Sent to you by vetkasi via Google Reader:
C.M
North Carolina
Answer: I am pleased to provide you with information on silage supplementation for pasture-based beef operations.
Types of silage
| Type | Crude Protein | Fiber | Energy |
|---|---|---|---|
| Grass and small grain silage | High | High | Low |
| Corn silage | Low | Low | High |
| Legume silage (clovers, alfalfa) | High | High | Low |
Supplementing pasture with silage
Silage is an excellent source of supplemental nutrients. Allow pasture to be the primary feedstuff for the cattle, and feed the supplement later in the day after the cattle have grazed for several hours. Feeding too much energy can reduce pasture intake and result in inefficient pasture utilization.
Silage should be fed to ruminants on pasture when either protein or energy is limiting, and if it is cost effective to make and feed silage, otherwise it is not worth it. Grass silage can be cut, baled, and wrapped much like hay is. This is referred to as haylage, and the ensiling process is completed within the wrapped bale.
High-quality pasture
Supplementation may not be necessary on well-managed, high-quality pastures. Examples are cool-season annual and perennial pastures (ryegrass, wheat, orchardgrass, timothy, and fescue) mixed with legumes (clover, trefoil, alfalfa, vetch) and managed with rotational grazing. Warm season annuals such as sorghum-sudan are excellent pastures that require little supplementation as well. When pastures are high in crude protein and low in fiber (such as during the spring) energy supplementation is helpful to feed rumen microbes and allow better utilization of forage protein. Corn silage might be advantageous at these times. However, large amounts of high fiber feeds will reduce pasture intake. Some other supplements to consider in this situation are corn gluten feed (corn gluten meal plus the bran), wheat midds (screenings from wheat flour processing), and whole cottonseed. If these by-products are available locally, they might be a good substitute for silage if you do not have the ability to make and feed it.
Low-quality or limited pasture
Supplementation of protein on low-quality forages will increase forage intake. If you are grazing limited forages, such as warm-season perennial pastures during the heat of the summer, grass or legume silages would be advantageous. A cost comparison of these silages vs. soybean or cottonseed meal would be good to determine the economic viability of silage feeding. However, the sustainability dimensions of the monocultural production of soy and cottonseed are questionable. Sustainable agriculture is more about balance, health, and appropriate gains as opposed to maximizing gains for economic profit alone. You might also consider other sources of protein you might have available, or can grow in rotation on your farm.
When supplementing ruminants on pasture, consider the following logistics and economic factors:
• Will the added production cover the expense, especially if the feed is shipped from off the farm?
• Is there an inexpensive local source of protein?
• Do you raise the feed on the farm?
• Do you have necessary harvest, storage, and feeding equipment?
• Substitution effect—forage intake decreases with less fibrous, more digestible supplements like corn.
Effect of feedstuff on consumer preference
Most of the work than has been done on consumer preference and palatability of beef has been done lately on pasture-finished vs. grain finished (Martz, 2000 and Rosmann & Rosmann, 2004). I have seen no data on the use of one forage type over another with respect to consumer preference except a study that points out that "beef from grass silage-fed animals had better overall quality in terms of color, lipid oxidation, and vitamin E than beef from maize (corn) silage-fed animals" (O’Sullivan, et al, 2001). Most of the silage ration work done lately involves protein supplementation on cattle eating silage-based diets, in confinement, and silage as a forage-extender. Two examples follow:
1. Growth and carcass characteristics of beef steers fed silage and different levels of energy with or without protein supplementation
Journal of Animal Science, Vol 72, Issue 12 3221-3229, Copyright © 1994 by American Society of Animal Science
H. V. Petit, D. M. Veira and Y. Yu
Experimental Farm, Agriculture and Agri-Food Canada, La Pocatiere, QC.
Fifty-six large-framed crossbred steers averaging 227 kg were used in an experiment including a growing period (24 wk) and a finishing period ending when the steers had approximately 4 to 10 mm of fat thickness (Canadian grade A1). Steers were individually fed and assigned to a completely randomized design with seven treatments for the growing period. From the end of the growing period until slaughter, all steers received the same basal diet. Half of the steers from each treatment used in the growing period received a supplement containing protein and the other half a supplement containing protein and fat. Treatments during the growing phase consisted of 1) timothy silage alone or mixed (on a DM basis) with 2) 7.5% molasses, 3) 15% molasses, 4) 7.5% canola meal, 5) 5.5% canola meal and 7.5% molasses, 6) 3.6% canola meal and 15% molasses, or 7) 15% canola meal. The total N intake from supplements 2, 5, or 6 was similar. Compared with silage fed alone, canola meal supplementation increased (P < .05) ADG, whereas molasses had no effect. Combining molasses and canola meal did not improve ADG compared with feeding only canola meal on an isonitrogenous basis. Canola meal supplementation compared with feeding only silage during the growing phase reduced (P < .05) days on feed, and molasses tended (P = .059) to reduce it. Carcass data were generally similar among treatments.
2. Grass & Forage Science
Volume 43 Issue 3 Page 215 - September 1988
doi:10.1111/j.1365-2494.1988.tb02147.x
Volume 43 Issue 3
The use of conserved forage as a supplement for grazing dairy cows
C. J. C. Phillips
The difficulty in matching the herbage requirements of grazing dairy cows to herbage production, due mainly to the unpredictability of the latter, causes stocking rates to be too low for maximum per hectare production and, thus, cows to be underfed at certain times in the grazing season. Conserved forage may be used as a supplement for grazing dairy cows in order to reduce variation in forage intake by the cow, to allow pasture stocking rates to be increased and to increase the efficiency of land use. The effect of offering conserved forage with herbage on intakes and production is reviewed in comparison to both ad libitum and restricted herbage. Total nutrient intakes and milk fat + protein yields are reduced for cows offered herbage and supplementary forage compared with cows offered ad libitum herbage, but increased compared with cows offered a restricted herbage level. Increasing pasture stocking rates may allow increases in utilized metabolizable energy levels from grassland but further research is needed in this area. Both grass and maize silage supplements offer potential for increasing the efficiency of land use, but in the case of grass silage this is only achieved in the best management practices.
Environmental Benefits of Pasture-based Beef Production
It is difficult to operate in an industry that has become increasingly integrated, as the American beef industry has. Often proponents of sustainable agriculture must take an incremental approach to achieving sustainability and balance in their farming systems. An example would be utilizing equipment and fossil fuels to make and feed grass silage over buying heavily subsidized and transported soybean meal to supplement cattle on pasture. A case can be made that on-farm production of feed is more sustainable than buying from off the farm.
References
Martz, F. 2000. Pasture-based finishing of cattle and eating quality of beef. University of Missouri-Columbia.
O’Sullivan, A., K. O’Sullivan, K. Galvin, A.P. Moloney, D.J. Troy, and J.P. Kerry. 2002. Grass silage versus maize silage effects on retail packaged beef quality, in J. Anim. Sci. 2002. 80:1556-1563.
Rosmann, R. and M. Rosmann. 2004. Feeding beef cattle to produce healthier and highly acceptable beef. Santa Cruz, CA: Organic Farming Research Foundation.
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