Forage and Minimizing Grain Intake in Bison Bulls Fed for Meat
Vern Anderson and
Eight bison ranchers in North and South Dakota participated in a North Central Region Sustainable Agriculture funded project to evaluate animal performance, carcass quality, and returns when the forage feeding period was lengthened and the grain feeding period was shortened in bison bulls fed for meat. Each rancher compared two treatments with 20 animals included in each treatment. Treatments were initiated at weaning and included 1) grain feeding to slaughter, 2) hay fed during the winter followed by grain fed to slaughter, 3) hay fed during the winter, grazing during the summer and grain fed to slaughter, and 4) hay fed during the winter, grazing during the summer, hay fed the second winter, and grain fed until slaughter. Extending the forage feeding period and reducing the grain feeding period appeared to have little effect on average daily gain and cost per pound of gain overall for treatments 1, 2, and 3. Carcass quality was reduced in treatments 3 and 4 and gross return above feed costs were lowest in treatment 4 by over $100 per head. Producer trials across a wide geographic area with variable genetics and management styles can be a challenge when summarizing data. However, data was generated in a commercial ranch setting in every case by producers using feeds common to their operations.
Key Words: Bison, Forage, Grain, Feeding, Returns.
Bison are being raised for meat throughout the Northern Plains states and provinces. The feeding of bison bull calves from weaning to slaughter has not been the major profit center for this new livestock species. Most producers want to maximize the use of forage in bison diets as grazing or hay feeding is thought to be less costly than feeding grain and purchased feed. However, carcass quality or eating satisfaction are important to repeat bison meat customers, and feeding grain for a period of time is recommended by many as a measure to increase meat quality and consistency. Little data is available on the nutrition and management of bison bulls fed for meat. Some information is emerging on performance of bison using different feeds, different energy levels, and the effects of season on feed intake and gain. Since bison gain at a modest rate, the concept of feeding grain from weaning to market, often taking more than one year, is being challenged by extending the forage feeding period with potentially lower costs. This research trial was conducted to compare performance and returns from extending the forage feeding time and reducing the grain feeding period for bison bulls fed for meat.
Treatments were initiated at weaning and included 1) grain feeding to slaughter, 2) hay fed during the winter followed by grain fed to slaughter, 3) hay fed during the winter, grazing during the summer and grain fed to slaughter, and 4) hay fed during the winter, grazing during the summer, hay fed the second winter, and grain fed until slaughter. Start weights and end weights, with daily gains calculated, and feed intake were recorded for each respective period. Carcass criteria and grades were compared. Nutrients in meat from respective treatments and taste panel evaluation will be presented in future publications. Carcasses were evaluated using the criteria established by the North American Bison Cooperative.
Producers were sought for this trial through the North Dakota Buffalo Association. Individuals indicating interest were provided with a detailed protocol to aid in deciding to participate. Producers were provided partial funding at the outset to install necessary fencing or other needs to conduct the trial. Final payment was made after data was collected and was based on a pre-determined per head fee which was equal for all treatments. A technical staff person from the Carrington Research Extension Center visited each producer to further explain the research requirements and evaluate the pens and the working facilities used for the study. The trial was initiated when the technician was on site, in most cases.
There was some variation from farm to farm in dates weighed, type of feed used, and numbers of animals on trial. Winter hay feeding was accomplished using bale feeders, which can result in some waste. Feed samples were collected from each producer and submitted for analysis. The hay offered during the winter was primarily native grass with some brome mixtures. Grazing occurred on native, mixed-grass pastures. Intake was not recorded during the grazing period. The grain component of the diet varied from commercial pelleted bison feed to ground wheat screenings. The grain was offered in a self feeder in every case.
Data were summarized by treatment group for each period and compared on a per head basis. In some cases, multiple treatment groups contributed to one coefficient, such as the summary of hay feeding during the winter (treatments 2, 3, and 4) or grazing during the summer (treatments 3 and 4). Feed costs were consistent across all cooperators for similar feeds and represented typical feed prices for the region during the study.
Animal performance was generally less than desired probably due to low energy concentrations in the diet, poor quality hay, or other factors. Periods presented in table 1 are generally representative of the first winter after weaning (period 1), the summer following weaning (period 2), second winter after weaning (period 3), and the second summer after weaning (period 4). During period 1 (Table 1), grain fed bison (treatment 1) averaged only 1.36 lbs. per day and consumed 12.32 lbs. of dry matter. Period 2 gains increased to 1.52 lbs./day from 16.85 lbs. of dry matter intake. During the second winter, however, gains decreased to .80 lb. per day, a disappointing level of gain for these animals. Overall, the treatment 1 animals gained 1.22 lbs/hd/day consuming 16.84 lbs. of dry matter during the 488 day feeding period.
Bison fed hay the first winter (treatment 2) gained .36 lb. while consuming 10.69 lbs. of dry matter. When placed on feed the following spring, these animals gained 1.54 lb/hd/d and consumed 17.92 lbs. of dry matter. Gains dropped to 1.34 during the winter of period 3. The grain feeding period extended to 401 days for treatment 2 animals. Overall gains averaged only 1.23 lb/hd/day with dry matter consumption in the feedyard calculated at 19.04 lbs/hd/d.
Treatment 3 animals gained .26 lb. during the first winter when fed only hay, 1.28 while grazing the following summer, and 1.39 during the 232 day feedlot period after grazing. Overall, gains averaged 1.11 for treatment 3 animals that consumed 18.18 lbs. of dry matter during the grain feeding period.
No data were available for treatment 4 during the winter hay feeding phase but treatment 2 (.36) and treatment 3 (.26) data suggest very modest but positive gains. Summer grazing of yearling bison bulls produced .91 lb/hd/d of gain. The final feedlot phase produced gains of 1.89 during the 139-day feeding period on 28.34 lbs. of dry matter intake. Overall, bulls in this treatment gained 1.12 during the entire feeding period.
Gains from hay fed during the winter averaged .35 lb/hd/d over all treatments. Gains from grazing averaged 1.10. Gains from grain feeding over all treatments and periods averaged 1.41.
Carcass data provided additional insights into desired feeding scenarios. Dressing percent appears to decrease as the time on feed decreases (55.37 for treatment 1 to 53.36 for treatment 4). Fat cover (mm) is numerically less in treatment 4, as well. Fat color score appears to contradict the other age criteria with lighter average scores in treatments 3 and 4. Permanent teeth increase with age at slaughter, as expected, but bone ossification was not affected. Percentage of carcasses grading Number 1 (most desirable) decreases with age from treatment 1 to treatment 3 but shows a slight numerical improvement in treatment 4.
Days on feed increased very little from treatment 1 (488) to treatment 4 (502) with variable intermediate points. The days on feed may be artificially influenced by the scheduled day of slaughter, which can be affected by a number of variables. The slaughter schedule may also have had some influence on the carcass criteria.
Finally, the gross return for each animal appears to be similar for treatments 1 and 2, slightly higher for treatment 3 in spite of lower carcass grade, and much lower for treatment 4.
Gains from grain feeding periods were less than reported in other trials. Increasing the energy concentration should shorten the feeding period and increase the feed efficiency, and lower feed cost. Hay feeding and grazing are useful in utilizing forage produced on the farm or ranch but hay/forage quality should be given some consideration. Timely supplementation of hay fed or grazing may improve animal performance and make the transition to high concentrate diets less stressful.
Costs for interest, facilities, equipment, and labor are not included in the gross return but would all increase with extended feeding time.
This trial provided data from a wide geographic range of bison producers in the Northern Plains. It is clear that gains from bison fed grains were less than desired for a profitable operation. The variability in bison genetics, management, feeds used, and data gathered from the different operations may reduce the confidence in the results. This trial should be repeated on one site with uniform animals representative of the bison population to validate or refute results observed here.
Appreciation is expressed to the USDA North Central Sustainable Agriculture and Education program for financial support of this project.
of age, 1=white (most desirable), 10=yellow
a Feed prices included all hay and pasture costs
and grains fed. Prices used were
consistent for all producers for the commodities throughout the region during