North Dakota State University
NDSU Extension Service

Vol. 8, No. 1, January 1998

Editorial
Calf Management: Supplemental fat in liquid diets for calves
Reproductive Management: Seven steps to a successful heat detection program
Health Management: Reasons for treatment failures
Milk Management: Spraying vs. dipping
Milk Management: How does your SCC compare
Nutrition Management: Cows make good recyclers
Cow College '98

Editorial - Dairying in Transition

Seasons Greetings to all! With the first edition for 1998, I'm a bit flabbergasted about how little of the 20^th century is left. For many of us the extent to which change has affected our lives and industry is significant. The most notable is the decline in numbers of our dairy neighbors. Low commodity prices, ever increasing costs of doing business and an aging agricultural population have contributed much in the way of change.

Yet, fortunately, there are those who see a brighter future ahead. While optimism has had its setbacks, many are forging ahead, work-ing toward a future in an industry they love. One such group is the `Dairy Summit' committee. This steering committee is a spin-off of the results from an August 18, 1997 Dairy Summit sponsored by the North Dakota Department of Agriculture. Their role in agriculture is obvious, but perhaps less apparent is the startling realization among many communities that losing their dairy producers, processors, and related businesses will have significant negative impact on rural economics.

The North Dakota input-output economic model tells us that animal agriculture has a bigger impact on a community than even crop production. This model suggests that for each $1 input (into livestock), $3.49 of output is generated in the community. As rural North Dakota loses its dairies, it loses tax-base, a major user of feed and forage and a primary consumer of electricity. That's why the Department of Agricul-ture has suggested the formation of a Dairy Summit Steering Committee. Their challenge is to look at our current situation and suggest changes that will enhance the dairy industry's future. No small task!

The steering committee is made up of people who represent a cross-section of the industry, yet held to a manageable size in order to conduct business. If you like to discuss your ideas about the future of dairy in North Dakota, please feel free to contact one of the members listed below.

Doug Dukart, Kristy Klusmann, Jim Winger, Lila Krebs, Mike Zimmerman, Sue Steckler, Victor Mathern, Nancy Planteen, Rita Mosset, Blaine Goetz, Bob Gaebe, Tom Keidell, Ruth Pagle, Mike Rose, Dwight Aakre, Gary Hoffman and J.W. Schroeder.

Thanks in advance for your input, kind thoughts and future support.

J.W. Schroeder
Extension Specialist-Dairy

Calf Management

Supplemental fat in liquid diets for calves

Raising young dairy calves in the winter can be a challenge for both the calf and the producer. Freezing temperatures, increased precipitation, and added stress can markedly reduce growth rates of calves. In addition, bedding tends to stay wetter longer, making the overall envi-ronment less comfortable. This can increase stress on the calves, further increasing the animals need for energy to maintain body temperature.

Calf raisers know the difficulties of raising calves in winter — especially in North Dakota and northern U.S. To be sure, the cold weather is difficult for calves and calf raisers as well. Dealing with frozen pipes, frozen buckets, sick calves, cold weather, snow, rain, ice and all the other challenges that winter brings can test the resolve of even the most dedicated of calf raisers.

Calves raised in cold conditions need more energy. Researchers at Penn State estimated that maintenance energy requirement for calves fed milk replacers was increased by 32% when they were housed at -4C (25F) compared with calves housed at 10C (50F). So, in very cold weather, calves will require additional energy to maintain their body weight, and to grow. There are several options for providing additional energy for calves. These include additional milk or milk replacer feeding, increasing the concentration of milk replacer solids fed to calves, or the use of supplemental fat in milk or milk replacers.

Supplemental fat products are high fat (usually about 60%) and usually contain about 7 to 10% protein. They are added to milk or milk replacer at ¼ to ½ lb/day to provide extra energy for maintenance and growth. The primary benefit is from increased energy for maintenance and growth. The primary benefit is from increased energy and subsequent body weight gain. However, there may be other, less well defined benefits. When calves are subjected to cold conditions, more energy is directed toward maintenance of body temperature. Thus, less energy is available for growth — or to support immune competence. If the animal is challenged with an enteric pathogen during the liquid feeding period (e.g., Cryptosporidium), the amount of energy available to support the immune response may be limited. In this situation, the animal's ability to fight off disease may be impaired, resulting in increased severity or extent of disease.

What are the potential problems with adding supplemental fat to liquid diets? There are several. These include:

• Economics. Supplemental fat products are expensive. Retail prices are approximately $0.08/calf per day (excluding labor for mixing, etc.). If you have a lot of calves and feed them a fat supplement for an extended period, this can be expensive.
• Starter intake. Calves consuming additional energy from supple-mental fat products may show a depression in calf starter intake. The degree of this depression depends on the calf's age, energy needs, and extent of rumen development. This depression may be due to the animal meeting it's energy needs from the liquid + supplement. Simply put, if the animal is meeting its energy needs from milk replacer and supplement, then it has less of a need to consume calf starter. Generally, research suggests that in very cold conditions (<0C, 32F), there is less (or little) depression in starter intake with added fat, and more of a depression in starter intake when the temperature is not so cold.

The decision to use supplemental fat in liquid feeds depends on your personal situation. In certain situations, adding fat supplements may provide the extra energy your calves need to more readily handle the cold, cruel winter.

Source: Dr. Jim Quigley, University of Tennessee.

Reproductive Management

Seven steps to a successful heat detection program

Eight times out of ten, the area of reproductive management that needs improvement is heat detection. Research from Virginia Tech revealed that an increase in heat detection from 40 to 50 percent increased income $34 per cow per year. There are very few farms that could not reduce the average days in milk and culling rate by spending a little more time and effort on heat detection.

1. Establish a proactive aggressive program: Use time efficiently. Cows should be observed at times and at a location where they are likely to express estrus. Establish a hormone program to induce estrus in cows not detected by 60 days in milk. Interval between voluntary waiting period (50 to 60 days) and average days to first service should be less than 20 days. Less than 20% of the cows should be open at monthly pregnancy exam.
2. Utilize records: All heat periods detected should be recorded. A 50% conception rate means half the cows bred will become pregnant and half will return to heat in 18 to 24 days. Breeding wheels, calendars, and heat expectancy charts are inexpensive and effective tools.
3. Cow interaction: Watch for sexually active groups of cows. Cows in heat and cows that will be in heat in the next 48 hours commonly congregate together. Cows usually alter their normal routine of behavior when approaching heat.
4. Minimize sore feet: A cow with sore feet and legs usually does not mount or permit other cows to mount her. Trimming hoofs on a regular basis and treating infected or sore feet as soon as possible is important.
5. Timing and location is everything: Visual observations should be where cows have a good footing surface with few obstacles to hinder interaction. Cows should be observed many times (3 to 4) during the day because the average heat period lasts for only 8 hours.
6. Use aids wisely: Heat detection aids, such as Kamar™ or Beacon® heatmount devices should be used to supplement not replace visual detection. Pedometer based systems and the HeatWatch® electronic heat detection system requires management decisions on suspect cows and interpretation of information for timely insemination.
7. Induced heat or ovulation prufusrufusrograms: Inducing heat and(or) ovulation with hormonal treatments that include GnRH and PGF _2a increases the probability of detecting estrus or allows. AI without estrus detection (timed insemination). To achieve accurate and efficient heat detection requires extra effort and organization, it doesn't just happen.

Source: Dairy Pipeline, Ray Nebel, Blacksburg, VA

Health Management

Reasons for treatment failures

Mastitis results when bacteria penetrate teat duct keratin, overcome the defenses in milk, and multiply within the gland. The establishment of an infection is greatly influenced by the interaction of bacteria with milk leukocytes. These leukocytes function by phagocytosing bacteria and killing the organisms intra cellularly. However, phagocytosis is inefficient in the udder due to the lack of an energy source, low opsonic activity, and interference caused by casein and butterfat. Therefore, antibiotics continue to be relied upon in attempts to treat clinical quarters during lactation. However, antibiotic treatment often fails.

Reasons for treatment failure include:

• lack of contact between bacteria and antibiotics due to scar tissue formation.
• protection within leukocytes
• poor drug diffusion
• inactivation by milk and tissue proteins
• microbial resistance to antibiotics
• development of bacterial L-forms
• metabolically inactive organisms
• improper treatment procedures

For effective intramammary therapy, antibiotics must reach infection sites at concentrations exceeding the drug's minimum inhibitory concentration (M.C.) and remain at adequate concentrations for sufficient time to kill or inhibit growth of the infective agent. Unfortunately, therapeutic concentrations may not be achieved in mammary tissue for a sufficient period of time when presently used doses of antibiotics are administered intramammarily. Infections are frequently refractory to intra mammary therapy because of the inaccessibility to bacteria this inaccessibility is due to deep tissue lesions, swelling, and reduced potency of milk ducts.

A hallmark of acute inflammation is the formation of inflammatory exudates composed of necrotic tissue debris, leukocytes, bacteria, fibrin, and other blood components that occlude milk ducts draining areas of secretory tissue. The frequent therapy failures during acute mastitis are due, in part, to poor or uneven distribution of the drug throughout the intensely swollen udder parenchyma in which the duct system is either compressed or blocked by inflammatory products.

If bacteria and their toxins are eliminated (by host defenses combined with antibiotic therapy), inflammation subsides, occluded ducts open, and milk composition returns to normal in several days or weeks. However, if occluded areas are not flushed at every milking and continued bacterial growth and toxin production occur, the bacteria may become inaccessible to drug action.

Source: 1996 Western Canadian Dairy Seminar Proceedings, Vol. 8. Red Deer, Alberta. Clinical Mastitis: To Treat or Not to Treat. p. 355

Milk Management

Spraying vs. dipping

Postmilking teat spraying has become popular, particularly in large dairy herds. Whether a hand-operated pump and reservoir or an electric pump with drop hoses located near each milking unit is used, there are advantages in using this disinfection system. The most obvious and probably the greatest benefit is that the disinfectant is free of contamination by milk, manure, and dirt. Other advantages include reduced milking time and decreased disinfectant loss due to spillage.

A Louisiana State University study compared teat spraying with teat dipping under natural exposure conditions. A hypochlorous acid germicide was used to determine differences in new intra mammary infection (IMI) rate between the two methods. There were 75 cows in each group.

From mid March through June 1997, there were 28 new IMI in the dip group and 25 new IMI in the spray group. There were more new Staphylococcus aureus IMI in the spray group (8) than the dip group (3). New Streptococcus spp. IMI were the same in both groups. For coliforms, there were three IMI in the dip group and none in the spray group. The greatest difference in new IMI was for Staphylococcus spp. (15 new IMI in the dip group and 9 in the spray group). When IMI caused by all microorganisms were considered, teat spraying and teat dipping were equally effective.

To be effective, the milker must assure that the spray is applied to the teat from directly below and that the entire teat is covered so that a drop of germicide collects at the teat end.

Source: Hill Farm Res. Station, 1997 Research Report, p 307

How does your SCC compare

Multiple component pricing (MCP) was adopted in five Midwestern Federal Milk Orders, including the Upper Midwest Order, effective January 1, 1996. Under the MCP plan, producer milk is priced primarily on the basis of butterfat, protein and other solids (solids-not-fat less protein) with adjustments for somatic cell count (SCC).

A report was recently published analyzing milk components and SCC in milk from all producers associated with the Upper Midwest Order during 1996. The data include component levels for butterfat, protein, other solids, solids-not-fat ISNF) and somatic cell count (SCC). The study determined average component levels and SCC, season and regional variation, and relationships among components in individual herd milk at the farm level.

The weighted average component levels during 1996 were 3.75% butterfat; 3.19% protein; 5.50% other solids and 8.69% SNF. Weighted average butterfat, protein and SNF levels were lowest in July and highest during fall and winter. In contrast, other solids levels varied little during the year.

The weighted average SCC during 1996 was 362,000 cells/ml. The lowest weighted average was 330,000 in November; the highest was 404,000 in July. SCC ranged from 13,000 to 1,500,000 cells/ml, however, during the year most producers had SCC levels that were within one standard deviation of the mean (196,000 - 568,000). As a comparison, the weighted average SCC in the Upper Midwest Order during 1995 (samples analyzed from approximately 68% of the producers associated with the market) was 360,000; with the lowest weighted average in January (320,000) and the highest in August (434,000).

The annual weighted average values of butterfat, protein and other solids adjusted for SCC was $13.63 per hundred weight (cwt) for the market in 1996. Protein was the most valuable component, contributing nearly half of the total value ($6.16). The SCC adjust-ment for the year amounted to about minus $1.1 million or 1 cent per cwt from aggregated component value of more than $1.5 billion.

Source: Analysis of Component Levels and Somatic Cell Count in Individual Herd Milk at the Farm Level: 1996 Federal Milk Market Administrators Office, Minneapolis, MN

Nutrition Management

Cows make good recyclers

While dairy cows generate manure that must be managed carefully to preserve the environment, they are also top-notch recyclers for society. From whole cottonseed to brewer's grains, many of the by-products from the food and fiber industries are kept out of landfills because cattle eat them as feed. A University of Florida survey shows that each year dairy cattle in the state of Florida consume more than 600,000 cubic yards of Florida-produced by-products such as citrus pulp, whole cottonseed, wet brewer's grains, bakery waste, potato waste, wheat middlings and liquid whey. For comparison purposes, that's about the same volume as a football field piled 120 yards deep in feed.

Feeding these by-product feeds to dairy cattle diverts approximately 4,780 tons of nitrogen, 3,100 tons of phosphorus and 6,230 tons of potassium from the landfills and environment.

It's a win-win situation. Industries don't have to pay for by-product disposal, when producers have access to economical feed sources for their cattle, and society receives milk and meat produced from material which people could not use directly.

Cow College '98

The annual Cow College circuit is set. Be watching for fliers from your local county extension office, envelope stuffers with your milk check and various other ads. This year's program will include the extension veterinarian, Dr. Charles Stoltenow and me.

In addition to our traditional locations, Jamestown will be included as a new site for this year. The dates and places are as follows:

Dairy Connection, Vol. 8, No. 1, January 1998.

NDSU Extension Service, North Dakota State University of Agriculture and Applied Science, and U.S. Department of Agriculture cooperating. Sharon D. Anderson, Director, Fargo, North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. We offer our programs and facilities to all persons regardless of race, color, national origin, religion, sex, disability, age, Vietnam era veterans status, or sexual orientation; and are an equal opportunity employer.
This publication will be made available in alternative formats for people with disabilities upon request, 701/231-7881.

North Dakota State University
NDSU Extension Service