The objective of this experiment was to examine the long-term effects of distillers grain supple-mentation and nitrogen (N) fertilization on animal per-formance to determine whether cattle supplemented with dry distillers grains plus solubles (DDGS) can be stocked at the same rate as nonsupplemented cattle on N-fertilized smooth bromegrass pastures. Each year, 45 steer calves weighing 321 ± 27 kg were assigned to 1 of 3 treatments. Treatments consisted of (1) steers grazing nonfertilized smooth bromegrass pastures supplemented with DDGS at 0.6% of BW (DM basis; SUPP); (2) steers grazing smooth bromegrass pastures fertilized with 90 kg of N/ha (FERT); or (3) steers grazing unfertilized smooth bromegrass pas-tures without DDGS supplementation (CONT). Pasture was the experimental unit, with 3 replications per treat-ment each year, and pastures were rotationally grazed during the grazing season. The CONT treatment pastures were 30% larger than the SUPP and FERT pastures, based on previous research indicating that nonfertilized pastures produced ~70% as much forage as fertilized pastures. Across the 17 yr, cattle on the SUPP treatment had greater ADG (1.03 kg) than those on CONT (0.73 kg) and FERT treatments (0.73 kg), which were similar to one another. Similar ADG between the CONT and FERT demonstrate that forage availability was the same and appropriate pasture sizes were used. Body weight gain per hectare was greatest for the SUPP treatment (378 kg/ha), intermediate for the FERT treat-ment (271 kg/ha), and least for the CONT treatment (186 kg/ha). Pasture use efficien-cy is increased through DDGS supplementation or fertil-ization of pastures, with the SUPP treatment being the most productive per hectare. Responses vary across years due to precipitation and pasture performance.
Hodges et al. (Wed,) studied this question.