Cool-season grazing typically affords the cattle producer an excellent opportunity to achieve competitive and cost effective gains on stocker cattle throughout the fall and winter months.  Cool-season forages are generally better quality than their warm-season counterparts and several varieties are available to suit growing conditions throughout the United States.  The most commonly utilized cool-season forages include annual ryegrass, tall fescue, small grains (oat, wheat, triticale, and rye), clovers, and winter peas.  Climate, soil type, and management will ultimately determine which variety or combinations of varieties are available.

Small grain pastures (namely wheat) are versatile in that income can be derived from both the grain crop and added weight gain from livestock grazing.  Dual purpose opportunities are a viable option for a large percentage of the country stretching from the central and southwestern states to the East Coast.  Due to its longevity and increasing popularity with rising feed costs, the remainder of this article will focus primarily on nutrition management strategies for wheat pasture.  However, the general principles can be applied to the majority of cool-season forages.   

 

MINERAL
Wheat forage is an extremely succulent and highly nutritious feed for beef cattle.  The amounts of calcium (Ca), phosphorous (P), magnesium (Mg), and potassium (K) provided by typical wheat forage and that required by 300 and 500 lb steers for 2 lb/day gain is displayed in Table 1.  These values indicate marginal to sufficient Mg and P, excess K, and deficient levels of Ca for growing cattle. 

 

Table 1: Nutrient Content of Wheat Forage versus Animal Requirement
Item	Protein  (%)	Ca       (%)	P          (%)	Mg           (%)	K              (%)
Composition, % of DM	25 to 31	0.35	.25  to .40	0.15	3 to 5
Animal Requirement
300 lb calf a	16.2	0.80	0.36	0.10	0.70
500 lb calf b	12.9	0.53	0.26	0.10	0.70
a Based on 300 lb steer calf consuming 8.6 lb forage DM per day and gaining 2 lb/d, with mature BW of   1200 lb at 28% fat (NRC, 1996).
b Based on 500 lb steer calf consuming 12.6 lb forage DM per day and gaining 2 lb/d, with mature BW of   1200 lb at 28% fat (NRC, 1996).

 
One common misconception is that high levels of Mg are needed by stockers on wheat pasture to help minimize bloat and/or decrease the incidence of grass tetany (wheat pasture poisoning, magnesium tetany, wheat tetany).  Bloat refers to excessive accumulation of gas in the rumen of the animal.  This gas can be in free form (dry gas bloat) or mixed with ingested material to form froth (frothy bloat).  Wheat pasture bloat is most commonly a frothy-type bloat that results during lush growth in the fall and early spring.  While Mg supplementation won’t decrease the incidence of bloat, the strategies listed in Table 2 will provide some relief.

 

Table 2: Strategies to Decrease Bloat Potential on Wheat Pasture
1	Do not turn hungry cattle onto lush pasture
2	Identify animals more prone to bloat and remove from herd
3	Use poloxalene during periods of lush growth (must be fed daily)
4	Feed high-quality grass hay, silage, and/or grain mix
5	Include Rumensin or Bovatec in mineral or hand-fed ration

 
Tetany is a noninfectious metabolic disorder that occurs most frequently in mature cows that are in the latter stages of gestation or are nursing calves and have been grazing wheat pasture for sixty days or more.  Low blood concentrations of both Ca and Mg are the signature signs of grass tetany.  While a similar, tetany-like condition can occur in stocker cattle, the incidence is very rare.  In other words, higher levels of magnesium should be provided to gestating and lactating cows on wheat pasture, but not for stocker cattle.

 

Some researchers have postulated that the “tetany-like” condition and/or “dry-bloat” problems sometimes observed in wheat pasture stockers may be related to subclinical deficiencies of calcium. Huber et al. (1981) determined that Ca shortages greatly compromised ruminal and gut motility.  Adequate ‘motility’ or movement within the rumen enables cattle to eructate and release fermentation gases produced during digestion.  Physical and metabolic issues result when these gases become trapped and cannot escape.  Therefore, calcium supplementation is two fold: 1) to meet requirements for growth and 2) to decrease bloat incidences resulting from reduced rumen motility.

 

Wheat forage trace mineral levels vary widely among location, soil type, fertilizer application, and management.  Zinc and copper are two notable trace minerals that are commonly low or deficient in wheat and other small grain pastures.  Providing a complete, balanced mineral with both macro and micro (trace) minerals is cost effective insurance and will help eliminate potential profit robbing deficiencies. 

Salt or trace-mineralized salt are commonly the only supplement provided to cattle on wheat pasture.  Sodium (salt) is important for wheat pasture cattle, as it helps to balance the excess potassium inherent in the forage.  Salt or trace mineralized salt alone, however, will not adequately provide the calcium and trace minerals needed to maximize growth and production.

As shown in Figure 1, digestibility of protein, fiber, and total digestible nutrients (TDN) were significantly improved by simply providing a complete, balanced mineral versus salt alone.  The information in Table 3 further illustrates the performance and economic benefits of providing a complete mineral mix to cattle versus salt alone. 

 

Table 3: Performance Comparison of Mineral vs. Salt
			Average Daily Gain (lb/head/day)
State	Head #	Days	ADM Mineral	Salt	Net Return
OK	869	73	1.68	1.23	21.22
OK	771	96	1.99	1.37	36.64
WY	100	47	1.64	1.27	10.53
MT	398	143	1.63	1.44	15.27
WY	400	75	2.53	2.12	19.23
NM	270	76	2.20	1.99	7.02
NM	195	143	2.26	2.01	16.98
TX	387	125	2.50	2.28	13.35
KS	504	124	1.99	1.43	22.10
TX	178	111	1.50	0.66	61.27
	Average	101	1.99	1.58	22.36

 

Another common question from producers is, “Should I feed an ionophore (Rumensin^®* or Bovatec^®*) and/or antibiotic (tetracycline) to my wheat cattle?”  Unless the cattle are destined for an “all-natural” program, the answer is most definitely yes to an ionophore and possibly to the antibiotic. 

 

IONOPHORES

Both monensin (Rumensin) and lasalocid (Bovatec) consistently increase gains of cattle grazing all types of forages. Numerous research and field studies have been referenced over the years showing gain advantages.  Ionophores will increase daily gains an average 0.18-0.24 lb/hd/day.  The increase in performance is due primarily to the change in rumen fermentation that results in improved protein digestibility and extra energy available from each bite of feed.  Better protein utilization may explain why cattle are less “washy” when ionophores are provided to cattle on lush wheat pasture.

Improved performance benefits from ionophores may also be associated with the fact that monensin has been shown to increase the absorption of several macro- and micro- minerals (primarily Na, Mg, P, and Zn) by the animal.  In other words, you get a better ‘bang for your buck’ on your mineral package and are allotted some insurance benefits if cattle do not consistently consume the recommended daily amount of mineral.

Research has also indicated that ionophores may provide bloat protection by decreasing rumen methane production and reducing the amount of stable foam created during fermentation.  A bloat outbreak, however, will require an anti-foaming agent like poloxalene (marketed under various trade names).  Poloxalene is expensive, prevents bloat for only a short period of time (12 hours), and must be consumed in adequate amounts (1-2 grams/50 kg of body weight) on a daily basis.   To minimize costs, a fair number of cattle producers prefer to use poloxalene during the three to four weeks of lush growth during the fall and spring and use an ionophore during the rest of the grazing season.  Keep in mind, ionophores and poloxalene are not cleared to be fed together.

Another final benefit of ionophores is their ability to prevent coccidiosis, an extremely contagious and ubiquitous protozoan related disease that is very common in most phases of cattle production.  Clinical outbreaks of cocci will need to be treated with either decoquinate (Deccox^®*) or amprolium (Corid^®*) for 5-30 days (follow specific label instructions).  Prudent and consistent use of an ionophore at labeled rates, however, will usually prevent outbreaks.  When looking at research data and field observations, monensin appears to be slightly more potent than lasalocid in terms of coccidiosis control.

 

ANTIBIOTICS

Ensuring optimum health status of cattle will be one of the first priorities of producers utilizing grazing programs.  Some producers confine the animals for a period of two to four weeks to thoroughly monitor and treat prior to turning them out on pasture.  In these situations, once the cattle are turned out, mass antibiotic use is not typically required or economical if an ionophore is used to prevent coccidiosis. 

If cattle are under an extreme amount of stress and/or are not confined and thoroughly treated before turnout or have contracted a bout of foot rot or pinkeye, a mass antibiotic treatment regimen can be beneficial on pasture.  There are several suitable products available that should be used in the appropriate situations shown in Table 4 (specific dosing and treatment time recommendations can be found on labels for each individual product).

 

Table 4: Mass Antibiotic Treatment Options for Pasture Cattle
Disease(s)	Treatment Options
Respiratory Distress/Pneumonia	chlortetracycline (CTC), oxytetracycline (OTC) or AS-700 (CTC & sulfamethazine)
Coccidiosis	decoquinate or amprolium

 

SUPPLEMENTAL FEED AND FORAGE

To further improve animal performance, various combinations of dry hay, silage, grains, or grain by-products have been utilized in wheat pasture programs.  Some of these combinations have been extremely successful, while others have not.  Due to the extreme scope of this topic, Part 2 of this series, which will be featured in the Spring/Sumer 2008 Beef Performance Edge, will provide in-depth information on successfully supplementing wheat pasture cattle for optimal performance and economic returns.

As a precursor, here are few points to keep in mind:

1)      Providing an energy supplement comprised of grains and/or grain by-products to wheat cattle at 0.65-1% of body weight (dry matter basis) will increase daily gains an average 0.2-0.3 lb and carrying capacity of wheat pasture by about 20-35%.   

2)      Feeding low-quality roughages (corn or milo stalks, wheat straw, etc) to wheat cattle does not affect forage intake, digestibility, rumen rate of passage, or incidence of bloat. 

3)      When forage is completely covered with snow or heavy rains (flooded) and inaccessible to cattle, decent dry hay and/or silage should be provided to maintain rumen health and prevent disease.

4)      When not supplemented, cattle performance begins to decline rapidly when total wheat herbage mass drops below 800-850 lb of dry matter per acre (roughly 4000 lb of actual as-fed forage per acre).  

 

CONCLUSION

Overall, small grain or other cool-season forages can potentially provide an excellent medium for cost effective growth of stocker cattle when coupled with a complete and balanced mineral and additive program. 

ADM Alliance Nutrition carries a proven line of custom tailored wheat pasture minerals to fit every need.  A variety of forms are available (loose, block, or tub) and come either with or without many of the recommended additives.  If a loose mineral is preferred, you can be sure your mineral will ‘weather the winter grazing season’ with ADM’s new WeatherMaster^® weatherization process.  Your local ADM Alliance Nutrition dealer, sales representative, or nutrition specialist can assist in custom tailoring a program to maximize performance and income potential of your winter grazing cattle.