Different nutritional problems may cause the same responses on the farm. This article presents ideas and methods for determining problem areas in dairy operations.
It is often said that there are four rations for a group of cows: the ration that is formulated by a nutritionist (the paper ration), the ration that is fed, the ration that is eaten by the cows, and the ration which is digested. Often, these four rations can be radically different. It is the job of the person who is troubleshooting to evaluate the ration on paper and then to determine if that is actually what the cows are consuming. Often this mission will involve much time spent with the person feeding the cows as well as time spent watching the cows’ feeding behavior, cud-chewing activity, manure condition, and the available ration at different times during the day. If at all possible, use the “team approach” when doing nutrition troubleshooting. Even though the farm manager may not intentionally be misleading, his perception of day-to-day feeding and management on the farm may not be reality. Also, it is sometimes helpful to involve the feed dealer, veterinarian, Extension agent, and others who may have valuable input into understanding the farm situation.
For nutrition troubleshooting, here are some tools you might find helpful:
References: nutritional requirements, computerized feed program, latest farm forage analyses, common feed ingredient analyses
Measuring tools: scales, pail, moisture tester, body weight tape, measuring tape, temperature/humidity measuring device, light meter, long-stemmed thermometer, particle size separator
Sampling devices: hay corer, plastic bags, feed testing lab mailers, containers for water
Recording devices: note pad and pen, computer, calculator
Records: DHI records, breeding and health records, feed tags, feed delivery slips
Evaluation of The Paper Ration
- Is the ration on paper adequate for the desired production level?
- Is the expected dry matter intake reasonable?
- Is the expected dry matter intake close to the actual dry matter intake?
- Is the expected forage NDF consumption reasonable?
- Is the expected forage NDF consumption close to the actual forage NDF consumption?
- Are NFC’s adequate in the ration or are they too high or too low?
- Is there too much or too little fast degradable starch and sugar?
- Is there adequate DIP as well as UIP?
- Is the ration balanced for amino acids?
- Is adequate supplemental buffer in the ration?
- Are mineral needs being met without being in excess?
- Are current analyses of the forages and byproducts being used?
- Is dry matter analysis of forages and wet by-product feeds being conducted regularly and are the appropriate dry matter adjustments made in the ration?
Evaluation of The Ration Which Was Fed
Communicating with the Person Feeding the Cows
The feeder is an important person on the farm. Unfortunately, often the nutritionist has very little contact with the feeder or poorly communicates with him. Here is a list of daily decisions that the feeder must make and areas where the nutritionist might be able to provide guidance.
- What batch size should be mixed? This involves knowing how many cows are in the group, how many pounds of refusals were left (and how much should be left over), and how to do math.
- What should be done with feed refusals? Finding a home for feed refusals may prevent problems related to underfeeding and feeding to an empty bunk.
- How should a batch of TMR be mixed? This involves knowing the correct inclusion sequence and mixing time. The feeder must understand the importance of effective fiber and uniform mixing. It also means that the feeder should know the difference between fresh, good ingredients and ingredients which may have gone bad.
- How should the bunker silo be maintained? Feeders should understand how to best work on the face of the bunker silo to maintain maximum feed freshness. They should also understand the consequences of poor bunker silo management.
- How does the feeder account for variations in forage dry matter and other high-moisture ingredients? The feeder needs to understand that cows receive their nutrients from the ration dry matter and that rations are balanced on a dry matter basis. There should be scheduled days (at least weekly) for doing routine dry matter analysis and additional dry matter analysis should be done when an obvious forage change is made (like changing to a different silo). The feeder needs to have the math skills to re-calculate the amounts to be fed. The nutritionist could help by providing batch mix sheets to provide the As-Fed pounds for different ingredient dry matters.
- How should the feeder compensate if too much of a single ingredient was added to a batch? Here a basic understanding of nutrition and ingredients would be helpful.
- If the farm is not feeding a TMR, feeding sequence (such as, hay before grain) should be discussed. The average weight of scoops of grain, forkfuls of forage, and bales of hay should be determined.
Look at the Feedbunk:
- Is the feed fresh? If it’s a TMR, is it uniformly mixed?
- Does it feel warm or cool? Warmth indicates a secondary fermentation and feed deterioration.
- Ask about feeding frequency, time of feeding, bunk cleaning and refusals.
- Measure feedbunk space per cow (it should be >18 inches (46 cm)/cow)
- If a computerized feeder is used, evaluate individual cow usage, cows/feeder, feed freshness, and amount fed per cow visit.
- If feeding pellets, are there a lot of fines?
For adequate cud-chewing and rumen mat formation, there must be adequate total fiber and adequate fiber length. An easy recommendation to remember is that 15% of the particles in the total ration should be greater than 1.5 inches (3.8 cm) in length.
The Penn State Particle Size Separator can also be used to evaluate the particle size of the individual forages in the ration and that of the mixed ration. It can also be used to estimate overmixing of TMR’s. You can hand mix a TMR together, seive to estimate particle size, and then compare with the seived material from the mixer wagon. You can also compare different mixing times. (See Forage Particle Size)
General Recommendations for Particle Size:
||Coarse, >0.75 inch
||Fine, <0.31 inch
|Processed Corn Silage
|Unprocessed Corn Silage
|Hay Crop Silage
Note: Some researchers suggest that only 6-10% of the TMR needs to remain on the top screen. The exact recommendation depends in part on the make up of the NFC’s in the diet and feeding management. The author has had the most success across diets with the above recommendations.
Total Ration Dry Matter
Generally, nutritionists will agree that intake of rations containing anywhere from 40-60% dry matter should be fine. Rations having less than 40% dry matter where most of the water is in the form of silage juice can inhibit intake. But, depending on the ingredients in the ration and their particle size, cows could sort dry rations, causing acidosis. Positive field experiences have resulted by adding water to rations that were over 50% dry matter to reduce dry matter to 43%. (See Intake & Total Mixed Rations)
Use a Koster tester or microwave oven to determine moisture of forages (See Feed and Forage Analysis). Calculate the percent dry matter in the total ration. Most feed programs print this on the ration summary. If the ration is too dry, add water. Here’s an example of how to calculate how much water to add. If your ration is 50% DM and it’s balanced for 50 pounds of dry matter intake, you will have 100 pounds of TMR (As-Fed). To make that ration contain 43% DM, divide 50 (pounds of dry matter intake) by 0.43. You get 116 pounds. So, you would need to add 16 pounds of water (116-100) per cow.
Although nothing replaces actual dry matter analysis with a Koster tester or microwave oven, it is sometimes helpful to have a quick idea of what forage dry matter is. The Penn State Dairy Reference Manuel (1995) outlines the squeeze test for dry matter. Tightly squeeze a handful of finely cut forage. Release your grip and note the condition of the ball in your hand. Consult the following table to determine the approximate DM content.
|Forage condition after squeezing
||Estimated DM content (%)
|Juice runs freely or seeps between fingers
|Ball holds its shape; hand is moist
|Ball expands slowly; no dampness on hand
|Ball springs out upon opening hand
||40% or more
The troubleshooting nutritionist should always make a trip to the silos to evaluate silage quality. The amount of milk produced from silage will depend not only on its nutrient content but also on its pH, temperature and volatile fatty acids. Does the silage have a good fermented smell? There should be little evidence of molds and mycotoxins. All of these factors affect silage consumption. If feeding corn silage, are the kernels cracked and can they be broken open with the fingernail?
Expected Range in pH for ensiled crops (PA Dairy Reference Manual, 1995)
Note: A pH above 5.0 may enable bacteria, such as Listeria and Clostridia, and molds to produce toxins that are harmful to animals
|Crop ||pH range
Goals for Stable Silage:
||% Dry Matter (DM)
Adapted from Mahanna (1997)
|Goals when Evaluating of Silage Temperature:
|Not More than 15-20oF (8-11oC)above Air Temperature at Ensiling Time
|Not More than 1-2oF (0.5-1oC) above Air Temp. During the Stable Phase
|Protein Goals for Silage:
|Ammonia Nitrogen (NH3-N)
||Less than 10-15% of N in grass/legume silage, less than 5% in corn/cereal silage
|Bound Protein (ADIN, ADF-CP)
||<12% of the crude protein (CP). If greater, use Available CP to balance ration.
Adapted from Mahanna (1997)
Evaluate Silo Management
- The recommendation is to pack more than 1000 hour-pounds per ton of silage. This means that if you have a 38,000 lb tractor (or 2 tractors totaling 38,000 lbs), 38 tons can be delivered per hour.
- If silage is packed well, grabbing handfuls at the face will be difficult.
- Bunker Silo: > 3” in winter, > 5” in summer per day
- Tower Silo: 2 to 3 inches per day
- Remove bottom foot first. Then, chip down from the top, one or two feet at a time, without penetrating the silage more than the needed amount for the day.
(See Silage Production and Molds and Mycotoxins)
The Consumed Ration
Dry Matter Intake
It is to the benefit of the farm and the nutritionist to record daily dry matter intakes for groups of cows. The feeder can do this by calculating the amount of dry matter offered and subtracting the amount refused. But, he must first understand its importance and understand how to do it. His boss, the farm manager, must also be supportive. Everyone must understand that if the cows consume less dry matter than the nutritionist assumes the cows will eat, then the ration is not balanced for the desired level of milk production. Nutrient density may need to increase or the reason for the low intake must be found. If the cows consume more dry matter than the nutritionist has assumed there may be opportunity to reduce ration nutrient density and reduce cost. It may be helpful to check the amount of grain that was recorded fed with feed delivery slips. Determine if nutrient intake matches up with that needed for current production (See Intake)
Cows May Select What They Want to Eat
If cows select what they want to eat rather than eating what the nutritionist planned for them to eat, production will likely suffer.
As previously discussed, cows often will sort out what they want to eat from a TMR. They eat the grain soon after the TMR is offered and eat long, fibrous particles later. This creates hours of high rumen acidity, reduces intake, and reduces milk production. Sorting can be reduced. Add water to dry rations. Avoid adding more than 4 pounds (1.8 kg) of hay in a TMR. Use processed hay and corn silage. Maintain adequate but consistent particle length (avoid long, very coarse fiber). (See Total Mixed Rations)
When a TMR isn’t used, there are more problems with cows selecting what they want to eat. If hay and grain are offered separately, some cows will consume more grain than they should and other will consume a greater percentage of hay than recommended. We know that cows will be individuals, but an attempt should be made to minimize it as much as possible by offering fresh feeds immediately after milking, offering grain at least 3 or 4 times per day, and feeding ration ingredients on top of one another rather than separate.
The Excreted Ration --- Manure Evaluation
Manure evaluation is critical to nutrition troubleshooting. Determine how consistent manure is from cow to cow. Evaluate its general appearance. Evaluate for the presence of undigested particles within it. (See Manure Evaluation)
Although water is not a nutrient on the feed program, it is vital for maintaining healthy, high-producing cows. Don’t forget that milk is 87% water!
Evaluate Water Availability
- Is there a water tank at the parlor exit? Cows will drink 30% of their water within a half hour after milking
- Is there a water tank for every 20 cows in a group that is at least three feet long and two feet wide (91 cm by 61 cm)
Evaluate Water Quality
- Laboratory Analysis
- Cleanliness (Scrub weekly; add 2 oz Clorox bleach for every 50 gallons)
Measure Water Intake
- Use a meter and compare actual intake to expected
For expected water intakes and water analysis, see Water
Physical Condition of Cows
1. Feet and Legs
Watch for signs of laminitis or hairy warts. Watch for “strawberry” lesions on cows’ hocks. This is a sign of too much abrasion, often from inadequate bedding
2. Body Condition Score
The average body condition score of a group of cows indicates if the energy needs of the cows have been being met, if the cows are able to produce more milk, and if reproduction will be compromised. Both thin and fat cows are at risk for problems. (See Body Condition Score)
Target Body Condition Scores:
|Stage of Lactation
|Heifers at Calving
Source: Body Condition Score Guide, Church&Dwight Co., Inc.
A cow’s hair condition indicates her general health. If it is rough, worms or lice may be a problem. An abnormal reddish color could indicate a copper deficiency.
Cows’ eyes should be bright and alert. Eyes are just another indication of general health.
The incidence of cud-chewing reveals the effectiveness of dietary fiber. Cows need to chew their cud about 8 hours per day. Evaluate cud-chewing activity of the cows that aren’t eating a few hours after feeding time, you should see at least 50-60% of the cows chewing their cud.
6. Disposition (Lethargic, Excitable)
Disposition is an indication of general health and cattle management. Lethargic animals could be acidotic. Cows that are easily excitable and run the other way when you enter their pen may not be being handled properly. Cows may also show signs of stray volatage (lapping water, twitching tails, etc).
Talk With the Farm Manager and His Team - What Are The Concerns?
Define the Problem
- Major + Minor complaints
- When did it start?
- Are metabolic problems occurring – what is the extent, when do they occur, how do the cows respond to treatment?
- What feeding and management changes occurred at the time of or since the time the problem began?
- Is the problem in a specific group of cows?
- Look at the records.
Evaluating Milk Production
If Poor Peaks, check protein (SIP, DIP, UIP, amino acid profile of UIP) and check starches and sugars. Too much fast starch and sugar could cause acidosis. An improper balance of fast and slow starches and sugars and DIP could reduce microbial protein yield. Check the prefresh and fresh cow diet and evaluate incidence of fresh cow metabolic problems.
If Poor Persistency, check body condition in early lactation and energy supplied from the early lactation ration. Check the prefresh diet and for fresh cow metabolic problems. Also, check on nutrient concentration of rations for different groups of animals. For example, there may be too big of a change from the high cow to the medium cow ration.
Comparison to Previous Years gives an indication of genetics and management potential.
Milkfat and Milk Protein Analysis:
Low milkfat – check for acidosis, check both levels and types of rumen active fat in the diet
Low milk protein – check amino acid profile of UIP, check on degradable proteins, starches, and sugars that could be limiting microbial protein synthesis.
(See Milk Components)
- If poor heats, look at mineral and energy adequacy.
- If show heat but not getting pregnant, look at energy balance and trace minerals.
- If early embryonic deaths (irregular heat cycles), look at MUN”s and energy balance.
- If cystic ovaries, check for cows that are too thin or too fat. Also, check P and Se. Also, check for infectious diseases.
- If abortions, check for mycotoxins and infectious diseases.
Transition Cow Metabolic Problems
Calving difficulties – check on BCS and sub-clinical milk fever
If no anionic salts, Ca = 0.45%, P= 0.3-0.4%, K <1.4%, Mg=0.35-0.4%, Se = 0.14 mg/lb (0.3 ppm), Vit E = 1000 IU
If using anionic salts, Ca = 0.80-1.0%, DCAB = -5 meq/100g or less
- Urine pH – Holsteins 6.0-6.5, Jerseys 5.8-6.3
Watch DMI (23 pounds (10.5 kg) per day = average prefresh intake of a Holstein cow)
Retained Placenta and Metritis
Determine if cows are too fat or had twins. Check adequacy of vitamin E, Se, and protein in the dry cow diet. Check for subclinical milk fever. Avoid stress at calving time.
Determine if intakes were low, if effective fiber intakes are low, and control sub-clinical milk fever.
Ketosis and Poor Appetite after Calving
- Control sub-clinical milk fever
- Control BCS
- Maintain feed intake
- Increase energy content of the prefresh diet (.68-.70 Mcal/lb)
- Include niacin and calcium propionate in the diet
(See Transition Cow Metabolic Problems)
Evaluate age, weight and height at breeding and at first calving. (See Heifers)
Scours in first two weeks – Check colostrum intake and vaccination program
Coccidiosis – check for adequacy of coccidiostat intake
Starter Intake at Weaning – check calf starter quality and weaning age
Age at Weaning – check starter intake, milk replacer intake, health problems, and weaning protocol
Evaluate Average Daily Gain
Common Nutritional Problems
1. Observed Dry Matter Intake Different than Expected
- Need to set ration nutrient densities based on accurate DMI estimation
- Need to resolve problems which may inhibit DMI
- Moisture content of wet feeds and their fermentation quality
- NDF analyses of forages (Higher or lower NDF may affect intake)
- Forage particle length and cud-chewing activity of cows
- Scale calibration
- Emptiness of bunk and number of feedings and sweep-ups per day
- Presence or abrupt inclusion of unpalatable ingredients (silage, tallow, animal protein, bypass fat)
- Ration moisture, Is it >60% using fermented feeds?
- Cow comfort
- Adequate protein and salt supplementation?
- Shortage of UIP?
- Water quality or availability. Measure water intake.
- Orts – Are the bunks cleaned daily?
- Do the orts look like the original offered ration?
- Bunk Space – at least 18” (46 cm) per animal
- Eating Time vs. Time in Holding Area (not more than 1 h waiting to be milked)
- Low Rumen pH
- Rollercoaster intake and milk production, especially in early lactation
- Inconsistent manure – some stiff, some loose, some pasty with bubbles, some with fiber
- Lack of cud-chewing
- Milkfat depression
- General cow depression – cows that don’t want to move to come into the parlor
- Dry matter of forages (is the paper ration the same as the consumed ration?)
- NFC (it should be <40%) and Fast Degradable Starch too high?
- Avoid sudden increases in NFC’s – use a prefresh diet and gradually increase grain after calving (1 pound (0.45 kg) per day)
- Avoid slug feeding grain (no more than 10 lbs. at once)
- Provide adequate SIP and DIP to ferment in conjunction with starches in the rumen
- Make sure 15% of particles are greater than 1.5 inches
- Forage NDF should not be less than 19% of DM with poorly digestible forages and not less than 21% with good forages
- Increase Forage NDF when feeding highly digestible forages
- Feed forage prior to grain
- Have forage or TMR available 24 h per day
- Buffer level (1 oz per 10 lbs of milk)
- Aggressive social interaction problems (dominant cows)
- Animals “plod” as they walk or look like they are “walking on eggs” lame
Pinkness or puffiness of the coronary band
Sole hemorrhages may appear and there may be white line separation
- Hooves widen, flatten, and become ridged.
- Cows are obviously lame
- the above checklist for acidosis
- add 2-4 g of chelated zinc to increase hoof hardness
- exercise – lack of movement allows blood to pool in the hoof and the tissues have less opportunity to be oxygenated
- cow comfort – as cows lie down, they ruminate more and when cows are standing, blood pools in the hoof
- functional hoof trimming
- footbaths – harden hooves, prevent infections
Body Condition Score Guide, Church & Dwight Co., Inc., 1991
Bucholtz, H. 1999. Communicating with the person mixing the feed. In: Proceedings of the Tri-State Dairy Nutrition Conference, April 20-21, 1999, Fort Wayne, Indiana.
Chase, L.E. and C.J. Sniffen. Problem solving techniques in dairy cattle nutrition. de Ondarza, M.B., 2000. Feed sorting leads to acidosis, other problems. Hoard’s Dairyman, April 10, 2000, p. 286
Dairy Reference Manual, The Pennsylvania State University, Cooperative Extension, NRAES-63, June 1995.
Greenough, P.R., L.M. Schugel, and A.B. Johnson. Zinpro Corporation’s Illustrated Handbook on Cattle Lameness. Zinpro Corporation, USA.
Howard, W.T and R.D. Shaver. 1991. Troubleshooting TMR’s. In: Proceedings of the Advanced Nutrition Seminar for Feed Professionals, August 28, 1991, Arlington, WI.
Mahanna, B. 1997. Troubleshooting Silage Problems. Pioneer Hi-Bred International, Inc. Website (www.pioneer.com)
Martin, R, L. Armentano, and C. Leonardi. 2000. Feed sorting and acidosis: Is there a link? Hoard’s Dairyman, September 25, 2000, p. 625.
Ruppell, K.A. and D.R. Specker. 1996. Pioneer Field Encounters: Enhancing Value from Seed to Feed. Proceedings from the Seed of Animal Nutrition Conference, October 22, 1996, Rochester, NY.
How to Compute Your Cost of Producing Milk
A step by step guide to filling out a worksheet computing cost of production. Helps interpret results at the end.
In: Feeding the Dairy Herd, North Central Regional Extension Publication, J.G. Linn et al.
Feeding the Dairy Herd
In: Feeding the Dairy Herd, North Central Regional Extension Publication, J.G. Linn et al.
Eating and Feeding Behavior of Dairy Cows: Dietary Influences and Impact on Production
David Christensen, University of Saskatchewan
Scroll down to "proceedings" menu and select "2000". Click on "Table of Contents" Scroll down to "Session V. Nutrition and Management" Click on second link. Detailed review of literature pertaining to feeding behavior. Author tries to relate findings to practical application on dairy farms to increase milk production.
Identifying Limiting Nutritional Constraints to Profitability
M.F. Hutjens, University of Illinois
Scroll down to "proceedings" menu. Select "1995". Click on "Table of Contents" Scroll down to the second "Plenary Session". Click on link. Author relates areas of nutritional management on farms to effects on economic parameters. Article is quite technical.
Trouble-Shooting Nutritional Problems
Article covers important nutritional areas for management and discusses them by age groups in dairy cattle.