The Cow-Calf Manager
Livestock Update, August 2002
John Hall, Extension Animal Scientist, Beef, VA Tech
Fall Calving Cows Will Need Special Treatment in Late Summer
Usually late summer management of fall calving cows is simple, wean the calves in July and allow the cows to graze the rest of the summer. In addition, stockpiling fescue for grazing after calving or during the breeding season has normally provided all the major nutrients needed by lactating fall calving cows. However, the rainfall patterns the last two years have left fall calving cows in lower body condition going into the calving season. Also, fall and early winter grazing has been limited.
Good Body Condition Critical -Cows need to calve in body condition score (BCS) 5 or 6 in order to have healthy calves and breed back quickly. Research from many states indicates that pregnancy rates for cows in BCS 5 or better are 85 to 90%, but pregnancy rates are less than 75% for cows in BCS 4 or lower. Body condition scoring is easy to do and is an excellent monitor of the nutritional status of the herd (see chart below).
Table 1. Body Condition Scores
|Outline of spine visible||yes||yes||yes||slight||no||no||no||no||no|
|Outline of ribs visible||all||all||all||3-5||1-2||0||0||0||0|
|Fat in brisket and flanks||no||no||no||no||no||some||full||full||extreme|
|Outline of hip & pin bones visible||yes||yes||yes||yes||yes||yes||slight||no||no|
|Fat udder & patchy fat around tail head||no||no||no||no||no||no||slight||yes||extreme|
Supplement Energy First - Energy is most likely the most limiting nutrient. Corn, barley and other grains are good sources of energy. Corn and barley are reasonably priced this year, but prices for these grains are above the last several years. These energy products will also reduce the amount of hay needed by cattle. When grains are fed at higher than 0.5% of BW forage intake is reduced. For example, a 1200 lb cow fed over 6 lbs of grain will reduce the amount of hay she will eat. This can be a good thing if we want to limit feed hay.
Grains can be fed at up to 50% of the diet without causing digestive upsets. Higher fiber feeds like corn gluten and poultry litter can be fed at much higher rates without worrying about cattle getting sick. The basic litter-based cow diet is 80% litter, 20% corn and 5 to 8 lbs of hay. Many places in Virginia are reporting that pelleted soyhulls are available at reasonable cost. This is a good energy source.
Below are some example diets for dry beef cows. All diets are designed for cows that will weigh 1250 lbs. at BCS 5. The diets to gain weight are designed for cows that are BCS 3 and weigh 1050 lbs. now, but should weigh 1250 lbs. These diets are good examples, but feedstuffs on individual farms will vary. For accurate ration formulation, producers should have a nutrient analysis of their feeds, and consult your county extension agent or nutritionist to help design a ration.
Table 2. Diets to help dry cows gain weight
|Diet Composition (lbs. per cow per day as fed basis)|
|Ingredient||Diet 1||Diet 2||Diet 3||Diet 4||Diet 5|
|Corn Gluten Feed||0||7.0||16.0||0||0|
|Days to gain 1 condition score||46||57||27||21||34|
|Cost per cow per day||$1.00||$0.89||$1.04||$0.94||$0.65|
Table 3. Diets to help dry cows maintain weight
|Diet Composition (lbs. per cow per day)|
|Ingredient||Diet 1||Diet 2||Diet 3||Diet 4|
|Corn Gluten Feed||0||7.0||0||8.0|
|Days to gain 1 condition score||448||261||120||150|
|Cost per cow per day||$0.99||$0.99||$0.91||$0.96|
The diets in table 2. Assume that cattle will be brought up on grain gradually, and all diets are relatively high in fiber. These diets do not guarantee breeding success in thin cows unless cows reach BCS 5 or better by calving. However, research indicates that thin cows that are gaining weight prior to breeding have a 20% better conception rate than thin cows that don't gain weight.
Diet 4 in table 3 is a hay saving diet. It meets the nutrient needs of the cow, but will not fill them up (doesn't meet the dry matter requirement). Cows on this diet will be fine nutritionally but will act hungry, and they may try to get out to get more to eat.
All diets should be fed with free choice mineral mix of 2/3 high selenium trace mineralized salt and 1/3 ground limestone.
The drought has made it tough again this year, but many feeds are good alternatives to hay. It will cost more to let cows remain in thin condition than to get them in good shape. In addition, many regions of the country are liquidating cow herds due to the drought. Producers that can keep their cows though the drought by cost effective feeding may be rewarded in the future with higher calf prices.