Monday, November 30, 2015

Finding Sick Calves in Group Housing

How does one find a sick preweaned calf in group housing?

If the pen of calves is fed twice or three times a day, then is seems logical to look for any calf that does not get up at feeding time.

However, what if the calves are being fed with a computer-controlled automatic feeder? There is no special feeding time even though there are hours of the day when feeding is more frequent. Thus, looking for any calf that is lying down when we are in the barn could be a pretty unreliable method of spotting sick calves. 

Recent research observed the behavior of preweaned dairy calves (N=75) in group housing (8 pens). To test for approaching a human the researcher walked calmly to the center of the pen and remained motionless for 60 seconds. To test for approaching an object the researcher walked in the center of the pen and left behind a blue plastic cone (8.5" tall, 5.5" at base). The calf behaviors were video taped for later analysis. An "approach" was defined as taking a step toward the object/human. 

The calves were observed daily by farm staff and weekly by the research team. They recorded all the cases of diarrhea (65% had at least one case of scours) and bovine respiratory disease (59% had at least one episode of treatable pneumonia).

Using both measures of exploratory behavior (that is, approaching either or both the cone or human) they found a positive association between sickness and failing to approach. The same failure to approach was found when calves had a fever (anything equal to or greater than 103F [39.4C]).

Implications for me: In addition to watching for the familiar symptoms of scours and pneumonia (that is, coughing, runny noses, dirty rumps) these finding suggest that lack of exploratory activity (approaching a stationary person or object) might tip us off to a calf running a fever or feeling sick. These are the "need to check" calves. Just one more tool in our health toolbox. 

Reference: Cramer, M.C. and A. L Stanton, "Associations between health status and the probability of approaching a novel object or stationary human in preweaned group-housed dairy calves." Journal of Dairy Science 98:7298-7308. 2015

Monday, November 23, 2015

Value of Transition Milk

During a farm visit last Friday we talked over a persistent problem with scours during the first two weeks of life for their calves.

The farm milks all their cows into a bucket milker for the first four milkings. Currently that milk is diluted with line milk and fed to the calves over four weeks of age.

Recall that compared to first milking (usually we call this colostrum) the second and third milkings post calving have about 70 and 40 percent respectively antibody concentration. 

This dairy was feeding this "liquid gold" to the older calves.

My recommendation, especially given the scours issues among the youngest calves, was to change their feeding practices for this "transition" milk. Save it separately - feed it fresh to the youngest calves for as many days as the supply will permit. My best guess is that when this change is made there will be a big drop in scours cases among the young calves. 

By the way, they are now checking colostrum for antibody concentration with a Brix refractometer. Any low quality colostrum will be pooled with the transition milk - that will give a nice boost to the antibody content as well. 

Friday, November 13, 2015

Another Colostrum Q

I ran across this resource that talks about cleanliness of colostrum. The work, "quenliness" is coined to describe the bacteria count in colostrum.

Find the article HERE by Jim Salfer of the University of Minnesota Extension service. 

The article provides a great review of best management practices to achieve low bacteria counts in colostrum.

Have fun with this new word - QUENLINESS!

Wednesday, November 11, 2015

The Transition from Hay to Fermented Feeds

I had the opportunity to visit two dairies the same day. In each case I walked the transition heifer pens. I must admit that I did not have any scale data in order calculate growth rates for these heifers - I just walked by slowing making visual assessments of the animals. 

On dairy #1 heifers are moved from individual to group pens of 10 calves, the ration for these heifers age 9 to 13 weeks was free-choice grower pelleted concentrate, free-choice medium-quality hay and water. Before coming into these transition pens their ration was the same pellet and water free-choice. 

Around 13 weeks old their ration changes from the pellets and hay to a heifer TMR formulated specifically for heifers 3-12 months of age. 

On dairy #2  heifers are moved from individual to group pens of 10 calves, the ration for these heifers 9 to 10 weeks was free-choice grower pelleted concentrate, the amount of good-quality hay they can clean up in an hour and free-choice water. Before coming into these transition pens their ration was the same pellet and water free-choice. 

At 11 weeks these heifer are moved to another barn, pens of 10 heifers, ration changes to free-choice hay, pellets and water.

At 13 weeks the ration changes by adding the amount of heifer TMR they will clean up in about an hour - several large shovels-full it look like to me. 

At 15 weeks the rations changes entirely to the heifer TMR formulated specifically for heifers 4-12 months of age. 

What is the difference between the two feeding protocols?

Dairy #2 - the heifers had close to two weeks of eating the fermented feed before they moved to entirely TMR.
Dairy #1 - there was an abrupt change from dry forage to fermented forage in one day.

What are the plus and minus factors involved at these two dairies?

On dairy #1 it is likely to be nearly a full week before these heifers are able to achieve a new balance of fiber-digesting microbes that work on fermented feeds. Thus, these heifers will be short on energy and protein. As long as there are no stress factors (abrupt change in weather, over-crowding, vaccinations, introduction of new animals into the pen) these shortages are not likely to have any negative effects other than some compromised growth.

On dairy #2 the switch to fermented feeds is likely to have little effect on the availability of energy and protein for these heifers - they have received rumen pre-conditioning to smooth the change in forage from dry hay to the TMR.

I am sure you can see my preference for pre-conditioning the rumen when making a ration change. I believe this management choice is better than buying a feed-grade antibiotic (for example, AS700, Aureomycin) to top dress the ration while the heifers adapt to the ration change. 

Tuesday, November 3, 2015

November 2015 Calf Management Newsletter
"Are Your Weaned Calves Rumen Ready?"

The newsletter is available HERE or at, click on Calving Ease in left hand menu, click on November newsletter. 

Key points:
  • Rumen review – the fermentation center for a ruminant.
  • Changing from a pig to a ruminant – strong rumen wall muscles, well grown-out papillae.
  • Tips for encouraging early rumen readiness:
1.      Know what is “normal” grain intake.
2.      Keep the grain dry.
3.      Keep the grain fresh, especially avoid moldy grain.
4.      For the youngest calves begin with only enough grain to cover the bottom of the pail.
  • Hunger is a great incentive to eat more grain – cut back on the milk near weaning.
No Hay to Free-Choice Hay in One Day?

Here we are in the transition heifer housing. Heifers at this dairy move from hutches into small outdoor group pens (10 calves) where they continue their ration of free-choice pelleted grower concentrate (18% protein) and water.

Then they come into this transition heifer barn - starting at one end and in several months moving to pens in the other end. On this in-coming end the ration continues with free-choice pelleted growth concentrate and water AND free-choice hay.

Yes, the heifers go from no hay to free-choice hay in one day.

By my visual inspection I cannot see any significant growth until the heifers have been in this barn for nearly a month. Today there is a small amount of coughing among heifers in the youngest pens. 

What is going on in this situation?

These youngest heifers appear to be enjoying the hay today - all I can think of is the lack of the appropriate fiber-digesting microbes in their rumens necessary for breaking down all this fiber. Hay goes in the front, turns brown, goes out the back without any significant nutrition received.

Net result of hay intake the first week or two? Fills up the very small rumen displacing the grower pellet. Available energy and protein drops drastically - growth flat lines - some calves show symptoms of bovine respiratory disease.

Recommended introduction of hay at this dairy

1. For at least a few days after moving into this barn continue same ration used in outdoor pens.

2. For the first week or ten days for feeding hay, limit hay to what the heifers will clean up in an hour. By the way, this dairy has enough bunk space for all the heifers to eat at one time - good. 

3. After ten to fourteen days (time enough for the fiber-digesting microbial population to reach a new balance in the rumen) then move to free-choice hay.