27 April 2007

3 minute read

North America

Evaluating the notations in the calving book is important. For the most part, due to ease, things that happen in the field are noted in the calving book by means of codes. In the case of the North Dakota Beef Cattle Improvement Association production program, calving ease is scored numerically from one to five.

A one score means there was no difficulty and no assistance. A two score means minor difficulty, with some assistance. A three score means major difficulty, usually involving mechanical assistance. Four is utilized to indicate a caesarean section, while a score of five is for calves that are presented abnormally.

Keep in mind that the three and five score may be confusing. Many abnormally presented calves are the result of major difficulty because the cow tries to give birth to a normally presented calf. The size of the calf or birth canal can cause the calf to become abnormally positioned.

Calving is a time to reflect and note that converting an event to a number may not explain the extenuating circumstance. Cows sometimes need to end up on the cull list, even though they did not need assistance. On the other hand, just because a cow needed assistance doesn't automatically mean she belongs on the cull list.

Intervention during the birthing process may slow a cow's recovery process and delay her rebreeding. However, unless the cow was late in the season, she still should rebreed.

The added stress that is on the first-calf heifers is demanding. The heifer must recover from calving, continue to grow and then produce milk for its calf.

This scenario has caused the Dickinson Research Extension Center to try different breeding schemes and calving-ease bulls. Lately, all the heifers have been bred to Loala bulls with the hope of lowering birth weight and still having an acceptable calf.

Before the current experience is shared, one must note that the opportunity for calving ease is available through proper sire selection and utilization of expected progeny differences (EPDs). Most breeds actively engaged in the U.S. beef industry offer EPDs for sires.

In the case of the heifers bred at the DREC, the question was simply a management alternative focused on providing calves for a research project. However, the last three calving seasons have produced notable results. The heifers, typically black and black baldy heifers, have calved with very little oversight.

In 2004, the nine calves averaged 68.6 pounds and all the calves scored a one (no assistance provided). In 2005, more heifers were bred with Loala bulls. The 25 calves averaged 64.9 pounds, with 24 calves scoring a one for calving ease and one calf scoring a two (requiring minor assistance).

The 48 calves born in 2006 averaged 63.8 pounds, with no assistance provided to any heifers. In preparation for the 2007 calving season, the heifers were moved from lot-calving to pasture- calving, given the minimal assistance required the previous three years.

The heifers are not done calving for this year, but the 44 calves that have been born have averaged 74.7 pounds and all but two have required no assistance. The two heifers that were brought in needed minimal assistance.

The experience has cut some of our worries about calving heifers and provided virtually no stress on the heifers. So, although not all of the heifers have raised their calves, calving difficulty is not the culprit. More on that later.

May you find all your ear tags.

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