ABSTRACT
We conducted two studies to compare wheat middlings as a low-protein, highly digestible fiber supplement to soybean meal and corn-soybean meal supplement for cows grazing winter range. In two 60-d winter grazing trials (December to February) cows (BW 500 kg) were allotted by age and weight to a 2 x 4 factorial with two forage availabilities and four supplements. Cows received either soybean meal (SBM), corn-soybean meal (CS), low wheat middlings (LWM), or high wheat middlings (HWM). The SBM and LWM supplements were formulated to provide the same daily CP, and CS and HWM provided the same daily CP and ME. In a 4 x 4 Latin square, four ruminally fistulated steers (BW 765 kg) received the same supplements and had free access to mature prairie hay. Cows grazing the high forage pasture gained more (P < .01) weight than cows grazing the low forage pasture. Cows supplemented with HWM gained less weight (P = .05) than cows supplemented with a similar amount of CP and ME from CS. Weight change of cows receiving SBM or LWM was similar. Increasing the amount of wheat middlings from LWM to HWM increased weight change (P = .04). In Exp. 2, SBM and LWM had similar total digestible DMI (DDMI). Steers supplemented with CS had higher total (P = .08) DDMI than HWM. Supplementation with HWM resulted in lower total (P = .02) DDMI than LWM. Response to SBM and LWM was similar. The CS and HWM resulted in beneficial performance responses as well as increasing the level of wheat middlings from low to high.
Subject(s)
Animal Feed , Digestion , Food, Fortified , Triticum , Animals , Cattle , Dietary Fiber , Female , Meat , Poaceae , SeasonsABSTRACT
Three experiments were conducted to determine the relative feeding value of frost-damaged soybeans (FDS) for ruminants. Frost-damaged soybean ether-extract content was variable and differed (P less than .05) from mature soybeans. Isonitrogenous supplementation of corn silage diets with soybean meal (SBM), SBM+soybean oil (SBO), mature raw soybeans (MSB), and FDS was compared in sheep. Acid detergent fiber and apparent N digestion were lower (P less than .001) for supplements containing oil. Nitrogen retention was reduced (P less than .07) only for raw soybean supplements. Ruminal NH3 N and branched-chain VFA concentrations differed (P less than .01) between SBM and supplements containing oil. Maximum tolerable inclusion level of FDS in corn silage diets was tested in wethers using diets containing 0, 7, 14, or 21% FDS. Dry matter and ADF digestibility declined linearly (P less than .01) with increasing dietary FDS. Ether extract digestibility was unchanged due to treatment, but GE digestibility decreased quadratically (P less than .01). The most pronounced decline in GE digestibility occurred when FDS increased from 14 to 21% of the diet. The effects of FDS on corn silage utilization were similar to MSB effects. Oil content and antinutritional factors contributed to detrimental effects. Frost-damaged soybeans should not exceed 14% of corn silage diets fed to growing wethers.
Subject(s)
Animal Feed , Digestion , Glycine max , Sheep/physiology , Ammonia/analysis , Animals , Dietary Fats, Unsaturated/administration & dosage , Dietary Fiber/administration & dosage , Dietary Fiber/metabolism , Fatty Acids, Volatile/analysis , Fermentation , Freezing , Humans , Infant, Newborn , Intestinal Absorption , Male , Nutritive Value , Rumen/chemistry , Rumen/metabolism , Sheep/growth & development , Silage , Zea maysABSTRACT
Population development of lesion nematodes was measured in 17 inbred lines of South Dakota and A619Ht dent corn. In two greenhouse groundbed tests, lines SD 101, SD 102, and SD 103 supported fewer than 1,000 Pratylenchus hexincisus per gram of dry root after 12 weeks. In an irrigated field test, inbred SD101 supported fewer than 1,000 P. scribneri per gram of dry root on each of two sampling dates, whereas line A619Ht supplied high populations of P. scribnerni on both dates. Inbreds SD45, 84742, and 84763 supported high populations of both P. hexincisus and P. scribneri.
