducted to determine gestational age in the ewe and doe by measuring placentomes with a B-mode ultrasonograph and a 5 MHz transducer. Transrectal measurements were obtained by placing the female over a bale of hay. In Experiment 1, ewes (n = 12) and does (n = 15) were examined by transrectal ultrasonography every week from breeding to parturition to determine the growth pattern of placentomes during pregnancy. In Experiment 2, placentomes from 132 ewes and 169 does were measured between 30 and 90 d of gestation. A linear regression relationship between fetal age in days and placentome size in mm was calculated and adjusted for does (gestational age = 28.74 + 1.80PL + e, r(2) = 70.34) and for ewes (age = 47.98 + 0.62PL + e, r(2) = 15.59). In Experiment 3, the placentomes of 63 does were measured to validate this relationship by using linear regression. Gestational age was determined correctly in 66% of the does, with a range of +/- 7 d and in 96% with a margin of +/- 14 d. In conclusion, transrectal ultrasonography allowed for the measurement of placentome size, which increased rapidly during the first 70 to 90 d of gestation in ewes and does. In ewes, however, there was a poor correlation of placentome size with gestational age, while in goats, measurement of placentomes could be used along with pregnancy diagnosis by transrectal ultrasonography as an indication of gestation age.
进行了三项实验，通过使用B型超声仪和5兆赫换能器测量胎盘小叶来确定母羊和母鹿的妊娠年龄。将雌性动物放在一捆干草上进行经直肠测量。在实验1中，从配种到分娩每周对母羊（n = 12）和母鹿（n = 15）进行经直肠超声检查，以确定妊娠期间胎盘小叶的生长模式。在实验2中，在妊娠30至90天期间测量了132只母羊和169只母鹿的胎盘小叶。计算了以天为单位的胎龄与以毫米为单位的胎盘小叶大小之间的线性回归关系，并针对母鹿（妊娠年龄= 28.74 + 1.80PL + e，r² = 70.34）和母羊（年龄= 47.98 + 0.62PL + e，r² = 15.59）进行了调整。在实验3中，测量了63只母鹿的胎盘小叶，通过线性回归验证这种关系。66%的母鹿妊娠年龄确定正确，误差范围为±7天，96%的母鹿误差范围为±14天。总之，经直肠超声检查能够测量胎盘小叶大小，在母羊和母鹿妊娠的前70至90天期间，胎盘小叶大小迅速增加。然而，在母羊中，胎盘小叶大小与妊娠年龄的相关性较差，而在山羊中，胎盘小叶的测量可与经直肠超声检查进行妊娠诊断一起用于指示妊娠年龄。
