Wednesday, September 28, 2016

Extended Weaning Time Needed

Many dairies have adopted some form of intensive milk/milk replacer feeding programs for their calves. [Intensive feeding is used here to refer to any program that feeds more than 1# of m.r. daily.] 

Research findings are emerging that emphasize the need for extending weaning times for intensive-fed calves in order to provide for adequate rumen development when they are fully weaned.

Recently published research (Hill and others, 2016) fed three intensive-feeding preweaned rations:
(weights are as-fed milk replacer powder, 28-20 and it was reconstituted at 14% solids)
  • Lowest    = 1.45#(0,66kg) for 39 days, 0.7#(0.33kg) for 3 days (2x feeding at 6:30AM and 2:00PM)
  • Middle    = 1.9#(0.88kg) for 5 days, 2.4#(1.1kg) for 23 days, 1.45#(0.66kg) for 18 days, 0.7#(0.33kg) for 7 days
  • Highest   = 1.9#(0.88kg) for 5 days, 2.4#(1.1kg) for 37 days, 1.2#(0.56kg) for 7 days
Note that they fed a 28-20 milk replacer - this provides a very high energy input at feeding levels of 2.4#(1.1kg) daily and depending on environmental challenges (cold weather) the energy:protein ratio may over feed energy. The authors suggest that lower fat levels might be considered - and, I would add, "depending on cold weather challenges."

Note that the feeding interval was 7.5 hours (6:30 and 2:00PM). When calves were fed 2.4#(1.1kg) daily that was 4 quarts twice daily. I wonder if the study results (efficiency of m.r. digestion) might have been different if the feeding interval had been stretched out to 9 to 10 hours? Or, even 3x feeding?

Note that for the "Middle" ration how the "step-down" period starts at 28 days of age (4 weeks) providing a 25 day-long step-down. This is in contrast to the 7 day-long "step-down" for the highest treatment group.

So, was the milk replacer ration (Lowest, Middle, Highest) related to rumen maturity at 11 and 16 weeks of age?

Number One: If we compare the Lowest m.r. feeding rate (i.e., 1.45#(0.66kg) daily) to the Middle ration with the extended step-down protocol they found similar levels of rumen maturity as measured by ADF and NDF at both 11 and 16 weeks of age.

Number Two: The heifers fed with the Highest m.r. feeding protocol had less rumen maturity than either the Lowest or Middle rations.

If "step-down" interval has to be uniform for all calves (in contrast to weaning based on calf starter grain intake) longer intervals work better than shorter ones in achieving higher levels of rumen maturity.

Reference: T.M. Hill and Others, "Effect of milk replacer program on calf performance and digestion on nutrients in dairy calves to 4 months of age." Journal of Dairy Science 99:8103-8110 October 2016.

Tuesday, September 20, 2016

Clean Bottles Don't Stay Clean

During a routine sanitation audit on a dairy farm I always include checking a nursing bottle and nipple carried on the milk feeding cart. I use a luminometer to pick up the presence of bacteria (see note below on this tool). This dairy is using an ATP value of 100 as an upper threshold for acceptable cleanliness.

The audits in March and June showed these values respectively:

Bottle:  0 and 83
Nipple: 0 and 7

At the September audit the values were:

Bottle:  3027
Nipple: 7976

What is going on here?

As a result of very high ATP values last year a sanitizing protocol was being followed before each feeding. The bottle was filled with a warm strong bleach solution at the beginning of each feeding. It was dumped out before using or if not used dumped out at the end of the feeding routine. 

With a change in personnel this sanitizing protocol was discontinued. The "clean" equipment sat unused for a full week before I checked the bottle and nipple. 

The lesson here is that "clean" equipment does not stay clean. 



[I use the Hygiena SystemSure Plus unit (luminometer) to do adenosine triphosphate (ATP) monitoring. The ATP test is a process of rapidly measuring organic matter including actively growing microorganisms through the detection of adenosine triphosphate. An ATP monitoring system can detect the amount of potential microbial contamination that remains after cleaning a surface (for example, calf feeding equipment). 

Thresholds used in the food processing industry are less than10 RLU for direct food contact surfaces and less than 50 RLU for environmental surfaces. I often use a reading of 100 RLU as realistic on-farm upper threshold for calf feeding equipment.]

Wednesday, September 14, 2016

Old Gaskets on Milker Lids

While on farm on Tuesday, September 13th, I checked the resident bacteria levels on milking equipment used to collect colostrum.

The stainless steel milker buckets were just fine. Nice low bacteria counts on the clean inside surfaces.

The lids were another matter. The flat stainless steel surfaces that were easy to brush had low bacteria counts. When I swabbed the inside of the two tubes to which the vacuum and claw hoses are attached to the lid the bacteria count went up a little.Then I added swabbing at the edge where the gasket came together with the inside of the lid - the count went up a lot. I did add lifting the edge of the gasket and the bacteria count skyrocketed up. 

The herdsman and I examined the gaskets closely. They were checked and had small cracks along all surfaces. Time to replace them.

Moral of the story? Take a close look at milker lid gaskets. If there are any signs of aging, let's replace them and stay ahead of bacteria buildup.

Friday, September 9, 2016

New Calf Management Letter
Fall Weather and Newborn Calves: Part 1

The link to this issue is http://www.atticacows.com/documentView.asp?docID=6193 or click HERE.

In brief this two-part series looks like this:
 Maintaining a constant body temperature in variable environmental conditions. (this issue)
 Defending against pathogen challenges. (Part 2)
 Developing the gut capacity to digest food. (Part 2)
 Eating enough easily digestible food to meet maintenance and growth requirements. (Part 2)

Enjoy.

Thursday, September 8, 2016

Biofilms and Calf Care Equipment

I am preparing for a presentation focused on sanitation procedures. While doing this I have been reading a lot of literature on biofilms. How do they develop? Where do they develop?  How do they grow? 

One of the examples of biofilms in the articles I was reading related to dental plaque formation.

Yes, dental plaque in your mouth is a biofilm. They form when bacteria stick to our teeth. If we do not remove these bacteria through frequent and regular flossing and brushing within 48 hours the bacteria can begin to stick to the tooth surfaces. This article continued by telling me that after two days this coating or plaque will begin to harden becoming more difficult to brush away.

Within ten days the plaque hardens and the dental hygienist will recognize this as dental tartar. This is the stuff that ultimately damages teeth and surrounding tissues. 

Other literature (mostly from the food processing industry) mentioned how difficult it is to be sure that ALL surfaces get cleaned. That's why food slicers and grinders are made to breakdown for cleaning. 

As I thought about calf feeding equipment I thought about mixers, whisks and pails. Where are the "hidden" places that never get brushed? [This assumes that you know that brushing is one of the key elements in removing the residues that hide bacteria and provide food for them to develop biofilms.]

For example, many of us use calf pails for feeding both milk and water. They do not get washed between feedings. Whoa! What a great place to grow biofilms. And, get this, ATP meters are ineffective in picking up biofilms as well as swabbing for culturing because the bacteria can be below the biofilm surfaces.

Or, we mix milk replacer with a whisk (often stainless steel). How well is this cleaned? The part up by the handle where the individual strands are anchored is a perfect place for biofilms - hard to brush - potentially a huge reservoir for bacteria even if it looks clean.

Literature suggests that one pretty reliable indicator of biofilm presence on supposedly clean equipment is a slimy feeling when touched. Yum! I want to run right out and eat food prepared with slimy equipment.

Friday, September 2, 2016

More Than One Feeding of Colostrum?

Apart from the process of creating immune defenses against pathogens another good reason to feed colostrum to newborn calves is to provide energy.

In a unique analysis of energy needs of newborn calves and energy provided by colostrum we can see how colostrum feeding provides for maintenance needs of these young animals. 

The author selected four difference environmental temperatures: Thermoneutral (about 60F), 52F, 43F and 34F. then she calculated the number of grams of fat needed per hour to meet the newborn calf's needs to maintain her normal body temperature (102F). 

This is what is needed:
                                    Environmental Temperature (F)
                                         60       52       43       34
Grams of Fat                    8.2      9.9      11.6    13.4

It's easy to see that as the temperature goes down the grams of fat needed go up. 

Then she calculated how many hours at each temperature one 3.8L (4 quarts) feeding of maternal colostrum containing 20 percent fat would sustain the calf.

These are the hours one feeding of 4 quarts of 20 percent fat colostrum would support the calf:
                                    Environmental Temperature (F)
                                         60      52       43       34
Hours of support              9.2     7.7      6.5      5.6

What do these numbers tell us? 

First, as temperatures go down, the number of hours one 4 qt. feeding of colostrum also go down. 

Second, when temperatures come close to freezing at less than six hours post feeding with the 20% fat colostrum the calf must begin to draw on body stores of fat to maintain her core body temperature.

Using data from Davis, C.L. and J. K.Drackley,"The Development, Nutrition and Management of the Young Calf." Iowa State Univ. Press, 1998, p 182 I picked up the the average dairy cow colostrum (first milking) fat content as 28.8 percent. That is higher than the 20 percent used by the author. 

Using the 28.8 percent fat value the hours of support given by one 4 quart feeding look like this:
                                     Environmental Temperature (F)
                                          60       52       43       34
Hours of support               13.2    11.1    9.4      8.1

If one uses a colostrum replacer with 25 percent fat the same support hours values are:
                                     Environmental Temperature (F)                                                                                                                     60       52       43       34
Hours of support               11.5    9.6      8.1      7.0
[note that this colostrum replacer fat content is much higher than the average replacer.]

BOTTOM LINE? Second and third feedings of colostrum can do a lot to support the energy needs of newborn calves.

And, as temperature fall closer to or below freezing the additional feedings of colostrum with its highly digestible fat are an ideal way to meet energy needs of newborn calves.
                              




Reference: Haines, Debbie, "Colostral Immunity - Improving Passive Transfer in Calves." 25th DISCOVER conference, "New Developments in Immunity, Nutrition and Management of the Preruminant Calf." May 2013

Friday, August 26, 2016

Calves and Forage Consumption

Are calves clever enough to sort a TMR for different length particles?

A study initially offered calves both TMR (49% dry matter) and a pelleted concentrate after weaning on an ad libitum basis. The concentrate was fed separately from the TMR. Feed was managed so there was always some TMR and concentrate available. During the time both feed sources were offered free-choice the calves were quite effective in sorting the long particles out of the TMR. 

Then, the pelleted concentrate was withdrawn. Calves had free-choice access to the TMR. The particle size distribution of the left-over feed was compared to the TMR as delivered. This showed that the calves pretty much stopped sorting for long particles and began eating the TMR as delivered. There was some preference for fine particles (ground concentrates).

Yes, calves are clever enough to sort a TMR even at two months of age. 

Reference: J.H.C.Costa and Others, " Short Communication: Effect of diet changes on sorting behavior of weaned dairy calves." Journal of Dairy Science 99;5635-5639 September 2016