Maternal nutrition of beef cattle at pasture mediates long-term consequences for offspring primarily through effects on growth early in life

This study tested the hypothesis that there are long-term consequences for offspring due to nutrition of the dam, beyond effects that result from variation in growth early in life (see Greenwood and Cafe 2007). Hereford cows were mated in consecutive years to Piedmontese or Wagyu sires. When confirmed pregnant, cows (n = 513) commenced low or high pasture quality and availability treatments until parturition and/or weaning. At weaning, offspring (n = 240) within steer and heifer cohorts were selected into 4 early-life growth groups (Low-Low, Low-High, High-Low and High-High), resulting in multi-modal distributions based on maternal nutrition and offspring growth to birth and weaning. Subsequent growth, efficiency, carcass and beef quality characteristics were determined (Table 1). Stepwise regression was used to test whether there were effects of the cow's nutrition during pregnancy and lactation, over and above effects due to birth and weaning weight. The model included covariates for birth (B) and weaning (W) weight and age at measurement (A), and fixed effects of nutrition during pregnancy (P) and lactation (L), calf sex (S), year (Y) and sire breed (G). First order interactions between fixed effects, and between covariates and fixed effects were included in the analyses.