Nutrient intake in the bovine during early and mid-gestation causes sex-specific changes in progeny plasma IGF-I, liveweight, height and carcass traits
2010
Micke, G.C. | Sullivan, T.M. | Gatford, K.L. | Owens, J.A. | Perry, V.E.A.
Fetal and postnatal growth are mediated by insulin-like growth factors (IGFs) and their binding proteins (IGFBPs). Maternal nutrient intake during gestation can program the postnatal IGF-axis. This may have significant economic implications for beef cattle production. We investigated the effect of high (H =240%) and low (L =70%) levels of recommended daily crude protein (CP) intake for heifers during the first and second trimesters of gestation in a two-by-two factorial design on progeny (n =68) plasma IGF-I, IGF-II, total IGFBP (tIGFBP), postnatal growth and carcass traits. Calves were heavier at birth following high CP diets during the second trimester (P =0.03) and this persisted to 29d. Plasma IGF-I concentrations of males were greater for HL compared to LL (P <0.01) and HH (P >0.04) from 29 to 657d, and for LH compared to LL from 29 until 379d (P =0.02). Exposure to low CP diets during the first trimester resulted in heavier males from 191d onwards (P =0.04) but a tendency for lighter females from 552d onwards (P =0.07) that had lighter carcass weights (P =0.04). Longissimus dorsi cross-sectional area of all carcasses was greater following exposure to low CP diets during the second trimester (P =0.04). Heifer nutrient intake during the first and second trimesters causes persistent and sex-specific programming of progeny plasma IGF-I, postnatal liveweight and carcass weight. Refining heifer nutritional programs during early gestation may optimize production objectives in progeny.
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