Practical Lessons in Feeding Bison Bulls for Meat

Introduction

Bison production is increasing in the Northern plains states and provinces due to producers’ individual efforts and the organization of a cooperative to process and market bison meat. Bison are native ruminants that roamed the prairie regions prior to settlement by man. They are highly adapted to the region’s climate and plant communities. Privately owned bison cow herds are currently managed for commercial production using modern grazing practices developed for beef. Bison bulls not selected for breeding are harvested for meat. However, feeding bison bulls for meat poses unique challenges due to several behavioral factors that are specific to the species. Few commercial feed yards feed bison. Most producers feed their own bulls using anecdotal information and trial and error practices. Little is known about the nutrient requirements of bison and optimum bison feeding systems. A formal bison research program is being developed at the North Dakota State University Carrington Research Extension Center to provide both basic and practical information to bison producers throughout the continent. In the meantime, practical feeding studies are being conducted with cooperating bison producers. Three studies reported here focus on alternative feeds, energy levels, corn type and processing, and feed delivery systems for bison bulls fed for meat.

Materials and Methods

Three on-farm bison feeding trials were conducted at the Double MM Bison Ranch, Carrington ND, in successive years starting in 1994. The trials were conducted using a 4 x 4 Latin Square experimental design. Approximately 80-day feeding periods closely associated with season were used in Experiments 1 and 2. There were approximately 20 bison bulls assigned per pen. Bulls were managed together for at least 60 days prior to the start of each trial. Bison were weighed at the start of each trial and assigned to initial treatment/pen by order through the chute. Pens were identical in size (50 x 100 ft), fence construction, waterer type and orientation, drainage pattern, and wind protection. At the end of each feeding period, bison were weighed and moved to a new treatment/pen based on pre-planned random assignment. Feed consumption and gains were summarized for each period.

Experiment 1

Four different diets were compared to study alternative feeds in manufactured pelleted bison rations (Anderson and Miller, 1995). The treatments were based on unique ingredients in the diets. The diets were described as: 1) wheat screenings; 2) wheat middlings (mill run); 3) crambe meal; and 4) a proprietary commercial bison diet. Diet formulation and nutrient analysis of the diets is presented in Tables 1 and 2. The pelleted diets were offered in self-feeders and big round bales of long stemmed grass hay placed in ring feeders. Bison bulls (avg. wt. 470 lbs. ± 29.5) were placed on trial February 15, 1994.

Experiment 2

Energy level, corn type, and corn processing were evaluated using four different diets (Table 3). Treatments were: 1) 85% wheat screenings with 15% corn pelleted as an homogenous product (Screenings); 2) 75% rolled dent corn and 25% pelleted screenings supplement (RolledDent); 3) 75% rolled waxy corn and 25% pelleted screenings supplement (RolledWxy); and 4) 75% whole waxy corn and 25% pelleted screenings supplement (WholeWxy). Bison bulls (avg. wt. 604 ± 15.6 lbs.) were placed on trial June 21, 1995.

Experiment 3

Treatments were methods of delivering feed to bison bulls (avg. wt 653 ± 172 lbs.) fed for meat. They were: 1) totally mixed ration (TMR) (75% pelleted concentrate and 25 % chopped grass hay fed once daily to appetite in a fence line bunk; 2) separate feeding of pelleted concentrate (fed daily to appetite in a fence line bunk) and grass hay (SEP); 3) pelleted concentrate fed in an automatic feeder (AUTO) with grass hay available, and 4) pelleted concentrate offered free choice in a self-feeder (SELF) with grass hay available. The self-feeder was a conventional calf creep feeder mounted on wheels. The pelleted concentrate was formulated using 75%wheat screenings, 15% corn grain, 5% dried molasses and 5% salt and mineral supplement. The commercially manufactured pelleted bison ration averaged 90.32% dry matter, 14.96% crude protein, 15.24% ADF and 28.67% NDF, and 8.17% ash. Long stemmed grass hay (89.16% dry matter, 7.55% protein, 43.02% ADF, 72.63% NDF, and 9.58% ash) was fed as large round bales in ring feeders. The trial started August 6, 1996 and animals were rotated to a new feeding system in a pre-planned random order every 49 days. The TMR and SEP animals were fed to appetite based on daily bunk readings. The AUTO feed was delivered 5 times daily to a bunk placed under the discharge spouts. The “Chuck Wagon” feeder was manufactured by Sheyenne Advanced Feeding Systems, Cooperstown, ND.

Statistical Analysis

Data were analyzed using general linear model procedures according to SAS (SAS, 1988). Pen was the experimental unit and period the replicate for dietary comparison. In Experiment 1, diet treatments were initially compared using all four periods (seasons). Significant effects of winter (P<.01) suggest more sensitive dietary comparisons may be made using only spring, summer and fall periods. Granted that winter-feeding is important for evaluation of rations, in this study, variation caused by decreased winter gains and differential feed intake suggested a second comparison. All periods were used as replicates in Experiments 2 and 3. In Experiments 1 and 2, data were pooled across dietary treatments to compare effects of season.

Results

Experiment 1

Dietary comparisons indicate intake of pelleted feed, hay, and total dry matter was not affected by diet treatment (P>.10) within the range of this study (Table 4). Average daily gain for bison fed the wheat screenings diet was higher (P=.07) than for bison consuming the crambe meal diet with the other two treatments intermediate. In comparing effects of season, daily gains averaged 1.72 lbs. during spring, 1.39 lbs. during summer, 1.76 lbs. during fall, and .37 lb. during the winter ± .24 lb. Winter gains were lower (P<.01) than the other seasons (Table 5) and feed per unit gain was severely affected. Dry matter intake per unit body weight was not affected by season (P>.10).

Experiment 2

In dietary evaluations (Table 6), hay intake was higher (P<.05) for Screenings than RolledWxy and WholeWxy with RolledDent intermediate. Total DM intake was similar for all treatments. While not significant (P>.10), DM/Gain was 27% more efficient for the rolled corn diets compared to the Screenings treatment. Gains increased numerically (23%) but not to a significant level (P>.10) with 75% rolled corn in the diet. The sensitivity of this experimental design may be questioned but trends are useful in early work with bison.

Differences (P<.05) were observed due to season with improved performance during summer and fall vs. winter and spring. (Table 7). Dry matter intake expressed as percent of bodyweight was greater (P<.05) for summer and fall vs. winter and spring (2.91 and 2.74 vs. 1.84 and 1.76, respectively). Average daily gains were greater (P<.05) during the summer and fall (1.85 and 1.94 lb/hd/day) vs. winter (.99 lb/hd/day) with spring gains intermediate. Dry matter intake was reduced during the winter and spring enough to offset the reduced gains and render feed efficiency similar (P<.05) over all periods.

Experiment 3

The results of this study (Table 8) suggest feeding system may have some impact on the feed intake but limited effect on the performance of bison. Average dry matter intake was less (P<.05) for TMR at 24.26 lb/hd/day compared to the other three treatments averaging 26.9 lbs. This may be due to differences in hay intake as the TMR diet was consumed with virtually no waste while the ring feeders had more waste. The TMR hay level was established at 25% of the ration as fed. This is less hay intake than occurred in the other three treatments with free choice hay. No estimate of hay consumption vs. waste was made in this study but hay placed in the feeders average 13.27 lb/hd/day vs. 6.79 consumed in the TMR (P<.05). Animals compensated for the apparent increased hay intake by reducing (P<.05) pelleted concentrate intake in the three diets with free choice hay. Comparing the three free choice hay treatments, pelleted concentrate intake was lowest (P<.10) for the SELF (15.83 lb/hd/day) and highest for the SEP (17.64 lb) with intermediate intake in the AUTO (17.00) treatment.

Estimated dry matter intake was 2.65 lbs. less for the TMR vs. the other three diets (P<.05). A higher proportion of hay should possibly have been used in the TMR for equivalent ingredient intake. The higher concentrate level in the TMR (P<.05) would be expected to produce improved daily gains, which it did not. The TMR and SEP treatments yielded gains of 1.39 and 1.37 lb/hd/day compared to 1.50 for both AUTO and SELF during the 195-day trial. Individual treatment means for gains were not different (P>.10), nor were pooled means for bunk feeding (TMR and SEP) vs. self-feeding systems (AUTO and SELF).

Bison exposed to the AUTO feeder became conditioned to the sound of the auger motor, and readily came to eat when it started. However, the natural tendency of delivery system worked well throughout the feeding trial and proved to be a convenient method of delivering a concentrate. The self-feeder was a conventional rectangular calf creep feeder accessible from both sides.

Discussion

Bison feeders currently prefer to use large amounts of the relatively inexpensive high fiber feeds, such as wheat screenings, prior to the inclusion of other feeds in the ration. Bison digest high fiber feeds more thoroughly than cattle (DeLiberto, 1995). However, in Experiment 2 and a Colorado study, bison gained faster and more economically using higher energy diets (70 and 90% concentrate vs. 30 and 50% concentrate) (Stanton et al., 1996). The modest energy levels in many commercial bison diets may limit growth rate and feed efficiency, and increase cost of gain. Higher energy diets are recommended.

Lower feed intake and gains, and reduced activity have been observed in bison during colder, darker months (Christopherson, et al., 1979). Reduced activity is probably an effort to conserve energy expenditure (Rutley, 1992) in sometimes futile or difficult searches for food under snow. Other studies support the theory of shortening day length impacting intake and gains in bison (Stanton et al., 1995) and cattle (Peters et al., 1980; Zinn et al., 1986a,b; and Tucker et al., 1984). Separating photoperiod and cold temperatures effects is difficult and may be a moot point as neither can be controlled. However, the cold tolerance of bison would suggest photoperiod may have a greater effect (Christopherson et al., 1979). In the wild, bison may respond to changing season by exhibiting preparatory increase in feed intake and compensatory feed intake with resulting faster growth in the spring and fall. Increased intake of hay during the winter may be an evolutionary response as a method of increasing body heat production. It also had the effect of reducing energy concentration of the ration. More research is needed on photoperiod and/or cold effects in an effort to develop different feed management strategies, lighting techniques, diet manipulation, or other approaches to counter this phenomenon. The seasonal differences observed in these studies agree with reduced animal performance during the winter concluded by Rutley and Church, (1995) and Stanton et al., (1996). Bison feeders are challenged by the substantial seasonal effects on animal performance. Potential strategies to counter these effects include altering diet (revert to grass hay), manipulating the environment (supplemental light), and selection of herd sires for year round performance.

Feeds and feeding systems appear to have some impact on feed intake patterns but limited effect on performance of bison bulls. Economies of scale will dictate choice of feeding systems but small scale feeding of bison appears to be possible with self-feeders.Although bison nutrition research is difficult to conduct due to the behavior patterns and unique social structure of bison, this growing industry is in great need of information applicable to feeding bison for meat.

Table 1. Formulation of diets with alternative feeds fed to bison bulls

(Experiment 1)

Item	Wheat Screenings	Crambe Meal	Wheat Midds
	————— (Percent, DM Basis) —————
Wheat screenings*	66.80	—	—
Corn grain	15.00	16.00	12.50
Crambe meal	—	14.00	—
Durum midds	—	30.00	66.20
Oat hulls	7.50	30.20	11.50
Molasses	5.00	5.00	5.00
TM salt	2.50	2.50	2.50
Vitamin/mineral	3.20	2.30	2.30
Total	100.00	100.00	100.00

* Wheat screenings are highly variable in composition. Principle components are green and yellow foxtail seed (pigeon grass) (50-80%), cracked wheat (10-20%) and other weed seeds.

Table 2. Nutrient analysis of concentrates with alternative ingredients fed to bison bulls (Experiment 1)

	———————— Treatments ——————-
Item	Wheat Screenings	Crambe Meal	Wheat Midds	Commercial Diet	Hay
	————— Percent, DM basis —————
Dry Matter	90.03	89.68	90.01	91.58	87.66
Crude Protein	14.89	15.11	14.35	14.24	8.29
Acid Detergent Fiber	12.34	16.60	11.10	17.91	50.31
Neutral Detergent Fiber	21.94	29.53	22.91	35.06	74.10
Fat	3.37	3.20	3.39	3.93	1.02
Calcium	.77	1.10	.94	1.14	.59
Phosphorous	.75	.71	.52	.61	.09

Table 3. Nutrient analysis of ration ingredients for bison bulls

(Experiment 2)

Item	Wheat Screenings	Waxy Corn	Dent Corn	Pelleted Supplement	Grass Hay
	————— Percent, DM basis —————
Dry Matter	89.83	86.04	85.35	90.82	90.10
Crude Protein	14.95	10.20	9.62	20.88	10.97
Acid Detergent Fiber	14.59	2.85	3.39	8.78	50.98
Neutral Detergent Fiber	22.97	15.19	15.87	22.32	73.94
Fat	4.43	4.74	4.25	3.84	1.21
Calcium	.76	.07	.18	2.89	.41
Phosphorous	.37	.18	.17	.34	.13

Table 4. Performance of bison bulls fed diets with alternative feeds

(Experiment 1)

	————— Treatments —————
Item	Wheat Screenings	Crambe Meal	Wheat Middlings	Commercial Diet		StErr
Initial Wt, lb	476	467	463	217478	29.5
Conc. Intake, lb/hd/day	14.00	15.61	15.81	16.78	2.40
Hay Intake, lb/hd/day	7.56	6.59	7.43	6.99	.33
DM Intake, lb/hd/day	19.01	20.04	20.99	20.31	.2.16
DM Intake, % Body Wt	2.90	2.99	3.15	3.16	3.44
ADG, lb/hd/day	1.72^a	1.52^b	1.63^ab	1.61^ab	.04
DM/Gain	11.62	13.21	12.86	13.19	1.70

^{a, b} values with different superscripts are significantly different, (P<.10)

Table 5. Performance of bison bulls by season

(Experiment 1)

	————— Season —————
Item	Spring	Summer	Fall	Winter		StErr
Initial Wt, lb	540	666	796	875	—
Conc. Intake, lb/hd/day	13.69^a	13.34^a	19.62^b	15.96^ab	2.22
Hay Intake, lb/hd/day	5.93^a	7.21^ab	8.29^b	11.53^c	.97
DM Intake, lb/hd/day	17.66^a	18.50^a	25.14^b	24.74^b	1.96
DM Intake, % Body Wt	3.28	2.78	3.18	2.83	2.73
ADG, lb/hd/day	1.72^a	1.39^a	1.76^a	.37^b	.24
DM/Gain	10.24^a	13.51^a	14.41^a	66.00^b	19.85

^{a, b, c} – values with different superscripts are significantly different, (P<.10)

Table 6. Performance of feedlot bison on two energy levels, two corn types and two processing methods (Experiment 2)

	————— Treatment —————
Item	Pelleted Wheat Screenings	Rolled Dent Corn	Rolled Waxy Corn	Whole Waxy Corn	StErr
Initial Wt, lb	611	617	608	578	7.10
Conc. Intake, lb/hd/day	13.01	13.01	13.58	13.97	1.08
Hay Intake, lb/hd/day	6.68^a	6.44^ab	5.82^b	5.69^b	.53
Total DM Intake lb/hd/day	16.96	19.45	19.40	19.65	1.50
DM Intake, % Body Wt	2.32	2.30	2.29	2.35	3.21
ADG, lb/hd/day	1.35	1.63	1.68	1.46	.29
DM/Gain	16.46	12.21	11.87	15.03	1.44

^{a, b} – values with different superscripts are significantly different, (P<.10)

Table 7. Bison bull performance in the feedlot during four different seasons of the year (Experiment 2)

	————— Season —————
Item	Summer		Fall	Winter	Spring		StErr
Initial Wt, lb	472	752		908	986	—
Conc. Intake, lb/hd/day	13.76^a	17.11^b		10.50^c	12.22^a	.66
Hay Intake, lb/hd/day	5.95^ab	5.60^a		6.90^b	6.23^ab	.23
Total DM Intake, lb/hd/day	19.71^a	22.71^b		17.42^c	18.37^ac	.61
DM Intake, % Body Wt	2.91^a	2.74^a		1.84^b	1.76^b	.03
ADG, lb/hd/day	1.85^a	1.94^a		.99^b	1.32^ab	.19
DM/Gain	10.80^a	11.99^a		18.71^b	14.05^ab	1.26

^{a, b, c} – values with different superscripts are significantly different, (P<.05)

Table 8. Effect of feeding system on feedlot performance of bison bulls

(Experiment 3)

	————— Feeding System —————
Item	TMR	Separate Grain/Hay	Automatic Feeder	Self Feeder	StErr
Initial Wt, lb	648	648	657	653	9.92
Conc. Intake, lb/hd/day	20.37^a	17.64^b	17.00^b,c	15.83^c	1.08
Hay Intake, lb/hd/day	6.79^a	11.82^b	12.88^b	15.10^c	.72
DM Intake, lb/hd/day	24.26^a	26.35^b	26.70^b	27.65^b	1.06
DM Intake, % Body Wt	3.01^a	3.28^b	3.32^b	3.38^b	.15
ADG, lb/hd/day	1.39	1.37	1.50	1.50	.33
DM/Gain	17.46	19.27	17.81	<p class=”MsoBodyText” align=”r

Literature Cited

Anderson, V.L. and Bryan Miller. 1997. Influence of season and diet on feedlot performance of bison. Prof. An. Sci. 13:14-17.

Christopherson, R.J., R.J. Hudson, and M.K. Christopherson. 1979. Seasonal energy expenditures and thermoregulatory responses of bison and cattle. Can. J. Anim. Sci. 59:611.

DeLiberto, Thomas J. 1995. Comparative digestive physiology of American Bison and Hereford Cattle. Doctor of Philosophy Dissertation, Utah State University.

Peters, R.R., L.T. Chapin, R.S. Emery and H.A. Tucker. 1980. Growth and hormonal response of heifers to various photoperiods. J. Anim. Sci. 51:1148.

Rutley, B. 1992. Average daily gains of feedlot finished plains bison. Bison Evaluation Unit Bison Bulletin. BB 92:1.

Rutley, Bruce, D. and John S. Church. 1995. Effect of time of year on average daily gain of feedlot finished bison (Bison bison). Peace Country Bison Association, Northern Lights College, Dawson Creek, B.C. Canada.

SAS, 1988. SAS/STATR, Users Guide (6.03 Ed.) SAS Institute Inc., Cary, NC.

Stanton, T.L., D. Schutz, M. McFarlane, R. Seedig, and D. Stewart. 1996. Concentrate level in bison finishing rations on feedyard performance. Prof. An. Sci. 12:6.

Tucker, H.A., D. Petitclerc and S.A. Zinn. 1984. The influence of photoperiod on body weight gain, body composition, nutrient intake and hormone secretions. J. Anim. Sci. 59:1610.

Zinn, S.A., L.T. Chapin and H.A. Tucker. 1986a. Response of body weight and clearance and secretion rates of growth hormone to photoperiod in Holstein heifers. J. Anim. Sci. 62:1273.

Zinn, S.A., L.T. Chapin, W.J. Enright, and H.A. Tucker. 1986b. Body growth and carcass composition responses to photoperiod and plane of nutrition in steers. J. Anim. Sci. 63 (Suppl 1): 237.