Management in the Last Trimester of Pregnancy

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 Points to remember | Good management practices | Plan ahead

Management Objective - Cows to have strong healthy calves and be ready to rebreed in 45 to 60 days.

Points to Remember

  • The last trimester of pregnancy is a critical time in the yearly cycle of the cow. The way she is fed and managed at this time will have a direct effect on her rebreeding schedule and the health of her calf.
  • If a cow is to calve every 365 days, she must be bred within 83 days after calving.
  • From calving until the uterus is in condition for pregnancy is approximately 40 days. This leaves only two heat periods for her to rebreed.
  • The nutritional needs of cows increase rapidly during the last 3 months of pregnancy because the fetus makes 70% of its growth in the last 3 months. A lack of energy and protein is the greatest cause of poor reproductive performance.
  • Low quality winter feeds and poor management practices allow serious nutritional problems to develop.
  • Thin cows should be fed to gain weight during the winter.
  • Older and weak cows and first calf heifers need extra feed and care. Cows should be fed in groups according to condition and age of the cow.
  • Because the unborn calf is largely protein, the need for protein increases as calving time approaches.
  • "Precalving" nutrition of the mother cow has many important implications in the resistance of the calf to stress and disease.
  • A dry, pregnant beef cow weighing 1,100 pounds would require about 22 pounds of dry matter feed per day and about 1.3 pounds of crude protein. Increase the ration by 10% for each 10 degree C below -20 degrees C.
  • Extra nutrients are required 90 days pre-calving to assure proper fetal growth, a healthy calf at birth and a cow that can milk.
Good Management Practices

Divide cows for feeding
To meet the nutritional needs of the different groups that make up the cow herd, divide them into groups with the same needs such as:
  1. replacement heifer calves,
  2. first calf heifer,
  3. older thin cows, and
  4. prime-of-life cows.

Provide mineral mixture either mixed into the feed or fed free choice
Trace mineral salt/phosphorus mixture should be provided at all times. Special minerals such as magnesium, to prevent winter tetany and selenium should be added as needed especially if cereals, straw or weathered hay is a major part of the diet.

Watch cows for
  • Vaginal prolapse - Greatest incidence during last third of pregnancy.
  • Abortion - Any abortions should be submitted to a veterinarian for diagnosis.
  • Unexpected early calves - As calving time draws near, don't be caught off guard by early calves.
  • If cows have external parasite buildup, provide dust bags at this time, or treat cows with injectable or topically applied insecticides.
  • Minimize handling stress as much as possible with well-designed facilities.
  • Feeding pregnant cows after 6:00 p.m. may result in more calves being born in daylight hours.
  • Vaccinate cows for calf scours if scours have been a problem the previous years.
  • Use this time before the pressure of calving season to increase your knowledge of the beef business.
  • Read research and extension publications
  • Attend extension meetings
  • Study farm and cattlemen's magazines
  • Attend breed and commodity association meetings
Prepare for calving
  • Get the hospital pens ready
  • Collect, clean and repair calving instruments and equipment.
  • Have on hand all necessary sanitation equipment, obstetrical gloves, soaps, lubricants, etc.
  • Have on hand some frozen colostrum, electrolytes for liquid supplements, bottles, nipples, probe feeder, etc.
  • Prepare calving grounds which should be clean and dry.
  • Arrange to have cows with new born calves transferred to a clean, dry, well protected site away from cows who are yet to calve.
  • Prepare shelters so that calves can seek shelter away from the rest of the herd.
  • If AI will be used, study sire records. Begin planning for assembling supplies, updating inseminating technique, ordering semen, etc.

Other Documents in the Series

  Management in the Last Trimester of Pregnancy - Current Document
Calving Season - Cows
Achieving a Successful Calving Season
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For more information about the content of this document, contact Barry Yaremcio.
This document is maintained by Brenda McLellan.
This information published to the web on September 25, 2001.
Last Reviewed/Revised on January 30, 2019.