Roughage Levels in Feedlot Rations - PDF Document

Presentation Transcript

  1. during chopping. In after harvest had almost as much effect on protein as ammoniation vitro digestibility tended to be greater In the second trial, very high levels of ammonia, Levels of insoluble protein were much higher in this trial than the other. This reflects the high variability of corn silage. Recovery of nitrogen added as ammonia percent while all of the nitrogen added as urea was recovered. crude protein present increased similarly Addition of soluble carbohydrate (glucose) had no effect on insoluble protein content. Results suggest that NPN addition to corn silage may increase the content of insoluble, potential bypass protein. Whether this increased insoluble protein does escape ruminal digestion remains to be proven. A number ammoniated corn silage suggest that ammoniated cattle. If increased protein bypass is responsible, useful for starting cattle fed low protein rations. with ammoniation. urea or glucose were added. averaged 82 of insoluble The amounts of both urea and ammonia. with addition of feeding studies corn silage is used more efficiently by ammoniation froin Michigan with should prove most Roughage Levels in Feedlot Rations D. R. Gill, F. N. Owens, J. J. Martin, D. E. Williams, R. A. Zinn and R.J. Hillier Story in Brief (8 to 24 percent of ration dry matter) steam-flaked and a mixture for 121 days. Roughage thirds corn silage. Feed intake was about 7percent less and metabolizable 8.7 percent greater with steam-flaked and efficiencies of feed use were greatest steam-flaked grain, l2-percent roughage roughage with high-moisture corn 8-percent roughage ration increased high-moisture corn, it actually increased pound of gain. The greatest advantage roughage level. Rumination tended steers gained weight at a slower rate (3.30 vs. 3.38 pounds daily) than non-ruminating penmate~. The optimal level of roughage in a feedlot ration appears processsmg. Five levels of roughage corn types (high-moisture, pounds initially) were fed with three of the two) to 240 steers (747 ground alfalfa hay and two- was one-third energy about than with high-moisture for steers with grain. Although feed intake and replaced the amount of steam-flaked for steam-flaked to increase with added corn in the ration. Gains fed 8-percent the corn mixture addition of roughage corn energy for steers fed grain required grain was with the lowest roughage, roughage and with l6-percent to the per but ruminating to depend on grain Introduction Roughages of the ration or the rumen founder. Second, added roughage in the rumen both by reducing pH. Roughage may also aid ruminal fermentation. Certain ration. are included in high-concentrate contents increases rumination, particle size and by increasing mixing roughages also contribute for several helps avoid acidosis which may increase digestion saliva flow and ruminal to avoid abnormal protein, minerals rations reasons. First, and dilution with roughage or slimy types of and vitamins to the 1981 Animal Science Research Report 141

  2. .---.-----....--- However, feeding high levels of roughage to feedlot cattle is not always advantage- ous. High roughage levels will decrease gains and feed efficiency of feedlot cattle by reducing I) feed and energy intake and/or small intestine. In addition; certain regions of the US have a deficiency and roughage is an expensive dietary constituent. level on liver abscess incidence and animal investigation. The objective of this experiment processing and roughage level on performance Materials and Methods 2) fiber or starch digestion in the rumen or of roughage, the influence of roughage is an area needing was to determine the influence of corn of growing feedlot steers. Finally, behavior further Two hundred pens of eight steers each at Panhandle Angus, three black baldy, two Hereford Steers were implanted again on day 56 of the trial. Two types of processed percent moisture) or steam-flaked steers. A mixture of 50-percent fed to another 10 pens of steers. Five levels of roughage percent of ration dry matter (Table and 33 percent tub-ground used across roughage levels with little change in protein, potassium trations. To bring steers on feed, the roughage 30 percent for the next 5 days with further days until the final roughage level was reached. tylosin (Table I). The number determined on day 118. Steers were fed for 121 days and then trucked to Booker, Texas, for slaughter. Carcass measurements were obtained forty steers with an initial weight of747 pounds were allocated State University, and two exotic cross steers were in each pen. with Ralgro at the start of the experiment to 30 One Goodwell, Oklahoma. (April, 1980) and corn (24 grain, were each fed to 10 pens of and 50-percent steam-flaked were fed-8, I). The roughage consisted of67 percent corn silage alfalfa hay. This mixture permitted high-moisture corn (26 Ib/bushel), high-moisture grain was 12, 16,20 and 24 one supplement or calcium concen- to be level was 40 percent for the first 4 days, reduction by 4 percent All rations contained ruminating during a 12-hour period each subsequent monensin 5 and was of animals at slaughter. Results and Discussion Daily gains of steers are presented processing had little effect on live weight gain, but similar to most trials with various roughage levels, less roughage produced slightly higher dressing gave the lower roughage level an advantage in Tables 2 and 3. Roughage level and grain percentages, which when gain was calculated from carcass Table 1. Ration composition 1t8m Roughage Alfalfahay, tub ground 1/3 Cornsilage Concentrate Corn grain Soybean meal Cottonseed meal Urea Limestone Dicalciumphosphate KC1 Dehydratedalfalfameal Salt % 8-24 2/3 69-85 2.4 2.6 .35 .80 .20 .15 .20 .30 Trace mineral mix, monensin (30 gllOn), tylosin (9 gllon), vitamin A. added. Oklahoma Agricultural Experiment Station 142

  3. Table 2. Dally gain (final live wt - 4 percent) Roughage level(%ofOM) 16 3.07 3.20 3.22 3.05 3.09 3.07 3.13 3.10 Corn HMC V2HMC, V2SF SF x B 12 20 3.01 3.21 3.05 3.09 24 3.11 3.12 3.10 3.11 I 3.04 3.06 3.26 3.12 3.09 3.13 3.11 Table 3. Dally gain (carcass wt/62 percent) Roughagelevel (% of OM) 12 16 3.48 3.57 3.34 3.35 3.33 Corn 20 I B 24 3.34 3.49 3.49 HMC V2-V2 SF 3.31 3.52 3.70 3.36 3.50 3.28 3.39 3.48 3.43 3.45 3.51 3.45 3.38 3.38 3.44 Table 4. Dallyfeed Roughage level(%ofOM) 16 20.0 20.3 20.3 19.5 18.1 19.1 19.58 19.7ab I Corn HMC V2-V2 SF B 12 20 20.8 20.9 19.0 20.2b 24 21.7 19.6 20.2 20.5b 20.SC 19.8b 19.08 19.5 19.0 18.6 19.08 abcMeans in a row or column With different superscripts differ significanUy (P< .05). Table 5. Dally concentrate Intake Roughage level(%ofOM) 16 17.1 16.7 17.4 16.1 15.5 15.8 I 16.8 16.3 15.6 20 16.4 16.5 15.0 24 16.4 14.7 15.2 Corn HMC V2- V2 SF 12 B 17.3 16.8 16.4 15.4 16.2 16.0 16.8 16.7 weight. The optimal roughage level for rate of gain differed with grain processing. With high-moisture corn, 16percent roughage produced the greatest gain while with steam- flaked corn, gain was greatest with 8 percent roughagein the ration. Feed and concentrate intakes were about 7 percent grain. Since gains were equal, this indicates that the increased energy availability reducing feed intake. Feed and concentrate intakes are presented in Tables 4-and 5. Averaged across corn type, for every percentage of the ration in which roughage substituted for grain, feed intake increased by .5 percent. Amounts of feed and concentrate required per pound ofgain are presented in Tables 6 and 7.As a higher roughage level was used, feed required per pound ofgain increased. Flaking half the grain improved feed efficiency by 5.7 percent, and total flaking improved feed efficiency by 8.2 percent compared with high-moisture grain. Metabolizable energy (ME) provided from steer weights and gains, is presented together with standard values from the literature in Table 8. Metabolizable energy was 6.3 percent greater for steam-flaked less for steam-flaked than high-moisture was by the rations, calculated 143 1981 Animal Science Research Report

  4. Table 6. Feed/gain (based on carcass gain) Roughage level(%ofOM) 16 5.80 5.83 5.69 5.85 5.41 5.75 X 6.05b 5.708 5.55a Com HMC Y2-V2 SF 8 12 20 6.18 5.96 5.79 24 6.52 5.60 5.78 5.92 5.39 5.03 5.47a 5.63ab 5.81bc 5.98c 5.97" abcMeans in a row or column with different superscripts differ significanUy (P< .05). Table 7. Feed/gain (concentrate portion only) Roughage level (% of OM) 16 4.96 4.85 4.87 4.82 4.63 4.74 Com HMC V2- V2 SF 8 12 20 4.88 4.71 4.57 24 4.91 4.22 4.36 X 4.96b 4.68 4.55a 5.24 4.78 4.45 4.82 4.82 4.78 4.72 4.50 abMeans in a column with different superscripts differ significantly (P< .05). Table 8. Metabolizable energy of ration (Kcal/g) Roughage level(% 01OM) 16 3.23 3.23 3.31 3.21 3.39 3.28 Com HMC Y2- V2 SF 8 12 20 3.09 3.20 3.27 24 3.02 3.27 3.26 x 3.16a 3.27b 3.36c 3.28 3.36 3.57 3.38a 3.31ab 3.24bc 3.19c 3.19c Literature for rations value 3.11 3.08 3.05 3.02 2.99 abcMeans in a row or column with different superscripts differ significantly (P< .05). Table 9. Metabolizable energy advantage of rations above literature values 00 Roughage level(%01OM) Com 8 12 HMC + 5.4 + 4.9 Y2- V2 + 8.0 + 7.5 SF + 14.8 + 10.1 24 16 20 x + 5.9 + 5.2 + 7.5 + 2.3 + 6.0 + 8.3 + 1.0 + 9.4 + 9.0 + 3.6 + 7.2 +10.2 + 8.7 + 7.5 + 6.2 + 5.6 + 6.7 than high-moisture energy in the flaked than in high-moisture ration were lower than metabolizable energy value of the ration by an average of.35 percent for every I percent roughage. Comparisons with specific rations are shown in Table 9. The advantage ME for steam-flaked grain and the mixture roughage while with the high-moisture corn, the 16-percent roughage lated ME the most. Results again indicate moisture corn tends to replace the corn whereas adding a similar amount of roughage to steam-flaked corn is detrimental. This suggests rations, so the grain alone had 8.7 percent form. Literature the observed ME in all cases. Added more metabolizable values for the ME of the roughage decreased in of grains was greatest with 8-percent exceeded calcu- roughage that adding 8-percent to high- that the associative effect of addin~ 144 Oklahoma Agricultural Experiment Station --

  5. Table 10. Carcass traits or measurements across roughage levels Com Carcass wi Dress, % Liver abscess incidence, % Cooler shrink, % Rib eye area, in.2 Fat thickness, in. KHP, % Marbling scorea Cutability, % Dark cutters, % Fed gradeb Choice, % a13 = smallminus; 14 = small. b12 = highgood; 13 = lowchOice. Va-Va 722 61.8 5.2 1.7 12.4 "MC 719 61.4 7.5 1.6 12.1 SF 721 61.5 6.2 1.5 12.3 .59 3.14 14.1 48.8 5.2 13.0 74.8 .62 .60 3.06 14.0 48.9 7.5 12.9 73.8 3.05 14.2 48.8 5.0 13.0 74.8 Table 11. Carcass traits and rumination averaged across corn types Roughage, % . 12 Carcass weight 723 722 Dress, % 62.0 61.5 Liver abscess, % 6.2 6.2 Cooler shrink, % 1.6 1.6 Rib eye area, in.2 12.5 12.3 Fat thickness, in. .58 .63 KHP, % 3.03 3.03 Marbling score 13.7 13.8 Cutability, % 49.1 48.7 Dark cutters, % 8.6a 8.3a Federal grade 12.9 12.9 Choice, % 76.8 70.8 Ruminating, % 17 22 16 716 61.3 6.2 1.5 12.4 20 721 61.4 8.6 1.7 12.1 24 723 61.6 4.2 1.5 12.1 .57 .62 .62 3.09 13.9 49.1 4.1ab 12.9 77.1 37 3.17 14.0 48.5 8.3a 12.8 70.5 31 3.07 14.8 48.6 O.Qb 13.2 77.1 45 abMeans in a row with different superscripts differ significantly (P< .05). roughage with high-moisture adverse effects of roughage their ruminal degree of any associative 1980). Grain type and roughage level effects on rumination small (Tables 10 and II). 12-hour observation period Incidence of liver abscesses lower roughage levels. This suggests agement, engorgement and acidosis Because incidence of ruminantion performance and carcass non-ruminating pen mates (Table cattle fed higher roughage levels, there is no indication superior for ruminating steers. Ruminating than non-ruminating steers and had a slightly higher incidence to grain varies with grain processing, grains. with poorly processed grain only. Since roughages retention time, digestibility effect also varies with the type of roughage being greater with steam-flaked it had been assumed than Previously, that one would expect differ in time, the and effect on intestinal transit fed (Teeterel al., and carcass composition ruminating with roughage with 20-percent roughage that liver abscesses more than ration composition. increased with roughage characteristics of steers ruminating 12). Despite the trend for increased were The percentage tended was greatest of steers observed to increase during a level in the ration. rather probably reflect feed man- than the level in the ration, were compared rumination that performance steers actually gained weight less rapidly with of or health was of abscessed livers. 1981 Animal Science Research Report 145 ---

  6. Table 12. Comparison of ruminating with non-ruminating penmate steers Itlm Non-ruminating Daily gain 3.388 Abscess incidence, % 6.7 Marbling score 14.3 Cutability, % 48.7 Fat thickness .6~ Choice, % 76 Ruminating 3.30b 7.4 14.2 48.9 .58d 76 abMeans differ at the 5 percent cdMeans differ at the 10 percent probability probability level. level. Higher roughage of roughage recent trials digested in the rumen. acidosis, the amount roughage. If roughages forage for feedlot time, such as particle will simplify management, the level of roughage of high-concentrate If roughage simply of roughage needed depends primarily are fed as a safety factor, cattle are not justified. Instead, size, density and bulk Literature the type and form in the ration. indicate that in the rumen on the residence premiums for more digestible influencing ruminal of the roughage, are of major Cited but, again, rations may be more important with high than Some intakes rations grain no fiber to prevent time of the is dilutes price factors retention interest. Teeter, R. G. elai. 1980. Okla. Agr. Exp. Sta. Res. Rep. MP-107:156. Influence of Level of Feed Intake on Digestive Function. I. Nitrogen Metabolism R. A. Zinn and F. N. Owens Story in Brief Four Angus steers (568 pounds) equipped with "T" duodenum and distal ileum were used to study the influence of feed intake level on nitrogen metabolism. Treatments consisted ofan 80-percent concentrate diet fed at 1.6, 1.8,2.0 and 2.2 percent of body weight. Increasing level of intake from 1.6to 2.2 percent resulted in a 52-percent increase in bypass and a 59-percent increase in metabolizable protein content offeed. There was an apparent curvilinear relationship between level of feed intake and bypass which led to the following conditions of this study, the break point at which feedintake isdirectly related to rumen retention occurs in the neighborhood of 1.8 percent body weight; 2) as feed intake cannulas in the proximal conclusions: I) under the given 146 Oklahoma Agricultural Experiment Station