Steam-flaked Corn Research Articles

Effects of concentration and composition of wet corn gluten feed in steam-flaked corn-based finishing diets.

Two finishing experiments were conducted to determine the effects of concentration (Exp. 1) and composition of wet corn gluten feed (Exp. 2) in steam-flaked corn-based diets on feedlot steer performance. In Exp. 1, 192 English x Continental crossbred steer calves (299 +/- 0.6 kg) were used in a completely randomized design with six dietary treatments (four pens per treatment). Treatments were six concentrations of wet corn gluten feed (Sweet Bran, Cargill Inc., Blair, NE; 0, 10, 20, 25, 30, and 35%) replacing steam-flaked corn (DM basis). All diets contained 10% corn silage, 5% supplement, and 3.5% tallow (DM basis). Gain efficiency and ADG were similar (P > 0.25) among treatments. Dry matter intake was lower (P < 0.10) with 0% wet corn gluten feed than with concentrations of 20, 25, and 35% WCGF. Dry matter intake did not differ among treatments containing wet corn gluten feed. In Exp. 2, 160 English x Continental crossbred steer calves (315 +/- 0.6 kg) were used in a completely randomized design with five dietary treatments (four pens/treatment). Treatments were assigned based on four ratios of steep to corn bran/germ meal mix in wet corn gluten feed plus a negative control (CON). Wet corn gluten feed was fed at 25% of the dietary DM and was made by mixing steep and corn bran/germ meal into the diet. The four concentrations of steep in wet corn gluten feed that comprised the ratios were 37.5, 41.7, 45.8, and 50% (DM basis), with the remaining proportion being the bran/germ meal mix. Bran/germ meal mix was comprised of 60% dry corn bran, 24% germ meal, and 16% fine-cracked corn (DM basis). All diets contained 10% corn silage, 5% supplement, and 3.5% tallow (DM basis). Daily gain did not differ (P = 0.18) among treatments. Gain efficiency did not differ between CON and 50% steep; however, G:F was decreased (P < 0.05) for concentrations of 37.5, 41.7, and 45.8% steep compared with CON. A linear improvement (P < 0.05) was observed for G:F as concentration of steep increased as a proportion of wet corn gluten feed. These data suggest that wet corn gluten feed can be used at concentrations up to 35% of the dietary DM without adversely affecting performance, and that steep has more energy than bran/germ meal in steam-flaked corn-based diets.

The Effect of Steam Flaked or Dry Ground Corn and Supplemental Phytic Acid on Nitrogen Partitioning in Lactating Cows and Ammonia Emission from Manure

The effect of starch source and supplemental phytic acid (PA) on N partitioning and excretion and ammonia volatilization from dairy manure was evaluated with 8 midlactation cows. Cows were randomly assigned to treatments in replicated 4×4 Latin squares with four 18-d periods. Diets were 61% forage, 25% starch, 17.2% crude protein, and 31% neutral detergent fiber and included dry ground corn (DG) or steam flaked corn (SF) with no supplemental P (L; 0.34% P) or supplemental purified PA (0.45% P) to provide additional P from a non-mineral source. Total collection of milk, urine, and feces was conducted on d 16 to 18 of each period. Cows fed SF had lower dry matter (DM) intakes than those fed DG, which, in addition to increased starch digestibility and ruminal fermentation, contributed to higher DM digestibility. Cows fed SF had reduced feces and urine excretion compared with cows fed DG. Also, N intake for cows fed SF was lower, and N digestibility was higher, compared with cows fed DG; therefore, N excretion in both feces and urine was reduced in these cows. Despite the differences in DM intake, lactation performance was not affected by starch sources. Therefore, the efficiency of N utilization increased with SF. Addition of PA did not affect N intake or utilization. Feces and urine were subsampled from each cow, and wet feces and urine were mixed in sealed chambers in the proportions excreted. Ammonia volatilization was measured for 36h using acid traps sampled on a planned time course. Nitrogen at time zero (Ao), rate of ammonia emission (k), and residual N (R) were calculated using the exponential decay model At = Ao e−kt + R. Rate of ammonia loss from mixed feces and urine was lower from cows fed SF than from those fed DG. Altering dietary starch source to improve nutrient digestibility and to reduce N excretion by lactating cows may provide opportunity to reduce ammonia losses from manure.

Increasing Amounts of Conjugated Linoleic Acid (CLA) Progressively Reduces Milk Fat Synthesis Immediately Postpartum

Mixed conjugated linoleic acid (CLA) isomers decrease milk fat synthesis during established lactation, but their ability to cause milk fat depression (MFD) immediately postpartum remains unclear. Multiparous Holstein cows (n=19) were randomly assigned to 1 of 4 doses of rumen-protected (RP) CLA supplements (0, 200, 400, and 600 g/d); each dose provided equal amounts of fatty acids by replacing and balancing treatments with an RP supplement of palm fatty acid distallate. Doses provided a total of 468g fatty acids/d and 0, 62, 125, or 187g of mixed CLA isomers/d, respectively. The CLA supplement contained a variety of CLA isomers: 5.4% trans-8, cis-10; 6.3% cis-9, trans-11; 7.9% trans-10, cis-12; and 8.2% cis-11, trans-13 CLA. Each group received treatments from approximately −10 to 21 d relative to calving. To improve palatability and ensure complete consumption, doses were mixed with equal amounts of steam-flaked corn and dried molasses; one-half the supplement was fed at 0600h, and the remaining supplement was fed at 1800h. Milk yield and individual feed intake were recorded daily, and milk samples were obtained from each cow every 2nd day (at both milkings) starting on d 1 postpartum. There were no differences in dry matter intake (17.1 kg/d), milk yield (34.2 kg/d), protein content (3.74%), lactose content (4.61%), or yield of milk protein or lactose. The CLA supplementation decreased overall milk fat content in a dose-responsive manner (4.57, 3.97, 3.32, and 3.10, respectively), and milk fat yield displayed the same progressive decline. The dose-dependent decrease in milk fat content was evident during wk 1 and became highly significant during wk 2 and 3. The milk fat yield response pattern was similar, and by d 21, the highest RP-CLA supplement decreased milk fat content and yield by 49 and 56%, respectively. These data clearly indicate RP-CLA can markedly (40 to 50%) induce MFD immediately postpartum without negatively affecting other production parameters.

Degradabilidade no rúmen bovino de grãos de milho processados de diferentes formas

O objetivo deste trabalho foi avaliar o efeito de formas de processamento de milho na degradabilidade da matéria seca, amido e proteína em rúmen de bovinos. Foram utilizadas 12 fêmeas bovinas mestiças, não gestantes e não lactantes, portadoras de cânulas ruminais e com peso médio de 647 kg. Foi utilizado um delineamento inteiramente casualizado com três tratamentos: quebra (1,6 mm), moagem fina (0,8 mm) e floculação (8,25 mm; 270 g/L) dos grãos de milho, com 4 repetições por tratamento. Os sacos de náilon contendo milho nos diferentes processamentos foram incubados nos animais durante 0, 1,5, 3, 6, 12, 24 e 48 horas. Foi observado aumento na degradabilidade efetiva da matéria seca e do amido do milho pela floculação, em relação à moagem fina e à quebra. Contudo, a degradabilidade efetiva da proteína do milho foi diminuída pela floculação, em relação à moagem fina.

Effect of supplemental L-lysine-HCL and corn source on rumen fermentation and amino acid flow to the small intestine.

Four lactating Jersey cows fitted with ruminal and duodenal cannulae were used in a 4 x 4 Latin square design trial to determine the effect of supplemental lysine in diets containing dry ground (GC) or steam-flaked (SFC, 360 g/L) corn on ruminal fermentation and amino acid (AA) flow to the duodenum. Supplemental L-lysine-HCL provided 10 g/d of additional Lys to the total mixed rations. There were no interactions between supplemental Lys and corn source. Supplemental Lys increased Lys intake, but did not alter nutrient intake and digestibility or N flow to the duodenum. Intake of dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF) and ruminal digestibility of starch tended to be higher, whereas ruminal digestibility of DM, OM, acid detergent fiber, and NDF was lower for diets supplemented with SFC compared with GC. Whole-tract digestibility was similar for both corn supplements. Ruminal pH and molar proportions of volatile fatty acids were not affected by supplemental Lys or corn source; however, ruminal NH(3) concentrations were lowest when SFC was fed. Intake of N tended to be higher and the flow of total N and individual AA to the duodenum was higher for diets supplemented with SFC. There was a trend for increased flow of microbial N for diets supplemented with SFC. Supplemental L-lysine-HCL did not alter ruminal fermentation, flow of amino acid to the small intestine, or nutrient digestibility, but feeding SFC reduced ruminal fiber digestion and increased microbial protein synthesis and flow of amino acid to the duodenum.

Effect of corn endosperm type and corn containing the Cry1F protein on performance of beef heifers fed finishing diets based on steam-flaked corn (2004)

Eighty beef heifers (initial body weight = 795 ± 18 lb) were individually fed finishing diets based on steam-flaked corn for 118 days. Dietary treatments consisted of corn hybrids containing vitreous (HARD), opaque (SOFT), or intermediate (INT) types of corn endosperm. Within the HARD endosperm type, a transgenic hybrid (HARD-GMO) containing the Herculex I Cry1F protein was compared with its nontransgenic, conventional (HARDCONV) counterpart. Dry matter intake, average daily gain, and gain efficiencies were similar among treatments. Likewise, hot carcass weight, dressing percentage, and ribeye area were unaffected by dietary treatment. Heifers fed HARD-CONV were fatter than heifers fed HARD-GMO, having fewer (P<0.01) USDA Yield Grade 1 and 2 carcasses. In this experiment, feeding flaked corn finishing diets that contained different endosperm types did not alter performance or carcass characteristics. Feeding heifers HARD-GMO compared with HARD-CONV corn resulted in similar performance, although heifers fed HARD-CONV had higher USDA Yield Grades, perhaps because of greater starch availability of HARD-CONV flaked corn than HARD-GMO corn.

Growth performance and carcass characteristics of finishing beef steers implanted with component TE-S or component TE-S with Tylan (2004)

Component TE-S and Component TE-S with Tylan growth-promoting implants were compared in an experiment conducted at a commercial feedlot operation (Ward Feed Yard; Larned, Kansas) to evaluate effects on growth performance and carcass characteristics. Crossbred steers (n=1843; 827 lb body weight) were implanted with either Component TE-S or Component TE-S with Tylan and were fed a finishing ration based on steam-flaked corn for an average of 116 days before slaughter. Cattle were assigned randomly to the implant treatments at processing and were allotted to 12 pens, containing an average of 154 steers each. No differences were detected in dry matter intake (P=0.18), average daily gain (P=0.41), or feed efficiency (P=0.59) of cattle administered the different implants. Component TE-S with Tylan produced fewer (P<0.05) buller steers. Cattle implanted with Component TE-S with Tylan were more heavily conditioned than cattle implanted with Component TE-S. Cattle with the implant including Tylan had a greater percentage of USDA Choice or Prime carcasses (P=0.11) and a greater percentage of USDA Yield Grade 4 carcasses (P=0.03). Component TE-S with Tylan also tended to produce fewer (P=0.12) USDA Yield Grade 1 carcasses compared with cattle implanted with Component TE-S. Total carcass value was also greater for the Component TE-S with Tylan cattle, as calculated by either a muscle-based or quality-based marketing grid. Inclusion of a pellet of the antibiotic Tylan within Component TE-S implants seems to result in modest changes in carcass fattening, as well as significant reductions in the incidence of buller activity among feedlot steers.

Wet corn gluten feed and alfalfa hay combinations in steam-flaked corn finishing cattle diets.

One finishing trial and one digestibility trial were used to evaluate wet corn gluten feed (WCGF) and alfalfa hay (AH) combinations in steam-flaked corn (SFC) finishing diets. In Exp. 1, 631 crossbred heifers (initial BW = 284 +/- 7.9 kg) were fed SFC-based diets containing combinations of WCGF (25, 35, or 45% of diet DM) and AH (2 or 6% of dietary DM) in a 2 x 3 factorial arrangement of treatments. No interactions existed between WCGF and AH for heifer performance. Increasing dietary WCGF linearly decreased gain efficiency (P < 0.01), dietary NEg concentration (P < 0.05), and 12th-rib fat thickness (P = 0.10). Cattle fed 35% WCGF had the lowest occurrence of abscessed livers, resulting in a quadratic response (P < 0.05) as dietary WCGF increased. In Exp. 2, 12 ruminally cannulated Jersey steers (585 kg) were fed SFC-based diets containing combinations of WCGF (25 or 45% of diet DM) and AH (0, 2, or 6% of diet DM) in an incomplete Latin square design with a 2 x 3 factorial arrangement of treatments. Starch intake was lower (P < 0.05), but NDF intake was greater (P < 0.05) as AH and WCGF increased in the diet. Ruminal pH was increased by AH (linear, P < 0.05) and tended (P < 0.07) to increase with WCGF. Feeding 2% AH led to the greatest ruminal NH3 but the lowest total VFA and propionate (quadratic, P < 0.05). Addition of AH to diets containing 25% WCGF increased acetate to a greater extent than addition to diets containing 45% WCGF (AH x WCGF interaction, P < 0.05). Feeding 45% WCGF tended to increase passage rate (P = 0.17) and decrease (P < 0.05) total tract OM digestibility but increase (P < 0.05) in situ degradation of DM from AH and WCGF. Interactions between AH and WCGF existed (P < 0.05) for ruminal fluid volume (quadratic effect of AH x WCGF level), in situ SFC degradation (linear effect of AH x WCGF level), and in situ rate of WCGF DM disappearance (quadratic effect of AH x WCGF level). We conclude that AH levels may be decreased when WCGF is added to SFC diets as 25% or more of the dietary DM.

The effect of steam-flaked or dry ground corn and supplemental phytic acid on phosphorus partitioning and ruminal phytase activity in lactating cows.

The effect of starch source and phytic acid (PA) supplementation on phosphorus (P) partitioning and ruminal phytase activity was evaluated in eight midlactation cows (four ruminally cannulated). Cows were randomly assigned to treatments in replicated 4 x 4 Latin squares with four 18-d periods. Diets included dry ground corn (DG) or steam-flaked corn (SF), with no supplemental P (L; 0.33% P) or supplemental purified PA (0.44% P) to provide additional P from a nonmineral source. Total collection of milk, urine, and feces was conducted on d 16 to 18 of each period. Ruminal fluid was sampled and ruminal pH measured every 8 h on d 17 and 18. Milk yield was unaffected by starch source, despite lower DMI by cows fed SF. Cows fed SF had increased DM digestibility compared with those fed DG, and tended to have higher efficiency of milk yield (1.40 vs. 1.35 kg of milk/kg of DMI). Intake and fecal excretion of P was lower in cows fed SF than in cows fed DG. In cows fed SF, milk P as a percentage of P intake increased compared with cows fed DG. Ruminal pH was unaffected by diet, but milk fat content was lower for cows fed SF. Milk yield, DMI, and feed to milk ratio were not affected by supplementation with PA. Although cows fed PA had increased P intake compared with cows fed low P diet, increased P excretion resulted in no differences in apparent P digestibility. Phosphorus balance tended to be higher in cows fed PA, but milk P as a percentage of intake was reduced. The interaction of starch source and PA affected ruminal phytase activity. Altering starch source to improve efficiency of milk yield in lactating dairy cows may help reduce P losses from dairy farms.

Extent of Hypophagia Caused by Propionate Infusion Is Related to Plasma Glucose Concentration in Lactating Dairy Cows

Two experiments were conducted to evaluate how dose-response effects of intraruminal infusion of propionate on feeding behavior and plasma metabolites are altered by diets differing in fermentability. Twelve ruminally cannulated Holstein cows were used in each experiment. Cows were fed diets containing either steam flaked corn or dry cracked corn (30% of dietary dry matter) in expt. 1, and diets differing in forage-to-concentrate ratio (66:34 vs. 36:64) in expt. 2. For both experiments, the experimental design was a crossover for dietary treatment, and a 6 x 6 Latin square for infusion treatment within a diet for each period. Infusion treatments were mixtures of sodium propionate and sodium acetate, containing propionate at 0, 0.2, 0.4, 0.6, 0.8 and 1.0 as a fraction of total volatile fatty acids infused. Treatment solutions were infused into the rumen continuously for 18 h starting 6 h before feeding at a rate of 23.1 mmol/min. Although propionate production from ruminal fermentation was expected to be different, dietary treatments did not affect dry matter intake (DMI) responses to propionate infusion for either experiment. However, propionate infusion decreased DMI linearly in expt. 1, but did not decrease DMI at lower rates of propionate infusion, which were much more effective at increasing plasma glucose concentration in expt. 2. Propionate had a smaller hypophagic effect at low concentrations of plasma glucose and had a greater hypophagic effect at elevated concentrations of plasma glucose, which could be explained by changes in the metabolism of propionate in the liver.

Supplemental Carbohydrate Sources for Lactating Dairy Cows on Pasture

Two experiments were conducted to evaluate steam-flaked corn and nonforage fiber sources as supplemental carbohydrates for lactating dairy cows on pasture. Cows were allotted to a new paddock of an orchardgrass (Dactylis glomerata L.) pasture twice daily in one group in both trials. In experiment 1, 28 Holstein cows, averaging 216 d in milk, were randomly assigned to either a cracked-corn (CC) or a steam-flaked (SFC) supplement in a split plot design. The supplement contained 66.7% of corn and a protein/mineral pellet. In experiment 2, 28 Holstein cows, averaging 182 d in milk, were randomly assigned to either a ground corn (GC) or a nonforage fiber (NFF)-based supplemented in a single reversal design. The GC supplement contained 85% ground corn plus protein, mineral, and vitamins. The NFF supplement contained 35% ground corn, 18% beet pulp, 18% soyhulls, 8% wheat middlings plus protein, mineral, and vitamins. In both experiments, cows were fed the grain supplement twice daily after each milking at 1 kg/4kg milk. In experiment 1, milk production (24.3 kg/d) and composition did not differ between treatments; however, plasma and milk urea N were lower with the SFC supplement. In experiment 2, milk production (27.5 kg/d) was not affected by treatments, which may be related to the medium quality of pasture grazed. The GC supplement tended to reduce plasma and milk urea N and increased milk protein percentage (3.23 vs. 3.19%). Pasture dry matter intake, measured using Cr2O3, did not differ between treatments in either experiment 1 (15.1 kg/d) or experiment 2 (12.2 kg/d). Milk production did not differ when mid-late lactation cows on pasture were supplemented with SFC or NFF instead of dry corn.

In vitro gas production as a method to compare fermentation characteristics of steam-flaked corn

An in vitro gas production technique was used to determine differences in starch availability that occurred with steam flaking of corn among eight feed mills (MILL) in California. Whole corn (WC) and steam-flaked corn (SFC) grain samples were obtained from six commercial mills and two mills at the University of California (Davis and El Centro, CA). The WC sample was collected prior to the steam chest and represented unprocessed corn. The SFC sample was collected at the rolls and represented a typically processed corn. Ground samples of WC and SFC were evaluated by incubation in buffered rumen fluid using an in vitro gas technique for a 72 h incubation period to compare processing (PROCESS) method. Starch reactivity was determined as the percentage of starch degraded to glucose by amylase after 4 h of incubation. Starch reactivity of SFC was higher ( P<0.01) than WC. Starch reactivity was different for MILL ( P<0.01) and the interaction of MILL and PROCESS was significant ( P<0.01). Total gas produced at 8 h of incubation was higher ( P<0.01) for SFC than WC, but total gas production did not differ for PROCESS at 24 and 72 h. Gas production after 8 h also differed for MILL ( P<0.01). Time required for 25, 50, 75, and 90% disappearance of starch was estimated and in general disappearance of starch occurred sooner for SFC than WC. Fifty percent disappearance of starch occurred at 6.8 h for WC and at 5.5 h for SFC. Total volatile fatty acids (VFA) production did not differ for MILL or PROCESS at 8 or 72 h of incubation. Propionate production was higher ( P<0.01) for SFC than WC at both 8 and 72 h. This in vitro gas production technique can be used to determine the effect of grain processing on fermentation rate and to identify differences among mills in potential digestibility of the processed grain.

High moisture tempering of corn before flaking: effects on bacterial contamination from houseflies and fecal shedding in finishing cattle (2003)

Tempered and non-tempered steam-flaked corn samples along with total mixed rations containing either tempered or non-tempered steam-flaked corn were exposed to flies and the environment for 21 hours. Exposure to flies and the environment increased (P<0.05) generic E. coli, non-E. coli coliforms, total coliforms, and total plate count for the steamflaked corn samples independent of tempering. Tempering corn before steam-flaking increased total plate counts. Exposure to the environment and flies did not significantly (P>0.05) alter microbial counts of total mixed rations regardless of tempering (Table 1). Generic E. coli coliforms were greater in total mixed rations when the corn was tempered, both before and after exposure to flies and the environment (P<0.05). Similarly, total microbial plate counts were higher in steam-flaked corn samples when the corn was tempered (P<0.05). A significant increase in response to grain tempering was also noted in non-E. coli coliforms and total microbial plate counts for the total mixed ration samples after exposure (Table 1). Following the initial experiments, 96 finishing beef steers were used to evaluate the effects of tempering steam-flaked corn on acid-resistant E. coli and total fecal coliforms. On day 56 of the feeding period, fecal samples were collected and analyzed for total and acidresistant E. coli and coliforms. No significant treatment difference was observed in the total fecal coliforms (P>0.05), but acid-resistant (pH 2) non-E. coli and total fecal coliforms (Table 2) were lower in feces of cattle fed the tempered grain than those fed non-tempered grain.

Comparison of concentrated separator byproduct and cane molasses for finishing heifers (2003)

We compared concentrated separator byproduct (CSB) to cane molasses on feedlot performance and carcass merit of 394 crossbred yearling beef heifers fed for 148 days. Sugar beet molasses undergoes a process in which approximately half of the sugar is removed, concentrating protein and mineral in CSB. Compared with cane molasses, CSB has more crude protein, ash, and moisture. Two diets based on steam-flaked corn containing either CSB or cane molasses at 5% (dry matter basis) of the diet were fed. Feedlot performance was similar between heifers fed the two diets (P>0.23). Apparent dietary concentrations of net energy for gain (NEg), calculated from performance, were similar (P=0.21) for the CSB and cane molasses diets. The apparent NEg for cane molasses and CSB were not statistically different (P=0.20); the NEg concentrations of cane molasses and CSB were 0.21 and 0.50 ± 0.15 Mcal/lb, respectively. Carcass characteristics were similar between diets. Based on our data, CSB and cane molasses have a similar feeding value and energy content in beef finishing diets that are based on steam-flaked corn.

Comparison of dried full-fat corn germ and tallow in finishing feedlot diets for heifers (2003)

A trial was conducted using 588 finishing beef heifers (705 lb initially) to compare tallow and dried full-fat corn germ as supplemental energy sources. Pens of 20 to 50 heifers were fed finishing diets containing 1) tallow or 2) corn germ. The tallow diet contained (dry basis) 46% steam-flaked corn, 35% wet corn gluten feed, 3% alfalfa hay, 1.5% soybean meal, and 4% tallow. The corn germ diet contained 41% steam-flaked corn, 35% wet corn gluten feed, 3% alfalfa hay, and 10% corn germ. Diets provided 300 mg monensin, 90 mg tylosin, and 0.5 mg MGA per heifer daily and were fed ad libitum once daily for 110 days. Gains of 2.99 lb/day for tallow and 2.95 lb/day for corn germ were not different (P>0.30), but dry matter intake tended to be greater for cattle fed corn germ than for those fed tallow (P=0.10; 16.7 vs 16.4 lb/day, respectively). Consequently, cattle fed germ were 3.4% less efficient than cattle fed tallow (P 0.40) between treatments. Cattle fed corn germ had more carcasses grading prime (P=0.03), more carcasses grading average choice or higher (P<0.05), and tended to have more marbling (P=0.08) than cattle fed tallow. Incidence of liver abscesses was higher (P<0.02) for cattle fed corn germ than for those fed tallow (4.8% vs 1.8%, respectively). These results indicate that corn germ is a suitable substitute for tallow in finishing rations. Introduction

Effect of full-fat corn germ and Vitamin E on finishing performance and carcass characteristics of beef heifers (2003)

Eight hundred eighty-eight crossbred beef heifers weighing 837 lb were used in a 105- day finishing study to evaluate full-fat corn germ as a lipid source and added vitamin E in finishing diets containing steam-flaked corn. Treatments were arranged in a 2 x 4 factorial and consisted of finishing diets formulated to provide no added fat (Control), 4% tallow (Tallow), or 10% or 15% full fat corn germ on a dry matter basis (10%FFG and 15%FFG, respectively) with or without 2000 IU of additional vitamin E per heifer daily. No fat x vitamin E interaction was detected. Fat addition decreased (P<0.01) dry matter intake and tended (P<0.09) to improve gain efficiency, but marbling score and the number of carcasses grading USDA Choice were decreased by fat additions (P<0.01). Tallow and 10%FFG yielded similar finishing performance and carcass characteristics. Increasing full fat corn germ led to linear decreases (P<0.05) in dry matter intake, average daily gain, final body weight, and hot carcass weight, as well as marbling score and the number of carcasses grading USDA Choice. Gain efficiency was increased by addition of full fat corn germ at 10% of the diet, but not at 15% of the diet. Addition of full fat corn germ to the diet tended (linear, P<0.06) to decrease the incidence of liver abscesses. Addition of vitamin E did not affect finishing performance (P>0.12). This study suggests that full fat corn germ can serve as a supplemental lipid source for finishing cattle. Responses to 10% full fat corn germ were similar to those obtained when an equal amount of fat from tallow was incorporated into the diet.

Effects of MGA in receiving diets on health, performance, and carcass characteristics (2003)

A trial was conducted using 723 crossbred heifers (468 lb initially) to evaluate the effects of including melengestrol acetate (MGA) in receiving diets on growth performance, morbidity, mortality, and carcass characteristics. Treatments were: 1) MGA included in the receiving diet at a rate of 0.5 mg per heifer daily or 2) no MGA in the receiving diet. Diets were fed once daily and contained 42% steam-flaked corn, 45% alfalfa hay, 6% steep liquor, and 2% tallow; monensin and tylosin were included. Receiving diets were fed for 35 days. After 35 days MGA was fed to all heifers, and cattle were stepped up to common finishing diets. Cattle exhibiting clinical signs of bovine respiratory disease (BRD) were treated with Excenel (1 ml/100 lb body weight) for 3 days. Animals requiring followup treatment received the same therapy. Cattle pulled a third time received oxytetracycline (4.5 ml/100 lb body weight) and Predef (5 ml/heifer). Initial respiratory pulls (73.9% for MGA and 77.3% for no MGA), re-treatments, and death loss were not different (P>0.40) during the first 35 days. The number of heifers requiring a third antibiotic treatment tended (P=0.09) to be higher for heifers not receiving MGA. Average daily gain (deads out) for the first 35 days tended to be higher for heifers fed MGA (P=0.06), but dry matter intake and feed efficiency were not different between treatments (P>0.17). Gain throughout the 220-day feeding period was 2.6% higher for cattle fed MGA during the receiving phase (P=0.05). Overall, feed intake and feed efficiency were not different (P>0.50) between treatments, but heifers fed MGA during the initial receiving period tended to have heavier carcass weights (P=0.13). No differences were detected in quality grade, yield grade, or marbling (P>0.23). Feeding MGA during the initial 35 days after arrival may improve gain and carcass weights.

Effect of feeding conventional or high-moisture, steam-flaked corn to finishing heifers (2003)

Finishing heifers were fed diets containing either conventional (18% moisture) or highmoisture (36% moisture) steam-flaked corn. Increasing moisture concentration in flakes increased starch availability (P<0.01), but feeding heifers high-moisture flakes decreased (P<0.05) dry matter intake and average daily gain compared to heifers fed conventional flakes. Feeding heifers high-moisture flakes also numerically reduced hot carcass weight and ribeye area, but caused (P<0.01) heifers to deposit more fat over their 12th rib. Extreme levels of moisture in flaked corn improve starch availability but do not appear to increase heifer performance or carcass value. The interaction between moisture and flake density needs further evaluation.

Effect of processing variables on characteristics of steam-flaked corn (2003)

We evaluated tempering moisture concentration, addition of a surfactant to improve moisture uptake, steam conditioning time, and flake density to determine their impact on characteristics of steam-flaked corn. Increasing steam conditioning time from 20 to 40 minutes or adding a surfactant during tempering did not increase final flake moisture concentration, but moisture content of flaked corn was linearly increased by increasing tempering moisture concentration. Addition of Grain Prep surfactant during tempering decreased (P<0.05) the amount of moisture lost during flaking. Flake durability was increased by increasing tempering moisture concentration, but only if corn was steamed for 40 minutes (tempering moisture × steam time interaction; P<0.10). Decreasing flake density linearly increased both starch availability (P<0.01) and flake durability (P<0.05). In this experiment, tempering moisture concentration had the largest impact on flake moisture content, and flake density was the most influential variable altering flake durability and starch availability.

Effects of Proportions of Steam-Flaked Corn and Grain Sorghum and Switching Grain Sources During the Finishing Period on Performance and Carcass Characteristics of Finishing Beef Steers

Three studies were conducted to determine effects of proportions of steam-flaked corn (SFC) and steam-flaked grain sorghum (SFGS) in the finishing diet (Exp. 1), effects of switching grain sources on d 56 of the finishing period on performance and carcass characteristics of finishing beef steers (Exp. 2), and effects of these two dietary ingredients on in vitro DM disappearance (IVDMD) (Exp. 3). For Exp. 1, 180 medium-framed beef steers (British × Continental) were used. Treatments included (DM basis) 100% SFC:0% SFGS, 75% SFC:25% SFGS, 50% SFC:50% SFGS, 25% SFC:75% SFGS, and 0% SFC:100% SFGS. Increasing the proportion of SFGS in the finishing diet increased (P<0.01) feed:gain for the overall experiment and resulted in a linear decrease (P<0.01) in calculated NE, NE, and ME values of the diet. No differences (P>0.10) were noted among treatments for carcass characteristics. In Exp. 2, 144 medium-framed beef steers (British × Continental) were used. Treatments were SFC fed from d 0 to end (Treatment 1), SFC fed from d 0 to 56 and SFGS fed from d 57 to end (Treatment 2), SFGS fed from d 0 to 56 and SFC fed from d 57 to end (Treatment 3), and SFGS fed from d 0 to end (Treatment 4). Experiments 1 and 2 were conducted concurrently, and steers on Treatments 1 and 4 were the same steers used in Exp. 1 and fed 100:0 and 0:100, respectively. Average daily gain was decreased (P<0.10), and feed:gain was increased (P<0.05) for the average of Treatments 2 and 3 vs Treatment 1 for the overall experiment. In vitro DM disapperance of diets used in Exp. 1 was similar (P>0.10) among treatments after 4, 12, 24, and 48 h of incubation. Results suggest no benefit from mixing SFC and SFGS in finishing diets, and switching grain sources during the finishing period may adversely affect performance.