Harvest maturity of Eragrostis tef ‘Moxie’: Effects on ruminal fermentation, total-tract nutrient digestibility, and growth performance in backgrounding beef cattle

Abstract

ABSTRACT Objective The objective was to examine the effects of feeding teff (cv. Moxie) hay harvested at either the early-heading (EH) or late-heading (LH) stage of maturity on nutrient intake and digestibility, ruminal fermentation characteristics, and growth performance in backgrounding cattle. Materials and Methods A total of 114 steers (initial BW ± SD = 258 kg ± 19.4) were used in a completely randomized design. The dietary treatments were backgrounding diets containing either EH or LH teff hay (65% of diet DM) as the only source of forage. Steers were fed over a 56-d period. Body weight was measured at the beginning and end of the trial, with ruminal fluid, fecal, and blood samples collected on d 21, 42, and 56 to quantify metabolites. Results and Discussion Dry matter and nitrogen (N) intake and apparent total-tract digestibility were greater for EH than LH steers. Although greater for steers fed the EH than LH teff diet on d 21 and 42, both total ruminal short-chain fatty acid and ammonia-N (NH3-N) concentrations did not differ across diets on d 56. These observations suggest greater nutrient supply for EH than LH steers, possibly accounting for the greater ADG. Implications and Applications Delaying harvest of teff from the EH to LH stage of maturity compromised DM and N intake and apparent total-tract digestibility, and ADG. Therefore, the stage of maturity at harvest must be considered when developing teff (cv. Moxie) grass-based feeding systems for growing calves.