Effects of feeding nucleotides in diets containing corn germ meal or dried corn distillers grains and solubles on the performance and health of receiving and growing calves1

To improve profitability of newly arrived stressed feeder cattle, it is essential to minimize feed costs and health issues while optimizing growth performance. Effects of nucleotides (NA; PSB Complex; DSS Global LLC, McCormick, SC) in diets containing corn germ meal (CGM) or dried corn distillers grains with solubles (DDGS) on the health and performance of receiving and growing cattle were analyzed in 3 experiments. In Exp. 1, 213 crossbred heifers (BW 262 ± 67 kg) were used to compare CGM- and DDGS-containing diets and to determine the effects of NA in an 84-d trial. Treatments were a 2 × 3 factorial arrangement: 2 by-product-containing diets (CGM and DDGS) and 3 amounts of NA (0, 2, and 4 g/d). There were no effects of NA, corn by-product, or their interaction on growth performance (P ≥ 0.15). Experiment 2 evaluated performance and immunity effects of NA using 240 crossbred heifers (BW 268 ± 34 kg) in a 56-d trial. The diet contained DDGS, and treatments were 0, 2, and 4 g/d of NA. There were no effects of NA on growth performance (P ≥ 0.18) or fecal IgA concentration (P = 0.15). Experiment 3 used 4 ruminally cannulated Holstein heifers in a 4 × 4 Latin square design. Treatments were arranged as a 2 × 2 factorial: 2 by-product-containing diets (GCM and DDGS) and 2 amounts of NA (0 and 3 g/d). No treatment effects were observed for digestion. Ruminal pH was greater when NA was included (P < 0.05). Based on our results, diets can be formulated to contain 24.5% CGM (DM basis) in place of DDGS and maintain animal performance and digestibility. In our experiments, there was no benefit of supplementing NA in growing diets.