Daniel D. Loy

Factors Affecting Beef Cattle Performance and Profitability

Close-out information, consisting of data from 1836 pens of cattle that were placed on feed between January 1988 and December 1997, which had been submitted by Iowa cattle producers using the Iowa State University Feedlot Performance and Cost Monitoring program, was examined to determine factors affecting beef cattle performance and profitability. Information provided on close-out sheets included start and end date, cattle per pen, sex, housing type, days on feed, initial and sale BW, feed efficiency (FE), percentage of concentrate, ADG, percentage death loss, feed cost and total cost/45.4 kg of BW gain, breakeven sale price, non-feed variable cost, non-feed fixed cost, and corn price. Feeder cattle prices were calculated as feeder cattle price = [(breakeven sale price × sale BW) − (total cost of gain × gain)]/initial BW. Gains in 45.4-kg increments were calculated as gain = (sale BW − initial BW)/45.4. Fed cattle prices were obtained weekly from the report published by the USDA for Southern Minnesota and Iowa. Profit per head was calculated as profit = (sale BW × fed price) − [(total cost of gain × gain) + (feeder price × initial BW)]. Steers consumed more feed (P 0.30) than heifers. Cattle housed under shelter generally gained more BW (P 0.20). Fewer cattle per pen lead to greater (P<0.002) profit per head. Feeder and fed cattle prices explained ∼50% of the variation in profitability. Results indicate that performance and profitability of cattle feeding are rather complex and are affected by housing type, season, initial BW, concentrate level, sex, and pen cattle population.

Determining the preference, in vitro digestibility, in situ disappearance, and grower period performance of steers fed a novel algae meal derived from heterotrophic microalgae.

A series of 3 experiments were conducted to determine the in vitro and in situ disappearance, preference, and performance of steers consuming increasing concentrations of a novel feedstuff called algae meal (ALG). In Exp. 1 and 2, 3 ruminally cannulated steers (998 ± 103 kg BW) and 4 treatments were utilized: a dry-rolled corn-based diet (CON), or 15% ALG (A15), 30% ALG (A30), or 45% ALG (A45) as a DM replacement of corn. Experiment 1 was performed as a 3 × 6 unbalanced Latin square with six 5-d periods, and 6 paired diet combinations to determine steer preference, based on DMI for 4 h after feed delivery. Experiment 2 was conducted as a 3 × 4 unbalanced Latin square with 3 diets fed each period and four 14-d periods to determine in situ disappearance of ALG, soyhulls, corn, and hay as ALG increased in the diet. Experiment 3 utilized 48 individually fed steers (292 ± 22.4 kg; n = 12) in a 55-d grower trial, stratified by BW into 1 of 4 dietary treatments: a control wet corn gluten feed-based diet with no ALG (ALG0), or 15% ALG (ALG15), 30% ALG (ALG30), or 45% ALG (ALG45) in place of wet corn gluten feed on a DM basis. Digestibility of ALG was greater (P < 0.001) than soyhulls at 24 h, but was similar (P = 0.82) at 48 h, with hay being least (P < 0.001) digestible at 24 and 48 h. In Exp. 1, the proportion of total DM consumed by steers during the 4-h postfeeding was affected (P = 0.01) by paired diet combination. Steers preferred A15 or A30 diets over the A45 diet (P ≤ 0.008); however, no difference in preference between CON and A45 was noted (P = 0.76). Steers tended (P = 0.09) to prefer A30 over CON, but A15 and CON were not different (P = 0.75). No other paired diet combinations altered (P ≥ 0.23) DMI. In Exp. 2, inclusion of ALG in the diet did not affect (P ≥ 0.12) rate of, or overall in situ disappearance of, corn, soyhulls, or ALG. In Exp. 3, ADG tended ( = 0.06) to increase as ALG increased in the diet. There was a linear increase ( < 0.001) in DMI as ALG increased in the diet, and as a result, G:F linearly decreased ( = 0.01). In summary, ready consumption of the novel algae meal by steers and support of growth in steers at up to 45% of the diet suggest the algae meal is a viable feedstuff for ruminants.

Assessment of algae meal as a ruminant feedstuff: Nutrient digestibility in sheep as a model species.

Heterotrophic microalgae combined with soyhulls forms an algae meal (ALG), which contains partially deoiled microalgae (PDM; 57% DM basis) and soyhulls (43%). Two experiments were conducted to evaluate the effects of PDM and ALG on lamb digestibility. In Exp. 1, 8 wethers (23.02 ± 0.54 kg) were used in a 4 × 4 Latin square design to determine the effect of the PDM portion of ALG on total tract nutrient digestibility. Diets included a soyhull-based control (CON; 53% soyhulls), 10% PDM from ALG, 20% PDM from ALG (PDM20), and 30% PDM from ALG. Dry matter and OM intake and fecal DM and OM output were similar ( ≥ 0.11) between CON- and ALG-fed lambs. Urine output linearly increased ( = 0.02) as PDM increased in diets. Dry matter, OM, NDF, and ADF digestibility linearly decreased ( < 0.01) as PDM increased in diets. Ether extract digestibility did not differ ( = 0.24) between CON- and PDM-fed lambs. Nitrogen digestibility and N retention linearly decreased ( ≤ 0.05) as PDM increased in the diet. In Exp. 2, to determine the effects of ALG on diet and nutrient digestibility and N retention, 10 whiteface cross wethers (33.71 ± 0.55 kg) were used in a replicated 5 × 5 Latin square. Diets included a cracked corn-based control (CORN), 15% ALG, 30% ALG, 45% ALG (ALG45), and 60% ALG (ALG60). Dry matter and OM digestibility linearly ( < 0.001) decreased as ALG inclusion increased. Digestibility of NDF and ADF were lesser ( ≤ 0.03) for CORN-fed sheep than for ALG-fed sheep and linearly ( ≤ 0.03) increased as ALG increased in the diet. Ether extract digestibility was lesser ( = 0.002) for CORN than ALG, with a linear ( = 0.002) increase as ALG inclusion increased. There was a cubic ( = 0.03) effect for N digestibility with ALG45 and ALG60 being lesser and CORN being greater than all other treatments. Retention of N and plasma urea N concentration did not differ ( ≥ 0.22) between CORN and ALG. Nonfibrous carbohydrate digestibility linearly ( < 0.001) decreased as ALG increased in the diet. These results suggest that the PDM portion of ALG may be less digestible than soyhulls in ruminants, and differences in N retention in Exp. 1 may suggest an effect on growth in lambs. Furthermore, changes in digestibility of specific nutrients suggest that ALG is more characteristic of a concentrate rather than a fibrous feedstuff. However, lambs will readily consume ALG and this novel feedstuff could potentially serve as a viable component of ruminant diets.

Influence of distillers grains resulting from a cellulosic ethanol process utilizing corn kernel fiber on nutrient digestibility of lambs and steer feedlot performance

Two experiments evaluated the effects on animal performance of traditional wet distillers grains (T-WDG) compared to cellulosic wet distillers grains (C-WDG) from a new process converting corn kernel fiber into cellulosic ethanol. The resulting coproduct has greater CP and decreased starch and ether extract (EE) concentrations (34.0% CP, 1.6% starch, 7.3% EE) compared to T-WDG (32.5% CP, 5.1% starch, 7.7% EE). In Exp. 1, 10 wethers (34.1 ± 2.35 kg, SD) were used in a replicated 5 × 5 Latin square to evaluate digestibility of DM, fiber, EE, and N. Diets including a corn-based control with 7.5% T-WDG and 7.5% C-WDG (CORN); 30% or 45% inclusion of T-WDG; and 30% or 45% inclusion of C-WDG. Between CORN, 30% T-WDG, 45% T-WDG, or 45% C-WDG, DMI was not different (P ≥ 0.11), but lambs fed 30% C-WDG had decreased (P ≤ 0.05) DMI compared to other diets. Compared to CORN and 30% T-WDG, DM digestibility was lesser ( P< 0.05) for 45% T-WDG or 30% C-WDG, while 45% C-WDG has lesser (P ≤ 0.05) DM digestibility than all other treatments. Digestibility of NDF was not affected by treatment (P= 0.13), and ADF digestibility was not different ( 0.21) between CORN, 30% T-WDG, 30% C-WDG, or 45% C-WDG. However, digestibility of ADF tended to differ (P = 0.06) between 30% T-WDG and 45% C-WDG and was greater (P ≤ 0.05) in lambs fed 45% T-WDG compared to other treatments. In Exp. 2, 168 steers (421 ± 23.9 kg, SD) were used in a randomized complete block design to determine the impact of C-WDG or T-WDG on growth performance and carcass characteristics. Diets included a corn-based control (CON), 30% T-WDG (TRAD), 30% C-WDG (CEL), and 18% C-WDG and 12% condensed corn distillers solubles (CEL+CCDS; = 7 pens of 6 steers/pen). Steers fed TRAD had improved (P ≤ 0.01) ADG, G:F, and HCW compared to steers fed the CON diet. No differences (P ≥ 0.16) in ADG and HCW were noted for steers fed CEL compared to TRAD; however, steers fed CEL had decreased (P = 0.01) G:F due to increased (P = 0.02) DMI compared to TRAD-fed steers. Steers fed CEL or CEL+CCDS did not differ (P = 0.50) in G:F, but CEL+CCDS-fed steers had lesser (P ≤ 0.01) DMI and ADG likely due to greater S content of the CEL+CCDS diet. Overall, while DM digestibility of lambs fed 30% C-WDG was lesser than 30% T-WDG, performance of steers finished on C-WDG was similar to those fed T-WDG. However, WDG from the secondary fermentation appeared to have lesser energy than T-WDG, while maintaining similar cattle performance to corn-fed controls.

Comparing fed cattle performance in open lot and bedded confinement feedlot facilities

ABSTRACT Records of closeouts from 997 lots (i.e., pens or groups) of beef cattle fed in the Upper Midwest from 2007 to 2009 were analyzed to measure the difference in performance between cattle fed in open lot facilities and cattle fed in deep bedded confinement buildings. Cattle fed in bedded confinement buildings had greater (P

Effects of increased inclusion of algae meal on finishing steer performance and carcass characteristics.

The deoiled residue from the production of heterotrophic microalgae can be combined with soyhulls to form a novel feedstuff called algae meal (ALG). To determine the effects of replacing corn in a finishing diet with ALG on growth, mineral status, carcass characteristics, and longissimus thoracis fatty acid profile, crossbred steers (168) were blocked by BW (432 ± 30.8 kg) into pens of 6 steers (7 pens per treatment). Pens received 1 of 4 diets: a corn-based control (CON), 14% ALG, 28% ALG (ALG28), and 42% ALG (ALG42). Corn was replaced by ALG on a DM basis. Steer BW were taken on d 0, 1, 28, 56, 74, 101, and 102, and steers were harvested on d 103. Pen was the experimental unit and DMI, ADG, and G:F data were analyzed as repeated measures. Two steers per pen were selected for sampling of blood and liver (d -1 and 96) and collection of rib steaks at harvest. There was a treatment by × time effect ( = 0.10) for overall DMI, where DMI linearly increased ( ≤ 0.008) across all time periods except Day 28 through, 56 when DMI was not different between ALG28 and ALG42. There was a treatment by time effect for ADG ( < 0.01), with ADG linearly decreasing ( ≤ 0.03) in the first and third month, not differing ( = 0.95) in the second month, and linearly increasing ( < 0.01) in the fourth month as ALG increased in the diet. Final BW and HCW did not differ ( ≥ 0.50) between CON- and ALG-fed cattle. There was a treatment × time effect for G:F ( < 0.01), with G:F linearly decreasing ( ≤ 0.01) in the first 3 mo as ALG increased in the diet, whereas G:F linearly increased ( < 0.01) in the fourth month. Based on steer performance, calculated dietary NEg linearly decreased ( < 0.01) as ALG increased in the diet. Yield grade linearly decreased ( = 0.02) and there was a tendency for dressing percent and 12th-rib back fat to linearly decrease ( ≤ 0.10) as ALG increased in the diet. Plasma Cu, Fe, and Mg concentrations were not different ( ≥ 0.31) in CON vs. ALG cattle; however, plasma Zn concentrations linearly increased ( = 0.03) as ALG increased in the diet. Total lipid, SFA, MUFA, and PUFA concentrations in the longissimus thoracis did not differ ( ≥ 0.13) between CON- and ALG-fed cattle. Interestingly, the atherogenic index linearly decreased ( < 0.01) as ALG increased in the diet. Algae meal may have a lesser energy value than corn; however, a minimal effect on carcass performance suggests ALG may serve as a potential replacement for corn in feedlot diets.

Effect of varying trace mineral supplementation of steers with or without hormone implants on growth and carcass characteristics

To determine the effects of trace mineral (TM) supplementation and hormone implant strategy on growth and carcass characteristics of cattle, 72 Angus-cross steers (388 ± 17 kg) were blocked by body weight (six steers per pen) to a 2 × 3 factorial. Factors included growth-stimulating implant (GS): day 0 with Component TE-IS, reimplanted day 56 with Component TE-200 (IMP) or no implant (NoIMP), and TM supplementation (TM): no supplemental TM (CON), TM supplemented at national (NASEM, 2016). Nutrient requirements of beef cattle. 8th ed. Washington, DC: The National Academics Press) recommendations of 10 Cu, 30 Zn, 20 Mn, 0.10 Se, 0.15 Co, and 0.50 I (mg/kg; REC), or TM supplemented at feedlot consultant recommendations of 20 Cu, 100 Zn, 50 Mn, 0.30 Se, 0.20 Co, and 0.50 I (mg/kg; IND). Steers received a finishing diet for 124 d in GrowSafe bunks and were harvested on day 125. Data were analyzed in SAS as a 2 × 3 factorial with steer as the experimental unit (n = 12 per combination). Day -7 liver trace mineral concentrations were used as a covariate in analysis. There were no GS × TM effects for liver Zn, Mn, Se, or Co (P ≥ 0.11) on day 70 or 125. Implanted steers had lesser liver Cu and Mn on day 70 (P ≤ 0.05) and day 125 compared with NoIMP. There was a GS × TM interaction for liver Cu on day 125 (P = 0.05) where IMP/REC, IMP/IND, and NoIMP/REC had greater liver Cu than NoIMP/CON, which had greater liver Cu than IMP/CON. There was a TM effect for liver Cu on day 70 (P < 0.01) with IND having greater liver Cu than REC and CON. There was a TM effect (P ≤ 0.01) for liver Mn and Se on day 70 where IND had greater Mn and Se than CON, with REC being intermediate. There was a TM effect (P < 0.01) on liver Mn on day 125 where IND had greater liver Mn than CON and greater (P < 0.01) liver Se than CON and REC on day 125, whereas day 125 liver Se was greater in REC vs. CON. Implanted steers had greater (P < 0.01) dry matter intake (DMI), final body weight (BW), overall average daily gain (ADG), G:F, and hot carcass weight (HCW) than NoIMP. Overall DMI was affected by TM (P < 0.01) with REC and IND being greater than CON. There was a TM effect for carcass-adjusted final BW, ADG, and DMI (P ≥ 0.03) and a tendency for TM to affect adjusted G:F (P = 0.07). There was a TM effect (P = 0.03) for HCW where IND was greater than CON and REC. There was a GS × TM (P = 0.02) for ribeye area (REA); within IMP, CON were greater than IND, whereas REC were intermediate while NoIMP had smaller REA, regardless of TM supplementation. Additional research is needed to better determine trace mineral requirements of finishing beef steers for optimal performance.

Effect of post-ethanol extraction sorghum silage as a forage source in growing and finishing diets on steer performance, carcass characteristics, and nutrient digestibility1

Two experiments evaluated the use of post-ethanol extraction sorghum silage as an alternative forage source in feedlot diets. Seventy-two crossbred steers (397 kg [SD 23]) were used to evaluate growth and carcass characteristics. Steers were blocked by BW into pens of 6 steers and randomly assigned to growing diets containing 40% (DM basis) sorghum silage (SS; 57.6% NDF) or grass hay (CON; 63.3% NDF) for 56 d ( = 6 pens per treatment). Within each treatment, steers transitioned to dry-rolled corn-based finishing diets (fed for 56 d) containing 6% effective NDF contributed by the forage source, resulting in forage inclusions of 16% for SS and 13.1% for CON, where forage replaced corn. A subsample of steers ( = 12 per treatment) housed in pens equipped with GrowSafe bunks were used for determination of growing phase diet total tract digestibility. From d 28 to 42, steers received titanium dioxide at approximately 10 g∙steer∙d, and fecal samples were collected on d 41 and 42. Fecal and total mixed ration samples were dried and ground for analysis of DM, OM, NDF, ADF, CP, ether extract (EE), and starch. Data were analyzed with the MIXED procedure of SAS, with fixed effects of treatment and block for performance and carcass data or treatment for digestibility data; significance was determined at ≤ 0.05 and tendencies at ≤ 0.10. Growing phase DMI and ADG did not differ due to treatment ( ≥ 0.19); however, SS-fed steers had improved G:F compared with CON-fed steers ( = 0.04). Finishing period ADG and G:F did not differ ( ≥ 0.15) between treatments, despite SS-fed steers having lesser ( = 0.008) DMI than CON-fed steers. No differences in DMI, ADG, or G:F over the whole trial were noted between treatments ( ≥ 0.12) nor were any carcass traits affected ( ≥ 0.23). During the digestibility assessment period, DMI was less ( = 0.003) in SS-fed steers. Growing phase total tract apparent digestibility of DM and starch did not differ ( ≥ 0.19) due to treatment; however, OM digestibility tended to be greater ( = 0.09) in SS-fed steers. Steers fed SS had greater ( ≤ 0.03) digestibility of EE, CP, NDF, and hemicellulose than CON-fed steers. However, CON-fed steers had greater ( < 0.0001) ADF digestibility than SS-fed steers. These data suggest that postextraction sorghum silage can be effectively used in feedlot diets as an alternative forage source.

Effects of Increased Inclusion of Algae Meal on Lamb Total Tract Digestibility

and Implications Algae meal is a novel coproduct created by the unique combination of soybean hulls and oil-extracted heterotrophic micro algae. Algae meal is highly digestible by ruminants and was readily consumed by lambs when included at up to 60% of the diet dry matter. This suggests that algae meal could potentially replace corn or soybean hulls and serve as a valuable component of feedlot diets. Introduction Recently a new coproduct has become available from the large scale commercial production of heterotrophic microalgae utilized for bioenergy and oil. This coproduct, when combined with soyhulls, offers a unique combination of fiber, protein, and fat and may play a role as an alternative feedstuff in animal diets. The ruminant animal, with their unique capability to convert what would otherwise be waste products into nutritious animal protein via fermentation, serves as the ideal model for analyzing this coproduct. Naturally produced microalgae has been previously studied however, concentrations of Na, Fe, Cu, and Al, ultimately limited inclusion in diets because of potential for toxicity of micro-and macro minerals. The algae used in the current study is produced by a heterotrophic fermentation process and grown in dark fermenters, and the resulting algae meal is not limited by excess micronutrients. Previous research showed that beef cattle will readily consume algae meal at concentrations less than 45% diet DM. The nutrient composition of algae meal suggests that this feedstuff may serve as a valuable replacement for soyhulls or perhaps corn. Therefore the objective of this study was to determine the impact of replacing corn with increasing inclusions of algae meal on total tract nutrient digestibility in sheep.

Influence of Distillers Grains from a Cellulosic Ethanol Process Utilizing Corn Kernel Fiber on Nutrient Digestibility of Lambs and Steer Feedlot Performance

Two experiments were designed to evaluate the impact of traditional wet distillers grains (T-WDG) compared to wet distillers grains derived from a novel process for conversion of corn kernel fiber into cellulosic ethanol (C-WDG) on nutrient digestibility and animal performance. Experiment 1 utilized 10 wethers in a replicated 5 × 5 Latin square design to evaluate the digestibility of dry matter, fiber, fat, and crude protein in diets containing T-WDG or C-WDG. In experiment 2, 168 crossbred steers were used in a randomized complete block design to determine the impact of T-WDG or C-WDG in finishing diets on performance and carcass characteristics. Although digestibility of T-WDG and C-WDG slightly varied at moderate inclusions in the diet, performance and carcass characteristics of steers fed 30% T-WDG were similar to steers fed 30% C-WDG. Therefore, incorporation of a co-product from a novel, secondary fermentation process for conversion of corn kernel fiber into cellulosic ethanol maintained significant growth performance of cattle when replacing corn in finishing diets.