Source: Manitoba Agriculture, Food and Rural Initiatives
Severe Restriction of Roughage
Producers may need to severely restrict the amount of roughage fed daily. What is critical is the minimum amount that can be fed to the various classes of livestock which will maintain the rumination (cud chewing) necessary to avoid digestive disturbances. All roughages, regardless of nutritional worth, can be used to maintain and stimulate this vital process. This table shows the minimum daily roughages considered necessary to keep the digestive system working properly.
|Livestock Type||Air Dry kg/day||Air Dry lbs/day|
|Dairy Cows – Milking||5.5-7.0||12-15|
|Beef Cows – Dry Dairy Cows||2-2.5||4-6|
|Yearling Cattle and Calves||1.5||3-5|
|Sheep (All Ages)||0.2-0.45||0.5-1.0|
|Sheep – Milking||1.36||3|
Dry Cows, Heifers and Beef Cows
The problem of wintering and feeding dry cows, beef cows and bred heifers under conditions of limited roughage can be solved by using grains to replace a large proportion of the roughage.
Breeding Stock: Herds can be maintained on as little as 2 to 2.5 kg (4 to 6 lb) of roughage per animal per day provided sufficient grain is available. The amount of grain necessary for each cow will depend on the initial condition of the animal and the quality of the roughage. From 3 to 4.5 kg (6 to 10 lb) of grain is suggested, with poorer conditioned animals receiving the higher amount.
Dry Dairy Cows Fed Limited Roughage: Increase the grain allowance to 4.5 kg (10 lb) daily one month before calving.
Beef Cows: Increase the grain allowance during the last two months before calving and maintain it after calving to ensure a thrifty calf, satisfactory milk supply and good rebreeding performance.
Yearling and Older Heifers: These can be wintered on 2.5 kg (5 lb) per day of good roughage and an equal or greater quantity of a grain mixture.
If poor quality roughage such as straw is used, include a protein supplement in the ration during the last two months of pregnancy and until the cows are on satisfactory pasture. Vitamins A, D and E must be supplemented, especially when feeding low or poor quality roughage rations. Minerals must be properly supplemented.
Lactating Beef Cows: Feed 6 to 7 kg (14 to 16 lb) of straw per day plus 4.5 to 7 kg (10 to 15 lb) of grain if properly supplemented.
Good quality roughage, if very limited in supply should be reserved for young calves up to eight months. While calves intake can be restricted, what is consumed must be of good quality because calves have a restricted capacity to digest coarse, fibrous feeds.
After weaning, calves can be wintered on straw or poor quality roughage if it is ground, along with 50 to 60 per cent grain in the diet. This will support a rate of gain of 0.7 to 1 kg (1.5 to 2.0 lb) per day when properly supplemented with protein, vitamins and minerals.
Finishing Beef Cattle
Beef feedlot operators hesitant to undertake a finishing program because of a shortage of roughage or high grain and roughage prices, may well consider the results of an experiment conducted at the University of Manitoba.
Two groups of yearling steers were fed an all-grain ration (three parts barley – one part oats) during a 112 day test period. Prior to the test, a 28 day period was permitted for the steers to become adjusted gradually to the all-grain ration. An additional two groups were fed a more normal ration consisting of three parts of the above grain mixture and one part brome alfalfa hay.
Results showed that the groups provided hay gained at the rate of 1.10 kg (2.43 lb) per day as compared to 1.07 kg (2.36 lb) per day for the all-grain group. Efficiency of gain, however, was approximately six per cent higher for the grain group. No problems were encountered in either types of rations by animals going “off feed” even though the average daily feed consumption of the all-grain steers was 7.5 kg (16 lb).
Two points can be drawn from this experiment:
- Steer can be fed an all-grain ration without digestive disorders provided that an adjustment period is allowed during which hay is gradually removed from the ration.
- An all-grain ration when compared with a conventional ration, may lead to greater efficiency and economy of gain. The economy is more marked when hay prices are high.
Feedlot operators wishing to feed an all-grain ration are advised to adopt certain precautions:
- Allow at least one month for getting cattle on full grain feed.
- The grain should be rolled or very coarsely ground.
- Provide proper supplemental minerals and salt.
- Each animal should receive 30,000 I.U. of Vitamin A daily.
Many operators will feel more confident if some roughage is provided daily. For finishing beef the amount need not be large, 1-1.5 kg (2-3 lb) should be ample and the quality need not be a concern – poor quality hay or straw can be satisfactory.
The question of feeding wheat in an all-grain ration has not been answered. It does, however, appear that wheat can be fed provided it does not constitute more than one-third by weight of the grain mixture.
Note: While the above information was based on yearlings, feeder calves may also be placed on low roughage rations. Calves, however, are more prone to digestive disorders and, as a precautionary measure, it is advisable to include 1 to 1.5kg (2 to 3 lb) of roughage in their rations.
Most principles outlined for feeding low amounts of roughage to either fattening or over-wintering beef cattle can be applied to sheep flocks. Both feedlot lambs and over-wintering ewe flocks can perform well on a limited roughage intake, if adequate quantities of grain are fed, and time is allowed for sheep to adjust. Calcium intake is critical when feeding high levels of grain. A salt/limestone mixture may be necessary to ensure adequate calcium intake. Don’t feed more than 0.5 kg (1 lbs) of grain at a time. Divide the grain into several feedings daily.
Sheep of all ages require a minimum quantity of roughage to promote rumination. When the suggested minimum of .2 kg (.5 lb) daily is fed, ewes will also require .7 to 1.5 kg (1.5 to 3 lb) of grains depending on performance of ewes and their size. Replacement ewe lambs may also be carried through the winter on a minimum of roughage. Lambs can be raised on an all concentrate diet, but most should include roughage at one quarter of the daily intake, with intake being about four per cent of body weight.
For maximum lamb birth size, liveability and ewe milk production, increase the grain to 1.5 kg (3 lb) daily during the last six weeks of gestation and first six to eight weeks of lactation. Best quality roughage should be reserved for this time with daily limits increased to about 1.36 kg (3 lb). Do not feed more than .45 kg (1lbs) of grain at one time. Two or three feedings per day are necessary.
If the quality of roughage used is low, or quantity limited, add protein. One management practice used is to have a grain-protein – mineral – vitamin supplement pelleted and fed at a predetermined rate (example .2 kg daily). Feed a whole grain/supplement mix along with the roughage. The supplement should be in the form of a crumble to mix with the whole grain.
It is generally better not to roll grains for ewes and lambs over 18 kg (40 lb). Be sure that ewes and rams are in good shape prior to and during breeding. This can be achieved by grain supplementation to pasture, pasturing late seeded crops (oats, pasture rape, cereal second growth or combine aftermath, or drylotting sheep).
Grain: Feed is often the largest single cost item in livestock operations and as a result, factors influencing feed grain use affect the cost of gain and profits.
Generally, feed efficiency in cattle is improved by 10 to 15 per cent or more when compared to feeding whole grain. There is little, if any advantage to processing oats. Dry rolling and grinding are the principal on-farm methods of grain processing. The grain kernels are fractured to increase the surface area for microbial digestion.
The main advantage to pelleting grain is in mechanical handling and mixing. Compared to dry rolling or grinding, pelleting grain improves feed efficiency 5 to 10 per cent. However, this is often not sufficient to compensate for the added cost.
Forage: To determine the value of grinding roughages, the individual situation must be assessed. There is little or no advantage to grinding high quality roughages, but things change as forage matures. When poorer quality roughages or straws are included in the ration, there is an advantage to grinding [1.3 cm (1/2 inch) screen or larger], both from consumption and utilization aspects as well as rates of gain. The ground roughage gains in effective feed value, but needs balancing out for proteins, vitamins, minerals and energy. When ground or finely chopped hay rations are fed, care must be taken to watch for digestive disturbances and bloat. Changes in the ration must be made gradually.
Limited Grain Intake with Salt
Feeding grain to cattle on pasture can be an effective way to extend feed supplies. Self-feeding of supplements allows timid, slow-eating animals to get their share.
One management tool frequently used to reduce labor is regulating grain intake with salt. Salt is not a perfect regulator of supplement intake since certain animals will tolerate more salt than others. However, there are practical limits to the amount of salt cattle can eat and it can be used to effectively restrict consumption of a free-choice supplement.
Salt intake will be affected by forage intake, palatability of the supplement, salt content of water and forage, and adaptation to salt. Usually it is necessary to increase the salt content of the mix over a period of time as cattle become accustomed to a high salt level. Cattle tend to consume more of a salt-limited supplement when forage is scarce or unpalatable. Extra precautions should be taken under these and other emergency conditions to ensure that water supplies are adequate. As a rule of thumb, cattle on salt mixtures drink 50 to 75 per cent more water than normal or approximately five gallons of additional water for each pound of salt.
Provided ample water is available, salt toxicity is seldom seen in cattle because of their high tolerance for salt. The one-time lethal dose for mature cattle is 1.8 to 2.3 kg (4 to 5 lb) of salt.
Tables 1 and 2 can be used to estimate the percentage of salt needed to restrict consumption of a free-choice supplement.
Table 1. Estimated Salt Intake of Cattle Fed Salt-Limited Supplements
Find the expected daily intake of salt in Table 1. Then locate this in the left column of Table 2. Read acrossTable 2 to find the pounds of non-salt feed closest to what you would like. At the top of that column will be the per cent salt needed in the total supplement mixture.
Table 2. Daily Feed Consumption Expected with Various Salt Concentrations
|Salt Intake/Day||Salt in Supplement|
If a grain supplement is to be fed at the rate of 2.7 kg (6 lb) per day to a group of 500 kg (1100 lb) cows: Table 1 indicates that the daily salt consumption of 500 kg (1100 lb) cattle averages 500 grams (1.1 lb) when salt is used to limit supplement intake. In the left hand column of Table 2, locate 500 gm (1.1 lb) daily salt intake and look across the row labelled non-salt feed for a value nearest 2.7 kg (6 lb). In this example, a self-fed supplement composed of 16 per cent salt and 84 per cent grain would, on the average, regulate total intake to 2.7 kg (6 lb) grain and 500 gm (1.1 lb) salt. These percentages may need slight adjustment to achieve the desired feed intake.
Salt used in self-fed supplements should be coarse, plain white salt. Do not use trace mineralized salt since force feeding high levels could result in toxicity or mineral imbalances due to excessive intake of certain trace elements. If trace mineralized salt is required by cattle, the amount consumed daily should not exceed 0.02 per cent of the animal’s body weight.
For cattle accustomed to eating supplements but not to self-feeding, overeating can be prevented by starting with a high salt level (50:50 or 60:40 salt to meal). Then reduce salt levels to obtain desired level of intake. If cattle have not eaten concentrates before, a training period of a week or more of daily hand feeding supplement without salt may be necessary, especially with young cattle. Follow these precautions:
- Have plenty of clean water available.
- Grain should be coarsely ground or cracked and mixed with salt of similar particle size to prevent separation and overeating.
- Have adequate grass or hay available so that cattle are not forced to eat the supplement.
- Use coarse, plain white salt in the mixture.
Note: The above figures do not apply if Rumensin is included in the mixture, since it also limits consumption.
The basic question when purchasing feed is how to get the greatest nutritional benefit for the money spent.Under conditions where minimum quantities of roughage are fed to cattle and sheep, the approximate feeding values developed by Dr. Frank Whiting of Agriculture Canada apply (see Table 3).
Pricing Silage and Haylage
Since silage has no commercial market, pricing is left to you and your neighbor. University of Wisconsin economists have developed a table which makes pricing easier (see Table 4). Figures were prepared using this equation:
|% DM in Haylage||X Price of Baled Hay||= Price of Haylage|
|% DM in Baled Hay|
Table 3. Price of Haylage per Ton (As Is Basis) Based on the Price of Baled Hay
|Price of Baled Hay ($/ton)||% Moisture in Haylage|
Examples: Suppose baled hay is selling locally for $40 per ton, but you would rather buy your neighbor’s 48 per cent moisture haylage. What should you pay?
- Subtract 48 from 100 to find dry matter (DM) content of 52 per cent.
- Plug in a 90 per cent dry matter level for baled hay.
- Divide and multiply.
|0.52||x $40 = $23.11 per ton|
So, with $40 per ton hay, you can spend up to $23.11 per ton for haylage provided that the feeding quality of the hay and silage are equal.