Casey Macken

Effect of Supplemental Energy Source and Frequency on Growing Calf Performance

Crossbred heifers (n = 120; 265 kg, SD = 37) were fed individually (84 d) to determine the effect of supplement type, concentration, and frequency on intake and performance and to estimate the energy value of dry distillers grains plus solubles (DDGS) in a high-forage diet. Treatments were arranged in a 3 x 2 x 2 factorial, with 3 supplements, 2 concentrations, and 2 frequencies of supplementation. Supplements including dry-rolled corn (DRC), DRC with corn gluten meal (DRC + CGM), and DDGS were fed at 0.21% (LOW) or 0.81% (HIGH) of BW daily and were provided daily (DAILY) or 3 times weekly (ALT). Heifers were fed to consume grass hay (8.7% CP) ad libitum. Individual DMI, diet composition, BW, and ADG were used to calculate energy values for DDGS and DRC. Supplement type, concentration, frequency, and interactions were tested using the MIXED procedure of SAS, with BW included as a covariate. Supplement x concentration interactions for gain (P = 0.01) and G:F (P < 0.01) were detected. At the LOW concentration, heifers supplemented with DDGS gained more and were more efficient (P </= 0.03) than those supplemented with DRC or DRC + CGM. No performance differences were observed (P >/= 0.22) between DDGS and DRC + CGM in HIGH treatments, although both improved (P </= 0.01) gain and G:F relative to DRC. Calculated TDN content of DDGS was 18 to 30% greater than DRC. Gain and G:F were improved (P < 0.01) in heifers fed HIGH vs. LOW. Total intake was greater (P < 0.01) for HIGH than LOW, but LOW heifers consumed more hay (P < 0.01) than HIGH. The DAILY heifers consumed more (P < 0.01) hay and total DM than the ALT heifers. The DAILY heifers gained more (P < 0.01) than ALT, but G:F was not affected (P = 0.85) by supplementation frequency. In a high-forage diet, DDGS has greater energy value than corn.

Phosphorus requirement and excretion of finishing beef cattle fed different concentrations of phosphorus

Phosphorus is an expensive nutrient to supplement, and excess may lead to manure P challenges. Therefore, minimizing dietary P to meet requirements is important. Two experiments were conducted to determine the P requirement of finishing cattle (Exp. 1) and to evaluate the effects of feeding different P concentrations on the quantity and route of P excretion (Exp. 2). In Exp. 1, 60 heifers (BW = 278 kg +/- 17 kg) were individually fed 1 of 5 dietary P concentrations (0.10, 0.17, 0.24, 0.31, or 0.38% P). Cattle performance, plasma P concentration, bone characteristics, and bone P concentration were used to determine the P requirement. Intake and ADG increased quadratically (P < 0.01) as dietary P increased. Plasma P in heifers receiving the 0.10% treatment was less (P < 0.01) than the other treatments and suggested that these heifers were experiencing a P deficiency. Total ash weight of the phalanx bones increased linearly (P < 0.01) as dietary P increased. In Exp. 2 using a 5 x 5 Latin square design, 5 different diets varying in P concentration (0.12, 0.27, 0.42, 0.30, and 0.36% P) were fed to steers to evaluate route and quantity of P excreted. Steers excreted little (1.78 g/d on average) P in the urine as a percentage of total P excretion. Steers on the 0.12% P diet excreted very little P in urine (0.50 g/d). Excretion of P was less (P < 0.05) for the cattle fed 0.12% P compared with all other treatments. Results from cattle performance, plasma P concentrations, and bone characteristics indicate that the heifers fed 0.10% P were experiencing a deficiency and the P requirement of finishing heifers is between 0.10 and 0.17% P. Dietary P concentrations of 0.10 to 0.17% P resulted in decreased P excretion. Supplementation of mineral P is unnecessary in grain-based feedlot diets because dietary P will greatly exceed the requirements (<0.17%).

The Cost of Corn Processing for Finishing Cattle1

Abstract Three corn processing methods were compared for use in 5,000- and 20,000-head capacity feedlots. Processing methods were dry-rolled (DRC), early harvest and ensiling high-moisture (HMC), and steam-flaked corn (SFC). Processing costs were determined to be

Effects of Corn Processing Method and Protein Concentration in Finishing Diets Containing Wet Corn Gluten Feed on Cattle Performance1

1.58,

Sorting Strategies for Long Yearling Cattle Grown in an Extensive Forage Utilization Beef Production System1

4.71, and

Effect of corn bran and steep inclusion in finishing diets on diet digestibility, cattle performance, and nutrient mass balance

9.57/t (metric ton; DM basis) for DRC, HMC, and SFC, respectively, for the 5,000-capacity feedlot. Processing costs were less for the 20,000-capacity feedlot at

Effects of Final Implant Type and Supplementation of Melengestrol Acetate® on Finishing Feedlot Heifer Performance, Carcass Characteristics, and Feeding Economics1

0.81,

Effect of Intensive Winter Management, Partial Season Grazing, and Sorting on Performance and Economics of a Long Yearling Steer Production System1

3.07, and

Wet Corn Gluten Feed and Alfalfa Hay Levels in Dry-Rolled Corn Finishing Diets: Effects on Finishing Performance and Feedlot Nitrogen Mass Balance

6.23/t (DM basis) for DRC, HMC, and SFC, respectively. Using these economic calculations in an 85% corn diet (DM basis), an improvement of dietary feed efficiency would need to be 2.4 and 6.1% for feeding HMC or SFC, respectively, compared with feeding DRC in a 5,000-capacity feedlot to be of economical value. For the 20,000-capacity feedlot, an improvement of dietary feed efficiency would need to be 1.7 and 4.2% for feeding HMC or SFC, respectively, compared with feeding DRC. Variables such as corn price, feed efficiency response, energy cost, and feedlot size determine economic returns for corn processing. Feeding SFC appears to generate economic return in both sizes of feedlots compared with feeding HMC or DRC. Calculated economic returns involving HMC were more variable than the economic returns generated from DRC data.

EFFECT OF ORGANIC MATTER ADDITION TO THE PEN SURFACE AND PEN CLEANING FREQUENCY ON NITROGEN MASS BALANCE IN OPEN FEEDLOTS

Abstract Three hundred twenty crossbred steer calves (308 kg) were used to determine the effects of corn processing and addition of urea on performance with diets containing wet corn gluten feed (WCGF). The treatment design was a 5 x 2 factorial with factors of corn processing (dry-rolled, DRC; fine-ground, FGC; rolled high-moisture, RHMC; ground high-moisture, GHMC; or steam-flaked corn, SFC) and CP concentration (14 or 15%) with 4 pens per treatment and 8 steers per pen. The final diet contained 60% corn, 25% WCGF, 10% corn silage, and 5% supplement (DM basis). No significant protein x grain processing interactions occurred for feedlot performance or carcass variables. Steers fed DRC and FGC had similar DMI, but greater (P