Wednesday, June 29, 2016

Preventing Navel Infections - Full Newsletter Edition

In case the link to the June 2016 calf management newsletter did not work I have posted the full text below. My apologies to blog readers that may have encountered problems with a non-working link. 

Preventing Navel Infections

·        How often do navel infections occur?
·        What are the consequences of navel infections?
·        What are cost effective alternatives to reduce the rate of treatable cases of navel infections?

How often do navel infections occur?

It depends. National studies suggest the rate may be close to fifteen percent of calves retained on the farm as replacement animals. Smaller studies suggest a wider range varying from five to twenty percent.

It depends. Are calves observed to see if there is an infection present? During a study involving eighteen farms, vet college staff examined 410 heifer calves weekly (Virtala & Others, JDS 79). They felt of each navel area once a week for eight weeks in a row. They were looking for painful navels and/or thickening of the abdominal wall. They found fifty-seven calves with navel infections (fourteen percent infection rate).

In this study it was the owners’ responsibility to diagnose and treat sick calves. Of these fifty-seven calves with navel infections the owners diagnosed only seven cases. That is correct. In this study eighty-eight percent of the navel infections identified by the research staff were neither diagnosed nor treated by the owners!

Wisconsin School of Veterinary Medicine veterinarian Dr. Sheila McGuirk suggests this observation protocol:
“We encourage you to routinely screen all of your calves between 5 and 7 days of age. As the examiner gently compresses the skin of the navel at the point where it enters the abdomen, the umbilical stalk can be slipped between the thumb and fingers to reveal any enlargement (diameter greater than ½ inch), discharge, odor or pain.” (emphasis added)

The bottom line in answering the question of “How often do navel infections occur?” is to touch the calf. Unless there is a protocol for routinely placing your hand on the belly of the calf around one week of age there is a good chance that two-thirds or more of infections will not be diagnosed early.

What are the consequences of navel infections?

The consequences of navel infections depend, in part, on how early the infections are diagnosed and treated. However, in general it has been well documented that significant navel infections are associated with:
  • Increased rates of umbilical hernias
  • Increased rates of other diseases, especially respiratory illness
  • Increased rates of death
  • Decreased rates of growth
  • Decreased rates of herd survivorship

What are cost effective alternatives to reduce the rate of treatable cases of navel infections?

  1. Allow spontaneous rupture of umbilical cord. Biochemical exchanges begin at the time of rupture that act to protect the calf from infection.

  1. Provide a clean calving environment. Yes, now and again a calf will be born in the mud next to the water tank in the pasture or in the free-stall alley. However, well-managed calving means that as many calves as possible are born in a clean environment. Our biggest risk is adult cow manure – so plenty of clean bedding or a clean grass pasture reduce that risk.

  1. Move the calf away from adult animals as soon as she is breathing well and licked off. The longer she remains with the dam and/or other cows the greater the risk of bacterial exposure to the ruptured umbilical cord. However, be cautious about pens for newborn calves. Sometimes they are not well-maintained. These “hell-holes” can have sky-high bacteria levels and simply serve to be sure that all calves are equally exposed to near-lethal doses of pathogens.

  1. Navel disinfection. Spray or dip the cord with a commercial navel dip. If the dairy has a good examination protocol for identifying navel infections and the rate is less than five percent then dipping navels might not be cost effective. But, that is a big IF – unless infection rates are well documented, just buy product and dip all the navels.

  1. Do a good job of colostrum management. The data are clear – navel infection rates are significantly higher among calves with passive transfer failure due to poor colostrum management than among calves with strong passive immunity.

References:  A.M. Virtala and Others, “The effect of calfhood diseases on growth of female dairy calves during the first 3 months of life in New York State.” Journal of Dairy Science 79:1040-1049. A.M. Virtala and Others, “Morbidity from nonrespiratory diseases and mortality during the first 3 months of life in New York State.” JAVMA 208:2043-2046. Sheila McGuirk, “”See Many Infected Navels,” Veterinary Column in Hoard’s Dairyman. 

Monday, June 27, 2016

 Checking Concentrations of Disinfectants

The effectiveness of a disinfectant is partially determined by the concentration of the active ingredient. Using too little product sets us up for failure - we think we have done the right thing but by failing to use enough product we have essentially wasted our time. 

Using too much product set us up for inefficient disinfection. We spent too much money to achieve our goal of reducing pathogen populations. Just for review you may want to go to Disinfection 101 at this site  or click HERE.

One of my clients with a calf barn was using chlorine dioxide for disinfecting calf pens. I raised the question about the concentration being used. They intended to use 200ppm. I had a canister of test strips in the truck. The solution tested between 10 and 25ppm rather than 200ppm (it's a color strip so an exact value is not possible - Insta-Test by LaMotte).

So, they were doing a lot of work to accomplish very little. Now they check the solution every time before using it to see that all that spraying is likely to knock down the resident pathogen population

Wednesday, June 22, 2016

Use a Brush!

It is a simple fact that brushing a surface helps clean it better - especially equipment used to feed milk and colostrum to young calves. 

However, some persons seem to have an allergy to brushes or brushing. At one time I thought that this allergy was specifically concentrated in teenage boys. I had a devil of a time getting them to brush the inside of nursing bottles.

More recently I have run across more than one client where the esophageal tube feeder has been alive with bacteria. The bottle or bag was quite clean. However, when checking the end of the feeding tube (you know, the end with ball on it) the results were quite the opposite. 

We use a luminometer to check cleanliness (see paragraph below).
The ball-end tube feeder readings on one dairy were (monthly):
12, 36, 4837, 12, and 995

What was going on here?

Not the same person does this job from month to month. Can you pick out the months where there was a change in the person responsible for cleaning colostrum feeding equipment?

There is a cleaning protocol  posted in front of the sink where the cleaning is done - there is a brush at the sink - it is a matter of getting the hand in contact with the brush. 

We went from 4837 to 12 after the worker was retrained and "encouraged" to follow the protocol. We went back up to 995 when there was yet another change in workers - back to retraining.

Even when the same person does the cleaning for a long period of time there can be "protocol drift" during which the cleaning standards are compromised, short cuts added and things just "slide."

So, check to be sure the brushes needed to clean calf equipment are present and in good shape and encourage everyone to use them. Have more healthy calves.

Luminomter:  Hygiena SystemSure Plus unit does adenosine triphosphate (ATP) monitoring. The ATP test is a process of rapidly measuring actively growing microorganisms through the detection of adenosine triphosphate. An ATP monitoring system can detect the amount of 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 have been using a reading of 100 RLU as realistic on-farm upper threshold for calf feeding equipment

Saturday, June 18, 2016

Housing Weaned Calves in the Calf Barn

During a recent renovation of a calf barn the owners doubled the length of the barn. The original calf barn had space in four rows for 160 preweaned calves and at the east end there were two pens for weaned calves (10 calves per pen).

The addition is a carbon copy of the previous one. It was added to the west end of the original barn. Four rows of preweaned calves and at the east end of the addition are two pens for weaned calves (that puts the weaned calves just about in the middle of the blocks of preweaned calf pens).

The original barn was tunnel ventilated with seven large fans on the east end (that's the end where the weaned calf pens were located). The new barn has chimney fans at regular intervals (fans on east end are gone) to draw air up and out of the structure. The entire building has curtain sidewalls that are raised and lowered automatically based mostly on temperature. 

Note that the new ventilation system does not sweep the respiratory pathogen load from the weaned calves out of the barn the same way that the tunnel system was doing. 

Ever since the new barn has been fully populated there has been a chronic problem with clinical respiratory illness among calves less than four weeks of age. 

One idea that came up this past week was to take advantage of the summer weather and house the weaned calves outdoors - out of the calf barn. If we can get these pens set up to use the temperate weather in July and August maybe we can test the hypothesis that the weaned calves are part of the problem with so many treatable cases of respiratory illness among preweaned calves.

Keep tuned for the developments over the summer. 

Thursday, June 16, 2016

Preventing Navel Infections

"Preventing Navel Infections" is the title of the June 2016 issue of the calf management newsletter. It is now available by clicking HERE

The topics are:
·        How often do navel infections occur?
·        What are the consequences of navel infections?
·     What are cost effective alternatives to reduce the rate of treatable cases of navel infections?


Tuesday, June 7, 2016

Automatic Feeder - Maintenance Makes a Difference

The calf care person was running routine washes for an automatic feeder. After washing she sampled:
1. milk going into the feeder
2. hose going out of feeder to one of the four pumps leading to the nipples
3. milk from nipple

The culture results were (cfu/ml):
1. into feeder = 80 cfu/ml
2. hose to pump = 53,000 cfu/ml
3. milk from nipple = 86,500 cfu/ml

So, the automatic feeder was adding bacteria to the clean milk going into it. 

Changed a hose and valve that had been overlooked in previous maintenance.

Culture results were:
1. into feeder = 660 cfu/ml
2. hose to pump = 1,200 cfu/ml
3. milk from nipple = sample missing

It pays to know your machine very well and to stick to a regular maintenance schedule. 

Thursday, June 2, 2016

Jersey Calves on an Organic Dairy

Each year I volunteer to be an on-farm guide for the "baby calf station" for all the 6-year old children in our local area. Nearly two hundred and fifty children show up on a sunny day in early June to spend three hours on a small dairy farm.

Yesterday, June 1, was the day for 2016. The dairy had the youngest calves in individual fiberglass hutches (ages in days = 1, 3, 4, 6, 8, and 9). Once the calves are drinking well from a nursing bottle and a larger super hutch is available they are moved into one of these in groups of four. Yesterday they had four of these super hutches with calves about four, eight and ten weeks old.

These 6-year olds had questions mostly about:
1. age - how old are they?
2. food - what do they eat?
3. mother - where is her mother?
4. activity - can she really walk around when she is only 1 (3, 4) day old? (probably related to experience with kitten and puppies?)

Most popular calf to look at? The one-day old - all 40 pounds of her.

The eight and ten-week old calves were up and walking about their pens so they attracted attention as well. 

The children also visited the milking parlor (double 10 parallel swing design), milk room with plate cooler and milk tank, free stall barn with sand stalls, feed alley with TMR, milk tanker truck (with air horn) and the haylage harvesting equipment. This was sort of a guided tour where the whole class moved along as a group. They completed the tour with a visit with the Genesee County Dairy Princess and her helpers where they all had an opportunity to churn (shake a 30ml bottle) heavy cream into butter and eat the butter with pretzel sticks - anything that involves eating is popular. 

In addition, after the tour, there were sixteen more "learning stations" where small groups of children with an adult could visit as they were interested. 

They had a chance to sit on the shaded lawns and eat their bag lunches (along with donated cheese and milk from a local dairy cooperative). 

Each year I am impressed with the commitment of a mostly volunteer crew that supports the event. The teachers always comment on how good it is for the children to see where their milk (and milk products) come from.