Grazing on dormant native range improved feedlot performance due to compensatory gain but grazing winter wheat increased carcass merit. In this Oklahoma State University study, British crossbred steers were allotted to one of two treatments during the winter for a 180-day period: grazing dormant native range, or grazing winter wheat pastures.
Steers on winter wheat had greater average daily gain [(ADG); 1.98 vs. 0.73 lb./day] than those grazing native range. Conversely, feedyard ADG and feed/gain were improved in native range steers (4.15 lbs. vs. 3.86 lbs., and 5.46 lbs. vs. 6.06 lbs., respectively).
During a 26-day adaptation trial, steers were adapted to a 90% concentrate diet. It was determined that greater ruminal dry matter and fluid fill late in the grazing period and increased dry matter intake (as a percent of body weight) and digestibility early in the finishing period may account for some of the compensatory response by native range steers.
But, when fed to a similar external fat endpoint, wheat pasture steers required fewer days on feed (88 vs. 130), and had greater final weight (1,222 lbs. vs. 1,155 lbs.), dressing percent (63.4% vs. 62%), hot carcass wt. (774 lbs. vs. 717 lbs.) and marbling score (414 vs. 375). No difference was found in yield grade (3.5).
These results indicate that grazing dormant native range may result in improved feedlot performance, but grazing winter wheat reduces days on feed and results in heavier carcasses and overall improved carcass merit.
(Choat et al. 2003. J. Anim. Sci .81:3191)
Pennsylvania State University trial determines the nitrogen (N) application rate for three, cool-season grasses that optimize economic return while minimizing the remaining N in the soil.
Cool-season grasses are important in forage systems in various regions of the U.S. and Canada. Production of these grasses is largely dependent on the availability of N in the soil. Knowing the economically optimum N application rate [(ENOR); cost of N vs. increased yield] at levels that don't adversely affect the environment is critical.
Four N rates were applied to established stands of orchardgrass, tall fescue and timothy for three years, harvesting the grasses three to four times per year.
Results showed the EONR were 203, 263, and 204 lbs. of N/acre, or 54, 62, and 62 lbs. of N/ton of forage harvested for orchardgrass, tall fescue and timothy, respectively. Apparent N recovery ranged from 34 to 80% and was greatest at or near EONR.
The authors concluded that the EONR for these three grasses is about 11 to 15 lbs. of N/ton of forage greater than current recommendations for the Northeast quadrant of the U.S. They also concluded that soil N is not adversely elevated at this level of N application. (Hall et al. 2003. Proc. American Forage and Grassland Council Conf.)