AN ECONOMIC-EVALUATION OF PARASITE CONTROL, STOCKING RATE, AND BROILER LITTER GRAIN SUPPLEMENTATION FOR STOCKERS ON BERMUDAGRASS

An economic evaluation of stocking rate, parasite control, and supplem entation with a chicken (Gallus gallus) broiler litter/grain supplemen t for stockers (Bos taurus, B. indicus) on bermudagrass [Cynodon dacty lon (L.) Pers. var. dactylon] was conducted in southeast Alabama. Two years of experimental data (1989 and 1990) were collected, with grazin g beginning in mid-May of each year and continuing as long as forage l asted. The study used a nonreplicated, regression design, with stockin g rates of 2, 4, and 6 stockers/acre in the nonsupplemented groups (wi th and without parasite control) and 4, 8, 12, 16, and 20 stockers/acr e in the supplemented groups (with and without parasite control). The broiler litter/grain supplement was fed ad libitum. Steers allocated t o parasite control received recommended doses of subcutaneously inject ed Ivermectin [a mixture of 5-O-demethyl-22, 23-dihydroavermectin Ala with 5-O-demethyl-25-de(1-methylpropyl)-22, 23-dihydro-25-(1-methyleth yl) avermectin Ala] 14 d before the onset of the study and additional dosages on Days 28 and 84 of the study to ensure continual parasite co ntrol. The effect of time on pasture was also considered explicitly in this study, so that the optimal selling date could be determined. Sel ected weekly price data for Alabama from 1986 to 1991 were used to est imate equations relating price per pound to animal weight and season, With no supplementation, the highest per acre economic returns occurre d at a stocking rate of 2 steers/acre, with parasite control, and with animals left on pasture for as long as possible. With supplementation , the highest per acre returns occurred at stocking Fates of 10 steers /acre, sold after 84 d on pasture and supplement. Returns for the supp lemented enterprise were considerably higher on a per acre basis ($160 .81 vs. $43.36) than those for the nonsupplemented enterprise. Parasit e control was economically Justified in both cases.