Supplemental betaine and peroxide-treated feather meal for finishing cattle

These studies evaluated the effects of betaine, provided either as feed-grade betaine or as concentrated separator by-product (CSB; desugared beet molasses), on performance and carcass characteristics of finishing cattle. In Exp. 1, 175 steers (410 kg initial BW) were fed a finishing diet based on steam-flaked and dry-rolled corn, and treatments included 10.5 and 21 g/d feed-grade betaine and 250 and 500 g/d CSB (supplying 15.5 and 31 g/d of betaine, respectively). Steers fed feed-grade betaine had greater (linear and quadratic effects, P < 0.1) DMI than control steers, but ADG and gain efficiencies were not affected by treatment. Dressing percent and backfat thickness was greater (P < 0.1) for steers that received feed-grade betaine than for controls. Longissimus muscle area was lower (P < 0.1) for steers supplemented with either feed-grade betaine or CSB than for control steers. Yield grades were higher for cattle receiving feed-grade betaine (quadratic effect, P < 0.1) than for control steers. Marbling scores were not affected by supplemental betaine, but the percentage of carcasses grading USDA Select was lower (linear and quadratic effects, P < 0.1) for steers fed feed-grade betaine than for control steers, predominantly due to a greater percentage grading USDA Choice. In Exp. 2, 312 heifers (343 kg initial BW) were used in a finishing study to evaluate the effects of graded levels of feed-grade betaine and peroxide-treated feather meal on performance and carcass characteristics. Treatments included two finishing diets (containing peroxide-treated or untreated feather meal) and four levels (0, 4, 8, and 12 g/d) of feed-grade betaine arranged in a 2 x 4 factorial. No significant interactions occurred between treatment of feather meal and betaine. Treatment of feather meal with hydrogen peroxide (5% wt/wt) increased in situ protein degradability but did not alter DMI, ADG, gain efficiencies, or carcass characteristics of heifers when it replaced untreated feather meal in the diet. Top-dressing feed-grade betaine to the diets had no effect on DMI, ADG, and gain efficiencies. Marbling scores were greater (cubic effect, P < 0.05) for heifers fed diets top-dressed with 4 and 12 g/d of feed-grade betaine, but other carcass characteristics were not altered significantly. Overall, feed-grade betaine and CSB did not alter growth performance, but did have minor effects on carcass characteristics.     

Effects of restricted and ad libitum intake of diets containing wheat middlings on site and extent of digestion in steers

A 5 x 5 Latin square design was used to determine the effects of restricted and ad libitum intake of diets containing wheat middlings on the site and extent of digestion compared to ad libitum intake of a corn-based diet and ad libitum intake of chopped alfalfa hay. Five ruminally and duodenally cannulated Angus steers (519 +/- 41.5 kg BW) were used to compare five dietary treatments. The five treatments were as follows: ad libitum access to a corn-based finishing diet (control), the control diet with 25 percentage units of the corn and soybean meal replaced with wheat middlings offered ad libitum (WM), the WM diet restricted to 75% of predicted ad libitum intake (RWM), the RWM diet with wheat middlings replaced with ammoniated wheat middlings (RNWM), and ad libitum access to a chopped alfalfa hay diet. Although RWM steers were fed to consume 75% of ad libitum intake, RWM steers consumed 15.5% less DM than WM. Steers fed ad libitum hay consumed 28.6, 31.7, and 37.2% less (P < 0.01) DM, OM, and nitrogen than RWM steers. No differences in apparent or true ruminal digestibility were observed among steers fed the control vs WM, WM vs RWM, RWM vs RNWM, or RWM vs hay diets. However, the steers fed the hay diet had 32.5, 33.4, and 36.9% lower (P < 0.01) apparent total tract digestibilities of DM, OM, and N than those fed the RWM diet. Average ruminal pH was lower (P < 0.01) for control steers than those fed the WM diet and for those fed RWM compared to the hay diet. The acetate:propionate ratio was higher for cattle fed hay vs the RWM diet. Microbial DM and OM flow to the small intestine was higher (P < 0.02) for steers fed the RWM diet than those fed the hay diet. In addition, bacterial N flow to the small intestine was higher (P < 0.01) for cattle receiving the RWM diet than the hay diet. Feeding diets containing 25 percentage units of wheat middlings at 75% ad libitum intake had no effect on ruminal digestibility.     

Effects of L-carnitine on nitrogen retention and blood metabolites of growing steers and performance of finishing steers

Two experiments were conducted to evaluate L-carnitine supplementation to cattle fed grain-based diets. In Exp. 1, seven Angus-cross steers (216 kg) were used in a 7 x 4 incomplete Latin square experiment to evaluate the effects of supplemental L-carnitine on N balance and blood metabolites. Steers were fed a corn-based diet (17.5% CP) at 2.5% of BW. Treatments were 0, 0.25, 0.5, 1.0, 1.5, 2.0, and 3.0 g/d of supplemental carnitine. The 18-d periods included 13 d for adaptation and 5 d for collection of feces and urine. Blood was collected before feeding and 3 and 6 h after feeding on d 18 of each period. Dry matter intakes tended to be highest when 1.5 g/d of carnitine was supplied, but N retention was not affected by carnitine and averaged 29.3 g/d. Plasma carnitine concentrations and urinary excretion increased with increasing carnitine supply, indicating that at least some of the carnitine escaped ruminal degradation and was absorbed by the steers. Plasma concentrations of NEFA demonstrated a treatment x time interaction; they decreased linearly in response to carnitine before feeding but increased linearly in response to carnitine at 6 h after feeding. Serum insulin and plasma glucagon, IGF-I, cholesterol, triglyceride, and amino acids were not affected by carnitine. Plasma concentrations of glucose, glycerol, urea, and beta-hydroxybutyrate all were increased by some of the levels of carnitine supplementation, but results for these measurements did not follow easily described patterns and seemed to be related to differences in DMI. In Exp. 2, 95 crossbred steers (357 kg initial BW) were fed finishing diets (14.5% CP) for 129 d. Diets were based on steam-flaked corn and contained 6% alfalfa and 4% tallow. Feed intakes, gains, and feed efficiencies were not affected by supplementation with 2 g/d L-carnitine. However, steers receiving L-carnitine tended to have fatter carcasses, as indicated by tendencies (P < 0.2) for thicker backfat, higher marbling scores, and higher yield grades. In conclusion, carnitine supplementation did not alter lean deposition in growing steers but it did alter plasma NEFA concentrations of growing steers fed a corn-based diet and also seemed to increase fat deposition in finishing cattle.     

Effects of phase-feeding of crude protein on performance, carcass characteristics, serum urea nitrogen concentrations, and manure nitrogen of finishing beef steers

As cattle mature, the dietary protein requirement, as a percentage of the diet, decreases. Thus, decreasing the dietary CP concentration during the latter part of the finishing period might decrease feed costs and N losses to the environment. Three hundred eighteen medium-framed crossbred steers (315 +/- 5 kg) fed 90% (DM basis) concentrate, steam-flaked, corn-based diets were used to evaluate the effect of phase-feeding of CP on performance and carcass characteristics, serum urea N concentrations, and manure characteristics. Steers were blocked by BW and assigned randomly to 36 feedlot pens (8 to 10 steers per pen). After a 21-d step-up period, the following dietary treatments (DM basis) were assigned randomly to pens within a weight block: 1) 11.5% CP diet fed throughout; 2) 13% CP diet fed throughout; 3) switched from an 11.5 to a 10% CP diet when approximately 56 d remained in the feeding period; 4) switched from a 13 to an 11.5% CP diet when 56 d remained; 5) switched from a 13 to a 10% CP diet when 56 d remained; and 6) switched from a 13 to an 11.5% CP diet when 28 d remained. Blocks of cattle were slaughtered when approximately 60% of the cattle within the weight block were visually estimated to grade USDA Choice (average days on feed = 182). Nitrogen volatilization losses were estimated by the change in the N:P ratio of the diet and pen surface manure. Cattle switched from 13 to 10% CP diets with 56 d remaining on feed or from 13 to 11.5% CP with only 28 d remaining on feed had lower (P < 0.05) ADG, DMI, and G:F than steers fed a 13% CP diet throughout. Steers on the phase-feeding regimens had lower (P = 0.05) ADG and DMI during the last 56 d on feed than steers fed 13.0% CP diet throughout. Carcass characteristics were not affected by dietary regimen. Performance by cattle fed a constant 11.5% CP diet did not differ from those fed a 13% CP diet. Serum urea N concentrations increased (P < 0.05) with increasing dietary CP concentrations. Phase-feeding decreased estimated N excretion by 1.5 to 3.8 kg/steer and nitrogen volatilization losses by 3 to 5 kg/steer. The results suggest that modest changes in dietary CP concentration in the latter portion of the feeding period may have relatively small effects on overall beef cattle performance, but that decreasing dietary CP to 10% of DM would adversely affect performance of cattle fed high-concentrate, steam-flaked, corn-based diets.     

Effects of diet and Aspergillus oryzae extract or Saccharomyces cervisiae on growth and carcass characteristics of lambs and steers fed to meet requirements of natural markets

Two studies were conducted to determine the effects of diet and feed additive on growth and carcass characteristics of lambs and cattle destined for all natural markets. In Exp. 1, 48 Dorset × Hampshire lambs (initial BW 29.4 ± 0.1 kg) were used in a randomized complete block experiment to determine the effects of Aspergillus oryzae extract, Amaferm (AMF) supplementation (1 g/d) in an 85% concentrate diet on growth and carcass characteristics. Lambs were allotted to 12 pens (4 lambs per pen), and blocked by sex and BW. Lambs were fed until the average BW of each pen reached a target BW (55.4 kg for wethers and 50.0 kg for ewes), at which time the entire pen of lambs was slaughtered. Amaferm resulted in a greater (P=0.07) G:F. In Exp. 2, 168 crossbred steers (initial BW 300 ± 0.7 kg) were used in a trial with a 3 × 2 factorial arrangement of treatments to examine the effects of 0.5 g/d of Saccaromyces cervisiae boulardii CNCM 1079-Levucell SB (LEV), or 3 g/d of AMF with 2 corn sources, dry whole-shelled corn or high moisture corn, on growth and carcass characteristics. Neither LEV nor AMF improved (P>0.10) carcass characteristics compared with control or non-feed-supplemented steers. Addition of LEV to high-concentrate, corn-based diets did not improve (P>0.10) growth performance of feedlot steers. However, addition of AMF to a diet composed of dry whole-shelled corn resulted in an improvement (P<0.05) in G:F (0.208 vs. 0.194). Results indicate that at the amounts fed, AMF may improve G:F for lambs and steers fed dry corn-based finishing diets.     

Influence of L-Carnitine on Performance and Ruminal and Blood Metabolites of Grazing Calves and Finishing Lambs

Three experiments were conducted to study the influence of level and type of L-carnitine (LC) on performance and rumiasl and plasma metabolites of weanling calves and finishing lambs. Weanling calves (84) grazing dormant dallisgrass-bermudagrass forage were fed a 20% CP supplement to provide 0, 0.5, 1, or 2 g of ruminally unprotected (RUP) LC per calf daily in Exp. 1. There was a linear increase (P=0.01) and cubic response (P=0.03) to RUP LC in growth rate and quadratic changes (P=0.01) in plasma ammonia N (PAN) and plasma urea N (PUN). In Exp. 2, 32 lambs were individually fed 14% CP diets containing 0, 50, 100, or 200 ppm RUP LC or ruminally protected (RP) LC in a 2 × 4 arrangement of treatments. Lambs gained BW faster (P=0.03) and more efficiently (P=0.07) as the LC level increased to 100 ppm and then declined at 200 ppm (quadratic response). Longissimus area decreased (P=0.03), and fat cover tended (P=0.15) to decline, at 50 and 100 ppm LC and increased at 200 ppm (linear and quadratic response). Ruminal ammonia N levels were reduced at 50 ppm LC but increased at greater LC levels (linear, quadratic, and cubic response, P=0.02). Plasma carnitine concentrations increased (P=0.01) as the dietary level of LC increased. Protected LC was more effective than RUP LC in increasing growth rate (P=0.06) and reducing PAN (P=0.1). In Exp. 3, 16 wether and 16 ewe lambs were individually fed corn-based or soybean hull-based diets with 0 or 100 ppm RP LC in a 2 × 2 arrangement of treatments. Lambs fed RP LC gained BW faster and more efficiently (P=0.04) than lambs that were not fed LC. Lambs fed corn-based and soybean hull-based diets responded similarly to RP LC; however, performance was greater (P=0.03) for lambs fed the corn-based diet. Gender of lambs did not influence the response to diet or RP LC. Supplementing the diet with 100 ppm RP LC reduced (P=0.01) ruminal pH and ammonia N. Plasma carnitine concentrations were increased (P=0.01), and PAN was decreased (P=0.04) by feeding 100 ppm RP LC. Ruminnaly unprotected and RP LC were effective in improving growth rate in ruminants; the latter appeared to be more effective in finishing lambs. L-carnitine reduced ruminal ammonia N and plasma glucose and, in some cases, PAN and PUN.     

Evaluation of dairy food processing wash water solids as a protein source: III. Nitrogen utilization by heifers fed medium-concentrate diets

Eight multicannulated heifers (average BW 415 +/- 34 kg) were used in a replicated 4 x 4 Latin square to evaluate fluid milk processing wash water solids (WWS) as a dietary N source. Heifers were fed corn/cottonseed hull-based diets containing soybean meal (control, 0% WWS N) or WWS replacing soybean meal at 33, 67, or 100% of supplemental dietary N. Total tract and ruminal DM and OM digestibilities decreased linearly or cubically (P less than .05) as dietary WWS N increased. Total ruminal VFA concentration (P less than .05) and propionic acid molar proportion (P less than .10) were greater in heifers fed 0 vs 100% WWS N. Heifers fed 0% WWS N had the greatest (P less than .05) ruminal ammonia concentration at all sampling times. Dietary WWS did not affect (P greater than .10) ruminal pH, fluid dilution rate, fluid flow, fluid volume, or turnover time. Total tract N digestibility decreased quadratically (P less than .10) with increasing WWS N in the diet. Supplemental WWS N did not affect (P greater than .10) flow of duodenal ammonia N or bacterial N, or efficiency of microbial N synthesis. Diets containing WWS N resulted in a cubic increase (P less than .10) in duodenal flow of essential amino acids compared with 0% WWS N; however, there were no differences in small intestinal amino acid disappearance. Data indicate that WWS can replace 33% of the soybean meal N in a corn/cottonseed hull-based diet without decreasing ruminal fermentation, fluid digesta kinetics, microbial efficiency, or small intestinal amino acid utilization.     

Effects of protein concentration and source on nutrient digestibility by mature steers limit-fed high-concentrate diets.

Five ruminally fistulated 3-yr-old mature Holstein steers (average BW 691+/-23 kg) were used in a 5 x 5 Latin square experiment with a 2 x 2 + 1 fact orial arrangement of treatments. Effects of protein concentration and protein source on nutrient digestibility, excretion of DM and fecal N, ruminal fluid volume and dilution rate, ruminal characteristics, and in situ DM disappearance of whole shelled corn, ground corn, and orchardgrass hay were measured in steers limit-fed high-concentrate diets at 1.5% of BW. A negative control basal diet (NC; 9% CP) was supplemented to achieve either 11 or 14% CP; supplemental CP was either from soybean meal (11 and 14% SBM) or a 50:50 ratio of CP from urea and soybean meal (11 and 14% U). Dry matter and OM digestibilities were 5% greater (P < .07) for steers fed the SBM diets than for those fed the U diets. Starch digestibility did not differ (P > .10) among steers fed any of the diets. Nitrogen source did not affect (P > .10) apparent N digestibility or fecal N excretion; however, steers fed the NC diet had the lowest (P < .10) apparent N digestibility compared with those fed all other diets. Ruminal fluid volume was lower (P < .06) when steers were fed the NC diet compared with all other diets; there were no differences (P > .74) among diets for ruminal fluid dilution rate. In general, ruminal ammonia N and VFA molar proportions were not affected by protein source or concentration. Although CP concentration affected (P < .06) in situ DM disappearance of ground corn, CP concentration did not (P > .48) affect total tract digestion of DM or OM. This indicates that CP concentration may have affected site of digestion, but not extent of digestion. When mature ruminants were limit-fed a corn-based diet to meet primarily a maintenance function, protein source and concentration had little effect on measures of nutrient digestion.     

By-product feeds for meat goats: effects on digestibility,ruminal environment,and carcass characteristics

Crossbred wether goats (n = 24; 50% Boer, 6 per diet) initially averaging 27.4+/-0.4 kg were fed either wheat middlings (wheat midds), soybean hulls (soyhulls), or corn gluten feed at 1% BW (as-fed) along with orchardgrass hay (10.7% CP) offered to ad-libitum consumption for 72 d followed by 5 d total fecal collection. The Control (hay) diet was supplemented with 5.7% soybean meal to bring total dietary protein to 12.5%, by-products were brought to a higher Ca:P ratio with limestone or dicalcium phosphate to make total dietary Ca:P 1.5:1, and soybean meal was added to soyhulls to bring them up to 17% CP (wheat midds = 17% and corn gluten feed = 21% CP). Total DMI (916 g/d+/-57 or 3.2%+/-0.2 BW) did not differ (P > 0.92) among treatments. Initial BW (P = 0.25), final BW (P = 0.48), and ADG (P = 0.56) did not differ for the four treatments. Carcass weight was greater (P = 0.05) for goats fed soyhulls (16.0 kg) or wheat midds (15.6 kg) as compared with goats fed the hay diet (14.5 kg), with carcass weight from goats fed corn gluten feed being intermediate (15.3 kg, SEM = 0.3 kg). Carcass grade did not differ (P = 0.80) and averaged 5.42+/-0.4. Dressing percentage tended (P = 0.12) to be lower for goats fed the hay diet (46.4%) compared with soyhull (48.3%), corn gluten feed (48.3%), or wheat midd (48.8%) diets (SEM = 0.7). Ruminal pH was highest (P < 0.01) for goats fed the hay diet (6.52) and lowest for goats fed wheat midds (6.23) with soyhull (6.41) and corn gluten feed diets (6.35) being intermediate (SEM = 0.05). Digestibility of DM (70.1+/-2.5%), OM (70.3+/-2.6%,), CP (75.5+/-2.0%), GE (68.5+/-2.7%), NDF (68.1+/-3.0%), ADF (65.4+/-3.4%), cellulose (70.1+/-2.9%), and lignin (31.1+/-8.2%) did not differ (P > 0.15). Total ruminal VFA did not differ (86.0+/-6.1 mM, P = 0.59), but acetate:propionate ratio was higher (P < 0.01) for hay (3.1) and soyhull diets (3.3) than for corn gluten feed (2.4) and wheat midd diets (2.4, SEM = 0.11). Ruminal ammonia (mg/100 mL) was lower (P < 0.01) for goats fed hay (15.4) and soyhull diets (11.6) than those fed corn gluten feed (25.2) and wheat midd diets (23.0, SEM = 1.35). Ruminal pH was lower for goats fed the byproducts, but remained above 6. Serum urea nitrogen (mg/100 mL) averaged 21.0+/-1.0 (P = 0.11) with soyhulls tending to be lowest (19.3) and corn gluten feed tending to be highest (22.8). Soyhulls, corn gluten feed, and wheat midds appear to be viable feed ingredients for meat goat diets.     

Sulfur concentration in diets containing corn, soybean meal, and distillers dried grains with solubles does not affect feed preference or growth performance of weanling or growing-finishing pigs

Four experiments were conducted to investigate the effects of distillers dried grains with solubles (DDGS) and dietary S on feed preference and performance of pigs. In a 10-d feed preference experiment (Exp. 1), 48 barrows (20.1 ± 2.2 kg of BW) were randomly allotted to 3 treatment groups, with 8 replicate pens per treatment and 2 pigs per pen. A control diet based on corn and soybean meal, a DDGS diet containing 20% DDGS, and a DDGS-sulfur (DDGS-S) diet were prepared. The DDGS-S diet was similar to the DDGS diet with the exception that 0.74% CaSO(4) was added to the diet. Two diets were provided in separate feeders in each pen: 1) the control diet and the DDGS diet, 2) the control diet and the DDGS-S diet, or 3) the DDGS diet and the DDGS-S diet. Preference for the DDGS diet and the DDGS-S diet vs. the control diet was 35.2 and 32.6%, respectively (P < 0.05), but there was no difference between the DDGS diet and the DDGS-S diet. In Exp. 2, a total of 90 barrows (10.3 ± 1.4 kg of BW) were allotted to 3 treatments, with 10 replicate pens and 3 pigs per pen, and were fed the diets used in Exp. 1 for 28 d, but only 1 diet was provided per pen. Pigs fed the control diet gained more BW (497 vs. 423 and 416 g/d; P < 0.05) and had greater G:F (0.540 vs. 0.471 and 0.455; P < 0.05) than pigs fed the DDGS or the DDGS-S diet, but no differences between the DDGS and the DDGS-S diets were observed. In a 10-d feed preference experiment (Exp. 3), 30 barrows (49.6 ± 2.3 kg of BW) were allotted to 3 treatment groups, with 10 replicates per group. The experimental procedures were the same as in Exp. 1, except that 30% DDGS was included in the DDGS and DDGS-S diets and 1.10% CaSO(4) was added to the DDGS-S diet. Feed preference for the DDGS and the DDGS-S diets, compared with the control diet, was 29.8 and 32.9%, respectively (P < 0.01), but there was no difference between the DDGS and the DDGS-S diets. In Exp. 4, a total of 120 barrows (34.2 ± 2.3 kg of BW) were fed grower diets for 42 d and finisher diets for 42 d. Diets were formulated as in Exp. 3. Pigs on the control diets gained more BW (1,021 vs. 912 and 907 g/d; P < 0.05) and had greater G:F (0.335 vs. 0.316 and 0.307; P < 0.05) than pigs fed the DDGS or DDGS-S diet, respectively, but no differences between pigs fed the DDGS and the DDGS-S diets were observed. In conclusion, dietary S concentration does not negatively affect feed preference, feed intake, or growth performance of weanling or growing-finishing pigs fed diets based on corn, soybean meal, and DDGS.     

Effect of supplemental nutrient source on heifer growth and reproductive performance,and on utilization of corn silage-based diets by beef steers

Two experiments were conducted to determine effects of oilseeds or soybean hulls on growth and reproductive performance of heifers and utilization of corn silage diets by growing beef cattle. In Exp. 1, 96 beef heifers (249 kg of BW) were used in a randomized complete block design. Treatments were as follows: 1) corn and soybean meal (CON) at 56% of the DMI; 2) whole linted cottonseed at 15% of the DMI (COT); 3) whole raw soybeans at 15% of the DMI (SB); or 4) pelleted soyhulls at 30% of the DMI (SH). Diets were formulated to be isonitrogenous (13.8% CP) and fed to achieve target weights equal to 65% of expected mature BW at the time of AI. Estrus was synchronized and heifers were inseminated by AI in response to detected estrus. Because the energy value for SH was underestimated, cumulative ADG for SH (1.03 kg/d) was greater (P < or = 0.03) than for CON (0.89 kg/d), COT (0.87 kg/d), or SB (0.86 kg/d). Treatment did not affect (P > 0.10) the proportion of pubertal heifers at the beginning of the breeding season: CON (60%), COT (53%), SB (69%), SH (71%), or first-service conception rates: CON (37%); COT (38%); SB (57%); SH (42%). In Exp. 2, crossbred steers (387 kg) were used in a 6 x 6 Latin square design to evaluate the effects of supplemental nutrient source on utilization of corn silage diets. Treatments included diets used in Exp. 1, plus a negative control (soybean meal at 10% of the DMI; SIL) and whole raw soybeans at 25% of the DMI (SB25). Diets were formulated to be isonitrogenous (13.8% CP) except SB25 (17% CP), and were fed twice daily at 1.8 x NEm. Oilseed inclusion decreased (P < 0.10) acetate:propionate ratios and (P < 0.10) apparent ruminal OM and ruminal and total tract NDF digestibilities. The CON and SH diets had the greatest (P < 0.10) total-tract OM digestibilities. Microbial efficiencies were greatest (P < 0.10), and long chain fatty acid flow to the duodenum increased (P < 0.10) with oilseeds. Biohydrogenation averaged 90.4% and increased slightly (P < 0.10) when oilseeds were added to the diet. Adding oilseeds or soybean hulls to corn silage-based diets did not affect reproductive performance of heifers. Although oilseed additions increased total fatty acid flow to the duodenum, a high degree of biohydrogenation occurred, greatly increasing C18:0, with only marginal increases in unsaturated fatty acid flow. Depending on diet and feeding conditions, inclusion of whole oilseeds may not be an effective means of increasing linoleic acid supply for ruminant animals.     

Performance and digestibility characteristics of finishing diets containing distillers grains, composites of corn processing coproducts, or supplemental corn oil

Three experiments evaluated the lipids in distillers grains plus solubles compared with corn or other sources of lipid in finishing diets. Experiment 1 utilized 60 individually fed yearling heifers (349 +/- 34 kg of BW) fed treatments consisting of 0, 20, or 40% (DM basis) wet distillers grains plus solubles (WDGS), or 0, 2.5, or 5.0% (DM basis) corn oil in a finishing diet based on high-moisture corn (HMC) and dry-rolled corn. Cattle fed 20 and 40% WDGS had greater (P < 0.10) G:F than cattle fed 0% WDGS. Cattle fed the 5.0% corn oil had less overall performance than cattle fed the other diets. Results from Exp. 1 indicated that adding fat from WDGS improves performance, whereas supplementing 5.0% corn oil depressed G:F, suggesting that the fat within WDGS is different than corn oil. Experiment 2 used 234 yearling steers (352 +/- 16 kg of BW) fed 1 of 5 treatments consisting of 20 or 40% (DM basis) dry distillers grains plus solubles, 1.3 or 2.6% (DM basis) tallow, or HMC. All diets contained 20% (DM basis) wet corn gluten feed as a method of controlling acidosis. No differences between treatments for any performance variables were observed in Exp. 2. The dry distillers grains plus solubles may be similar to tallow and HMC in finishing diets containing 20% wet corn gluten feed. Experiment 3 used 5 Holstein steers equipped with ruminal and duodenal cannulas in a 5 x 5 Latin square design. Treatments were a 40% WDGS diet, 2 composites, one consisting of corn bran and corn gluten meal; and one consisting of corn bran, corn gluten meal, and corn oil; and 2 dry-rolled corn-based diets supplemented with corn oil or not. Cattle fed the WDGS diet had numerically less rumen pH compared with cattle fed other treatments. Cattle fed WDGS had greater (P < 0.10) molar proportions of propionate, decreased (P < 0.10) acetate:propionate ratios, greater (P < 0.10) total tract fat digestion, and a greater (P < 0.10) proportion of unsaturated fatty acids reaching the duodenum than cattle fed other treatments. Therefore, the greater energy value of WDGS compared with corn may be due to more propionate production, greater fat digestibility, and more unsaturated fatty acids reaching the duodenum.     

Effects of limit feeding corn or dried distillers grains with solubles at 2 intakes during the growing phase on the performance of feedlot cattle

Energy density in growing diets may affect carcass quality of cattle; however, few reports have described the impact of energy source. The objectives of this research were to determine effects of source [dried distillers grains with solubles (DDGS) vs. corn] and amount (limit-fed to gain 0.9 vs. 1.4 kg of BW/d) of energy during the growing phase on feedlot performance and marbling. Angus-cross steers (144 head) were blocked by BW (average initial BW = 252 ± 36 kg), allotted within each block to 8 pens (6 steers/pen, 24 pens total), and randomly assigned to 1 of 4 feeding systems in a 2 × 2 factorial arrangement of treatments: 1) 65% DDGS fed to gain 0.9 kg of BW/d, 2) 65% DDGS fed to gain 1.4 kg of BW/d, 3) 65% corn fed to gain 0.9 kg of BW/d, and 4) 65% corn fed to gain 1.4 kg of BW/d. Fecal grab samples were collected on d 52 of the growing phase to determine digestibility of DM, ADF, NDF, ether extract (EE), and CP. After the 98-d growing phase, all steers were fed the same finishing diet. Steers were slaughtered by pen when average BW within the pen was 544, 522, and 499 kg for the large, medium, and small BW blocks, respectively. Average daily gain and DMI differed (P<0.01) by design during the growing phase. Compared with the corn-based diets, digestibilities of DM, NDF, and EE were decreased (P<0.02) when DDGS-based diets were fed during the growing phase, whereas the digestibility of N was increased (P<0.01). The ADG was greatest (P=0.02) during the finishing phase for steers fed to gain 0.9 kg of BW/d initially, but source of energy during the growing phase did not affect (P=0.24) finishing phase ADG. Steers fed to gain 0.9 kg of BW/d during the growing phase also had less backfat (P=0.08), decreased USDA yield grades (P=0.03), and greater LM area (P<0.01) than steers fed to gain 1.4 kg of BW/d. There was an interaction between energy source and amount for marbling scores (P=0.02). Steers fed corn-based diets to gain 0.9 kg of BW/d during the growing phase had the most marbling, whereas those fed to gain 0.9 kg of BW/d on DDGS had the least marbling; the remaining feeding systems were intermediate. Overall ADG and DMI were affected (P < 0.06) by both source and amount of energy fed during the growing phase. Feeding the DDGS-based diet to achieve greater ADG during the growing phase increased marbling, whereas feeding the corn-based diet to increase ADG during the growing phase decreased marbling.     

Effect of creep feed supplementation and season on intake, microbial protein synthesis and efficiency, ruminal fermentation, digestion, and performance in nursing calves grazing native range in southeastern North Dakota

Nine ruminally and duodenally cannulated (172 +/- 23 kg of initial BW; Exp. 1) and 16 intact (153 +/- 28 kg of initial BW; Exp. 2) crossbred nursing steer calves were used to evaluate the effects of creep feed supplementation and advancing season on intake, digestion, microbial efficiency, ruminal fermentation, and performance while grazing native rangeland. Treatments in both experiments were no supplement or supplement fed at 0.45% of BW (DM basis) daily. Supplement consisted of 55% wheat middlings, 38.67% soyhulls, 5% molasses, and 1.33% limestone. Three 15-d collection periods occurred in June, July, and August. In Exp. 1, ruminal evacuations were performed and masticate samples were collected for diet quality analysis on d 1. Duodenal and fecal samples were collected from cannulated calves on d 7 to 12 at 0, 4, 8, and 12 h after supplementation. Ruminal fluid was drawn on d 9 and used as the inoculate for in vitro digestibility. On d 11, ruminal fluid was collected, and the pH was recorded at -1, 1, 2, 4, 8, 12, and 24 h postsupplementation. In Exp. 1 and 2, milk intake was estimated using weigh-suckle-weigh on d 15. Steers in Exp. 2 were fitted with fecal bags on d 6 to 11 to estimate forage intake. In Exp. 1, supplementation had no effect (P = 0.22 to 0.99) on grazed diet or milk composition. Apparent total tract OM disappearance increased (P = 0.03), and apparent total tract N disappearance tended (P = 0.11) to increase in supplemented calves. Microbial efficiency was not affected (P = 0.50) by supplementation. There were no differences in ruminal pH (P = 0.40) or total VFA concentration (P = 0.21) between treatments, whereas ruminal NH3 concentration increased (P = 0.03) in supplemented compared with control calves. In Exp. 2, supplementation decreased (P = 0.02) forage OM intake (OMI; % of BW) and increased (P = 0.06) total OMI (% of BW). Supplementation had no effect on ADG (P = 0.94) or G:F (P = 0.35). Supplementation with a wheat middlings and soybean hull-based creep feed reduced forage OMI but improved total tract OM and N digestion and had minimal effects on ruminal fermentation or performance. Supplementation with a wheat middlings and soybean hulls-based creep feed might improve OM and N digestion, but might not produce significantly greater BW gains compared with no supplementation.     

Effects of prepartum supplementation of linoleic and mid-oleic sunflower seed on cow performance, cow reproduction, and calf performance from birth through slaughter, and effects on intake and digestion in steers

Two experiments were conducted to determine the effects of sunflower seed supplements with varying fatty acid profiles on performance, reproduction, intake, and digestion in beef cattle. In Exp. 1, 127 multiparous spring-calving beef cows with free-choice access to bermudagrass hay were individually fed 1 of 3 supplements for an average of 83 d during mid to late gestation. Supplements (DM basis) included 1) 1.23 kg/d of a soybean hull-based supplement (control treatment); 2) 0.68 kg/d of linoleic sunflower seed plus 0.23 kg/d of the control supplement (linoleic treatment); and 3) 0.64 kg/d of mid-oleic sunflower seed plus 0.23 kg/d of the control supplement (oleic treatment). During the first 62 d of supplementation, the BW change was 11, 3, and -3 kg for cows fed the control, linoleic, and oleic supplements, respectively (P < 0.001). No difference in BW change was observed during the subsequent period (-65 kg, P = 0.83) or during the entire 303-d experiment (-31 kg, P = 0.49). During the first 62 d of supplementation, cows fed sunflower supplements tended (P = 0.08) to lose more body condition than cows fed the control diet, but BCS was not different (P > 0.22) for any subsequent measurement. At the beginning of the breeding season, the percentage of cows exhibiting luteal activity was greater for cows fed the control diet (43%; P = 0.02) than for cows fed either linoleic (20%) or oleic (16%) supplementation; however, first-service conception rate (67%; P = 0.22) and pregnancy rate at weaning (92%; P = 0.18) were not different among supplements. No differences were detected in calf birth (P = 0.46) or weaning BW (P = 0.74). In Exp. 2, 8 ruminally cannulated steers were used to determine the effects of sunflower seed supplementation on forage intake and digestion. Treatments (DM basis) included 1) no supplement; 2) a soybean hull-based supplement fed at 0.29% of BW/d; 3) whole linoleic sunflower seed fed at 0.16% of BW/d; and 4) whole high-oleic sunflower seed fed at 0.16% of BW/d. Hay intake was not influenced (P = 0.25) by supplement (1.51% of BW/d); however, DMI was greatest (P < 0.01) for steers fed the soybean hull-based supplement (1.93% of BW/d). Sunflower seed supplementation reduced (P < 0.01) NDF and ADF digestibility while increasing (P < 0.01) apparent CP and apparent lipid digestibility. In conclusion, whole sunflower seed supplementation resulted in reduced cow BW gain during mid to late gestation, but this reduction did not influence subsequent cow BW change, pregnancy rate, or calf performance.     

Effect of Maillard reaction products on ruminal and fecal acid-resistant E. coli, total coliforms, VFA profiles, and pH in steers

Six ruminally cannulated Angus-cross steers (362 kg) were used in a replicated 3 x 3 Latin square design to determine effects of supplementing Maillard reaction products (MRP) on acid-resistant E. coli and coliform populations. Steers were fed roughage-based diets supplemented (DM basis) with either 10% soybean meal (SBM), 10% nonenzymatically browned SBM (NESBM), or 10% SBM top-dressed with 45 g of a lysine-dextrose Maillard reaction product (LD-MRP). Equal weights of dextrose, lysine hydrochloride, and deionized water were refluxed to produce the LD-MRP. The NESBM was manufactured by treating SBM with invertase enzyme, followed by heating to induce nonenzymatic browning. Steers were allowed slightly less than ad libitum access to diets fed twice daily and were adapted to their respective treatments within 10 d. On d 11, ruminal and fecal samples were collected at 0, 2, 4, 6, 8, and 12 h after feeding from each of the steers and transported to the laboratory for microbial analysis. Ruminal samples and feces were analyzed for pH and VFA, and both ruminal fluid and feces were tested for acid-resistant E. coli and total coliforms by incubating samples in tryptic soy broth adjusted to pH 2, 4, and 7. Ruminal pH and total VFA concentrations did not differ among treatments. The molar proportion of ruminal acetate was higher (P < 0.05) for steers receiving NESBM than for steers receiving SBM and LD-MRP. At pH 4, steers that received NESBM had lower (P < 0.05) ruminal populations of E. coli and total coliforms than steers that received SBM. No differences were observed for ruminal E. coli and total coliforms at pH 2 and 7. Fecal pH was lower (P < 0.05) for steers fed NESBM than for steers fed SBM or LD-MRP. Molar proportions of fecal acetate were lower (P < 0.05) and proportions of butyrate and isovalerate were higher (P < 0.05) for steers fed NESBM compared with steers fed SBM. Fecal E. coli at pH 4 was lower (P < 0.05) for steers fed NESBM than for steers fed LD-MRP. Fecal E. coli and total coliforms at pH 2 and 7 did not differ among treatments. Dietary MRP had limited effectiveness at decreasing acid-resistant coliforms in the rumen and feces of cattle. Acid resistance in coliforms may depend on protein availability.     

Effects of DL-malate on ruminal metabolism and performance of cattle fed a high-concentrate diet.

To determine the effects of DL-malate on ruminal metabolism, four steers equipped with ruminal cannulas were fed an 80% rolled grain (75% corn:25% wheat) diet twice daily with a DMI equal to 2.0% of BW (485+/-24.8 kg). DL-Malate was infused into the rumen on two consecutive days in 500 mL of phosphate buffer to provide 0, 27, 54, or 80 g of DL-malate/d. Ruminal pH linearly increased (P < .01) with DL-malate concentration and was greater (P < .01) for DL-malate than for the control steers (6.07 vs 5.77). DL-Malate treatment linearly decreased (P < .10) total VFA and tended to linearly increase (P = .10) acetate concentration. Propionate, butyrate, and L-lactate concentrations and acetate:propionate ratio were not affected (P > .10) by DL-malate. Three finishing studies were conducted to determine the effects of feeding DL-malate on growth rate and feed efficiency. In a 98-d experiment, 33 crossbred steers were randomly allotted in a Calan gate feeding system to three DL-malate levels (0, 40, and 80 g/d). Steers (initial weight = 367+/-4.5 kg) were fed a rolled corn-based diet twice daily. After 84 d on feed, gain efficiency (gain:feed) tended to improve with more DL-malate (linear, P < .10) and was 8.1% greater (P < .05) for DL-malate than for the control. The ADG linearly increased (P < .05) with more DL-malate and was 8.6% greater (P = .10) for DL-malate than for the control. After 98-d on feed, ADG was linearly increased (P = .09) by DL--malate, and the greatest increase occurred with 80 g of DL-malate. In the second performance study, 27 Angus steers were randomly allotted in a Calan gate feeding system to three DL-malate concentrations (0, 60, and 120 g/d). Steers (initial weight = 432+/-4.6 kg) were fed diets used in the first finishing study twice daily, but DL-malate was included during the 10-d step-up period. During the 10-d step-up period, feed efficiency and ADG linearly increased (P = .01) with more DL-malate. DL-Malate had little effect on steer and heifer performance or plasma constituents in a 113-d finishing study. Collectively, these results suggest that feeding DL-malate to cattle consuming high-grain diets alleviates subclinical acidosis, and it improved animal performance in two finishing studies.     

Limit-feeding corn as an alternative to hay reduces manure and nutrient output by Holstein cows.

Efficiency of limit-feeding a whole shelled corn-based diet as an alternative to a conventional forage-based diet for nonlactating dairy cattle was determined. Twelve nonlactating, multiparous Holstein cows (initial BW 642+/-50 kg) were used in a randomized complete block design. Nutrient digestibility, excretion of DM, N, and P, performance of cows, and feed costs were measured. Both diets were formulated to provide equal daily intakes of NE1, protein, vitamins, and minerals, according to National Research Council recommendations. Dry matter intake was restricted by 30% for cows fed the high-corn diet compared with the high-forage diet (6.8 vs 9.6 kg/ d, respectively); therefore, concentrations of nutrients in the high-corn diet were increased to compensate for decreased DMI. Diets were fed once daily, and cows had unlimited access to fresh water. After a 28-d adaptation period, cows were placed in metabolism stalls for a 6-d total collection of feces and urine. The limit-fed, high-corn diet had a 15% greater DM digestibility than the high-forage diet. A 29% decrease in DMI for the high-corn diet vs the high-forage diet resulted in a 40% decrease in fecal DM excretion. Starch digestibility and digestibility of whole corn kernels were not affected (P > or = .62) by diet. Despite similar N intakes, total N excretion was 22% greater (P < .01) for cows fed the high-forage diet than for those limit-fed the high-grain diet. Cow weight and condition score change did not differ (P > .10) between diets. Feed costs were reduced by $.38/d with the high-corn diet vs the high-forage diet. Limit-feeding a corn-based diet is an economically and nutritionally viable alternative to forage-based diets for nonlactating Holstein cows.     

Ruminal ciliated protozoa in cattle fed finishing diets with or without supplemental fat

Ruminal samples were collected at slaughter from 364 unfasted steers fed different finishing diets to obtain information on numbers and species distribution of ciliated protozoa in feedlot cattle. Total numbers of protozoa averaged 1.59 X 10(5)/g of ruminal contents. A total of 47 steers (12.9%) were defaunated, but 4.1% of the steers possessed numbers of protozoa greater than 10(6)/g. Entodinium species did not always dominate the protozoan populations; 41 faunated steers (11.2%) were devoid of entodinia, and 79 additional steers (21.7%) possessed populations dominated (greater than 50%) by other genera. Isotricha was the most commonly occurring genus supplanting Entodinium, but Polyplastron and Epidinium were frequently present in high concentrations. Tallow and soybean soapstock supplementation reduced (P less than .05) numbers of protozoa in steers consuming wheat diets. However, yellow grease supplementation did not affect numbers of protozoa in steers fed either sorghum or corn diets. Average ruminal pH was 6.20 on the wheat diet, 6.05 on the corn diet, and 5.69 and 6.23 for the two sorghum diets, respectively. We found no correlation between ruminal pH and numbers of protozoa on any diet. The presence of relatively high protozoan concentrations and few defaunated animals in feedlot cattle necessitates reevaluation of the role that ciliated protozoa play in ruminal metabolism of animals fed processed, high-concentrate diets.     

Poultry Manure as a Supplement in High Concentrate Diets Limit-Fed to Beef Cows

Three trials were conducted to evaluate poultry manure as a CP and mineral supplement in high concentrate diets limit-fed to gestating and lactating beef cows and heifers. Trial 1 used 67 pregnant Simmental x Angus beef cows (BW, 640 ± 6 kg). During this 126-d trial, no differences (P>0.10) in BW changes or body condition scores (BCS) were observed between cows provided supplemental CP and minerals from either poultry manure or a soybean meal-based protein and mineral supplement. Feed costs per day were lower for cows fed diets supplemented with poultry manure ($0.82) than for those fed diets supplemented with the soybean meal-based protein and mineral supplement ($1.11) and were much lower than those for cows fed an all hay diet offered for ad libitum intake ($1.46). In Trial 2, 26 pregnant Simmental x Angus beef heifers (BW, 503 ± 11 kg) were used to determine the efficacy of poultry manure as a source of energy, protein, and minerals. No differences (P>0.10) in performance were observed between heifers consuming a low poultry manure diet (4.6 kg/d corn and 1.1 kg/d poultry manure) or a high poultry manure diet (3.1 kg/d corn and 3.2 kg/d poultry manure). Feed costs per day were lower for heifers on the high poultry manure treatment ($0.61 vs $0.73 for high and low poultry manure treatments, respectively). Trial 3 was conducted with 61 beef cows and 23 beef heifers in late gestation. Animals consuming the poultry manure-supplemented, corn-based diet lost more weight during both the gestation (P<0.10) and lactation periods (P<0.05) than those fed the soybean meal-based protein and mineral supplement. Overall BCS change was similar among treatments (P=0.31). Feed costs per day were lower for cows fed supplemental poultry manure ($0.82) than for those fed the soybean meal-based protein and mineral supplement ($1.11). Poultry manure was a more economical source of supplemental CP and minerals than a soybean meal-based protein and mineral supplement when fed to meet nutrient needs of cows that were limit-fed a corn-based diet. Effects on cow performance were minimal.