Thursday, August 25, 2016

How Good a Job Are We Doing Spotting Sick Calves?

As part of a research project that focused on diagnosing illness among preweaned calves 206 group-housed calves on a total of four farms were given health exams. The examination results were matched with treatment records on the farms. 

How well were the farm calf care workers doing finding and treating sick calves?

Diarrhea (scours) - the university staff found 45 calves (22 percent) with very loose feces. Of these 45 calves the calf care workers were treating 12 (27 percent identified and treated)

Navel infection - the university staff found 8 calves (4 percent) with infected navels. Of these 8 calves the calf care workers had treated 1 (13 percent identified and treated)

Severe pneumonia - the university staff found 31 calves (15 percent) with severe respiratory infections. Of these 31 calves the calf care workers were treating 9 (29 percent identified and treated).

Elevated temperature (fever) - the university staff found 25 calves (12 percent) with a temperature greater than 103F (39.4C). Of these 25 calves the calf care workers were treating 6 (24 percent identified and treated).

In summary, how good a job were the calf care workers doing in diagnosing and treating sick calves? What proportion of sick calves were not being diagnosed and treated?

87% of the calves with a navel infection not diagnosed and treated
76% of calves with a fever not diagnosed and treated
73% of calves with scours not diagnosed and treated
71% of calves with severe pneumonia not diagnosed and treated

[Note that there was some duplication in the categories of severe pneumonia and fever.]

Further, among the four farms there were large differences among percent of the sick calves identified and treated. For example, one farm diagnosed and treated all the calves with severe pneumonia (5 out of 5) while one of the other farms had not treated any of their pneumonia calves (0 out of 9). 

Reference: M.C. Cramer and Others, "Associations of behavior-based measurements and clinical disease in preweaned group-housed dairy calves." Journal of Dairy Science, 99:7434-7443 September 2016

Monday, August 22, 2016

Using a Brix Refractometer to Test Colostrum

The results of a study suggest using two criteria for assessing colostrum quality.

"Based on this study, the 2 cut-points could be alternatively used to select good quality colostrum (sample with Brix greater than or equal to 22%) or to discard poor quality colostrum (sample with Brix less than 18%). When sample results are between these 2 values, colostrum supplementation should be considered." [S. Buczinski and J. M. Vandeweerd, "Diagnostic accuracy of refractometry for assessing bovine colostrum quality: A systematic review and meta-analysis." Journal of Dairy Science 99:7381-7394 Sept 2016]

This two-cut point idea maintains the upper value that has been published in the dairy magazines in the past few years - greater than or equal to 22 percent. At or above this value it's okay to use for first feeding as fresh or frozen.

So what is different? Well, they are saying that on one hand there is enough uncertainty about the Brix values that tossing out anything below 22% can result in discarding a fair amount of pretty good colostrum.

On the other hand if the test value is below 18% the chances of correctly classifying this colostrum as poor are quite high - few mistakes.

Thus, we end up with the colostrum between 18 and 22% that may be important to fill our needs. I feel this is good stuff to feed as second or third feeding. If it has to be fed as first feeding their suggestion of using a colostrum supplement is good advice. 

Friday, August 19, 2016

August 2016 Calf Management Newsletter

The August issue of the calf management newsletter is now posted - click HERE.

This issue summarizes the content of 5 new calf management resources posted in the Calf Facts section of the www.atticacows.com website. These resources may be accessed directly at www.calffacts.com.

The five new resource titles are:

Colostrum: Feeding Strategies
Colostrum: Quantity and Quality
Ventilation- Managing Calf Barns
Surges in Calvings: Responding Positively Rather than "Muddling Through"
How Much Will Calves Drink? (Ad libitium milk intake by calves day 1 through 35)

Enjoy.

Monday, August 8, 2016

Benefits of Feeding 2nd, 3rd and 4th Milking to
Dairy Heifer Calves

Have you tried out a webinar? 

Dr. Robert James, retired professor of animal science at Virginia Tech, gave a webinar on calf rearing on Monday, August 8th. The webinar, "An Update on Raising Better Calves" was presented by Hoard's Dairyman and sponsored by DeLaval. The recording is available at http://www.hoards.com/webinars   or click HERE. You scroll to the bottom the page to find the archived webinars.

Among many other ideas, Dr. James made a point of talking about the value of feeding the "colostrum" or what is usually called transition milk that comes from the cow during the 2nd, 3rd and 4th milkings post calving. 

The first benefit is the increased presence of antibodies on the surface of the gut. They help defend the calf against the pathogens that enter the calf through her mouth. 

The next benefit is the continuing presence of assorted compounds that promote the normal development of the intestinal lining. They support the "normal" maturation that has to take place in the first few days of life. 

The other benefit is the enhanced nutrition (i.e., fat and protein) in this post-calving milk. Transition milk is much higher than regular milk in both fat and protein. Compared to powdered milk replacers often fed to calves after the first day of life this early post-calving milk is a very nutrient-rich feed. 

The entire webinar was a really rewarding hour for me. If you choose to watch and listen I am sure you will find at least one new idea for strengthening your calf management program. 

Wednesday, August 3, 2016

Helping Calves Find Water

We all know that calves need water. Once calves know where to find water they usually do a pretty good job of keeping themselves hydrated.

But ... sometimes we have to help calves FIND the water. When livestock producers move older feeder calves into large pens they often help feeder calves find water by either placing waterers perpendicular to the outside fence or let the waterers run over for a couple of days.

In a recent farm visit we talked about an idea for helping young dairy calves find water during the first two weeks of life. These calves are group housed and fed with an automatic computer-controlled milk feeder. The pen has a water basin attached to the same wall of the utility building as the stalls for the automatic feeder. 

It takes three to five days to fill the pen with about fifty calves. All the calves segregated and fed with a bottle for the first three days. Then they are introduced to the group pen and taught to use the feeder nipple. The staff noticed that very few calves used the waterer during the first seven to ten days in the group pen. 

An idea came up to help these young calves find water. The bottom foot of a 55-gallon barrel was placed in the pen near the entrance to the autofeeder stalls. It was filled half full with water. Amazing! Calves were observed repeatedly exploring this THING that was in their pen. And, they discovered they could drink water. The barrel is placed on a concrete apron near the feeder stalls where it can be dumped daily in an adjacent floor drain.

Right now by observing how much water disappears from the barrel waterer the staff can tell calves are busy drinking from it. The current challenge is to figure out when to remove this water source and have the calves drink from the waterer on the wall of the utility building.

Wednesday, July 27, 2016

Coccidiosis: Our Constant Companion

A new calf management resource sheet with this title is now posted at our www.atticacows.com website. Click HERE to access the sheet.

A quick summary of content:

  1. The chances of 100 percent of our calves in their first week of life avoiding an infective dose of coccidia oocysts is close to zero. 
  2. Reducing shedding of oocysts is an effective control measure. 
  3. Coccidia infections, called coccidiosis, may begin to decrease feed efficiency as early as the first week of life.
  4. Immunity to coccidia comes from successful response of calves’ immune system, not from colostrum.
  5. Successful immune response to coccidia depends on limiting the infection and keeping the calves well fed and healthy.
  6. Treating all calves with coccidiostatic drugs to limit infections before some of them get sick is more cost effective than waiting to treat the clinically ill calves. 

Tuesday, July 26, 2016

How Much Milk Should We Expect Calves to Drink?

As part of a study looking at the effects of ad libitum consumption of milk by calves, milk intakes were recorded daily for days one through thirty-five.

What did they find?

Not surprisingly, intakes go up the first week in life. Average intakes for Holstein calves peaked a little over 9 quarts (8.5L) daily at six to seven days of age. There was considerable variation among calves with some calves peaking at 8.5 quarts (8L) and others going up to 10.5 quarts (10L). 

Not so anticipated was the uniform decline in milk consumption from day seven through thirteen. The average intakes dropped from a peak of 9 quarts (8.5L) to 6.5 quarts (6.2L) over those six days. The lowest-intake calves dropped just below 6 quarts (5.7L) daily.

The research dairy environment has a history of cryptosporidia exposure for calves. One might speculate that a mild case of cyptosporidiosis may have contributed to some degree of gastrointestinal upset that was associated with a reduction in appetite.

After day thirteen the trend was up and up and up. Most calves reached peak intake around twenty-three to twenty-five days. Again, lots of variation among calves. A few peaked as high as 12.5 quarts (11.9L) while a few others peaked well below that at 10.5 quarts (10L). 

When expressed as a percentage of live weight, naturally the percentages go down as the calves grow. While the intakes started out at an average of about twenty-one percent of live weight (days four-seven) they declined steadily to an average of fourteen percent (days twenty-two through twenty-eight).

Bottom line: One, when milk availability is not restricted we should expect calves to drink large amounts of milk. Two, lots of differences of intakes among calves is normal biological variation, not necessarily some aspect of mismanagement on our part.

For graphs showing intakes by age click HERE.

Reference: J. Jasper and D.M. Weary "Effects of ad libitum milk intake on dairy calves." Journal of Dairy Science 85:3054-3058.