Late Weaning –

 Following last week’s PCC Update, we received several questions about late weaning and why we choose to leave calves on their mothers over the winter. 

 For starters, it’s natural.   In nature, there is no herdsman to wean the offspring.   In fact, when a doe gives birth to a fawn, there is often a yearling not far away.   Along with mimicking nature, running one herd requires less time, labor and money.   Late weaning will allow the calves to learn what to eat, what not to eat, where to find water and how to survive harsh winters.   Late weaning will also allow the calf’s rumen to fully develop.   This increased rumen development will result in increased feed efficiency leading to better body condition and improved fertility. 

 Dr. Anibal Pordomingo, from Argentina, has research showing that the average cow digests only 50% of what she ingests.   He suggests that leaving calves on their dams until 10 months of age can results in a 15 to 20% increase in rumen efficiency.   This increase in rumen efficiency would allow a cow to digest 65-70% of what she eats. 

 Several producers are having great success wintering calves on the cow and weaning at 10 months of age.   Below is a list of the reported benefits observed:

  • 16% less fed feed in winter
  • 5-10% increase in average body weight following winter
  • 5-10% increase in fertility/conception rate
  • Grassfed cattle finished in 22 months vs 27 months

 In addition to the results listed above, I believe producers will see improvements in herd health.  The immune system is developed and maintained in the gut.   If the increased efficiency in the rumen leads to greater mineral uptake, then it is reasonable to believe herd health will improve.

 I am fully aware status quo producers will scoff at the idea of wintering calves on the cow.   Most will say it can’t be done.   With mainstream genetics, they are 100% correct!   Tall, lean, high-maintenance cows, will quickly fall apart without expensive supplementation.   It is amazing what can be done with the right genetics!


6 responses to “Late Weaning –

  1. Please explain the increase in fertility and conception. Surely the cow loses condition with late weaning and especially at 10 months. As I understand it there is a direct correlation between the cows condition  at calving and conception hence fertility. Obviously the longer the calves is suckling the poorer the cows condition will be at calving. 

    1. Peter, the increase in fertility and conception applies to the heifer calves that were allowed to stay with their mothers for 10 months. They have much greater rumen efficiency than heifers weaned earlier. The right kind of cows are not negatively affected by late weaning. The right kind of cows are low-maintenance cows with low milk production. We do not grow calves on milk. We grow calves on grass and supplement the grass with milk. The right kind of cow will reduce milk production and eventually wean her calf. As Tim said in the article, this will not work with mainstream cattle — without heavy levels of supplementation.

      1. You also need to be calving in sync with nature or with your forage resources to increase body condition prior to calving. 

      2. Ok. Your systems and conditions are  obviously different to mine. I gather your winters are colder and am I correct to say it snows.
        I wean at 7 months and only retain the Heifers greater than 220 kg. Put them with a bull between 15 and 18 months( only if they’re heavier than 300 kgs) Run 2 months with a bull and retain only those that have conceived. 
        Weaning at 7 months gives the cow ample time to improve condition and go into calving season 3 months later. Cow must give a calf once per year. 

  2. We want high fertility in our herd, both bulls and heifers.  We wean late, around 10 months, and have a pretty low maintenance herd and select small framed cows.  The last time we left bull and heifer calves with the mothers out until 10 months, we ended up with our nicest, highest fertility heifers dying giving birth at 18months because they were bred too early by highly fertile young bulls.  These were nice heifers, but just too small to give birth.  Our calving weight is not high.   Ever since, we have weaned bull calves sooner.  How do you deal with this?  Bull calves benefit from staying with mother as long as possible too.

    1. I’m sure that can be a problem.   In an extremely low input (no-input) program, it is almost impossible for anything to cycle before green grass is available.   Do you feed hay and/or protein supplement?

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