The Center for the Study of Fetal Programming, Laramie, WY 82071, USA.
J Anim Sci. 2012 Jan;90(1):197-206. doi: 10.2527/jas.2011-4237. Epub 2011 Sep 9.
Angus × Gelbvieh cows with 2 to 3 previous pregnancies were used to evaluate effects of maternal nutrient restriction on offspring adipose tissue morphology at standard production endpoints. At 45 d after AI to a single sire, pregnancy was confirmed and cows randomly allotted into groups and fed a control (Con, 100% of NRC recommendations), nutrient-restricted (NR, 70% of Con diet), or nutrient-restricted + protein-supplemented (NRP, 70% of Con + essential AA supply to the small intestine equal to Con) diet. At d 185 of gestation, cows were commingled and received the Con diet thereafter. Bull calves were castrated at 2 mo of age. Calves were weaned at 210 d, backgrounded for 28 d, and then placed in the feedlot for 195 d. Steers and heifers were slaughtered at an average 12th-rib fat thickness of 7.6 mm. Adipose tissue from selected depots was collected for adipocyte size analysis. There was no significant difference in BW or BCS between Con, NRP, and NR cows at d 45 of gestation, which averaged 489.7 ± 17.7 kg and 5.35 ± 0.13, respectively. At d 185 of gestation, Con and NRP groups had similar BW (566.1 ± 14.8 and 550.2 ± 14.8 kg) and BCS (6.34 ± 0.27 and 5.59 ± 0.27), but NR cows exhibited reduced (P < 0.05) BW (517.9 ± 14.8 kg) and BCS (4.81 ± 0.27). Among offspring (steers and heifers) at slaughter, there were no significant differences in BW or organ weights among treatment groups. Yield grade was reduced (P < 0.05) and semitendinosus weight/HCW tended (P = 0.09) to be reduced in NR offspring compared with Con and NRP offspring. Average adipocyte diameter was increased (P < 0.05) in subcutaneous, mesenteric, and omental adipose tissue and tended (P = 0.09) to increase in perirenal adipose tissue in NR compared with Con offspring with NRP offspring adipocyte diameter being either intermediate or similar to Con calves. The adipocyte size alterations observed in NR offspring were confirmed by DNA concentration of the adipose tissue depots. There also was an increased mRNA expression (P < 0.05) of fatty acid transporter 1 in subcutaneous adipose tissue from NR offspring compared with Con and NRP offspring. Nutritional restriction during early and mid gestation increased or tended to increase (P < 0.09) adipocyte diameter in all adipose tissue depots in finished steer and heifer calves.
Angus × Gelbvieh 奶牛有 2 到 3 次以前的怀孕经历，用于评估母体营养限制对标准生产终点后代脂肪组织形态的影响。在人工授精后 45 天，确认怀孕后，奶牛被随机分为三组，并喂食对照（Con，满足 NRC 推荐的 100%营养）、营养限制（NR，Con 饮食的 70%）或营养限制+蛋白质补充（NRP，满足 Con 饮食的 100%营养，同时向小肠提供必需氨基酸以满足营养需求）饮食。在妊娠 185 天，奶牛混合喂养，并随后接受 Con 饮食。公牛犊在 2 月龄时去势。犊牛在 210 日龄断奶，在背景下饲养 28 天，然后放入育肥场饲养 195 天。公牛和小母牛在第 12 肋骨脂肪厚度为 7.6 毫米时进行屠宰。从选定的脂肪组织中收集脂肪细胞大小分析。妊娠 45 天时，Con、NRP 和 NR 奶牛的体重或体况评分（BCS）之间没有显著差异，分别为 489.7 ± 17.7 公斤和 5.35 ± 0.13。在妊娠 185 天时，Con 和 NRP 组的体重（566.1 ± 14.8 和 550.2 ± 14.8 公斤）和 BCS（6.34 ± 0.27 和 5.59 ± 0.27）相似，但 NR 组的体重（517.9 ± 14.8 公斤）和 BCS（4.81 ± 0.27）均较低（P＜0.05）。在屠宰时的后代（公牛和小母牛）中，各组间体重或器官重量无显著差异。NR 后代的产肉等级降低（P＜0.05），半腱肌重量/HCW 趋于降低（P=0.09），与 Con 和 NRP 后代相比。与 Con 后代相比，NR 后代的皮下、肠系膜和大网膜脂肪组织中的平均脂肪细胞直径增加（P＜0.05），肾周脂肪组织中的脂肪细胞直径也有增加的趋势（P=0.09），而 NRP 后代的脂肪细胞直径介于 Con 犊牛之间或与 Con 犊牛相似。NR 后代脂肪组织中的脂肪细胞大小变化通过脂肪组织的 DNA 浓度得到证实。与 Con 和 NRP 后代相比，NR 后代的皮下脂肪组织中脂肪酸转运蛋白 1 的 mRNA 表达也增加（P＜0.05）。在育肥的公牛和小母牛中，妊娠早期和中期的营养限制增加或趋于增加（P＜0.09）所有脂肪组织中的脂肪细胞直径。
