T. W. Perry

Performance of Lambs Fed Diets Containing Whole Corn Plant Ensiled with Swine Manure Solids1234

Two nitrogen (N) balance trials and one group feeding trial were conducted with growing crossbred lambs to determine the nutritive value of fermented swine manure solids with whole corn plant. Manure solids collected from an open concrete growing-finishing swine feedlot were ensiled with chopped mature whole corn plant at a 26:74 ratio (DMB) in balance trials and a 14:86 ratio (DMB) in the group feeding trial. Fermentation characteristics of the swine manure-corn forage mixtures were evaluated. Diets for the first balance trial were; (1) corn silage alone, (2) waste silage alone, (3) corn silage plus urea and (4) waste silage plus corn grain. Dry matter (DM) intake was highest (P ◄ .01) for the waste silage-corn diet. Intake of corn silage-based diets were lowest. Nitrogen digestibility (P ◄ .01), N intake (P ◄ .01) and N retention (P ◄ .05) were higher for waste silage-based diets than for corn silage-based diets. Dry matter and organic matter (OM) digestibilities followed a similar trend. Diets for the second balance trial were; (1) corn silage plus soybean meal and (2) waste silage plus corn grain. Dry matter intake was highest (P ◄ .01) for the waste silage-corn diet. Nitrogen, DM and OM digestibilities, and N retention were similar (P ► .05) for both diets. Diets for the group feeding trial were: (1) corn silage plus soybean meal and corn grain and (2) waste silage plus corn grain. Average daily gain, feed efficiency, carcass yield and grades and concentrations of Cu, Zn and Fe in lean tissue were similar (P ► .05) for both diets. Higher liver Zn (P = .002), higher kidney Fe (P = .001) and lower kidney Cu (P = .035) concentrations were found in lambs fed the manure silage diet compared to the control corn silage diet. Ensiling swine manure solids with whole corn plant resulted in higher VFA, N, and ash contents compared to corn silage. Total coliform, fecal coliforms, streptococci and salmonella were eliminated after 5 d of fermentation. Swine manure fermented with whole corn plant resulted in a safe and preserved feed that supported efficient iamb growth when balanced with corn grain.

Effect of Combinations of Feather Meal, Corn Gluten Meal, Soybean Meal, and Urea as Sources of Supplemental Protein on Nitrogen Balance and Characteristics of Rumen Contents of Cattle1

Steers in metabolism stalls and ruminally cannulated steers were used in two separate 8 x 8 Latin Square experiments to evaluate several combinations of protein sources that supplied 33% of the total dietary protein. Protein sources compared were urea (U), hydrolyzed feather meal (HFM), hydrolyzed feather meal plus urea (HFM+U), soy-bean meal (SBM), hydrolyzed feathermeal plus soybean meal (HFM+SBM), corn gluten meal (CGM), corn gluten meal plus urea (CGM+U), and corn gluten meal plus soybean meal (CGM+SBM), with the combinations being a 50:50 CP mixture. There were no differences among protein sources compared in N retention (45.9 ± 5.09 g/d) or N retention as a percentage of N intake 29.8 + 3.24%). Hydrolyzed feather meal N was less (P<.05) digestible (64.0%) than that from U (73.7), HFM+U (68.4), SBM (72.6), HFM+SBM (69.3), CGM (70.0), CGM+U (71.6), or CGM+SBM (72.3). Urea-N digestibility was higher (P<.05) than was HFM+U-N and HFM+SBM-N. Blood urea-N was not affected by protein source at 2 h, but was higher (P<.05) for U at 4 and 6 h vs. other treatments. Ruminal fluid NH3-N and pH were increased (P<.05) by protein source at 2 and 4 h but not at 6 h. Total VFA concentrations were not affected by protein source at 2, 4, and 6 h. Urea or SBM used in combination with CGM or HFM may reduce the cost of protein supplementation without affecting N utilization by steers.

Serum Amino Acid Levels and Nitrogen Balance in Ponies Fed Urea and Soybean Meal as Sources of Supplemental Dietary Nitrogen1

Abstract Metabolism trials with mature gelded ponies were conducted employing a 2 x 3 factorial design with two sources of supplemental nitrogen (urea vs soybean meal) which included three levels of added urea (1, 2 and 4% of the diet) or isonitrogenous levels of soybean meal. A basal diet of ground shelled corn and ground corn cobs containing 6% crude protein was supplemented with the two sources and three levels of nitrogen to contain 8.8, 11.6 and 17.2% protein, respectively. Apparent nitrogen absorption was not affected by either source or level of dietary nitrogen, but nitrogen retention was higher (P ◄ .05) for ponies fed soybean meal, irrespective of dietary nitrogen level; percent of absorbed nitrogen retained also was greater (P ◄ .05) for ponies fed soybean meal. Blood urea nitrogen was higher (P ◄ .01) for ponies fed urea than for those fed soybean meal, but neither blood serum orotic acid concentrations nor serum ammonia concentrations were affected by nitrogen source at any of the three levels. Urinary urea nitrogen concentrations were higher (P ◄ .05) for ponies fed urea-supplemented diets, and urinary ammonia and orotic acid concentrations increased (P ◄ .05) with increasing levels of nitrogen, irrespective of source of nitrogen. Only seven of the usually accepted 10 dietary essential amino acids for nonruminant animals were found to be affected in pony blood serum levels. Ponies fed soybean meal, irrespective of level, had higher concentrations (P ◄ .01) of isoleucine, leucine, lysine, phenylalanine, threonine, tryptophan and valine than ponies that received urea. Arginine, histidine and methionine concentrations of the serum were not affected by source or level of supplemental nitrogen. The highest level of supplemental soybean meal resulted in greater (P ◄ .01) serum concentrations of isoleucine, leucine, lysine, threonine, tryptophan and valine than the two lower levels of soybean meal. There was an increase (P ◄ .01) in concentration of four of the dietary nonessential amino acids in the serum due to source (soybean), but not level, of supplemental nitrogen, namely, alaninie, proline, serine and tyrosine. (Key Words: Pony, Urea, Essential Amino Acids, Nitrogen Metabolism.)

Salt or Limestone to Control Corn Intake of Cattle on Pasture1,2

Summary Two summer pasture experiments were conducted with finishing yearling cattle to determine the effect of incorporating 5 or 10% salt or calcium carbonate, or 5% of each, with corn offered ad libitum during the pasture season. Five percent added salt depressed corn consumption 8.6 and 22% and 5% calcium carbonate depressed corn consumption 8%; 10% salt reduced corn consumption 29 and 24% and 10% calcium carbonate reduced corn consumption 16%; 5% each of salt and calcium carbonate decreased corn consumption 12%. Gains were not depressed consistently, indicating cattle which ate less corn due to its dilution with salt or calcium carbonate probably were consuming more herbage.