Thursday, September 24, 2015

Good Article on Energy for Calves

In a recent issue of Progressive Dairyman the article appears,
"Focus on energy sources for optimal calf performance." [Dr. Tom Earlywine, pp 15-16, September 12, issue 15]

He reviews how much energy calves need for selected rates of gain and under temperatures from 68F to -20F. An example is given for a newborn calf at 32F. 

In addition to this he reviews sources of energy in milk/milk replacers and talks about a desirable protein-to-energy balance.

Enjoy. 

Tuesday, September 15, 2015

Colostrum Does the Job Regardless 
Whether It Comes from Mom or Her Sister(s)

In research reported in the Spring issue of the Bovine Practitioner the research team compared outcomes from feeding 4 quarts of colostrum from the calf's dam or colostrum from another cow. All of the colostrum was of good quality (i.e., >90 g/L antibodies). Colostrum was fed soon after birth resulting in only 4 of the 180 calves have a blood serum total protein test value under 5.5 g/dL. 

The comparisons were:
  • what proportion died (mortality)
  • what proportion were ill (morbidity)
  • how well did they grow
The number of calves involved were:
  • fresh colostrum = 104
  • refrigerated colostrum = 40
  • frozen colostrum = 36
Calves dying:
  • fresh colostrum = 5%
  • stored colostrum = 4%
Calves sick
  • fresh colostrum = 56%
  • stored colostrum = 51%
Growth - average daily gain was the same for both categories of calves - the research was done in the summer in north Florida where heat stress generally leads to only modest rates of gain - they averaged just under 1 1/4 pounds a day at 60 days.

The message here is clear - feed plenty of good quality colostrum soon after birth regardless of the source. 

Source: L. Judd Sims, Pablo J. Pinedo and G. Arthur Donovan "Health and performance of calves fed fresh colostrum from their dams compared to those fed stored colostrum from non-dams." Bovine Practitioner, Spring 2015 pp 13-17.

Friday, September 11, 2015

Water Intake at Weaning:
Intensively Fed Calves

Research on weaning dairy calves provided the opportunity to very accurately measure water intakes. Because the sample size was very small (n=10) we must be somewhat careful in generalizing to all intensively-fed calves. 

The calves were fed 26-16 milk replacer mixed at 15% solids at the rate of 8.5 quarts (8L) daily. That's 2.6 pounds (1.2kg) of powder a day. The calves were raised in a naturally ventilated barn. Given the research design I was able to conclude that the calves were raised in non-freezing weather - probably between May and September. 

Daily water intakes were: [water free access]

Age of calf  Quarts (Liters)
Week 5          0.6 (0.6) - still drinking 8.5 quarts milk replacer
Week 6          1.5 (1.4) - still drinking 8.5 quarts milk replacer
Week 7          3.7 (3.5) - milk replacer cut back to 4.25 quarts at 49 days
Week 8          9.5 (9.0) - no milk on day 56
Week 10      11.7 (11.1) - this is second week after full weaning

The main point of passing on these data is to emphasize how important it is to provide free access (ad lib.) water at weaning time. During weaning when milk replacer was cut back to one-half these calves drank 150 percent more water than the week before. 

For the weaned calves the research team had to provide two 8-quarts pails for water for each calf to be sure they did not run out of water! 

I used to switch to a 5-gallon pails tied to the hutch at weaning time for my calves so they did not run out of water between my AM and PM feeding times - especially during hot summer weather.

There are 10 resource sheets on water and water feeding at www.calffacts.com. The one comparing weight gains for intensively-fed calves with and without free choice water is HERE.

E. Eckert and Others, " Weaning age affects growth, feed intake, gastrointestinal development, and behavior in Holsten calves fed an elevated plane of nutrition during the preweaning stage." Journal of Dairy Science 98: 6315-6326 (2015).




Monday, September 7, 2015

Gradual vs. Abrupt Weaning: 
The Case for a Step-Down Strategy

A research trial compared rates of gain both during and after weaning for dairy calves that were abruptly weaned at 48 days with those calves weaned gradually (35 to 48 days) (N=55).

On one hand, the gradually weaned calves gained more slowly during the weaning period than calves left on full feed until 48 days of age.

Gradually weaned (days 35-48) - gained  1 pound per day (0.48kg).
Left on full milk (days 35-48) - gained 2.2 pounds per day (1.0kg).

I estimated the cumulative difference in gain between the two feeding treatments over the 14 day period between 35 and 48 days as slightly above 15 pounds (7kg).

On the other hand, the gradually weaned calves gained more rapidly after full weaning period than the calves that were weaned abruptly at 48 days.

Gradually weaned calves post-weaning gain was 1.9 pounds per day (0.86kg).
Abruptly weaned calves post-weaning gain was 0.3 pounds per day (0.15kg). Basically, flat lined!

I estimated the cumulative difference in gain between the two feeding treatments for the first 14 days after full weaning as slightly below 22 pounds (10kg).

Thus, the net effect in terms of gain at two weeks post-weaning (62 days) was plus 6.6 pounds (3kg) in favor of the gradually-weaned calves. 

And, the chemical composition of the rumen fluids was much more favorable for the gradually-weaned calves on the day of full weaning compared to the abrupt-weaned calves (volatile fatty acids were measured). This partially explains why the gradually-weaned calves did not suffer from the transition-calf growth slump observed in the abrupt-weaned calves.

For a checklist of best management practices for weaning dairy calves click HERE or go to www.calffacts.com and click on "Weaning calves: A Checklist."

[M. A. Steele, "Gradual weaning affects pre- and postweaning feed intake, growth, and gastrointestinal development in Holstein calves fed an elevated plane of nutrition during the pre-weaning stage." Journal of Dairy Science, 98 Suppl 2, page 242, abstract 158.]

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]