Guilbault L A, Thatcher W W, Collier R J, Wilcox C J
J Anim Sci. 1985 Dec;61(6):1505-15. doi: 10.2527/jas1985.6161505x.
Holstein heifers (n = 21) were balanced across sires and assigned to three service-sire-breed groups in which heifers were inseminated artificially to either purebred Angus (n = 7), Holstein (n = 7) or Brahman (n = 7) bulls. Semen from four bulls was used for each service sire-breed group. Blood samples were collected from a jugular vein thrice weekly from d 160 to 265 of pregnancy, daily thereafter until 15 d postpartum, and then thrice weekly until d 60 postpartum. Concentrations of progesterone, estrone, estradiol, and estrone sulfate from 23 d prepartum to parturition, and of 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) from 2 d prepartum to d 15 postpartum were measured by radioimmunoassay. Heifers within the Brahman-service-sire group had longer gestations (P less than .05) than those of Holstein- or Angus-service-sire groups (285.0 vs 278.7), 279.0 d). Calf birth weight was lower (P less than .05) in Angus- than Holstein- and Brahman-service-sire groups (30.6 vs 36.1, 43.4 kg). Daily trends of prepartum maternal progesterone concentrations were approximately 1 ng/ml lower (P less than .01) in Angus- than Holstein- or Brahman-service-sire groups until luteolysis occurred. Heifers bearing crossbred Angus conceptuses had lower daily trends of prepartum estrogens concentrations (P less than .01), whereas heifers of the Holstein- and, even more dramatically, of the Brahman-service-sire groups had a higher magnitude and greater rise of plasma estrogens concentrations between d -10 and -1 prepartum (less than .01). Postpartum mean concentrations (P less than .05) and response curves of PGFM were lower (P less than .01) in the Angus- than in the Holstein- or Brahman-service-sire groups. Calf birth weights were correlated with least-squares means for maternal concentrations of prepartum estrone (r = .57), estradiol (r = .59) and estrone sulfate (r = .64) and postpartum maternal concentrations of PGFM (r = .56). Functional responses of the conceptus (e.g., estrogens) and maternal units (e.g., progesterone and PGFM) were influenced by conceptus genotype during the periparturient period.
选用21头荷斯坦小母牛，按父系进行均衡分组，并分为三个配种公牛品种组，分别用纯种安格斯公牛（n = 7）、荷斯坦公牛（n = 7）或婆罗门公牛（n = 7）对小母牛进行人工授精。每个配种公牛品种组使用来自4头公牛的精液。从妊娠第160天至265天，每周三次从颈静脉采集血样，此后每天采集直至产后15天，然后每周三次直至产后60天。采用放射免疫分析法测定产前23天至分娩期间孕酮、雌酮、雌二醇和硫酸雌酮的浓度，以及产前2天至产后15天15 - 酮 - 13,14 - 二氢 - 前列腺素F2α（PGFM）的浓度。婆罗门配种公牛组的小母牛妊娠期比荷斯坦或安格斯配种公牛组的小母牛长（P < 0.05）（分别为285.0天、278.7天和279.0天）。安格斯配种公牛组的犊牛出生体重低于荷斯坦和婆罗门配种公牛组（P < 0.05）（分别为30.6千克、36.1千克和43.4千克）。在黄体溶解发生前，安格斯配种公牛组的产前母体孕酮浓度的每日变化趋势比荷斯坦或婆罗门配种公牛组低约1 ng/ml（P < 0.01）。怀有杂交安格斯胚胎的小母牛产前雌激素浓度的每日变化趋势较低（P < 0.01），而荷斯坦配种公牛组尤其是婆罗门配种公牛组的小母牛在产前第 - 10天至 - 1天之间血浆雌激素浓度的升高幅度更大（P < 0.01）。产后PGFM的平均浓度（P < 0.05）和反应曲线安格斯配种公牛组低于荷斯坦或婆罗门配种公牛组（P < 0.01）。犊牛出生体重与产前母体雌酮（r = 0.57）、雌二醇（r = 0.59）和硫酸雌酮（r = 0.64）以及产后母体PGFM浓度的最小二乘均值相关（r = 0.56）。在围产期，胚胎（如雌激素）和母体单位（如孕酮和PGFM）的功能反应受胚胎基因型的影响。
