Feeding First Time Calf Beef Heifers After Calving for Rebreeding

By Peter Vitti

It’s easy to envision beef heifers that give birth to their 1st calf as younger versions of mature brood cows.

However, they have extra challenges after calving that must be addressed in order to get rebred in the next few months. As young animals, giving birth for the first time as well as nursing a newborn is real shock to their system. All of which take weeks for them to recover. That is why; good feeding programs should be continued after calving in preparation for a successful breeding season.

Many profitable cow-calf operations that I have dealt with for years; as a matter of routine already separated their bred 1st calf heifers going into the winter. They also have bred them (last year) about three weeks ahead of the main cowherd, so they calve out earlier (in the present year) and to allow a natural 20-30 days of extra postpartum interval.

It’s precious time to return and repair their uterus to normal involution as well as return to active estrus cycles. All the while, they are nursing a newborn calf and maybe putting on some growth, themselves. In the end, it should also synchronize the future calving seasons of these young cows with the older brood cows.

All of these undertakings actually start on the day of calving. And good body condition at this time must be maintained over the next few months that will dictate good upcoming reproductive performance. That’s because, an optimum body condition score of 5 – 6 on a scale of 0 – 9 is an indication of her current nutritional status, which is the single most important factor that controls: post-partum interval, milk production, estrus strength, services per conception and ultimately successful rebreeding.

As a ruminant nutritionist, I believe that maintenance of optimum BCS from calving to breeding season in 1st calf heifers starts in hindsight - with a well-balanced overwinter feeding program containing 55 – 58% TDN and 10 – 11% protein. Then, ever so slightly increasing this plane of nutrition within weeks of calving. Ending with a post-calving/ lactation diet of 62 – 63% TDN and 11 – 12% protein – a fortified continuation of these previous gestation diets.

The dietary nutrient requirements of these calved- out 1st calf heifers are really no different than a mature beef cows’ on a kilo for kilo basis. Yet, they must be condensed into a denser post-calving diet due to the heifers’ smaller dry matter intake (DMI) and lower forage gut-capacity. Furthermore, 1st calf heifers within a few weeks of calving experience about a 20% decrease in DMI, which must be built back up after calving or be prone to a drop in precious body condition.

Given that a post-calving 1st calf heifer should consume about 2.5% of her bodyweight in feed; a typical heifer weighting 1000 – 1100 lbs. should consume 25 lbs. of feed on a dm basis per day. Therefore, here are three lactation diets that I have set up for a few prairie beef producers in the last few months. They are geared for replacement heifers that are ready to calve in midFebruary to the beginning of March:

1. 25 lbs. mixed alfalfa-grass hay, 3 lbs. of barley and 3 oz. of a 1:1 breeder mineral.

2. 30 lbs. of barley silage, 12 lbs. of grass hay, 2 lbs. of DDGS and 3 oz of a 2:1 breeder mineral.

3. 20 lbs. barley silage, 15 lbs. of 1st cut alfalfa hay and

Good feeding programs should be continued after calving in preparation for a successful breeding season. Submitted photo

4 lbs. of screening pellets. The common thread amongst these diets is that forages were taken from onfarm inventories that were saved for the latter winter to help meet these post-calving nutrient requirements. I didn’t feed lower quality forages such as straw to avoid challenging a heifer’s limited feed intake. Yet, I allowed some extra energy - such a couple more pounds of grain or DDGS added in each diet when the windchill temperature dips below -18 °C.

However, I expect as the weather gets warmer and these heifers are 60 days post-partum – all grain feed will likely be eliminated as well as less barley silage might be fed in #2 and #3 and replaced by grass hay. This is done to still help them grow, still produce milk and prevent any animal from getting too fat. Best of all, prepares them for a successful breeding season.