Corn stalk residue grazing and feedlot waste management

A series of experiments were conducted to aid in the integration of crop and livestock systems. A study was initiated to evaluate the impact of spring corn residue grazing and tillage on subsequent crop yields in a corn-soybean rotation. Crop yields were evaluated for two different stocking rates. Normal stocking rates showed no detrimental impacts of grazing or tillage on subsequent crop yields. At higher stocking rates (2.5 times normal) grazing increased soybean yields. However, corn yields were depressed under no-tillage 2 years post grazing. The results from this study suggest that producers can maintain livestock on crop acres in the spring if soybeans are planted the subsequent growing season. Another study evaluated transgenic (Corn Rootworm protected and Roundup Ready®) corn and non-transgenic corn for residue grazing. Growth performance of steers grazing corn residue from transgenic corn or their respective non-transgenic control was not different. This demonstrates that the feeding value of corn residue does not differ between transgenic corn hybrids and their parental controls. A trial was conducted to evaluate the effects of increasing levels of salt (NaCl) inclusion on animal performance and feed intake. Cattle were individually fed one of five treatments to include increasing levels of NaCl in the supplement from 0 to 0.5% of diet DM. Overall, NaCl supplementation was not effective in increasing animal performance or feed intake. Results suggest that NaCl inclusion in diets is not necessary. An experiment was conducted to evaluate pen cleaning frequency and the impact on nitrogen (N) volatilization during summer months and during composting of manure. Either monthly cleaning (MC) or cleaning pens at the end of the feeding period (EC) were evaluated. Within cleaning frequency, collected manure was composted with and without sawdust amendment. Monthly cleaning was more effective in recovering N in manure and reducing the overall loss from the pen surface than EC. Nitrogen recovery percentages were similar between pen cleaning treatments following composting and additional sawdust amendment was not beneficial