Nasser L F, Reis E L, Oliveira M A, Bó G A, Baruselli P S
Departamento de Reprodução Animal, FMVZ-USP, CEP 05508-000 Saã Paulo, Brazil.
Theriogenology. 2004 Dec;62(9):1577-84. doi: 10.1016/j.theriogenology.2004.03.013.
The objective was to evaluate the effects of 400 IU of eCG given on Days 5 or 8 of an estrus synchronization protocol with progesterone-releasing intravaginal devices (PRID) and estradiol benzoate (EB), in recipients for fixed-time embryo transfer. A secondary objective was to determine the effects of injectable progesterone (given concurrent with EB treatment). Three-hundred-and-four crossbred Bos taurus x Bos indicus beef heifers were randomly assigned to one of four treatment groups (2 x 2 factorial design). At unknown stages of the estrous cycle (Day 0), all heifers received a progesterone-releasing intravaginal device (PRID), plus 2mg of EB i.m., with or without a concurrent treatment of 50mg of progesterone i.m. Heifers were further subdivided to receive 0.15 mg of d-cloprostenol (PGF) i.m. and 400 IU of eCG i.m. on Days 5 or 8. In all heifers, intravaginal devices were removed on Day 8 and 1mg of EB was given i.m. on Day 9 (Day 10 was arbitrarily considered the day of estrus). On Day 17, all heifers with >1 CL or a single CL with a diameter > or =18 mm (based on ultrasonographic examination), received an in vitro produced (IVP) embryo by non-surgical transfer. On Day 17, there was an effect of day of eCG administration on the number of CL (1.35 +/- 0.08 versus 1.13 +/- 0.04, for Day 5 versus Day 8, respectively; P = 0.02) and (in a subset of 154 heifers) mean (+/-S.E.M.) plasma progesterone concentrations (2.41 +/- 0.26 versus 1.74 +/- 0.19 ng/mL; P = 0.03). Although the proportion of recipients transferred/treated and pregnant/transferred did not differ among groups, the proportion of recipients pregnant/treated tended (P = 0.1) to be higher in heifers treated with eCG on Day 5 versus Day 8 (47.0% versus 40.7%, respectively). Progesterone treatment had no significant effect. In conclusion, treatment with eCG (and D-cloprostenol) on Day 5 significantly increased the number of CL and plasma progesterone concentrations and tended to increase pregnancy rates, although progesterone treatment had no significant effect.
目的是评估在使用含孕酮的阴道内装置（PRID）和苯甲酸雌二醇（EB）的同期发情方案的第5天或第8天给予400国际单位孕马血清促性腺激素（eCG）对定时胚胎移植受体的影响。第二个目的是确定注射用孕酮（与EB治疗同时给予）的影响。304头杂交牛（Bos taurus×Bos indicus）肉用小母牛被随机分配到四个处理组之一（2×2析因设计）。在发情周期的未知阶段（第0天），所有小母牛都接受一个含孕酮的阴道内装置（PRID），加2毫克EB肌肉注射，同时给予或不给予50毫克孕酮肌肉注射。小母牛进一步细分，在第5天或第8天接受0.15毫克氯前列醇（PGF）肌肉注射和400国际单位eCG肌肉注射。在所有小母牛中，阴道内装置在第8天取出，第9天给予1毫克EB肌肉注射（第10天被任意视为发情日）。在第17天，所有有一个以上黄体或单个直径大于或等于18毫米的黄体（基于超声检查）的小母牛，通过非手术移植接受一个体外生产（IVP）胚胎。在第17天，eCG给药日对黄体数量有影响（第5天与第8天分别为1.35±0.08和1.13±0.04；P = 0.02），并且（在154头小母牛的一个亚组中）平均（±标准误）血浆孕酮浓度有影响（2.41±0.26与1.74±0.19纳克/毫升；P = 0.03）。虽然各处理组间移植/处理受体和妊娠/移植受体的比例没有差异，但第5天接受eCG治疗的小母牛与第8天相比，妊娠/处理受体的比例有升高趋势（P = 0.1）（分别为47.0%和40.7%）。孕酮治疗没有显著影响。总之，第5天用eCG（和氯前列醇）治疗显著增加了黄体数量和血浆孕酮浓度，并倾向于提高妊娠率，尽管孕酮治疗没有显著影响。
