Copping Katrina J, Callaghan Matthew J, Geesink Geert H, Gugusheff Jessica R, McMillen I Caroline, Rodgers Raymond J, Muhlhausler Beverly S, Vithayathil Mini A, Perry Viv E A
Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.
Ridley Agriproducts, Toowong, QLD, Australia.
Front Genet. 2021 Sep 3;12:720242. doi: 10.3389/fgene.2021.720242. eCollection 2021.
Nulliparous yearling beef heifers (=360) were used to evaluate the effects of maternal dietary protein during the periconception and first trimester periods of gestation on postnatal growth, feedlot performance, carcass characteristics, and the expression of genes associated with appetite in the arcuate nucleus of their male progeny. Heifers were individually fed a diet of 1.18g crude protein (CP)/day High protein (HPeri) or 0.62g CP/day Low protein (LPeri) beginning 60days before conception. From 24 to 98days post-conception (dpc), half of each treatment group changed to the alternative post-conception diet and were fed 1.49g CP/day (HPost) or 0.88g CP/day (LPost) yielding four treatment groups in a 2×2 factorial design. From day 98 of gestation, heifers received a common diet until parturition. Calves were weaned at 183days and developed on pasture before feedlot entry. Bulls underwent a 70-day Residual Feed Intake (RFI) feedlot test commencing at 528days of age. Feedlot entry and final body weight (BW), feedlot average daily gain (ADG) and RFI were not different (>0.05). Progeny of dams that had a change in diet (LPeri/HPost and HPeri/LPost) had 9% higher daily dry matter intake (DMI) during the RFI test (<0.05) than progeny of dams that received low diet throughout both the peri-conception period and first trimester (LPeri/LPost). Further, mRNA expression of the appetite-stimulating agouti-related protein (AGRP) was increased in the arcuate nucleus of High Peri/LPost bulls (<0.05). muscle cross sectional area, carcass dressing percentage, and estimated retail beef yield (RBY) were all higher (<0.05), and rump (P8) fat tended to be lower (=0.07), for bulls from HPost dams despite no difference in carcass weight (<0.05). This study is of commercial importance to the livestock industry as specific periods of maternal dietary supplementation may increase feed intake, enhance progeny muscling, and alter fat deposition leading to improvement in efficiency of meat production in beef cattle.
选用360头未产的一岁肉用小母牛来评估妊娠前期和孕早期母体日粮蛋白质对其雄性后代出生后生长、育肥性能、胴体特征以及弓状核中与食欲相关基因表达的影响。从配种前60天开始，给小母牛分别饲喂高蛋白（HPeri）日粮（1.18克粗蛋白/天）或低蛋白（LPeri）日粮（0.62克粗蛋白/天）。在配种后24至98天（dpc），每个处理组的一半改为另一种配种后日粮，分别饲喂1.49克粗蛋白/天（HPost）或0.88克粗蛋白/天（LPost），形成2×2析因设计的四个处理组。从妊娠98天起，小母牛改为普通日粮直至分娩。犊牛在183天时断奶，在进入育肥场前在牧场上饲养。公牛在528日龄时开始进行为期70天的剩余采食量（RFI）育肥试验。育肥场入场体重和最终体重（BW）、育肥场平均日增重（ADG）和RFI没有差异（>0.05）。日粮有变化（LPeri/HPost和HPeri/LPost）的母畜后代在RFI试验期间的每日干物质摄入量（DMI）比在妊娠前期和孕早期都采食低蛋白日粮的母畜后代（LPeri/LPost）高9%（<0.05）。此外，高Peri/LPost公牛弓状核中促食欲的刺鼠相关蛋白（AGRP）的mRNA表达增加（<0.05）。尽管胴体重没有差异（<0.05），但来自HPost母畜的公牛的肌肉横截面积、胴体屠宰率和估计零售牛肉产量（RBY）都更高（<0.05），臀部（P8）脂肪含量趋于更低（=0.07）。本研究对畜牧业具有商业重要性，因为母体日粮补充的特定时期可能会增加采食量、增强后代肌肉发育并改变脂肪沉积，从而提高肉牛的肉类生产效率。
