Hay: Too much, too soon
Here's the situation. Continuous flow automatic feeder barn. Calves come into pen 1. Stay 4 weeks on auto feeder. Move to pen 2, 4 more weeks on auto feeder with a week-long step-down weaning period. Ration in both pens 1 and 2 is 22:20 milk replacer with Bovatec - fed on a step-up schedule for first week, stays at 10 liters per day until day 49 followed by 7-day step-down. Free choice water and calf starter grain (22% c.p.). Calves move to pen 3 (transition pen) around 60-65 days of age.
Pen 3 ration is free-choice water , one-half of feeder space is calf starter grain, one-quarter of feeder is free-choice good quality mixed alfalfa-grass hay, and one-quarter of feeder is free-choice haylage.
Health situation - low scours treatment rates in both pens 1 and 2. Some pneumonia treatments for calves when moved from pen 1 to pen 2. Many pneumonia treatments when calves are moved from pen 2 to pen 3 - usually 5 to 9 days after being moved. Owners observed that the newest calves in this pen "stand still" for the first week or two. Calves receive intranasal vaccination on day 1.
Pen 3 has a feeder with slanted dividers - 44 spaces. Pen population usually runs between 15 and 25.
I recommended maintaining one-half of the feeder space for the grain ration. I recommended changing the forage ration. First, eliminate the haylage for this pen. Second, for the other half of the feeder, feed only enough of the good quality alfalfa-grass hay to last about one hour once a day.
Reasoning? Prevent the new entrants to the pen from pigging out on the quite palatable hay by limiting access to only one hour. With the hay spread out with access (22 slants) the newest calves will very likely consume less than one pound of hay each day. That will be enough to stimulate the growth of the appropriate microorganisms in the rumen to digest the hay. Having eliminated the large amounts of hay there will be plenty of grain consumed to maintain enough energy and protein to meet both maintenance and growth needs. And, with the coccidiostat in the grain they will continue to be protected from cocci growth.
Too much hay too soon.