Friday, September 4, 2015

Why TMR Works So Poorly
for Calves

Recently completed research compared growth rates among calves fed one of four rations in addition to their milk:
  • Silage-based TMR
  • Concentrate
  • Concentrate with chopped hay mixed in
  • Concentrate with chopped hay fed separately
Calves were offered up to 12.7 quarts per day of acidified milk daily free-access (12L)for the first 38 days and then they began weaning until no milk was fed at 50 days. For a resource on free-access feeding of acidified milk click HERE.

Preweaning - all calves gained about the same - about 2.4 pounds per day (1.1kg).

During Weaning:
  • The TMR calves dropped to about 0.4lbs/day.
  • The other three treatments dropped back to about 1.5lbs/day from 2.4lbs/day.
There was a big disadvantage for TMR calves.

After Weaning
  • The TMR calves improved coming up to 1.1 pounds a day from 0.4lbs/day.
  • The other three treatments averaged around 2.6 pounds a day up from 1.5lbs/day.
There was a big disadvantage for TMR calves. 

[By the way, no significant differences appeared in this study among the other three treatments - all offered free-choice along with free-choice water.]

Note - all four treatments had about the same "as-fed" level of intakes. The disadvantage for the TMR calves was that their ration was only 54 percent dry matter while all the other calves had rations that were 89-90 percent dry matter.

So, why does TMR work so poorly for calves? They have limited rumen volume capacity. Consuming high dry matter feeds provides them with more energy and protein than feeds with high moisture levels like silage-based TMR.

Reference: M. A. Overest and Others, "Effect of feed type and presentation on feeding behavior, intake,and growth of dairy calves fed a high level of milk." Journal of Dairy Science 98 Suppl 2, page 240, Abstract 154. 

Thursday, September 3, 2015

Does Feeding More Colostrum Make
a Difference for Immunity?

The research group set up 4 different colostrum feeding procedures: (76 calves, 19 calves per procedure)
  • 3-2-2: That is 3 quarts at birth, 2 more quarts at 6 hours and 2 more quarts at 12 hours.
  • 4-0-2: That is 4 quarts at birth, none at 6 hours and 2 more quarts at 12 hours.
  • 4-0-0: That is 4 quarts at birth and no more later.
  • 2-2-0: That is 2 quarts at birth, 2 more quarts at 6 hours and no more later. 
How did the 48-hour blood test results come out for these treatments? (average for group)

  • 3-2-2    6.37g/dL
  • 4-0-2    6.12g/dL
  • 4-0-0    5.58g/dL
  • 2-2-0    5.66g/dL
Conclusion: Feeding more colostrum gives better results for passive immunity. Note that none of these test values are considered "poor."

My goals for these tests are 95% at or above 5.0g/dL and 75% at or above 5.5. For more on testing for passive transfer of immunity click HERE or go to www.calffacts.com and select "Passive transfer of immunity: How to test for."

One of my clients follows a 4-2-2 protocol (that is, 4 quarts at birth, 2 more quarts at 6 hours and 2 more quarts at 12 hours, (all colostrum at Brix at least 22). I just checked my latest report for them - for the last 616 calves for which blood serum total protein values are available the average value was 6.4g/dL. The 3-2-2 procedure in this research trial came up with about the same results. 

As a side note the research group also kept track of scours and concentrate intake.

The frequency and incidence of scours tended to follow the colostrum intake pattern - more colostrum was associated with lower rates of scours. 

How did the first week post-weaning concentrate intakes compare for these treatments? (56-63 days of age)

  • 3-2-2    3.4 pounds per day (1536g/d)
  • 4-0-0    2.9 pounds per day (1321g/d)
  • 2-2-0    2.6 pounds per day (1162g/d)
Calves receiving higher rates of colostrum ate significantly more concentrate.

Reference: W. Shi and Zhijun Cao, " Effects of colostrum feeding program on passive immunity, health, and performance of Holstein dairy calves." Journal of Dairy Science 98 Suppl 2 p240 abstract 152.

Tuesday, September 1, 2015

Feed Efficiency for 
Intensively Fed Dairy Calves

A recently presented research abstract  reported the feed efficiency for their dairy calves. 

This was a small sample - 18 calves. They were fed free-access milk up to 16L (17 US Quarts) per day. 

At the end of 7 weeks of milk feeding the average feed conversion was 0.10kg weight gain per kg of milk intake.

I used this equation to figure feed conversion.

gain/intake

0.10kg gain / 1 kg intake

I figured 1kg of milk at 12.5% solids = .125kg of dry matter

Thus, 
0.10kg gain / .125kg dry matter intake = .8 or 80% feed conversion.

They are repeating the trial this coming winter (Ontario province in Canada) so maybe by this time next year we will find out the impact of a cold environment on feed conversion.

[L.M. Wormsbecher and Others, "An outdoor method of housing dairy calves in groups using individual calf hutches." Journal of Dairy Science, 98, Suppl 2, pg 563, Abstract 496]

Monday, August 31, 2015

Harvest Illness

"Harvest illness usually rears its ugly head when farms can’t dedicate an employee to calves full-time.  It’s also challenging for farms that do their own harvesting. Harvest illness isn't caused by a strain of bug that shows up at a certain time of the year, but is due to the producer needing to direct their attention elsewhere on the farm."

This is a quote from an interesting column that you can access HERE. The author, Rebecca LaBerge, offers several practical steps to minimize this unique kind of illness. 

When I was responsible for calves on a 1,200 cow dairy I also found myself "paddling upstream" trying to keep calves healthy for about a month - but in contrast, for me it was in the spring - I called it "Spring Work Blues." It was the same issue of too much work at a peak time and too few folks to maintain high quality care especially for newborn calves. 

I found it helpful to track immunity levels during these stressful times. For a "how-to" guide on measuring immunity levels you may go to www.calffacts.com and click on "Passive transfer of immunity - how to test for." Or just click HERE

Thursday, August 27, 2015

Staff Turnover and Training

In an August 25 article entitled "A Fresh Perspective on Cleaning Calf Housing" published in Progressive Dairyman Brian Wesemann made a great point about staff turnover.

He pointed out that relative to cleaning and sanitizing calf housing the calf supervisor must keep in mind that cleaning calf housing does not have the repetition cycle that many other jobs do. Feeding is every day. Cleaning equipment is daily. Cleaning calf housing is almost always on a significantly longer cycle.

The cleaning cycle for calf housing may be long enough to span employee changes. Therefore, it is good to keep in mind the need for both training and re-training. 

For example, if part of sanitizing includes using a foaming agent to prolong the disinfectant exposure time the worker must follow the correct steps in measuring the foaming agent, mixing with the proper volume of water and applying the foam according to the manufacturer's recommendations. 

Doing this step correctly depends on receiving instructions that are more complete than, "Foam the hutches after you pressure wash them."

Thanks to Brian for reminding us of the implications of staff turnover for training. 


Thursday, August 20, 2015

Failure Rate for Calves Nursing Colostrum on Their Own

Yet another study has documented the passive transfer failure rate for dairy calves allowed to nurse from the dam on their own. This is in contrast to hand feeding a known volume of colostrum with a known concentration of antibodies. 

The study included 2,500 calves from 50 dairy farms. Cows were Holsteins, Jersey and Holstein-Jersey crosses.  Blood was drawn between 1 and 7 days of age, refrigerated overnight, centrifuged and the serum separated from the clot within 24 hours of collection. The average blood serum total protein level for 2,500 calves as 5.9 g/dL. Successful passive immunity was defined as a blood serum protein level of 5.5 or greater.

"Calves that were allowed to suckle their dams showed a 44 percent failure of passive immunity."

Can we do a better job when we hand-feed colostrum? One of my clients feeds six quarts of colostrum testing 22 or greater using a Brix refractometer within the first 12 hours of life. As of July 24, 2015 since September 2014 they have tested 756 calves. Ninety-seven percent of these tested at 5.5 or greater.

A. Elizondo-Salazar and Others, "Passive Transfer of immunity in dairy heifer calves on Costa Rican dairy farms," Journal of Dairy Science, Vol.98, Suppl.2, Abstract W23.


Tuesday, August 11, 2015

Efficiency of Antibody Absorption in 
Newborn Dairy Calves

Apparent efficiency of antibody absorption (abbreviated as AEA) is a measure of the movement of antibodies from the gut into the body plasma.

 [Quigley, J.D. and  J.J. Drewry, "Nutrient and immunity of the noenatal intestine and their relationship to immuniglobulin absorption and disease" Journal of Dairy Science 81:2779-2790]

In a recently published study AEA was compared for colostrum with either a low or high bacteria count.

[Geisinger, S.L. and Others, "Effect of colostrum heat treatment and bacterial population on immunoglobulin G absorption and health of neonatal calves." Journal of Dairy Science, 98:4640-4645. August, 2015.]

For colostrum with low bacteria counts the AEA was approximately thirty-four percent. That is, out of every 100 antibodies fed, about 34 made it into the blood of the calf. 

For colostrum with high bacteria counts the AEA was approximately fourteen percent. That is, out of every 100 antibodies fed, only 14 make it into the blood of the calf.

When we compare these transfer rates it is clear that the absorption rate for high bacteria-count colostrum is barely 43% of that for low bacteria-count colostrum - that is well under one-half the transfer rate due to just one factor - bacteria.

Thus, once we have done a good job of collecting clean colostrum the rule of thumb is to either feed it to the calf within 30 minutes of collection or get it chilled to at least 60 F (16C) with 30 minutes in order to suppress the bacteria count.