Evaluation of triticale dried distillers grains with solubles as a substitute for barley grain and barley silage in feedlot finishing diets.

The objective of this study was to assess the value of triticale dried distillers grains with solubles (DDGS) as a replacement for barley silage in addition to a portion of the dry-rolled barley (DRB) in a grain-based feedlot finishing diet. The trial used 160 crossbred yearling steers: 144 noncannulated (478 +/- 84 kg) in a complete randomized design, and 16 ruminally cannulated (494 +/- 50 kg) in a replicated 4 x 4 Latin square design. The noncannulated steers were assigned to 8 standard pens (10 per pen) and 8 pens equipped with the GrowSafe system (GrowSafe Systems Ltd., Airdrie, Alberta, Canada; 8 per pen). The cannulated steers were placed (2 per pen) in the 8 GrowSafe pens and moved between pens at 28-d intervals. Each of 4 experimental diets was fed in 2 standard and 2 GrowSafe pens. The diets contained (DM basis) 1) 85% DRB and 10% barley silage (CON); 2) 65% DRB, 20% triticale DDGS, and 10% barley silage (D-10S), 3) 65% DRB, 25% triticale DDGS, and 5% barley silage, and 4) 65% DRB, 30% triticale DDGS, and no barley silage. Supplement (5% of dietary DM) was included in all diets. Ruminal pH was measured over four 7-d periods using indwelling electrodes. Replacing barley silage with triticale DDGS linearly decreased mean ruminal pH (P = 0.006), linearly increased duration (P = 0.006 and P = 0.01) and area under the curve (P = 0.02 and P = 0.05) below pH 5.5 and 5.2, and linearly increased the frequency of subacute (P = 0.005) and acute (P = 0.05) bouts of ruminal acidosis. Variation in mean ruminal pH decreased (P = 0.008) in steers fed D-10S compared with CON. Similarly, variation in DMI was less for steers fed triticale DDGS compared with CON. Steers fed D-10S tended to have greater DMI (P = 0.08) but similar ADG and G:F compared with CON steers. Replacing barley silage with triticale DDGS tended to linearly decrease DMI (P = 0.10) and increase (P = 0.06) G:F. Compared with CON, steers fed D-10S tended to have greater backfat thickness (P = 0.10) and decreased dressing percentage (P = 0.06), ribeye area (P = 0.10), and meat yield (P = 0.06). Severity and number of abscessed livers was greater (P = 0.006) in steers fed D-10S compared with those fed CON. Although mean ruminal pH decreased as barley silage was replaced with triticale DDGS, the trend for improved growth suggests that reduced ruminal pH did not affect animal performance. Triticale DDGS can be substituted for barley silage in finishing diets in addition to a portion of barley grain without affecting growth performance or carcass quality, but it is recommended that an antimicrobial be included in the diet to reduce liver abscesses.

Feeding wheat dried distillers grains with solubles improves beef trans and conjugated linoleic acid profiles.

In western Canada, ethanol is produced mainly from wheat. As the demand for wheat increases, so do grain prices, which in turn creates incentives for feeding reduced-cost distillers coproducts to livestock. Substitution of wheat dried distillers grains plus solubles (DDGS) for barley grain may also create opportunities for enhancing beef fatty acid profiles because reducing starch concomitantly increases dietary fiber and oil and may shift PUFA biohydrogenation toward a healthier trans and CLA profile. To study this potential, heifers were fed diets containing 0, 20, 40, or 60% wheat DDGS (DM basis) substituted for rolled barley (n = 24; 133-d finishing period). Adding DDGS increased dietary oil (from 1.9 to 3.7%), but dietary fatty acid compositions remained consistent. Feeding increasing amounts of DDGS linearly decreased total diaphragm fatty acids on a milligram per gram basis (P = 0.031). For both brisket fat and diaphragm, feeding increasing amounts of DDGS caused linear increases in percentages of 18:2n-6 (P = 0.001) and total n-6 fatty acids (P = 0.001) but did not change the concentrations of individual or total n-3 fatty acids. Feeding increasing amounts of DDGS did not change the content of total trans MUFA in either brisket fat or diaphragm but led to linear decreases in 10t-18:1 (P = 0.033, brisket fat; P = 0.004, diaphragm) and increases in 11t-18:1 (P = 0.005, brisket fat; P = 0.003, diaphragm). Feeding increasing amounts of DDGS also caused a linear increase in 9c11t-18:2 (P = 0.044, brisket fat; P = 0.023, diaphragm) and total CLA (P = 0.086, brisket fat; P = 0.039, diaphragm). Overall, feeding DDGS enhanced the fatty acid composition of beef by decreasing 10t-18:1 while increasing the major CLA isomer (9c,11t-18:2) and its precursor 11t-18:1.

Effect of feed delivery fluctuations and feeding time on ruminal acidosis, growth performance, and feeding behavior of feedlot cattle.

Research was conducted to determine whether fluctuations in the amount of feed delivered and timing of feeding affect ruminal pH and growth of feedlot cattle. In Exp. 1, the effects of constant (C) vs. fluctuating (F) daily feed delivery on ruminal pH were assessed in a crossover experiment (two 28-d periods) involving six mature, ruminally cannulated steers. The diet consisted of 86.8% barley grain, 4.9% supplement, and 8.3% barley silage (DM basis) and was offered ad libitum for 2 wk to estimate DMI by individual steers. Steers in group C were offered a constant amount of feed daily equal to their predetermined DMI, whereas steers in group F were offered 10% more or less than their predetermined DMI on a rotating 3-d schedule. Ruminal pH of each steer was measured continuously via an indwelling electrode placed in the rumen during the last 6 d of each period. Mean pH tended to be lower (0.10 units) for F than C (5.63 vs. 5.73; P = 0.15), and ruminal pH of steers in group F tended to remain below 5.8 (P = 0.03) or 5.5 (P = 0.14) for greater proportions of the day than steers in group C. Inconsistent delivery of feed lowered ruminal pH, suggesting increased risk of subclinical acidosis. In Exp. 2, a 2 x 2 factorial was used to study the effects of pattern (C vs. F) and feeding time (morning [0900] vs. evening [2100]) on the feeding behavior and performance of 234 (310 +/- 23 kg) Charolais x Hereford beef steers during backgrounding and finishing phases over 209 d. One pen per treatment was equipped with a radio frequency identification (GrowSafe Systems Ltd., Airdrie, Canada) system that monitored bunk attendance by each steer throughout the trial. Pattern of feed delivery did not affect (P = 0.16) DMI (7.36 kg/d), ADG (1.23 kg/d), G:F (0.17), or time spent at the bunk (141 min/d), nor were pattern of feed delivery x time of feeding interactions observed (P = 0.18). Late feeding increased (P < 0.05) daily DMI (7.48 vs. 7.26 kg), ADG (1.28 vs. 1.00 kg/d), and G:F (0.21 vs. 0.15). These studies indicate that the risk of subclinical acidosis was increased with fluctuating delivery of feed, but the greater risk of acidosis did not impair growth performance by feedlot cattle. Consequently, daily intake fluctuations of 10% DMI or less that do not alter overall intake by feedlot cattle are unlikely to have any negative consequences on growth performance.

Value of sunflower seed in finishing diets of feedlot cattle.

The value of sunflower seed (SS) in finishing diets was assessed in two feeding trials. In Exp. 1, 60 yearling steers (479 +/- 45 kg) were fed five diets (n = 12). A basal diet (DM basis) of 84.5% steam-rolled barley, 9% barley silage, and 6.5% supplement was fed as is (control), with all the silage replaced (DM basis) with rolled SS, or with grain:silage mix replaced with 9% whole SS, 14% whole SS, or 14% rolled SS. Liver, diaphragm, and brisket samples were obtained from each carcass. In Exp. 2, 120 yearling steers (354 +/- 25 kg) were fed corn- or barley-based diets containing no SS, high-linoleic acid SS, or high-oleic acid SS (a 2 x 3 factorial arrangement, n = 20). Whole SS was included at 10.8% in the corn-based and 14% in the barley-based diets (DM basis). In Exp. 1, feeding whole SS linearly increased DMI (P = 0.02), ADG (P = 0.01), and G:F (P = 0.01). Regression of ME against level of whole SS indicated that SS contained 4.4 to 5.9 Mcal ME/kg. Substituting whole for rolled SS did not significantly alter DMI, ADG, or G:F (8.55 vs. 8.30 kg/d; 1.36 vs. 1.31 kg; and 0.157 vs. 0.158, respectively). Replacing the silage with rolled SS had no effect on DMI (P = 0.91) but marginally enhanced ADG (P = 0.10) and improved G:F (P = 0.01). Dressing percent increased linearly (P = 0.08) with level of SS in the diet. Feeding SS decreased (P < 0.05) levels of 16:0 and 18:3 in both diaphragm and subcutaneous fats, and increased (P = 0.05) the prevalence of 18:1, 18:2, cis-9,trans-11-CLA and trans-10,cis-12-CLA in subcutaneous fat. In Exp. 2, barley diets supplemented with high-linoleic SS decreased DMI (P = 0.02) and ADG (P = 0.007) by steers throughout the trial, whereas no decrease was noted with corn (interaction P = 0.06 for DMI and P = 0.01 for ADG). With barley, high-linoleic SS decreased final live weight (554 vs. 592 kg; P = 0.01), carcass weight (329 vs. 346 kg; P = 0.06), and dressing percent (58.5 vs. 59.4%; P = 0.04). Steers fed high-linoleic SS plus barley had less (P < 0.05) backfat than those fed other SS diets. No adverse effects of SS on liver abscess incidence or meat quality were detected. Although they provide protein and fiber useful in formulating finishing diets for cattle, and did improve performance in Exp. 1, no benefit from substituting SS for grain and roughage was detected in Exp. 2. Because of unexplained inconsistencies between the two experiments, additional research is warranted to confirm the feeding value of SS in diets for feedlot cattle.

Effect of a trainer cow on health, behavior, and performance of newly weaned beef calves.

Experiments were conducted to investigate the effects of the presence of a trainer cow on behavior, performance, health, and feeding patterns of newly weaned beef calves. In Exp. 1,252 weaned calves (270+/-18 kg) were allocated to 22 pens (11 to 15 calves per pen). A trainer cow was randomly assigned to each of 11 pens. Calves were weighed prior to feeding on d 0, 3, 7, 14, 21, and 28. Rectal temperatures were taken on each of these days (except d 28) and blood samples were collected on d 0, 3, and 7 and subsequently analyzed for serum haptoglobin and leukotoxin antibody titers. Instantaneous scan observations of calf behavior were made at 10-min intervals between 0730 and 1730 on d 1, 2, 4, 5, and 6. A similar protocol was used in Exp. 2, in which 297 calves (258+/-17 kg) were allocated to 24 pens. Blood analyses included haptoglobin, white blood cell counts (WBC), and neutrophil:lymphocyte (NL) ratios. In Exp. 3, the above protocol was followed and patterns of feed bunk attendance of individual calves were also monitored using radio frequency identification by passive transponder ear tags. Trainer cows did not influence (P > .10) calf rectal temperatures, requirements for antibiotic therapy, WBC, NL ratios, or leukotoxin antibody titers. Pooled across treatments, NL ratios were lower (P < .01) on d 0 (.31) than on d 3 (.36) or d 7 (.39). Although differences in weight gain were detected in some periods within the three experiments, there were no differences (P > .10) overall (d 0 to 28). Trainer cows did not affect (P > .05) frequency or duration of bunk visits by the calves. Averaged across treatments, frequency and duration of bunk visits increased (P < .001) from 9.6 visits/d and 56.7 min/d between d 0 and 3 to 12.3 visits/d and 108.9 min/d between d 15 and 21. The number of calves observed eating during scan sampling observations also increased from 16.4% on d 1 to 25% on d 4 (P < .10) and 29% on d 5 and 6 (P < .05). More (P < .05) calves were observed lying on d 1 (41.7%) and d 2 (45.3%) than on d 4 (37.5%), d 5 (34.8%), or d 6 (36.2%). With a trainer cow present, fewer (36.7% vs 41.5%; P < .001) calves were observed lying and more (11.7% vs 10.2%; P = .08) were observed walking than when no cow was present. Trainer cows did not improve calf health, time spent at the feed bunk, or performance of newly weaned calves.

Growth efficiency and digestibility of heated protein fed to growing ruminants.

Four trials were conducted to evaluate digestibility and growth efficiency caused by feeding heat-damaged protein. In Trial 1, 60 lambs (18.6 kg) were fed diets containing corn gluten meal (CGM) at five levels either of control (CGM-C) or heat-damaged (CGM-H), along with urea as the main supplemental N source. Efficiency of protein used for growth was determined by the slope-ratio technique. The heat damage to CGM decreased (P < .001) protein efficiency by 46%. In Trial 2, diets with the three highest CGM levels from Trial 1 were fed to 18 of the same lambs in a digestion trial. True N digestibility (TND) was 108% for CGM-C and was decreased (P < .05) 22% by heat damage. In Trial 3, 90 growing cattle (219 kg) were individually fed one of three protein supplements for 56 d. The protein supplement contained either a control source of dried distillers grains (DDG-C) or a heat-damaged source (DDG-H) at five levels, and a urea treatment was used as a negative control. Protein efficiency of DDG protein determined by the slope-ratio technique was decreased (P < .05) 34% by heat damage. In Trial 4, four yearling heifers (265 kg) were used in a 4 x 4 Latin square design to determine N digestibility of three diets used in Trial 3 (plus a diet not reported herein). True N digestibility averaged 98% for DDG-C and was decreased 7% by heat damage. These data suggest that some of the N in heat-damaged protein was absorbed postruminally but was not used for growth by growing ruminants.

Plasma amino acid response to graded levels of escape protein.

A trial was conducted to examine the potential of using plasma amino acid responses to graded levels of escape protein to determine limiting amino acids in cattle. Growing calves (n = 120; mean BW = 220 +/- 21 kg) were fed a basal diet of corncob:sorghum silage (61:39) and were individually supplemented with distillers' dried grains (DDG), heat-damaged DDG (H-DDG), feather meal (FTH), or urea. The urea supplement was mixed with DDG and H-DDG to allow 0, 20, 35, 50, 65, or 80% of the supplemental CP to come from distillers' protein and maintain an 11.5% CP diet. Urea supplement was mixed with FTH to allow 0, 22, 39, 56, 73, or 90% of the supplemental CP to come from FTH. Dietary CP ranged from 11.5% at the 0% level to 17.3% at the 90% level. Plasma concentration of most essential plasma amino acids responded (P less than .10) linearly and(or) quadratically to increased escape protein. The broken-line response of plasma methionine at low DDG intake suggested that methionine was limiting at low levels of escape protein. An initial decrease followed by a plateau fit by a broken line indicated that histidine became limiting in FTH diets, and lysine eventually became limiting for DDG, H-DDG, and FTH diets before maximum BW gain was reached. Results indicate that plasma amino acid responses may identify amino acids that become limiting with increasing escape protein.

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)