The Cow-Calf Manager: Spring Management of First Calf Heifers
Livestock Update, May 1999
John Hall, Extension Animal Scientist, Beef, Animal and Poultry Sciences, Virginia Tech
Whether you calve in the fall or spring, May and June are critical times for first calf heifers. It is an easy time to "forget" about the cows with all the good pastures, hay to make, fields to plant and spring recreational activities. But forgetting to monitor 2-year cows with their first calf can be disastrous for the future of the heifer.
Heifers need to calve in good body condition (6 or 7) in order to rebreed as fast as possible. In addition, they need to maintain a body condition score of at least 5 through breeding. Heifers need to be monitored about every 2 weeks to ensure they are not losing too much weight. Heifers that calved this fall should be checked as well. These fall calvers need to regain the body condition they lost this winter before they calve this fall. Three year-olds need to be in body condition 5 or better when they calve for the 2nd time in order to breed back.
Even though our spring pastures provide enough quality in terms of energy and protein content, it contains a lot of water. Since cattle only spend about 8-10 hours per day grazing, a heifer may not get enough dry matter to meet her nutritional needs. In other words, she is eating all she can, but there is so much water in the grass that she can't physically eat all she needs. Her stomach gets too full too quickly. Under these circumstances, heifers are not getting enough energy and will lose weight. If they lose too much they won't breed back. Therefore, some grain feeding may be needed to meet the 1st calf heifers energy needs.
Putting first calf heifers in the same pasture with mature cows can cause problems also. Mature cows will boss the young cows. As a result, mature cows get the best grass while young cows spend more time and energy looking for grazing and avoiding boss cows. These young cows then spend less time grazing.
Finally weaning calves early from 1st calf heifers can be a big boost to heifer lifetime productivity. Fall born calves should be weaned by May. This will allow the heifer to gain the body weight she needs by fall. Once a calf is over 5 months old he only gets 25% of his nutrition from milk. This percentage is even less for 1st calf heifers, so leaving the calves on the cow is of little benefit. Calves can be grazed by themselves on high quality pastures in the early summer to increase sale weights.
Like fall calvers, spring calving 2 year-olds can also benefit from weaning calves early. Calves should be weaned at 5 or 6 months, so 1st calf heifers can benefit from fall grass and gain weight before cold weather sets in. Again, weaned calves can be grazed on high quality forage or put through a backgrounding program. Backgrounded calves with proper vaccinations could be sold through the Virginia Quality Assured program. When heifers are extremely thin at calving feeding extra grain may not be enough to get heifers re-bred. In this case, calves should be weaned when they are 90 - 120 days old. These young calves will need some special diets, but that is less costly than losing a heifer because she is open at pregnancy check. Check with your extension agent on diets for early weaned calves.
Take extra good care of your 1st calf heifers this spring. There is no animal more expensive to replace than a 2 year old heifer who comes up open after her first calf. Mismanagement of 1st calf heifers is the number one reason 2 and 3 year-old cows leave the herd. You've spent a lot on her now treat her right!