Should I Early Wean My Calves This Year?
by John Paterson, MSU Extension Beef Specialist
Early weaning lowers the nutrient requirements of the cow and increases the carrying capacity of stressed pasture.
With continued drought and lack of available forage for the cow herd, early weaning may be one option for ranchers to consider this year. The following excerpts about the pros and cons of early weaning were summarized from recommendations made by beef extension specialists from around the United States.
Russ Danielson, North Dakota State University
Weaning calves early may become a necessary option when forage supplies are limited as a result of drought conditions. Early weaning lowers the nutrient requirements of the cow and increases the carrying capacity of stressed pasture. Weaning calves prior to the traditional age of six to seven months can increase stress and reduce calf performance if proper health, nutrition and management practices are not followed. Conversely, weaning after pastures have severely deteriorated will also result in poor calf performance. From the standpoint of the cow, the advantage of early weaning during drought periods is usually reflected in less body condition loss and improved conception rates. Overgrazing drought-stressed pastures will have long-term effects on forage production by reducing plant vigor and increasing less desirable plant populations.
How early can calves be weaned?
Calves have been weaned successfully at less than two months of age, but this is younger than is practical under most conditions. The rumens of calves are normally functioning sufficiently at 120 days of age to provide satisfactory gains without the benefit of milk or milk replacers. Therefore, weaning March- and April-born calves in late July/early August is preferred to an earlier weaning date.
Are there special health considerations?
The stress of early weaning directly influences the health and well-being of the calf after weaning. Complete castration, dehorning and branding at least 10 to 14 days prior to weaning. Provide protection from clostridial and viral infection by vaccinating calves prior to weaning with a seven-way clostridial injection, IBR-BVD vaccines and other veterinarian-recommended protection. If a "booster" or re-vaccination is required for any vaccine, it is essential that label recommendations are followed. Calves should always have access to clean water, and a complete mineral package should be offered in loose form. Monitor calves regularly for signs of respiratory problems, digestive disturbances, scours, coccidiosis and sorting of feed.
What is the best bunk management?
The palatability and acceptance of offered feed is critical to ensuring adequate feed intake by early weaned calves. Calves need to consume 2.5 to 3.0 percent of body weight in dry feed daily to have satisfactory performance. Offering high-quality, easily digested feeds and roughages in a form that calves will consume is important bunk management. Calves should be creep fed starting three weeks before weaning to minimize stress and ensure adequate feed intake following weaning. Initially, newly weaned calves should be offered long-stem grass hay, the form they are most familiar with. Once weaned and on feed, calves will prefer chopped forage to long-stem hay. Add alfalfa gradually over a 14-day period as calves start on feed. Mix the grain portion with the forage to encourage consumption of the concentrate. If the calves sort and consume the grain leaving the forage, adjust the type of forage to make the total ration more palatable. Over-consumption of grain can lead to bloat and/or acidosis in the calves. Minimize dust in the ration and control it by adding three to five percent molasses. Calves weighing 300 pounds should consume eight to nine pounds of dry feed daily. A 50:50 roughage-grain mix containing 13 to 15 percent protein generally will provide satisfactory calf performance, provided the feeds are high quality and not stale or rancid. A minimum average daily gain of two pounds is required to compete with calves weaned at six to seven months of age. Hand feeding whole oats or a commercial starter to ration with free choice, quality grass hay is an excellent way to start calves on feed. Once through the weaning process and on feed, calves may be switched to a balanced mixed ration offered in a self feeder.
What are the facility requirements?
Initially, calves should be penned in a small, secure, well-sheltered pen or pasture when weaned. A more confined area will reduce the amount of pen travel. In drought conditions, respiratory problems caused by dust are a real possibility. Provide sufficient, accessible bunk space and water sources. Locate the feed bunks and water source near the perimeter fence, forcing calves to access feed and water as they travel the fence line. If possible, place one or two older calves that are accustomed to bunk feeding with the younger calves to teach by example. Initially, limit the number of calves to 20 to 25 per pen for the first few days. Smaller, more timid calves may not be able to eat or drink adequate amounts when competing with a large number of calves. After 10 to 14 days, calves can be successfully grouped in a larger pen.
Jack Whittier, Colorado State University
Oklahoma researchers reported a 37 percent advantage (97% vs 59%) in conception rate for first-calf heifers that began calving in February and then had their calves weaned every two weeks at six to eight weeks of age compared to heifers whose calves were weaned at seven months. Additionally, the average interval from calving to conception was shortened by 18 days (91 vs. 73 days).
The positive results of this study are likely because the heifers were in thin or marginal body condition at calving. To evaluate the potential long-term effect of early weaning on reproduction in first-calf heifers, an experiment was conducted by Missouri researchers.
The objective of this study was to determine if weaning calves from first-calf heifers at the beginning of the breeding season following their first calving would allow them to gain sufficient weight and body condition to improve rebreeding in subsequent years with minimum feed inputs to the dam. Angus-sired heifers (n = 141) were assigned at breeding time to either normal weaning at seven to eight months or early weaning at the beginning of the breeding season. All heifers were synchronized for estrus using Syncro-Mate-B. At the time of implant removal, all calves were temporarily weaned for 48 hours. After 48 hours, the normal weaned calves were returned to their dams while the early weaned calves were placed in a drylot for feeding.
The early weaned dams were heavier and higher in body condition at their first weaning than the normal weaned dams. However, by their second weaning there was no differences between cows. There was no statistical difference in pregnancy rate at any year. However, the normal weaned dams had numerically lower pregnancy rates each year following the weaning management treatment. Remember, the only difference in management between the two treatments occurred during their first lactation.
Early Weaning in Mature Cows
There has been a good deal of research done with early weaning programs in mature cows. The results vary depending on available quality and quantity of forage and body condition of the cows. Weaning calves during or soon after the breeding season in drought years is an accepted practice for stretching a limited forage supply.
Success and performance of calves weaned from two to four months of age is greatest when high concentrate, highly palatable diets are fed. It is not necessary to use a milk substitute in calves at this age since their rumen is capable of some function by this age and will adapt rather quickly to a high concentrate diet. Calves older than four months will digest forages adequately, but their nutrient requirements are high and may not be met by only forage diets.
With proper management, it is possible for young, early weaned calves to perform well. Oklahoma researchers compared several management schemes. One
group of steers was weaned at 3.5 months of age and placed in a feedlot, while the other groups were weaned at eight months of age and managed on various growing and finishing programs. All steers were fed to similar fat thickness and slaughtered. The feedlot feed efficiency greatly favored the early weaned calves (5.3 pounds of feed per pound of gain) over older cattle (feed/gain of 8.4 for those weaned at eight months and grazed on native range the full season before entering the feedlot). There was also a significant economic advantage to the early weaned calves: They returned $176.62 per head, while the least favorable comparative group lost $106.56.
Other studies have shown reduced performance in calves that were early weaned. In most of these studies calves were not fed or managed intensively. Certainly the cost of more intensive feeding and management must be balanced against the benefits received. The potential cost savings or improved reproduction from the dam whose calf is early weaned must also be factored when evaluating calf performance.
Daryl Strohbehn, Dan Loy and Nolan Hartwig, Iowa State University
Early weaning trials at Iowa State University have shown that separating the calf from the cow at 45 days of age brought on heat 12 days earlier and improved conception rates six percent. In addition, cows were in a positive state of gain due to lower nutrient requirements. Calf performance up to 200 days was similar for early vs. late weaned calves, and that was during normal moisture years. In drought years, there is every reason to expect early weaned calves to perform better.
In order to accomplish early weaning, proper facilities and techniques are a must. An excellent fenced area is required. During the first week under dry conditions, the walking of calves will pulverize the top soil ,causing dusty conditions. It would be best to wet down the lot every day to minimize the dust problem, causing less irritation to the calves' respiratory tracts. Feed bunks are important. Bunks for lightweight, early weaned calves should not be over 18 inches tall. Allow at least 18 to 24 inches of bunk side for each calf.
At what age should you wean?
Results from Iowa State University and other universities show calves can be effectively weaned as early as 45 days. However, results are best when they are 90 to 120 days of age. No matter what age, it is best if the calves have been exposed to grain at least 10 days before weaning. Hopefully, within 10 days the calves will be consuming about one pound of grain mix daily per head. In starting early weaned calves on the feed ration, go slowly with gradual increases in feed offered. Don't load the feedbunk and leave it until the ration is gone. Remember, a one-pound change in feed intake withî light weight calf is considerable and can lead to digestive upsets. Light calves (200 to 300 pounds), need a ration that contains 14 to 17 percent crude protein and 70 to 80 percent TDN. This can not be done with a straight hay diet.
F.L. Fluharty, Department of Animal Sciences, The Ohio State University
Effects on Subsequent Performance
An experiment was conducted to determine the effects of diet on calves weaned at either 100 days of age (early-weaned) or 205 days of age (normal-weaned). Early-weaned calves had a greater average daily gain (ADG) than normal-weaned calves from 100 to 205 days of age. This resulted in early-weaned calves having heavier weights at 205 days of age if fed either 100% or 90% concentrate diets compared with normal-weaned calves. At slaughter, early-weaned calves had a higher quality grade than normal-weaned calves. Backfat, ribeye area, dressing percentage, and yield grade were not affected by age at weaning or diet prior to 205 days of age.
Keith Lusby, former Extension Beef Specialist, Oklahoma State University
Early weaning could have obvious economic benefits when forage for the lactating cows is lacking or when cows are in such poor condition at breeding that adequate rebreeding performance is impossible. However, the limiting factor for wide use of early weaning has been efficient management of the early-weaned calf. The benefits of early weaning to the cow can be realized only if weaned calves can be successfully and economically raised with minimal facilities, labor and feed costs.
If you would like to receive additional information on early weaning strategies, please call John Paterson (406-994-5562) or Rick Funston (406-232-8223).