An Economic Evaluation of Parasite Control, Stocking Rate, and Broiler Litter/Grain Supplementation for Stockers on Bermudagrass

摘要

An economic evaluation of stocking rate, parasite control, and supplementation with a chicken (Callus gallus) broiler litter/grain supplement for stockers (Bos taurus, B. indicus) on bermudagrass [Cynodon dactylon (L.) Pers. var. dactylon] was conducted in southeast Alabama. Two years of experimental data (1989 and 1990) were collected, with grazing beginning in mid-May of each year and continuing as long as forage lasted. The study used a nonreplicated, regression design, with stocking rates of 2, 4, and 6 stockers/acre in the nonsupplemented groups (with and without parasite control) and 4,8,12,16, and 20 stockers/acre in the supplemented groups (with and without parasite control). The broiler litter/grain supplement was fed ad libitum. Steers allocated to parasite control received recommended doses of subcutaneously injected Ivermectin [a mixture of S-O-demethyI-22, 23-dihydroavermectin Ala with 5-O-demethyl-25-de(l-methylpropyl)-22, 23-dihydro-25-(l-methylethyl) avermectin Ala] 14 d before theonset of the study and additional dosages on Days 28 and 84 of the study to ensure continual parasite control. The effect of time on pasture was also considered explicitly in this study, so that the optimal selling date could be determined. Selected weekly price data for Alabama from 1986 to 1991 were used to estimate equations relating price per pound to animal weight and season. With no supplementation, the highest per acre economic returns occurred 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 rates of 10 steers/acre, sold after 84 d on pasture and supplement. Returns for the supplemented enterprise were considerably higher on a per acre basis (160.81 dollar vs. 43.36 dollar) than those for the nonsupplemented enterprise. Parasite control was economically justified in both cases.