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Washington State University Dairy News

September 2015 WSU Dairy News

Check Your Forage for Nitrates

The recent heavy rains that have followed a summer of record heat have created a situation where we could see high nitrates in forages harvested in late August and early September.

The dry July and August likely resulted in soil that was low in moisture and did not allow soil microbes to effectively convert manure nitrogen into nitrate for uptake by forages.

Now that we have seen record rainfalls in recent weeks, the soil microbes have the moisture they need and are likely active again and converting organic nitrogen into nitrate.

If your forage is high in nitrate, it is possible for as much as 50 % of it will get converted to ammonia when in the silo. While this reduces the risk of nitrate on the animal, the silage will likely have high levels of soluble nitrogen. The higher level of soluble nitrogen in the diet can be a challenge for ration formulation.

Consider sending samples of the fresh cut forage for a nitrate test, and if high, be ready to have the silage tested for nitrates and soluble nitrogen prior to feeding.

Table 1. Guidelines for using Feeds of Known Nitrate Content.
Original Source: Hoards’s Dairyman August 25, 1970.

Some laboratories report nitrate analysis as percent or PPM (parts per million) of KNO3 or NO3-N. To use the above explanation tables, multiply % or PPM of KNO3 by 0.61, or the % or PPM of NO3-N by 4.4 to get the comparable % or PPM of NO3.

%NO3 on 100 % DM Basis Comment
Less than 0.44% (4400 PPM) Safe
0.44 to 0.88% (4400 to 8800 PPM) Generally safe when fed balanced rations. Best to limit it to half of the total dry ration for pregnant animals and also be sure water is low in nitrate.
0.88 to 1.5% (8800 to 15,000 PPM) Limit amount to less than half of total dry ration. Be sure ration is well fortified with energy, minerals and vitamin A.
Over 1.5 % (15,000 PPM) Potentially toxic—do not feed.

CUDS Update – WSU Cooperative University Dairy Students

The cooperative University Dairy Students are going strong with 13 new and continuing members. The herd continues to improve its productivity, reproductive performance and milk quality. They averaged between 87 to 90 lbs/d all summer and maintained over a fat test of over 3.6 and protein over 3.1. The SCC is routinely under 100,000.

Their attention to reproduction has been so diligent that they are now milking 12 fourth and fifth lactation cows out of a herd of 40! The pregnancy rate is consistently over 20%. They have one 90+ excellent Holstein, one 86 VG heifer and several animals classified over 85.

Current members are: Marcy Bartelheimer, Emily Beebe, Joe Britt, Chandler Byington (President), Parker Byington, Jennifer Callanan, Megan Chihak, Teresa Erwin, Kevin Gavin, Landon Macy, Dana McCurdy, Grace Montgomery, Maite Muse, Meghan Nyquist, Shane Reed, Conrad Reisenhauer, Lindsey Richmond, Kelby Stadt, Stephanie Van Volkenburg, Mark Vetter, Gavin Voelkers, and Kristen Wedam. The CUDS faculty advisor is John McNamara.

The undergraduate dairy program at WSU is going strong!

No Longer on the Horns of a Dilemma

Dairy producers know dehorning or disbudding of dairy cattle is a long-established best practice that benefits human and animal safety and welfare. With a growing research base supporting the need for and effectiveness of pain control during these routine practices, progressive producers are wondering if and how they should change their horn removal protocols.

Destroying horn buds by either caustic paste, burning, or gouging have long been the primary means of disbudding calves. Within the past decade, many studies have shown the use of local anesthetic and non-steroidal anti-inflammatories are inexpensive and effective ways to control disbudding-related pain in calves. The use of a sedative has the added benefit of reducing the stress calves experience when handled for disbudding.

Day-old calves are not yet very active and usually unable to scratch their head with a hind foot. They are also often placed in single-calf housing. Both these factors help make disbudding with caustic paste on Day 1 of life safer because risk to non-target tissues of the calf or other animals is minimal.

A protocol to consider, developed after a discussion with beef and dairy veterinarians:

  1. Make sure the day-old calf has a good meal before starting. Your veterinarian may recommend adding a non-steroidal anti-inflammatory to the bottle.
  2. Sedate the calf (ask veterinarian about medication and dosage).
  3. Block nerves with local anesthetic (again, consult veterinarian). Allow adequate time to pass before completing procedure.
  4. Clip hair around horn bud. A very close clip with clippers will allow use of less paste or burning time and less unnecessary tissue death will occur.
  5. If disbudding via gouging, switch to caustic paste or burning because these methods have fewer complications.
  6. If disbudding via burning, burn until a ring of tissue around the bud base has turned a uniform copper color; burn the bud itself as well.
  7. If using caustic paste, create an outer ring of petroleum jelly to confine paste to horn bud area. Use a designated syringe to apply a thin dime-sized amount of paste to the entire horn bud and base if hair has been clipped close; a thicker and larger area of paste may be needed if hair has not been clipped close. Scratch the horn bud and its base with the tip of the syringe to roughen up the targeted tissue a bit.
  8. Administer anti-inflammatory if not done before the procedure.

If caustic paste is used, some veterinarians recommend wiping it off with gauze after 1 hour, others say after 24 hours. The paste should have done its work after just a few hours and removal will reduce the risk of damage to non-target tissue. Also, if calves nurse from dams instead of a bottle, do the procedure after the evening meal and separate the cow and calf; remove paste before returning the calf to its mother.

Consult with your veterinarian for more information about medications that can reduce calfhood stress and pain related to disbudding, including medication names, dosages, routes of administration, and any withdrawal times.

A few added suggestions:

  • Protect calf from precipitation after paste application so paste doesn’t run down into eyes
  • Cover paste with duct tape if calves are in groups or if there is anything they could rub paste on and contact with another part of their body
  • Always use gloves when using caustic paste and avoid contact with human skin and non-target animal tissues; wash off promptly if paste contacts non-target tissue.
  • If inexperienced about disbudding, learn from someone who is experienced and effective
  • If disbudding with cautery, the key to success is to keep the iron HOT, HOT, HOT.

Try to prioritize disbudding at an early age by making it a routine part of neonatal calf processing. Disbudding calves at 1 to 2 days of age gets this important task accomplished and out of the way so calves can get on with the business of eating, growing, and staying healthy.

A bi-lingual publication that describes another disbudding protocol is available from Oregon State University Extension.

Whatcom County Dairy Education Opportunities

If you have free time between 2:00 and 3:00 pm on November 15 and will be in the Lynden area, drop in at the Fairway Café for a no-host pie, coffee, and chat session with other producers and regional Extension Specialist Susan Kerr. No reservation needed. Among other things, we’ll set the date for future such gatherings.

  • November 16, 2015 Meet, Greet and Eat, Fairway Café, Lynden, 2:00 PM
  • January 20, 2016 Dairy Producer College, Lynden, Mt. Baker Rotary Building

Amber’s Top Ten Tips: Managing Cold Stress in Calves

Now that we made it through one of our hottest summers on record, it’s time for us to turn our attention towards the cold weather that lies ahead. The average mortality rate of heifer calves is approximately 8% on dairies in the United States. Of course, higher incidences of calf morbidity and mortality occur during cold weather conditions when calves expend additional energy to regulate their body temperature, which leads to less energy available for health and growth functions. Take a look at the following tips on calf management during cold weather and consider them as you prepare for the upcoming winter.

What you need to know about cold stress in dairy calves:

  1. Calf Jackets

    Using calf jackets or blankets during a calf’s first two weeks of life increases the calf’s insulation by 52% and may increase average daily gain by up to 0.2 lbs./day.

  2. Thermoneutral Zone

    A calf’s thermoneutral zone is the range of environmental temperatures in which a calf does not need to use additional energy to maintain its body temperature. The thermoneutral zone is 50 – 78 °F for calves less than one month old and 32 – 78 °F for calves more than one month old.

  3. Nesting Scores

    Calf lying in hutch. A thick bed of straw completely covers the anima's legs.
    Nesting score 3; calf’s legs are completely covered with bedding.
    To conserve body heat, calves will burrow their bodies into their bedding (nesting behavior). The ability for calves to exhibit this behavior is scored according to a three-point scale. A nesting score of one means that the calf’s legs are completely visible when the calf lies down; whereas a score of two implies that the calf’s legs are partially visible. Ideally, each calf should receive a score of three so that the calf’s legs are completely covered with bedding.
  4. Water Intake

    Calves need access to at least one to two gallons of clean water every day and offering warm water at least twice a day during cold weather may help calves maintain their internal body temperatures. Restricted water access may decrease weight gain by 38%.

  5. Milk Feedings

    Increasing the number of milk feedings to three times per day or increasing the amount of milk offered by 30% will help ensure that calves have the energy they need when they need it.

  6. Fat Supplementation

    Adding supplemental fat to calf diets during cold weather conditions have been linked to increases in calf growth during the first three weeks of life.

  7. Housing

    Calves need to be sheltered from wet and windy conditions, but adequate airflow is still necessary to minimize ammonia build-up. Ammonia concentrations should be less than 10 ppm (parts per million).

  8. Physiology

    Winter calves have respiration rates and heart rates higher (8.8% and 4.4%, respectively) than calves born in the summer.

  9. Behavior

    Lying behavior decreases by up to 37% when calves are provided wet bedding versus dry bedding. This information encourages us to keep the bedding deep and dry.

  10. Hypothermia

    Shivering and blood shunting (diverting blood flow from the calf’s extremities) are two mechanisms a calf’s body uses to increase muscle heat production and reduce heat loss during cold weather. Early signs of blood shunting in a calf include a cold nose and cold hooves.