Values of grass silage for finishing beef heifers : in vitrio studies

A two-year study was conducted with 98 growing/ finishing Hereford heifers to: (1) determine if the initial starting weight of heifers affects their use of forage; (2) determine if winter feeding level affects subsequent performance on high forage rations; (3) to collect data regarding the potential grain savings with a predominantly forage ration. Heifers weighing 500-550 pounds had significantly (P < .05) higher final weights and carcass weights than 400-450 pound heifers. Lighter weight heifers had a greater economy of gain. Heifers on a restricted wintering level had slightly higher average daily gains in the feeding period directly following the wintering phase, however, overall average daily gains, final weights, and carcass weights were slightly higher for heifers fed ad libitum during the wintering period. There were no significant effects on carcass characteristics due to the initial weight of the heifers or to wintering level. Heifers finished on ground ear corn consumed 421 pounds (7.5 bu.) more corn per head than heifers finished on grass silage with limited concentrates. However, the finishing period was 75 days shorter for corn-fed heifers. In a second study, the chemical composition and in vitro dry matter digestibility (IVDDM) of ladino-orchardgrass silage and wheat silage were compared at four stages of maturity to determine: (1) the effect of stage of maturity on chemical composition and IVDDM; and (2) to compare the IVDDM of small grain silage and perennial grass silage. Comparisons of the pre-bloom, early bloom, late bloom, and post bloom stages of maturity showed that silage cut in the pre-bloom stage was higher in ash and crude protein and lower in lignin. IVDDM decreased with increasing maturity but this decrease was not significant for the first three cuttings. The IVDDM of wheat silage and ladino-orchardgrass silage was not significantly different.