Development of replacement heifers is not easy
By By Lance Bruce / 4-H livestock agent
Sept. 1, 2004
For most producers replacement heifers are easy to develop; they go and buy them. However, several producers keep heifers out of top producing cows in order to capture the genetic quality.
Replacement heifers can be a mixed blessing for most cow-calf operators. On one hand she represents the profitability of the future and on the other hand she is an inconvenience due to her management.
A heifer is basically unproductive for two years and therefore often gets mismanaged for that time. In order for her to become a productive, profitable member of your cow herd her development and management is of the utmost importance. This management can be divided into four phases: preweaning, weaning to breeding, breeding to calving, and calving to rebreeding.
Producers depend largely on the dam to nurture and care for the replacement heifers until meaning. Producers need to keep accurate records of birth dates and weaning weights so that high producing cows can be identified. A replacement heifer needs to wean off at 450-600 pounds depending on breed, frame size and feed supply. This weight needs to be true skeletal and muscle growth without a substantial amount of fat.
Weaning to breeding is a very important period in a heifer's development. This is the time to really exam the soundness of the animal and to cross reference with available records. In addition, heifers may be selection on criteria of soundness, disposition, fleshing ability, muscle, and frame size. The age at which a heifer reaches puberty is also important. A heifer cannot calve early if she cannot breed early. For a heifer to calve at 22-24 months of age a heifer must reach puberty by 12-15 months of age. Heifer puberty is largely a function of age, weight, and genotype. Nutrition from weaning to breeding also dictates early conception and reproductive performance. Heifers need to be in good body condition to breed. If they are too fat or too thin, their reproductive system may not function properly. Replacement heifers need to be bred three to four weeks earlier than the mature cow herd. This allows first calf heifers extra time to start cycling and stay on schedule with the mature herd.
The next step in profitable management is to ensure that a heifer has adequate growth and development from breeding until she calves as a 2 year old. If a heifer is under poor nutritional management during this period could cause several major problems including: lighter calves, weak calves, delay rebreeding and decrease in milk production.
From calving to time to rebreeding is a critical time for a 2-year-old heifer. The nutrient requirements of heifers after calving greatly increase because the heifer must lactate, continue to grow and prepare for rebreeding. Heifers not receiving the nutritional level that is need will have longer postpartum intervals and may even fail to rebreed.
Heifers that are developed under good management practices will have a better chance of early breeding, giving birth to a healthy calf, raise calf to good weaning weight, and breed back early for their second calf. These heifers will make you money. Heifers that are mismanaged will cost more in the long run due to lack of production and they eventually they will have to be culled.
For more information on the selection and development of replacement heifers contact the Lauderdale County Extension Office at 482-9764.
