Maternal nutrition during gestation affects fetal development, which has long-term programming effects on offspring postnatal growth performance. With a critical role in protein and lipid metabolism, essential fatty acids can influence the development of muscle and adipose tissue. The experiment investigated the effects of late gestation supplements (77 d prepartum), either rich in saturated and monounsaturated fatty acids (CON; 155 g/cow/d EnerGII) or polyunsaturated fatty acids (PUFA; 80 g/cow/d Strata and 80 g/cow/d Prequel), on cow performance and subsequent calf growth performance as well as mRNA expression in longissimus muscle (LM) and subcutaneous adipose tissue at birth and weaning. There was no difference (P ≥ 0.34) in cow body weight (BW) or body condition score from pre-supplementation through weaning. Relative concentrations of C18:3n-3 and C20:4n-6 decreased (P ≤ 0.05) to a greater extent from mid-supplementation to calving for PUFA compared with CON cows. Cow plasma C20:0, C20:5n-3, and C22:6n-3 were increased (P ≤ 0.01) in PUFA during supplementation period. At birth, PUFA steers had greater (P = 0.01) plasma C20:5n-3. No differences (P ≥ 0.33) were detected in steer birth BW or dam milk production, however, CON steers tended (P = 0.06) to have greater pre-weaning average daily gain and had greater (P = 0.05) weaning BW compared with PUFA. For mRNA expression in steers: MYH7 and C/EBPβ in LM increased (P ≤ 0.04) to a greater extent from birth to weaning for PUFA compared with CON; MYF5 in LM and C/EBPβ in adipose tissue tended (P ≤ 0.08) to decrease more from birth to weaning for CON compared with PUFA; SCD in PUFA adipose tissue tended (P = 0.08) to decrease to a greater extent from birth to weaning than CON. In addition, maternal PUFA supplementation tended (P = 0.08) to decrease MYOG mRNA expression in LM and decreased (P = 0.02) ZFP423 in adipose tissue during the pre-weaning stage. Late gestation PUFA supplementation decreased pre-weaning growth performance of the subsequent steer progeny compared with CON supplementation, which could have been a result of downregulated mRNA expression of myogenic genes during pre-weaning period.

中文翻译：

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脂肪酸谱不同的补充剂对妊娠晚期肉牛的影响对奶牛性能、小牛生长性能以及与肌生成和脂肪生成相关基因的 mRNA 表达的影响

孕期母体营养影响胎儿发育，对子代产后生长表现具有长期规划效应。必需脂肪酸在蛋白质和脂质代谢中起着关键作用，可以影响肌肉和脂肪组织的发育。该实验研究了妊娠晚期补充剂（产前 77 天）的影响，这些补充剂富含饱和和单不饱和脂肪酸（CON；155 克/奶牛/天 EnerGII）或多不饱和脂肪酸（PUFA；80 克/奶牛/天 Strata 和 80 g/cow/d Prequel)，对母牛生产性能和随后的小牛生长性能以及最长肌 (LM) 和皮下脂肪组织中出生和断奶时的 mRNA 表达的影响。从补充前到断奶，奶牛体重 (BW) 或身体状况评分没有差异 (P ≥ 0.34)。C18的相对浓度：与 CON 奶牛相比，3n-3 和 C20:4n-6 从 PUFA 的中期补充到产犊的降低幅度更大（P ≤ 0.05）。在补充期间，PUFA 中的奶牛血浆 C20:0、C20:5n-3 和 C22:6n-3 增加（P ≤ 0.01）。出生时，PUFA 阉牛的血浆 C20:5n-3 更高（P = 0.01）。公牛出生体重或母牛产奶量没有检测到差异 (P ≥ 0.33)，但是，与 PUFA 相比，CON 公牛倾向于 (P = 0.06) 断奶前平均日增重更大，断奶 BW 更大 (P = 0.05) . 对于公牛的mRNA表达：与CON相比，PUFA从出生到断奶，LM中的MYH7和C/EBPβ增加幅度更大（P≤0.04）；与 PUFA 相比，对于 CON，LM 中的 MYF5 和脂肪组织中的 C/EBPβ 倾向于（P ≤ 0.08）从出生到断奶减少更多；PUFA 脂肪组织中的 SCD 趋于 (P = 0. 08) 从出生到断奶的下降幅度大于 CON。此外，在断奶前阶段，母体 PUFA 补充剂倾向于 (P = 0.08) 降低 LM 中的 MYOG mRNA 表达并降低 (P = 0.02) 脂肪组织中的 ZFP423。与补充 CON 相比，妊娠晚期补充 PUFA 降低了后续阉牛后代的断奶前生长性能，这可能是断奶前生肌基因 mRNA 表达下调的结果。