Teff grass for continuous stocking in the Southern High Plains by growing beef steers receiving protein supplements

This experiment evaluated forage quality, total nutrient yield, water footprint, and growth performance of beef steers receiving protein supplements while grazing Teff grass ['Tiffany'Eragrostis tef (Zucc.) Trotter] over two consecutive growing seasons. Each year, four 2.66-ha irrigated paddocks (experimental units) were stocked with crossbred beef steers (n = 5 per paddock, initial BW = 289 ± 30 for yr 1; and n = 6, initial BW = 286 ± 23 for yr 2) in a randomized complete block design and stocked continuously for 63 d. Daily supplements [0.45 kg/d of cottonseed meal (Control) enough to avoid a negative ruminal N balance; and 0.50% mean paddock BW animal-daily (approximately 1.65 kg) of sorghum-dried distillers grains plus solubles, (DDGS)] were randomly assigned to two paddocks each. Supplement did not influence forage neutral detergent fiber (NDF), acid detergent fiber, crude protein, or in vitro true digestibility (P ≥ 0.54), except for a tendency (P = 0.08) for a numerical increase in NDF content of paddocks with steers that received DDGS supplementation. Paddock nutrient-yields were similar (P ≥ 0.43) between supplement treatments. Supplementation with DDGS produced greater (P = 0.01) cattle shrunk average daily gain (ADG). Predicted teff dry matter intake (DMI), net energy for maintenance (NE_m), and growth (NE_g) (P ≤ 0.03) were greater with cattle offered Control treatment. Predicted total DMI was similar (P = 0.14) although predicted dietary NE_m, NE_g, gain:feed, and total BW gain were greater (P ≤ 0.02) with DDGS. Predicted forage intake was greater (P ≤ 0.05) for cattle offered Control treatment. Teff nutrients remaining on d 56 were similar (P = 0.33) between treatments. Water footprint for total production of forage nutrient components did not differ (P ≥ 0.12) by treatments. Nutrient yield and water use efficiency of continuously stocked teff grass was not affected by supplemental regimen. Using DDGS as a supplement may increase BW gain through increased nutrient utilization without hindering teff nutrient production on a continuous stocking system.