Replacement Heifers

Management Objective: To select and grow heifers to produce cows that will have long productive lives.

Points to Remember

• To complete growth to maturity on schedule, heifers need extra care until their second calf.
• The number of heifers selected now will dictate the number of cows that can be culled a year from now.
• More replacement heifers will be needed if the herd is being reorganized by culling late calving cows to shorten the calving season.
• Heifers large at weaning will retain their advantage throughout life with proper care.
• Proper feeding in the first winter is critical to the cows' eventual development.
• Early cycling in heifers depends on age and weight at the time of the start of the breeding season,
• Heifers having calves in the first three weeks of the calving season will outproduce cows which do not have their calves until ninety days after the first calf was born.
• Heifers need more time to start cycling after their first calf than mature cows. Many breeders therefore start the breeding season for replacement heifers three to four weeks before the rest of the cows.
• Selecting and breeding more replacement heifers allows a manager to put more selection pressure on the cow herd for fertility and higher weaning weights.

• Extra feed is needed by younger females. Replacement heifers should be fed separately and given extra feed from weaning until their second calf.
• Keep enough replacements so that any cow that needs culling can be replaced.
• Cows calving beyond 60 days in the calving season should be replaced by heifers calving in the first 20 days.
• Calve heifers 20 days ahead of the cow herd to allow them more time to begin cycling before the breeding season begins.
• Calving problems can be minimized by selecting bulls for replacement heifers carefully. Bulls for replacement heifers may be selected from breeds which usually have lighter calving weights. This may compromise growth potential and heavier weaning weights. An alternative is to use the same breed of sire as for the main cow herd, but to choose bulls with lower birth weights for replacement heifers.

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