Proceedings, Western Section, American Society of Animal Science

 

Vol. 49, 1998
 

FEEDING VALUE OF BARLEY VARIETIES FOR FINISHING CATTLE1
 

L.M.M. Surber*, J.G.P. Bowman, T. K. Daniels, T. J. Milner, A. L. Lewis, D. M. Coulson, and T. K. Blake

Montana State University, Bozeman, MT 59717.

 

ABSTRACT: Eighty crossbred steers (avg initial wt 365 kg) were allotted to 16 pens in a randomized complete block design to determine the effects of four barley varieties on feedlot performance, nutrient digestion, and carcass characteristics. Four diets based on: 1) Baronesse (BAR); 2) Lewis (LEW); 3) Morex (MOR); and 4) Steptoe (STE) barley were balanced to be isonitrogenous (2.24% N), and isocaloric (1.39 Mcal NEg/kg). Pen was the experimental unit in the 125 d experiment. Steers were weighed, and diet, ort and fecal samples were obtained every 28 d. Diet and fecal samples were composited by pen and analyzed for DM, N, ADF, AIA, and starch. AIA was used as an internal marker to estimate fecal output and to calculate nutrient digestion. Steers were slaughtered when 70% were visually estimated to grade Choice. Hot carcass weight was used as a covariate for the analysis of carcass characteristics. Steers fed MOR were 19.7 kg heavier (P = .09) than those fed LEW and STE after 125 d. Average daily gain was 11% higher (P = .06) for MOR-fed steers compared with LEW- or STE-fed steers (1.61 vs avg 1.45 kg/d). Steers fed BAR were intermediate in final weight and ADG performance. Feed efficiency did not differ (P > .10) among diets (avg 16.8 kg gain/100kg feed). No differences (P > .10) were detected between diets for any carcass characteristic (avg 318 kg hot carcass wt, 1.9% KPH, 1.1 cm fat thickness, 74.3 cm2 longissimus muscle area, 2.9 yield grade, low choice quality grade). Digestible starch intake was greatest (P = .004) for MOR-fed steers ( 4.58 kg/d) compared with BAR- and LEW-fed steers (avg 4.22 kg/d), and least for STE-fed steers (3.67 kg/d). Barley variety influenced feedlot performance and nutrient digestion, however carcass characteristics were not affected. Morex, a malting variety, had superior feeding value for finishing steers compared with Baronesse, Lewis or Steptoe barleys. 
 

Key Words: Barley, Feed Quality, Feedlot Performance
 

Introduction
 

Presently, barley varieties are classified as either malt or feed quality. Specific criteria are used to determine malting standards. If a barley variety does not meet such standards it is classified as feed quality. No system is in place to evaluate the feeding value of barley. 

Differences exist between barley varieties for in vitro and in vivo digestibility, animal performance, and carcass characteristics (Ovenell et al., 1993; Boss and Bowman, 1996; Surber and Bowman, 1998). The causes of these different feeding values is undetermined. The focus of this research is to examine the factors that influence feeding value using a cattle feeding experiment.

The objectives of this study were to determine the effects of four barley varieties on feedlot performance, nutrient digestion, carcass characteristics. These factors will be used to express overall feeding value.
 

Materials and Methods
 

Eighty Angus x Hereford steers (avg initial wt 365 kg) were allotted to 16 pens in a randomized complete block design for 125 d growth trial. Four diets based on: 1) Baronesse (BAR); 2) Lewis (LEW); 3) Morex (MOR); and 4) Steptoe (STE) barley were balanced to be isonitrogenous (2.24% N), isocaloric (1.39 Mcal NEg/kg) and to meet or exceed NRC (1984) requirements for Ca, P, and other nutrients. The barley varieties chosen represent a range of genotypes available for feeding. Baronesse is a European two-row feed variety that was planted on over 161 thousand acres in Montana in 1996 (Montana Agricultural Statistics, 1996), making up 12.4 % of the total state barley acreage. Lewis is a two-row variety released by Montana Agricultural Experiment Station and planted to 32 thousand acres in 1996 (2.5 % of the state total). Morex is the American Malting Barley Association's standard malting variety, planted to 10 thousand acres in 1996, and Steptoe is a high-yielding six -row traditional feed variety. The barleys were grown at two locations near Havre, Montana. Composition of the grains is displayed in Table 1. All grains were coarsely cracked through a hammer mill prior to mixing. Grass hay was chopped to 5.1 cm. Diet composition is presented in Table 2.
 

Table 1. Composition of Baronesse, Lewis, Morex, and Steptoe barley varieties. 
 
Item BAR LEW MOR STE
DM, % 88.36 90.71 90.38 91.16
CP, % of DM 12.88 14.12 13.40 10.75
ADF, % of DM 5.14 4.33 5.21 7.52
Starch, % of DM 51.14 52.63 52.44 50.34
Density, kg/L .61 .62 .57 .56

 

Steers were implanted at the beginning of the study (Ralgro®, Mallinckrodt Veterinary, Mundelein, IL). A 28 d adaptation period was used to adjust steers to their respective diets. Steer were given ad libitum access to water and were offered feed once daily at approximately 0800. Feed bunks were inspected before feeding, and the amount of feed offered was adjusted daily. Steers were weighed, and diet, ort and fecal samples were obtained every 28 d. Initial and final weights were the average of weights obtained on two consecutive days. Diet and fecal samples were composited by pen and analyzed for DM, N, (AOAC, 1997) ADF (Van Soest et al., 1991), acid insoluble ash (AIA; Van Keulen and Young 1977), and starch (AOAC, 1997). AIA was used as an internal marker to estimate fecal output and to calculate apparent nutrient digestion. 

Steers were slaughtered when 70% were visually estimated to grade Choice (IBP, Pasco, WA). Hot carcass weight were obtained on the day of slaughter. All other carcass measurements were taken after a 24 h chill. Quality grade and marbling score were assigned by a USDA grader. 

Data were analyzed by the GLM procedure of SAS (1993) with pen as the experimental unit. Performance and carcass data were analyzed as a completely randomized design. Hot carcass weight was used as a covariate for the analysis of carcass characteristics. Digestibility data were analyzed utilizing the repeated measures procedure of SAS (1993). Sums of Squares were separated into effects of treatment, time on feed, and treatment x time interaction. Treatment least square means were separated by the LSD method (SAS, 1993) if the treatment F-test was significant (P < .10). 
 

Results and Discussion
 

Steers fed MOR were 19.7 kg heavier (P = .09) than those fed LEW and STE (avg 546.6 kg)after 125 d, while BAR was intermediate (554.8 kg) ( (Table 3). Average daily gain was 11% higher (P = .06) for MOR-fed steers compared with LEW- or STE-fed steers (1.61 vs avg 1.45 kg/d) (Table 3). Steers fed BAR were intermediate in final weight and ADG performance. During the adaptation period, there was difference (P > .10) between treatments for ADG (avg 2.03 kg/d). At 56 d , steers fed MOR gained 14.4 % faster (P = .04) (1.91 kg/d) than steers fed LEW and STE (avg 1.67 kg/d), with BAR intermediate to both. After 112 d, MOR-fed steers had superior gain (1.65 kg /d)(P = .03) when compared to BAR, LEW, and STE fed cattle(avg 1.49 kg/d). Boss and Bowman (1996) found that feeding Harrington resulted in superior ADG when compared to other feed grade varieties. Harrington is a two-row malting barley. Steptoe barley has resulted in reduced rate of gain in steers when compared to malting-type barley (Hinman, 1979; Ovenell and Nelson, 1992; Ovenell et al., 1993).

During the adaptation period there were no differences (P > .10) detected between treatments for DM intake (Table 3). However, steers fed MOR had better (P = .09) feed conversion (26.5 kg gain/100 kg feed) at this time point when compared to LEW (22.5 kg gain/100 kg feed). BAR and STE fed steers had intermediate feed efficiencies (avg 24.8 kg gain/100 kg feed). Steers consuming BAR, LEW and MOR had greater (P < .04) DM intakes when compared to STE at 56 d and 84 d. At 125 d, MOR-fed steers consumed 4.7 % more when compared to BAR and LEW and 10.7 % more than STE (P = .01). Feed efficiency did not differ (P > .10) among diets (avg 16.8 kg gain/100 kg feed) at 125 d. 

No differences (P > .10) were detected between diets for any carcass characteristic (avg 318 kg hot carcass wt, 1.9% KPH, 1.1 cm fat thickness, 74.3 cm2 longissimus muscle area, 2.9 yield grade, low choice quality grade) (Table 4). These non significant results are not uncommon as supported by the findings of Bradshaw et al., (1992) and Ovenell et al., (1993). However, our results disagree with the findings of Boss and Bowman (1996), who reported differences between barley varieties for hot carcass weight, marbling score, USDA quality grade, and USDA yield grade. 

No treatment x time on feed interaction was detected (P > .10) for apparent nutrient digestibilities therefore, main effects are presented (Table 4). Dry matter and starch intake were 4.4 % and 11.1 % greater (P >.01), respectively, for steers consuming MOR than BAR and LEW and 8.3 % and 25.6 % more than STE. Starch digestibility was lowest (P = .02) for LEW, intermediate STE, and highest for steers consuming BAR. Digestible starch intake was greatest (P = .004) for MOR-fed steers ( 4.58 kg/d) compared with BAR- and LEW-fed steers (avg 4.22 kg/d), and least for STE-fed steers (3.67 kg/d). Boss and Bowman (1996) suggested there is a linear relationship between ADG and digestible starch intake.

Our data would tend to support this theory. 

Time on feed affected (P > .01) intake, digestibility, and digestible intake of DM and starch (Table 6). Starch intake increased (P > .01) over the feeding period. Apparent starch digestibility was lower after 112 d on feed than earlier in the feeding period. Intake of digestible starch increased (P > .01) with time on feed. 
 

Implications
 

Barley variety influenced feedlot performance and nutrient digestion, however carcass characteristics were not affected. Morex, the American Malting Barley Association standard, had superior feeding value for finishing steers compared with Baronesse, Lewis or Steptoe barleys. 
 

Literature Cited
 

AOAC. 1997. Official Methods of Analysis of AOAC International (16th. Ed.) AOAC International, Gaithersburg , MD.

Boss, D. L., and J.G.P. Bowman. 1996. Barley Varieties for Finishing Steers: I. Feedlot Performance, In Vivo Diet Digestion, and Carcass Characteristics. J. Anim. Sci. 74:1967-1972.

Bradshaw, W. L., D. D. Hinman, R. C. Bull, and D. O. Everson. 1992. Steptoe vs Klages barley varieties and processing methods on feedlot steer nutrient digestibility, carcass characteristics, and performance. Proc. West. Sect. Am. Soc. Anim. Sci. 43:548

Hinman, D. D. 1979. A comparison of malting vs feed barley varieties on beef cattle performance. Proc. West. Sect. Am. Soc. Anim. Sci. 30: 49-50.

Montana Agricultural Statistics Service. 1996. Montana Agricultural Statistics, Volume XXXIII. Helena, MT.

NRC. 1984. Nutrient Requirements of Beef Cattle (6th Ed.). National Academy Press, Washington, DC.

Ovenell, K. H. and M. L. Nelson. 1992. Feedlot performance, carcass characteristics of steers, and digestibility of diets containing different barley cultivars. Proc. West. Sect. Am. Soc. Anim. Sci. 43:35-38.

Ovenell, K. H., M. L. Nelson, J. A. Froseth, S. M. Parish, and E. L. Martin. 1993. Feedlot performance, carcass characteristics of steers, and digestibility of diets containing different barley cultivars. Proc. West. Sect. Am. Soc. Anim. Sci. 44:416-419.

SAS. 1993. SAS/STAT User Guide. SAS Inst. Inc., Cary, NC.

Surber, L.M.M., and J.G.P. Bowman. 1998. Monensin effects on digestion of corn or barley high concentrate diets. J. Anim. Sci. 76:(In press). 

Van Keulen, J., and B. A. Young. 1977. Evaluation of Acid-insoluble ash as a natural marker in ruminant digestibility studies. J. Anim. Sci. 44:282.

Van Soest, P. J., J. B. Robertson, and B.A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:2866. 


Table 2. Composition of finishing diets based on Baronesse, Lewis, Morex, and Steptoe barley variteies.
 
Barley Variety
Item BAR LEW MOR STE
Ingredient
Cracked barley 83.000 83.000 83.000 83.000
Grass hay 6.000 6.000 6.000 6.000
Oil 2.910 2.000 2.000 2.000
Ground barley 2.989 2.989 2.989 1.489
Urea, 45% N 1.000 0.500 0.900 1.500
Calcium carbonate 1.363 1.863 1.300 1.363
Sodium bicarbonate 1.300 1.300 1.300 1.300
Soybean meal - - - 1.000
Oil in supplement 0.090 1.000 1.000 1.000
Sodium chloride 0.500 0.500 0.500 0.500
Potassium chloride 0.500 0.500 0.500 0.500
TM premix a 0.250 0.250 0.250 0.250
Vitamin A, D, E premix b 0.050 0.050 0.050 0.050
Rumensin premix c 0.024 0.024 0.024 0.024
Tylan premix d 0.013 0.013 0.013 0.013
Microgrits - color 0.011 0.011 0.011 0.011

a Contained 20.0% Mg, 6.0% Mn, 5.0% Fe, 2.7% S, 1.5% Cu, .11% I, .01% Se, and .01% Co.

b Contained 30,000 IU/g vitamin A, 6,000 IU/g vitamin D, and 7.5 IU/g vitamin E.

c Contained 132 g/kg of monensin.

d Contained 88 g/kg of tylosin.
 
 
 

Table 3. Performance of steer fed finishing diets based on Baronesse, Lewis, Morex, and Steptoe barley varieties.
 
Barley variety
Item BAR LEW MOR STE SE Pr > F
No. of pens 4 4 4 4 - -
Weight, kg
Initial 365.1 363.9 364.5 366.4 .65 .11
125 d 554.8ab 544.3a 566.2b 548.8a 5.64 .09
ADG, kg/d
0 - 28 d 2.04 1.89 2.23 1.94 .098 .13
0 - 56 d 1.79ab 1.68a 1.91b 1.66a .058 .04
0 - 84 d 1.63 1.56 1.7 1.52 .057 .19
0 - 112 d 1.53a 1.47a 1.65b 1.47a .039 .03
0 - 125 d 1.52ab 1.44a 1.61b 1.46a .042 .06
DMI, kg/d
28 d 8.22 8.36 8.41 7.88 .218 .35
56 d 8.66b 8.55b 8.77b 8.03a .167 .04
84 d 8.89b 8.81b 9.10b 8.20a .159 .01
112 d 8.95b 8.98b 9.37c 8.44a .163 .01
125 d 8.98b 9.02b 9.43c 8.52a .160 .01
FE, kg gain/100 kg feed
28 d 24.9ab 22.5a 26.5b 24.6ab .99 .09
56 d 20.6 19.6 21.7 20.7 .54 .12
84 d 18.4 17.7 18.7 18.6 .60 .67
112 d 17.1 16.4 17.6 17.5 .48 .34
125 d 17.0 16.0 17.1 17.1 .53 .40

a, b, c Means in a row that do not have a common superscript differ (P < .10).
 
 
 

Table 4. Carcass characteristics of steers fed finishing diets based on Baronesse, Lewis, Morex, and Steptoe barley varieties.
 
Barley variety
Item BAR LEW MOR STE SE Pr > F
No. of pens 4 4 4 4 - -
Hot carcass wt, kg 321.7 311.2 326.1 314.4 4.81 .18
Dressing %, unshunk 57.8 57.9 56.9 57..4 .50 .55
Kidney, pelvic, and heart fat, % 1.9 2.0 1.9 1.8 .13 .53
Fat thickness, cm 1.19 1.13 1.04 1.06 .088 .57
Longissimus muscle area, cm2 74.1 74.7 73.3 74.9 2.25 .97
Marbling scorex 4.6 4.9 4.5 4.4 .23 .49
USDA quality gradey 12.0 12.4 12.1 12.0 .23 .55
USDA yield grade 3.0 3.0 2.9 2.8 .05 .63

a, b, c Means in a row that do not have a common superscript differ (P < .10).

x Marbling score: Slight = 3, Small = 4, Modest = 5, etc.

y Coded as SE = 11, CM- = 12, CH = 13, CH+ = 14.
 

Table 5. In vivo nutrient digestibilities by steers fed finishing diets based on Baronesse, Lewis, Morex, and Steptoe barley varieties.
 
Barley variety
Item BAR LEW MOR STE SE Pr > F
No. of pens 4 4 4 4 - -
Intake, kg/d
DM 8.96b 8.99b 9.38c 8.44a .114 .01
Starch 4.44b 4.44b 4.81c 3.83a .115 .002
In vivo digestibility, %
DM 80.32b 78.60b 77.92b 75.40a 1.097 .03
Starch 96.70c 93.39a 95.27b 95.79bc .551 .02
Digestible Intake, kg/d
DM 7.20b 7.08b 7.30b 6.37a .145 .002
Starch 4.29b 4.15b 4.58c 3.67a .124 .004

a, b, c Means in a row that do not have a common superscript differ (P < .10).
 
 
 

Table 6. Effect of time on feed on in vivo nutrient digestibilities by steers fed finishing diets based on Baronesse, Lewis, Morex, and Steptoe barley varieties.
 
Time on feed
Item 28 d 56 d 84 d 112 d SE Pr > F
No. of pens 16 16 16 16 - -
Intake, kg/d
DM 8.22a 8.79b 9.26c 9.49c .114 .0001
Starch 4.02a 4.31b 4.44b 4.76c .115 .0007
In vivo digestibility, %
DM 77.05ab 74.90a 81.11c 79.17bc 1.098 .002
Starch 96.17b 93.74a 96.80b 94.46a .551 .001
Digestible Intake, kg/d
DM 6.33a 6.59a 7.50b 7.52b .145 .0001
Starch 3.86a 4.05ab 4.29bc 4.50c .124 .005

a, b, c Means in a row that do not have a common superscript differ (P < .10).