Alternating low quality hay with access to annual ryegrass pastures affected stocker performance1

Little is known about the effect of limiting access to high nutritive value pastures on subsequent pasture and stocker response when alternating with low quality bermudagrass (Cynodon dactylon) hay. In 3 consecutive years, 54 steers were randomly allotted to 3 treatments: (1) CON steers were continuously stocked on annual ryegrass (Lolium multiflorum Lamarck; Munz, 1973) pastures (1,040 kg of BW/ha); (2) HY24 steers grazed 50% of the area assigned to the CON treatment (2,081 kg of BW/ha) every other day. Steers grazed annual ryegrass for 24 h and then returned to a barn for 24 h where bermudagrass hay was fed; (3) HY72 steers grazed 50% of the area assigned to the CON treatment (2,079 kg of BW/ha) for 96 h and then returned to the barn for 72 h where bermudagrass hay was fed. There was a year effect (P < 0.05) on forage and animal performance. Treatment affected forage mass, nutritive value, and forage growth rate (P < 0.05). Estimated ryegrass DMI was influenced (P = 0.03) by treatments as was ADG (P < 0.001) and gain per hectare (P < 0.001). Treatment effect (P < 0.05) on plasma urea-N and nonesterified fatty acids is probably explained by the lower DMI in HY24 and HY72 compared with CON and the lower intake of hay in HY72. Alternating hay feeding with access to ryegrass (24 h pasture, 24 h hay) allowed for increasing stocking rates (kg of BW/ha) and productivity on annual ryegrass compared with longer periods of hay feeding, which negatively affected animal performance and BW gain per hectare.