Thursday, June 22, 2017

Automatic Calf Feeders - Bacteria Control Challenges

During a study including 38 farms over 18 months the research team assessed the bacteria contamination levels of milk consumed from automatic calf feeders. Each farm was sampled from both the automated feeder mixing tank (mixing tank) and the point of connection between the flexible dispensing tube and the nipple (tube end). 

Bacteria counts reported:


Source of Sample           Value                         Standard Plate Count      Coliform Count
                                                                                   (cfu/ml)                         (cfu/ml)
1. Mixer tank                  Median                              166,916                             336
                                        Range - lowest                         125                                 0
                                                   - highest              59,396,100               25,621,330

2. Tube end                     Median                            2,566,867                       10,430 
                                        Range - lowest                       6,668                              45
                                                   - highest              82,825,000               28,517,000

Using the thresholds of 10,000 cfu/ml coliforms and 100,000cfu/ml standard plate count (SPC) they reported:

Source of Sample                 SPC>100,000            Coliform Count >10,000
                                         (% farms above)            (% farms above)
1. Mixer tank                          32                                   15
2. Tube end                             68                                   28

What are the messages for me?

First, RANGE values for both SPC and coliforms demonstrate that while it is possible to deliver clean food to autofeeder calves it clearly is possible to screw up badly - very, very badly - 82,000,000 plus cfu/ml!

Second, when I culture "as-fed" milk samples for my clients we use these upper thresholds to determine if on-farm cleaning and handling procedures are being met (usually fed in bottles or buckets manually):
                              SPC     <10,000cfu/ml
                       Coliforms   <1,000cfu/ml

If my clients' samples came back looking like those from theses 38 farms I would be all over their cases - all cleaning procedures would be examined closely for protocol compliance slip-ups. Weekly samples would be taken all along the handling stream to isolate possible points of inoculation and growth.

Third, in terms of calf care and calf health, I consider feeding milk with these levels of bacteria contamination irresponsible and perhaps bordering on animal abuse.

As an aside, one time when we were monitoring bacteria levels with automatic feeders for a client we discovered that the warm-water holding reservoir was serving as a bacterial incubator because the feeders were being used most of the time for whole milk. Contaminated water was leaking into each batch of milk as it was heated. By changing the settings to use 10g of powder in every mixer bowl the reservoir problem was eliminated. So, I have to admit that issues beyond cleaning can sometimes contribute to high bacteria counts. 

References:
Jorgensen, M.W. and Others, "Factors associated with dairy calf health in automated feeding systems in the Upper Midwest United States." Journal of Dairy Science 100:5675-5686 June 2017. Dietrich, M. and Others, " Factors associated with aerobic plate count, coliform count, and log reduction of bacteria in automated calf feeders." Journal of Dairy Science, 93, Suppl. 2, p214 #86.

Monday, June 19, 2017

Variation in Colostrum Yields

In response to a recent question about variations in colostrum yields I pulled together data from two studies published in the Journal of Dairy Science in 2016 and 2017. All cows were second lactation and greater.

The first study was with Holstein breed cows from 9 farms with a total of 111 first milkings. They averaged 17 pounds of colostrum at first milking. However, the overall variation was from 1 pound to 87 pounds! Two-thirds of the samples (N=74) fell between 2 and 33 pounds.

The second study was with Jersey breed cows from one 3,500 cow dairy in California. They collected data on 134 first milkings. The average yield was 9 pounds. The overall variation was from less than 1 pound to 30 pounds. Two-thirds of the samples (N=90) fell between 3 and 15 pounds.

The answer to the question "How much variation in volume of colostrum production is 'normal'?" is:

1. Widely varying amounts among cows for any given lactation, length of dry period, dry-cow ration and season of the year are "normal." Further, predicting this variation based on production in previous lactation is not very reliable.

2. If we plan on feeding about 17 pounds (4 quarts) of colostrum for newborn calves during the first 4 hours of life (Jersey calves = 13 pounds or 3 quarts) then we need to be prepared to supplement the dam's yield for many of our calves.

3. Having a provision to store excess colostrum while minimizing bacteria contamination is a best management practice. Remember rapid chilling to 60F (16C) after collection is a cost effective way to maintain high colostrum cleanliness.




References: Cabral, R. G. and Others, " Predicting colostrum quality from performance in the previous lactation and environmental changes." Journal of Dairy Science 99:4048-4055 2016 Silva-del-Rio, N. and Others, "Colostrum immunoglobulin G concentration of multiparous Jersey cows at first and second milking is associated with parity, colostrum yield, and time of first milking, and can be estimated with Brix refractometry." Journal of Dairy Science 100:5774-5781.

Thursday, June 15, 2017

Second Milking - A Colostrum Resource?

Colostrum in short supply? Try collecting and testing second milking from fresh cows.

In a study involving second lactation and greater Jersey cows the investigators collected both first and second milking (N=68 cows).

This is what they found from the second milkings:

                                                                  Average(Mean)   Minimum    Maximum
Amount of colostrum collected (lbs.)            9.5                       0.9               25.3
Brix value (percent)                                     18.7                     13.4               29.3
Antibodies (IgG) in lab test                         46.9                       6.2              100

Nearly one-half of the second milkings (43 percent) had the industry standard of 50g/l minimum for colostrum acceptable for first-feeding newborn calves. 

TEST, DON'T GUESS.  That's the message - your second milking from cows may be a "hidden" colostrum resource on the dairy. 

Reference: Silva-del-Rio, N. and Others, " Colostrum immunglobulin G concentration of multiparous Jersey cows at first and second milking is associated with parity, colostrum yield and time of first milking, and be estimated with Brix refractometery." Journal of Dairy Science 100:5774-5781. July 2017.

Tuesday, June 13, 2017

The Value of Being Raised on a Farm

Right away you need to know that this post has nothing to do directly with animal science for managing calves.

A mom wrote this about her son, a recent college graduate, and his experiences on his first job. Click HERE to access or paste in your browser this URL
http://whminer.org/pdfs/06-17.pdf   Scroll down to the article on page 9.

For those of us who grew up working on farms it will resonate soundly with our life experiences.

By the way, it is in a really interesting  monthly report from the Miner Institute, a research and educational institution in northern New York State. It's easy to subscribe and receive it monthly. Just send an e-mail to dutil@whminer.com and tell her to sign you up for their monthly publication notice.

Enjoy. 


Monday, June 12, 2017

More on Group-Housed Calves
on Automatic Feeders

"A study of farms using automatic feeders and group housing revealed some practices that point to success in these calf rearing systems." This is the lead for an article by Dr. Marcia Endres (University of Minnesota, St. Paul) that summarized factors that can be important for the successful use of automated calf feeder systems.

She listed these nine factors:

"1. Reduced time to reach peak milk allowance.
2. Milk or milk replacer with low bacteria counts (cleanliness of equipment is key).
3. Positive pressure ventilation tubes.
4. Sufficient amount of space per calf in the resting area.
5. Small number of calves per group.
6. Adequate farm serum total  protein concentration averages (an indicator of passive immune transfer.
7. Drinking speed used as a warning signal to identify sick calves.
8. Consistent navel dipping and disinfecting.
9. Narrow age range within calf groups." (p349)

You may want to read the entire article including her nine "Rules of Thumb" or specific recommendations for automated calf feeder systems.

Reference: Endres, Marcia "Lessons learned from group-housed calves." Hoard's Dairyman May 25, 2017, page 349.


Friday, June 9, 2017

Hay for Preweaned Calves

"Hay for Preweaned Calves" is the subject for the June, 2017 issue of the calf management newsletter. In summary you will find:

  • Calf-care persons have widely different opinions about feeding hay to preweaned calves.
  • Discussions about feeding hay to preweaned calves need to to specify (1) the physical form of hay, (2) volume hay fed, (3) nutrient profile, (4) species present, and (5) calf age at which hay is introduced to the ration.
  • Discussions about feeding hay to preweaned calves may focus on papillae development and health and lack emphasis on the microbial population essential for forage digestion.
  • Recent research is leading me to conclude that limited hay intake has a variety of positive outcomes for preweaned calves.
  •  Practical aspects of feeding hay to preweaned calves.
If you have any stories to share dealing with feeding hay to calves please feel free to forward them to me at smleadley@yahoo.com. I would enjoy hearing from you. 

Sam