Charting Heifer Growth To Evaluate Heifer Management
Dairy Pipeline: July 1998
Tom L. Bailey
Dairy Production Medicine
Virginia-Maryland Regional College of Veterinary Medicine
(540) 231-3936; email: email@example.com
Charting heifer growth for body weight, skeletal development, and body condition scoring can evaluate performance and spot trends or problems in heifer management. Remember: IF WE CAN MEASURE IT, WE CAN MANAGE IT. We have records for monitoring milk weights, somatic cell counts, number of inseminations, and days open. Monitoring heifer growth and development affords us the opportunity to make changes in heifer management based on information derived from actual measurements. These charts show stages of growth and development in partitioned groups and determine either decreased skeletal development, overconditioning or underconditioning. All are good indicators of improper feeding or poor overall heifer management. Insufficient height is generally an indication of low protein in the diet. This usually occurs in heifers older than 7 months during periods of the summer when grass pastures are of poor quality or heifers are fed low protein corn or small grain silages without protein supplementation. Overconditioning heifers may indicate excessive amounts of corn silage in diets or feeding high energy rations, such as feeding refusal from the lactating cow ration. Body condition should be monitored to insure adequate skeletal development (height) and body tissue mass. Heifers should be charted at least 5 times before they reach 2 years of age. This can be done at times of deworming, vaccinations, breeding, or pregnancy checks, so it is not an additional chore. Unfortunately, once breeding occurs and heifers are examined pregnant, they are often neglected until calving. Heifers should be monitored during this time for adequate projected weight and height at calving. Our experience indicates that heifers typically fall below our target goals for average daily gain during the period between breeding and calving. Heifers should be first weighed or girth taped at 2.5 to 3 months. This could coincide with the time calves are removed from the hutches and delegated to smaller partitioned groups. The second measurement should be done as the calves are vaccinated for calf-hood diseases at about 5 to 6 months of age. Measure again at 9 to 12 months of age to evaluate the critical period up to puberty, when calf development is so important for udder growth. A prebreeding graph will determine if development is on target for breeding weight at 775 pounds to 800 pounds and height is 48 inches or greater. A fifth measurement, which is going to be an additional chore at 18 to 22 months, is taken to ensure heifer growth is adequate to meet our goals at calving. Heifer performance is often sub-optimal at this time, but can be clearly demonstrated with a simple chart of weights and heights in relation to optimal growth. So, why aren't more producers charting heifer growth? Primarily because heifers are in a non-productive state and are thought of as an additional chore to maintain. More often, producers have inadequate facilities for handling youngstock. Self-locking head gates at the feed bunk or a well designed pen and working chute could facilitate vaccinations, deworming programs, and monitoring growth. Producers with a large number of heifers may find the use of scales to be very cost effective. Hoard's Dairyman or your local extension office has chart guidelines for all breeds for both optimal height and weight.