Combinations of rendered protein meals for growing calves.

Complementary responses between rendered protein meals were investigated in this study. In a preliminary trial using 12 mature wethers in two replications, there was no difference (P greater than .20) in N digestibility between meat and bone meal (MBM; 96.7%), feather meal (FTH; 89.8%), and soybean meal (SBM; 98.7%). In a 112-d growth trial, individually fed calves (n = 120; 230 kg) received graded levels of FTH, MBM, 50:50 MBM-FTH (CP basis), or SBM with or without tryptophan (Trp) supplementation. Additions of Trp increased plasma Trp levels (P less than .05) but failed to improve efficiency of protein utilization (P greater than .35). Pooled results showed that this efficiency was greater (P less than .05) for FTH (1.47) than for MBM (1.04), FTH:MBM (.80), or SBM (.66). A trial was conducted to determine whether Trp addition reduces growth response to FTH:MBM (50:50) combinations. Calves (n = 230; 285 kg) were blocked by sex and weight into six replications and received FTH:MBM supplying 35% of the supplemental CP fed alone or with a high or low level of Trp supplement. Negative (urea only) and positive controls were included. Calves receiving FTH:MBM combinations gained faster (P less than .10) and were more efficient (P less than .10) than urea-supplemented calves. Performance was not altered by Trp addition. Calves (n = 120; 230 kg) were individually fed in two replications (43 or 48% CP MBM in Replications 1 and 2, respectively) of a growth trial to determine whether there was a complementary response between blood meal (BM) and MBM.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein value of feather meal for ruminants as affected by blood additions.

In situ digestion and growth studies were conducted to determine the effects of adding blood to feather meal. In the in situ and digestion studies, soybean meal (SBM), blood meal (BM), feather meal (Fth) and two combinations of 55% raw blood and 45% feathers (RB + F) were used. Feathers and blood were combined either before or after steam hydrolysis of feathers. Ruminal escape protein of Fth was greater than that of SBM but less than that of BM (P less than .10) determined in situ after 12 h of incubation. Ruminal in situ protein digestion was lower (P less than .10) than for the other treatments (P less than .10) when blood was hydrolyzed with feathers. Total tract digestibility was similar (P greater than .10) for SBM, BM and the mixture of RB + F when the blood was not hydrolyzed. In the growth study, calves were supplemented with urea, SBM, BM, Fth or a combination of BM and Fth (BM + Fth; each supplied an equal portion of supplemental protein). The slope ratio technique was used to evaluate the protein sources. The most efficiently used protein sources were BM and BM + Fth compared to SBM and Fth (P less than .05). There was a numerical but not significant (P greater than .1) complementary effect of adding BM to Fth. Soybean meal and Fth had similar protein efficiencies (P greater than .20). Estimated amino acid flow to the small intestine based on in situ amino acid degradation suggested that the complementary effect observed for BM + Fth was due to BM supplying lysine and Fth providing sulfur amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of grain type, roughage level and monensin level on finishing cattle performance.

Interactions among grain type (grain sorghum, corn or wheat), roughage level and monensin level were studied in four feedlot trials using pen-fed crossbred yearling cattle. In Trial 1, cattle fed high-moisture corn (HMC) were more efficient (.1537 vs .1406 for gain/feed; P less than .01) than cattle fed dry-rolled grain sorghum (DRGS). As level (0, 3, 6, 9%) of dietary roughage was increased, feed efficiency (gain/feed) decreased (.1566, .1461, .1479, .1382; linear, P less than .01). In Trial 2, a grain type (DRGS; dry-rolled corn, DRC; dry-rolled wheat, DRW) x roughage level interaction was observed for daily gain and feed efficiency. Feed efficiency (gain/feed) was decreased when roughage was added to diets containing DRC (.1608 vs .1750) or DRGS (.1674 vs .1465), but not to the diet containing DRW (.1664 vs .1607). In trial 3, a grain type x roughage level x monensin level interaction (P less than .08) was observed for feed efficiency. The addition of 27.5 mg of monensin per kilogram of the 0% roughage-DRC diet tended to improve feed efficiency (.1633 vs .1531), but the addition of monensin to the 7.5% roughage-DRC diet tended to depress feed efficiency (.1476 vs .1575). The addition of either roughage (.1493 vs .1420) or monensin (.1500 vs .1413) to the DRW diet improved feed efficiency. In Trial 4, cattle fed a combination of 75% DRW and 25% DRC were more efficient (.1618 vs .1591; P less than .06) than cattle fed DRC. As level of roughage (0, 3.75, 7.5%) increased, feed efficiency decreased linearly (.1645, .1599, .1569; P less than .0001). Monensin had no effect on feed efficiency. The value of feeding roughage and monensin was variable both across grain types and within similar grain types.

Hydrolysis time as a factor affecting the nutritive value of feather meal and feather meal-blood meal combinations for growing calves.

The objectives of this research were to determine 1) the effects of hydrolysis time on feather meal (FTH) protein digestion and ruminal escape and 2) whether adding blood meal (BM) to FTH evoked a complementary response in animal performance. A lamb digestion trial was conducted to estimate true protein digestibility of soybean meal (SBM), BM, and FTH hydrolyzed for 10, 12, 15, or 18 min. Ruminal escape was estimated in situ. Two 94-d growth trials were conducted using 60 growing calves (226 kg) per trial to evaluate urea, FTH, BM, and 87.5:12.5, 75:25, and 50:50 combinations (CP percentage basis) of FTH:BM. There were small numerical differences in estimated escape of protein from the rumen and DM and protein digestibilities due to hydrolysis time. True protein digestibility of the 10- and 18-min samples was 5% higher (P less than .05) than for the 12- or 15-min FTH samples. In the growth trial, the slope-ratio technique showed that the most efficiently used protein supplement was 100% BM (protein efficiency = 2.45 +/- .19). No differences (P = .30) in protein efficiency were observed among supplements containing various combinations of FTH:BM. There was a quadratic (P less than .01) response to the level of BM, indicating a complementary effect. The largest complementary effect occurred at the 12.5% level of the BM addition. There were no nutritionally important effects of hydrolysis time between 10 and 18 min. Furthermore, supplements can be formulated more economically using small amounts of BM with FTH without compromising biological efficiency.

Effect of fat type and forage level on performance of finishing cattle.

Four trials were conducted to determine the effects of adding various levels and types of fat to dry-rolled corn (DRC) finishing diets containing 0 or 7.5% forage. In Trial 1, 88 yearling steers (mean BW = 352 +/- 38 kg) and 176 heifers (mean BW 316 +/- 15 kg) were blocked by sex and weight into four replications. Treatments were 0, 2, 4, or 6% (DM basis) bleachable fancy tallow (BT) fed with 0 or 7.5% (DM basis) forage. Addition of BT to the 7.5% forage diet had no effect on ADG or gain/feed (G/F). However, adding BT to the all-concentrate diet decreased ADG (linear, P < .01) and G/F (linear, P = .08). In Trial 2, 184 yearling steers (mean BW = 347 +/- 21 kg) and 144 heifers (mean BW 322 +/- 8 kg) were blocked by sex and weight into six replications. Fat treatments were 0% fat, 4% BT, or 4% animal-vegetable oil blend (A-V); each fat treatment was fed with 0 or 7.5% forage. Across forage levels, the addition of fat increased (P < .01) ADG and G/F for cattle fed DRC. In Trial 3, 18 crossbred wether lambs (mean BW = 44.4 +/- 2.5 kg) were fed DRC and 7.5% forage and allotted randomly to the same fat treatments fed in Trial 2. Apparent total tract fat digestibility increased (P < .01) with the addition of BT or A-V. In Trial 4, 40 crossbred wethers (mean BW = 25 +/- 4.1 kg) and 16 ewes (mean BW = 23 +/- 2.7 kg) were individually fed 7.5% forage diets containing 0, 1, 2, or 4% BT. Addition of BT increased (linear, P = .10) G/F. In summary, fat addition to DRC finishing diets fed to yearling cattle did not consistently affect gain/feed, feed intake, and ADG.

Effect of sequential implanting with Synovex on steer and heifer performance.

Studies were conducted using 72 (Exp. 1) and 248 (Exp. 2) steer and heifer calves from 1 to 2 mo of age through slaughter to determine whether preweaning implants affect postweaning feed conversion of cattle that are rapidly grown and(or) finished in the feedlot. In Exp. 1, treatments were three Synovex (S) implants administered 0, 70, and 140 d postweaning (NSSS) or Synovex-C (C) administered preweaning and three implants administered postweaning (CSSS). In Exp. 2, treatments were no implants (NNNN), implants administered 0, 74, and 148 d postweaning to calves that had either received no preweaning implant (NSSS), or C (CSSS), and CSSS plus trenbolone acetate (TBA) administered with the last S implant (CSSS-TBA). Synovex-S or -H implants were administered postweaning to steers and heifers, respectively. Steer and heifer calves implanted with C in the preweaning phase were 9.0 and 13.0 kg (Exp. 1) and 7.5 and 15.0 kg (Exp. 2) heavier (P < .10), respectively, at weaning than nonimplanted steer and heifer calves. In Exp. 1, preweaning implant had no affect on postweaning performance or quality grade. In Exp. 2, preweaning implants (NSSS vs CSSS) decreased (P < .10) steer postweaning gains, whereas postweaning implants (NSSS vs NNNN) increased (P < .10) DM intake; however, feed:gain ratio was not affected by implant strategy. Heifers in Exp. 2 that received implants had greater postweaning (P < .10) DM intakes and daily gains than heifers not receiving implants (NNNN); however, feed:gain ratios among treatment groups were unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

High-lysine corn as a source of protein and energy for finishing calves.

Three trials evaluated the protein and energy value of high-lysine corn for finishing calves. In Trial 1, 60 finishing steer calves were used to evaluate corn source (high-lysine vs control) and protein source (urea, blood meal [BM], corn gluten meal [CGM]) and level (BM and CGM addition; low, medium, high). Calves were individually fed using Calan gates for 102 d, and then were pen-fed (two pens per corn treatment) the remaining 83 d. During the initial 102 d, calves fed high-lysine corn had similar gains but were 6% more efficient (P < .10) compared with calves fed control corn. Performance did not differ (P > .10) among sources or levels of protein supplementation. Over the entire feeding period (185 d), calves fed high-lysine corn were 10% more efficient (P < .10) than calves fed control corn. In the second study, in situ starch disappearance was faster (P < .10) and the proportion of CP degraded by 12 h was 27% greater (P < .10) for high-lysine corn than for control corn. In a metabolism trial, five steers fitted with ruminal, duodenal, and ileal cannulas were used in a randomized block design to evaluate the effect of corn source on site and extent of digestion. Intake and ruminal and total tract digestibility of OM and N did not differ (P > .10) between corn sources. Steers fed high-lysine corn tended to have greater ruminal (P = .23) and postruminal (P = .18) starch digestion, resulting in greater (P < .10) total tract starch digestibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Feeding value of wet distillers byproducts for finishing ruminants.

Yearling and calf finishing trials (replicated over 2 yr) evaluated the feeding value of wet distillers byproducts (wet distillers grains and thin stillage). An additional trial estimated the amount of thin stillage bypassing the rumen when consumed by drinking. Yearlings were 5, 10, and 20% more efficient (linear, P < .01; quadratic, P = .05), whereas calves were 2, 6, and 14% more efficient (linear, P < .01) when fed 5.2, 12.6, and 40.0% (DM basis) wet distillers byproducts, respectively, compared with cattle fed a 79% dry-rolled corn diet. Cattle fed 5.2 or 12.6% wet distillers byproducts, or the dry-rolled corn diet, received similar amounts of protein (crude or metabolizable), which exceeded the metabolizable protein requirement of all cattle. Therefore, differences in efficiency were attributed to differences in energy utilization of the diets. Wet distillers byproducts fed at 5.2, 12.6 and 40.0% contributed 80, 62, and 47% more net energy for gain than corn when fed to yearlings and 17, 33, and 29% more net energy for gain than corn when fed to calves, respectively. Wet distillers byproducts averaged 169% the energy value of corn (2.53 Mcal of NEg/kg) when fed to yearlings and 128% the energy value of corn (1.96 Mcal of NEg/kg) when fed to calves. The increased energy values cannot be explained by increased digestibility, but they may be due to a combination of factors (reduced acidosis, increased energy utilization, yeast end products, etc.) that increase the net energy content of distillers byproducts. Approximately 50% of the thin stillage consumed by drinking bypassed ruminal fermentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy value of hominy feed for finishing ruminants.

Three trials were conducted to evaluate the energy value of hominy feed in finishing diets for ruminants. Hominy feed contained 56.9% starch, 25.2% NDF, 11.1% CP, and 5.3% fat (DM basis). In all trials, hominy feed replaced dry-rolled corn. As the level of hominy feed or ground corn increased in a lamb digestion trial, DM digestibility decreased (P < .01); however, starch digestibility increased (P = .09). Hominy feed and ground corn interacted (linear, P = .08) with respect to NDF digestibility. As the level of ground corn increased, NDF digestibility decreased (linear, P = .10). In a finishing trial, yearling heifers were fed either hominy feed with or without fat added to hominy feed at 0, 13.3 (.67% added fat), 26.7 (1.33% added fat), and 40.0% (2.0% added fat) of diet DM. Fat addition did not interact with hominy feed level. Heifers fed 13.3 or 26.7% hominy feed or hominy feed + fat consumed more DM (P = .10) than heifers fed the 0 or 40.0% diets; however, gain and feed efficiency were similar. In a second finishing trial, steers fed 40% (diet DM) hominy feed consumed more (P = .05) DM, but daily gain and feed efficiency were similar to those of cattle fed dry-rolled corn. Steers fed all-concentrate diets were more efficient (P < .01) than cattle fed 7.5% forage. Results indicated that expeller-extracted hominy feed contained 1.35 Mcal of NEg/kg, or 87% of the energy of corn, when included at levels up to 40% of cattle finishing diets, despite its containing 20% less starch than corn.

Effect of a soybean hull:soy lecithin:soapstock mixture on ruminal digestion and performance of growing beef calves and lactating dairy cattle.

Four experiments were conducted to evaluate the effect of a soybean hull, soy lecithin, and soapstock mixture on ruminal fiber and protein digestion, growth efficiency of beef calves, and lactational performance of dairy cattle. An initial mixing experiment determined that a 4:1 ratio (DM basis) of soy lecithin:soapstock could be added to soybean hulls at 15% (wt/wt, DM basis); this mixture had acceptable mixing and handling characteristics. Dietary addition of a mixture of 85% soybean hulls, 12% soy lecithin, and 3% soapstock (DM basis; SLS) to provide 0, 3, 5, or 7% supplemental fat resulted in a linear (P < .01) decrease in in situ rate of ruminal NDF digestion with no effect on rate of CP digestion. Daily gain, DMI, and feed efficiency (kilograms of gain/kilogram of DMI) of growing beef calves were not affected (P > .10) as graded levels of SLS replaced corn grain. However, as graded levels of SLS replaced soybean hulls, daily gain and feed efficiency increased linearly (P < .01). Based on the results of these trials, Holstein dairy cattle were fed four isonitrogenous and isoenergetic diets that contained either high levels of nonfiber carbohydrates (43%) and no added fat, 1% ruminally inert fat, a 6% level of SLS, or a 12% SLS level (all on DM basis). Efficiency of 4% fat-corrected milk production (kilograms of milk/kilogram of DMI) was greatest for cows fed SLS at 6% of dietary DM. The SLS mixture was an excellent source of fiber and vegetable fat, comparable in feeding value to corn grain, for inclusion in the diets of beef calves and dairy cows.

High-moisture corn utilization in finishing cattle.

Two finishing trials, one laboratory trial and one metabolism trial were conducted with the following objectives: 1) to determine the associative effects of feeding high-moisture corn (HMC) with either dry-rolled grain sorghum (DRGS) or dry-rolled corn (DRC) and 2) to evaluate HMC when harvested at different moisture levels, stored in different structures, or fed as whole or rolled HMC. In Trial 1, yearling steers (BW, 328 kg) were fed diets containing mixtures of HMC and DRGS. As level (0, 33, 100%, as percentage of grain DM) of DRGS increased, ADG (P less than .03) and gain/feed (P less than .001) decreased linearly; gain/feed tended to be affected quadratically (P = .14). In Trial 2, yearling steers (BW, 382 kg) fed HMC, stored whole in an upright, oxygen-limiting silo and rolled coarsely before feeding, gained faster (1.46 vs 1.36 kg/d) and more efficiently (.142 vs. .131 gain/feed) than steers fed whole HMC (P less than .01). In Trial 3, as length of storage of bunker HMC increased, in vitro rate of starch digestion and soluble N content increased (20.4 and 36.8%, respectively) and grain pH decreased (10.9%). In Trial 4, steers fed HMC or a mixture of 75% HMC with 25% DRGS had similar ruminal pH throughout a grain adaptation period, but total ruminal VFA were greater (P less than .005) for steers fed HMC alone. These data are interpreted to suggest that feeding a mixture of HMC, ground and stored in a bunker or silo bag, with DRGS will result in a 3.2% associative effect. However, no associative effects were measured when a mixture of HMC, stored whole and fed whole or rolled, and DRC were fed.

Protein sources for finishing calves as affected by management system.

Two beef production systems were evaluated in conjunction with an evaluation of escape protein sources for finishing calves. Two hundred forty crossbred steers and 80 crossbred heifer calves (BW = 267 +/- 2 kg) were split into two groups: 1) control, finished (207 d) after a 3-wk feedlot adjustment period and 2) grazing cornstalks for 74 d after a 3-wk feedlot adjustment period, then finished (164 d). Finishing treatments were sources and proportions of supplemental CP: 1) urea 100%; 2) soybean meal (SBM) 100%; 3) blood meal (BM) 50%, urea 50%; 4) feather meal (FTH) 50%, urea 50%; 5) SBM 50%, FTH 25%, urea 25%; 6) SBM 25%, FTH 38%, urea 37%; 7) FTH 25%, BM 25%, urea 50%, and 8) FTH 38%, BM 13%, urea 50%. Treatments 1 to 8 were fed in dry-rolled corn (DRC)-based diets. Treatments 9 and 10 were supplement Treatments 1 and 7 fed in diets based on high-moisture corn. Calves finished after a 74-d period of grazing cornstalks consumed more feed (P < .01) and gained faster (P < .01) but were less efficient (P < .05) than calves finished directly after weaning. Although not statistically different, calves finished after grazing cornstalks and supplemented with natural protein in the feedlot were 7% more efficient than calves supplemented with urea alone. Efficiency of calves finished directly after weaning was similar for calves supplemented with natural protein or urea alone. Supplementing SBM/FTH/urea or BM/FTH/urea improved feed efficiency compared with supplementing FTH/urea alone. These data suggest that allowing calves to graze cornstalks before finishing is a possible management option, but this system may require more metabolizable protein in the finishing diet to maximize feed efficiency if the calves are expressing compensatory growth.

Effect of protein source and grain type on finishing calf performance and ruminal metabolism.

A finishing trial and a metabolism trial were conducted to evaluate sources of supplemental protein in dry-rolled corn (DRC) and dry-rolled grain sorghum (DRGS) diets fed to large-framed calves and to determine effects of grain and protein source on ruminal metabolism. In Exp. 1, 144 Charolais crossbred steer and heifer calves (BW = 269 +/- 3 kg) were used in a randomized complete block design and fed (199 d) DRC or DRGS diets supplemented with urea or urea plus a 60:40 combination (CP basis) of blood meal (BM) and feather meal (FTH). Calves supplemented with urea-BM/FTH were more efficient (P < .05) during the first 41 d of the trial than were calves supplemented with urea alone. After 41 d, daily gain and feed efficiency were not affected (P > .2) by source of protein. The NRC metabolizable protein (MP) requirements accurately predicted response to urea-BM/FTH. In Exp. 2, five ruminally cannulated steers (BW = 721 +/- 20 kg) were used in a 5 x 5 Latin square design and fed (on an ad libitum basis) diets similar to those used in Exp. 1. An additional treatment of DRC supplemented with soybean meal (SBM) was included. Rate (P < .01) and extent of 12-h (P = .14) and 18-h (P < .05) in situ N disappearance of SBM, BM, FTH, DRC, DRGS, and corn silage were greater when diets were supplemented with urea-BM/FTH or SBM. Estimates of escape N (percentage of total N) were 52.3, 93.3, 91.7, 65.7, 63.6, and 23.2% for SBM, BM, FTH, DRC, DRGS, and corn silage, respectively. Finishing calves supplemented with urea were deficient in MP during the early finishing period (0 to 41 d) but were adequate in MP from d 42 to slaughter. Supplementing urea-BM/FTH improved feed efficiency when MP was limiting but not when MP was adequate.