Wednesday, May 30, 2018

Why Differences in Starter Grain Consumption Among Limit-Fed Calves?

"How much starter grain should a pre-weaned dairy calf be eating?' That is title of a Washington State University Extension publication (Dr. Dale Moore, A. Adams-Progar, W.M. Sischo). They tracked starter grain intake for 90 calves on each of 3 calf ranches in Washington state.

They asked the question, "Why differences in starter grain consumption?" 

 1. Different levels of milk/milk replacer feeding. There were not wide differences among the 3 ranches in milk feeding levels - they were all limit-fed. At this level of milk feeding it took about 2 weeks for intakes to get up to 1 cup per day on all 3 ranches. So, this question was not really investigated in this research. 

My reading of other research findings suggest that when feeding rates of 4 quarts of 20/20 milk replacer (12.5%solids) daily are compared to 8 quarts of the same product daily both age at initial grain intake and subsequent level of consumption are delayed at the higher feeding rate.

At the time I was caring for 100 calves on milk I subscribed to the idea that calves need to be eating some calf starter grain for about 3 weeks before I began to cut back on their milk ration. I still think that Heinrich's work at Penn State supports this guideline. It was this concept of rumen development turning around in my head that got me started closely watching grain intakes among the calves that  should be at the "start eating grain" age. 

My own calves fed at the lowest rate (4 qts daily) averaged about 7-12 days for initial intake (1 cup per day) compared to the highest rate (8 qts = 2.2 pounds of m.r. powder daily) averaged in the range of 15-21 days for initial intake.

My most important observation from my own calves was the very wide variation among calves drinking the same volume of milk replacer for age at initial grain intake. Among the intensive-feeding program calves there were as much at 10 days or more differences on initial intake ages. Stated a different way, once I began tracking grain intakes about 20% of them turned out to be what I called "laggards" - slow to begin eating grain.

I began dumping and refreshing grain for all these young calves daily until they began to eat it. Then, when they cleaned up a generous cupful of grain several days in a row I snapped a tag to their hutch - that told us we could start the 3-week count-down for beginning the weaning process.

What's the problem with using this 3-week guideline? In my consulting practice between 2000 and 2018 I have not found many calf managers willing to spend time monitoring calf starter grain intakes. The dominant pattern is to dump a quart or more calf starter grain in a pail when the calf goes into the pen or hutch. Then, just leave it there until it disappears in the next 2 or 3 weeks. So much for grain pail management - that kind of benign neglect is non-management in my opinion,

2. Different levels of gastro-intestinal health - either scours or not scours. This is the unique finding for this research report. 

This research found significant differences among the 3 ranches in the percent of calves with diarrhea by day of age. For example, at 12 days of age one ranch had 38% of calves treated for scours while for comparison another ranch was only treating 4%.

The study authors conclude, "The percent of calves with diarrhea could explain about 42% to 51% of the variation in average daily starter grain consumption." (p4)

Rather than grain intakes continuing to climb day-by-day, it appears from the graphs shown in the publication when calves don't feel well (that is, suffer from scours) their intakes flat-line for 3 to 5 days.

This drop in grain intake is valuable information for calf management.
What would I like to see calf managers do when they spot this "flat-line" of grain intake for a calf?

1. Dump those grain pails every day, add a handful of fresh grain.
2. Spend a little extra time to watch these at-risk sick girls.

If you  have many, many calves mark or flag these "at-risk" pens or hutches. They need extra daily attention in case this gastro-intestinal upset slides into a case of treatable respiratory illness.

Reference: To access this publication click HERE or paste this URL in your web browser  [accessed 5/21/2018]

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