Characterization of mammary gland development in pregnant gilts
Characterization of mammary gland development in pregnant gilts
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DOI：
10.2527/2006.843579x
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发表时间：
2006-03-01
影响因子：
3.3
通讯作者：
Kim, SW
中科院分区：
文献类型：
--
作者：
Ji, F;Hurley, WL;Kim, SW
本研究的目的是量化后备母猪妊娠期间乳腺 (MG) 的生长，并确定解剖位置对腺体生长的影响。在 29 头初妊娠母猪妊娠期间测定了 MG 的大小、组成和组织形态学。将后备母猪随机分配至 6 个屠宰组：妊娠天数 45 (n = 6)、60 (n = 4)、75 (n = 5)、90 (n = 4)、102 (n = 5) 和 112 (n = 5)。屠宰时获取乳腺，去除皮肤和外来脂肪垫以获得实质MG组织。乳腺被进一步分成单独的 MG，并记录它们的位置。对单个 MG 进行称重并在近似正中矢状截面中平分以测量横截面积。乳腺被单独研磨并根据解剖区域合并：第一对 MG 和第二对 MG = 前 MG；第三、四、五对MG=中间MG；第六、第七和第八对 MG = 后 MG。测定DM、CP、乙醚提取物和粗灰分的含量。妊娠第 45 天至第 112 天期间，湿重、DM、CP 和总 MG 和个体 MG 的灰分含量均增加 (P < 0.01)。随着妊娠的进展，个体 MG 的横截面积增加（P < 0.01）。随着妊娠的进展，CP和灰分的百分比增加（P < 0.01），而乙醚提取物的百分比减少（P < 0.01）。 CP 和乙醚提取物百分比之间的这种反比关系（r = -0.999；P < 0.0001）与从妊娠早期主要是脂肪组织到妊娠晚期包含广泛的小叶肺泡组织的组织学转变一致。妊娠第 102、112 天，中部 MG 湿重大于后部 MG（P < 0.05）；妊娠 102、112 d，中部 MG CP 量高于前部和后部 MG（P < 0.05），表明妊娠后期中部 MG 比其他 MG 生长更快。妊娠第 74 天和第 75 天后，湿重增加率和蛋白质增加率分别加快（P < 0.01），表明妊娠最后三个月期间 MG 生长的重要性。第 75 天后蛋白质积累率的增加表明妊娠后期 MG 生长需要更多的蛋白质。
The purpose of this study was to quantify mammary gland (MG) growth during pregnancy in gilts and to determine the effect of anatomical location on gland growth. Size, composition, and histomorphology of MG were determined during gestation in 29 primigravid gilts. Gilts were allotted randomly to 6 slaughter groups: d 45 (n = 6), 60 (n = 4), 75 (n = 5), 90 (n = 4), 102 (n = 5), and 112 (n = 5) of gestation. Mammary glands were obtained at slaughter, and skin and extraneous fat pad were removed to obtain parenchymal MG tissue. Mammary glands were further separated into individual MG, and their locations were recorded. Individual MG were weighed and bisected in an approximate midsagittal section to measure cross-sectional area. Mammary glands were ground individually and pooled according to anatomical region: the first and second pairs of MG = anterior MG; the third, fourth, and fifth pairs of MG = middle MG; the sixth, seventh, and eighth pairs of MG = posterior MG. Contents of DM, CP, ether extract, and crude ash were measured. Wet weight, DM, CP, and ash content of total and individual MG increased (P < 0.01) between d 45 and 112 of gestation. Cross-sectional area of individual MG increased (P < 0.01) as gestation progressed. Percentage of CP and ash increased (P < 0.01), whereas percentage of ether extract decreased (P < 0.01) as gestation progressed. This inverse relationship between percentages of CP and ether extract (r = -0.999; P < 0.0001) was consistent with the histological shift from primarily an adipose tissue in early gestation to one containing extensive lobuloalveolar tissue in late gestation. Wet weight of middle MG was greater (P < 0.05) than that of posterior MG at d 102 and 112 of gestation, and amount of CP in middle MG was greater (P < 0.05) than that in anterior and posterior MG at d 102 and 112 of gestation, indicating that middle MG grow faster than other MG during late gestation. Rates of wet weight gain and protein accretion were accelerated (P < 0.01) after d 74 and 75 of gestation, respectively, indicating the importance of MG growth during the last trimester of gestation. The increase in rate of protein accretion after d 75 indicates a greater protein requirement for MG growth during later gestation.