The Cow-Calf Manager
Livestock Update, October 2005
John B. Hall, Extension Animal Scientist, Beef, Virginia Tech
Late Summer Drought Creates Challenges
Fall in the Mid-Atlantic is normally a time of cool weather and lush grass growth, not so this year. The late summer drought has greatly reduced pasture availability. In addition, only limited growth of stockpiled fescue has occurred to date. This means that cows are much more nutritionally stressed than they usually are in the fall. The National Drought Mitigation Center and NOAA predict that the drought will continue into early winter. Producers need to be proactive to prevent the drought from having a negative impact on cattle reproduction and condition.
Fall calving cows at greatest risk
Fall calving cows usually calve in good body condition and have adequate pasture quality and quantity to support milking and rebreeding. However, this year fall cows are one to two body condition scores thinner than normal. Cows need to calve in BCS 5 (1 = emaciated; 9 = obese) to rebreed successfully. In addition, cows that lose more than 50 lbs or 1/2 condition score between calving and breeding are delayed in resuming cycles.
In addition, calves from cows that lose weight during the last part of gestation will be slightly lighter. More importantly, they are less vigorous and more prone to scours and respiratory diseases. So early fall cow nutrition is important for both cow and calf.
The main nutrient lactating cows are going to need is energy. Producers with fall calving herds should take stock of their feed resources on hand, and begin planning to stretch them. If you have never tested your hay for nutrient content (quality) then this is the year to test. Extension agents or consulting nutritionists can use the information from the test to make diets that meet cow needs while keeping feed costs down.
Commodity feeds such as corn gluten feed and brewer's grains are good options. Corn is a cheap source of energy this year. Hay and lick tanks are expensive sources of energy. Feeding 8 to 10 lbs. of corn, corn gluten feed, soy hulls or dry brewer's grains will cut hay consumption in half while boosting energy intake for cows.
Protein is not usually limited in cow diets if cows are grazing or eating second cutting hay. First cutting hay will probably need supplementation of protein as well as energy. Corn gluten feed, soy hulls, wheat midds, and brewer's grain also contain protein. Feeding these commodity feeds to meet the energy needs of cows will also avoid any protein deficiencies.
A high quality mineral is also needed during times of stress for lactating cows. Make sure the mineral you are feeding has a minimum of 12-14 % magnesium (Mg), 1000-1500 ppm copper (Cu) and 26-52 ppm selenium (Se).
Finally, the amount and quality of water available needs to be considered when planning a feeding program for lactating fall cows. Water consumption increases dramatically with calving and milk production. Cows will generally need 25 to 40 gallons of water per animal each day. Ponds that are stagnant as a result of drought concentrate minerals and pathogens. If producers are unsure about water quality, they need to contact their county agent or health department for more information about water testing. Check water sources daily to ensure that cows have enough good water available. Poor or limited water supplies will impair milk production and reduce calf gains. In severe cases, cows may become ill.
Spring Calving Herds
Fall drought is less of a problem for spring calving herds than fall calvers, but there still can be dramatic effects on cow condition and calf performance due to drought. This is definitely a year producers should consider weaning calves early and backgrounding them for 45 to 60 days. The decision to wean early should be based on pasture availability and cow condition.
The first action producers should take is to evaluate cow and pasture condition. If cows are already in BCS 4 or less then calves should be weaned immediately. There needs to be 6 to 8 inches of grazable forage available in the pasture to meet the dry matter and nutritional needs of cows and calves. If there isn't enough pasture available then calves should be weaned.
The best strategy for spring calving cows is feed dry cows first cutting hay and save pasture and supplements for calves. Dry cows can gain needed weight on good quality (50-52% TDN, 8 to 10 % CP) first cutting hay. This will allow cows to gain needed weight and body condition before winter weather hits. Cows that are very thin (BCS 3 and below) will need 5 to 8 lbs of corn, corn gluten feed, soy hulls, or brewer's grains to gain needed weight.
Once calves are weaned (see last month's article for weaning practices), they can be self-fed soy hulls or corn gluten feed while on pasture or hay. These supplements should be fed daily in increasing amounts until calves are being fed 1% of their body weight in supplement. After they reach the 1% level then calves can be placed on a self feeder.
For more information on weaning calves or drought related information contact your County Extension Agent or http://www.apsc.vt.edu/Extension/Extension.cfm and click on the drought link.