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National Animal Health Monitoring System and the 5 Q’s
Publish Date:Spring 2016
VolNo:Vol. XI No. 2
Once upon a time there was a USDA agency called APHIS (the Animal and Plant Health Inspection Service). Every year, APHIS sent a decree out to all the land using NAHMS (the National Animal Health Monitoring System). The decree pertained to animal health and each year’s decree focused on a different type of livestock. “In 2014, we will focus on Dairy Cattle!” proclaimed APHIS. Thus, the 2014 NAHMS Dairy Study commenced.
Differences between Large and Small Farms
There is much to be gleaned from the findings of the 2014 NAHMS Dairy Study and its offshoot, the 2014- 15 Dairy Calf Study. This article will highlight data related to calf care. Many of the conclusions that can be drawn pertain to all sizes and types of dairies. In general, larger farms (> 500 head) did a better job meeting recommended goals pertaining to calf care, feeding, and management. This is because the larger a dairy gets, the more likely it is the farmer’s only job and source of income—there is no off-farm job to take them away from the cows. Larger farms have a bigger labor force with trained employees, too. Also, being professionals, large dairy operators usually have and pursue continuing education about dairying. Owners of very small dairies (
Some important issues were highlighted by this study—ways we are falling short of implementing research-based Best Management Practices (BMPs) and not achieving optimal calf health, growth, and welfare outcomes. These BMPs are applicable to even the smallest dairies. Calf BMPs are critical to getting the next generation of dairy cattle off to a good start on a long and healthy productive life. Because the NAHMS data revealed we could be doing a better job with colostrum quality, management, and feeding—and colostrum is critical to calf health—this article will focus on colostrum.
Colostrum = Liquid Gold
Colostrum is the first milk produced by a lactating mammal at the start of a new lactation. It is much higher in fat and vitamins than normal milk. It also contains antibodies, which neonates can absorb intact to receive immediate protection from disease. Farm animals need sufficient quantity of high-quality colostrum as soon as possible after birth to provide much-needed calories and passive immunity to disease-causing agents.
Dr. Sandra Gooden, University of Minnesota calf expert, refers to the “5Qs” of colostrum: quality, quantity, quickness, cleanliness, and quantification. We’ll start with quality. The BMP recommendation is to give 150 to 200 grams of immunoglobulin type G (IgG) of colostrum or colostrum replacer per newborn calf. How do you know how much IgG you are giving? First, you have to measure the IgG concentration of the colostrum—this is the measure of quality. High-quality colostrum has at least 50 grams of IgG per liter. Measurement tools include colostrometers (watch a short video at https://www.youtube.com/ watch?v=hGvk9KFTBCE) and Brix refractometers (https://www.youtube.com/watch?v=FlPModu8uzY). High-quality colostrum has a Brix refractometer value >22% or a colostrometer reading in the green zone.
A Brix refractometer is not very expensive, but a veterinarian should be consulted before purchasing one. Select a model with automatic temperature compensation. This tool can also be used to ensure milk replacer or whole milk feedings have the recommended concentration of 12.5% solids, which is 10 to 12% on the Brix scale.
Note that high-quality colostrum cannot be measured by an unaided human eye; “just looking” is of no use. Also, do not make assumptions that older cows produce higher-quality colostrum than heifers—the NAHMS study data refuted that common belief. Along similar lines, just because an individual produced high-quality colostrum one year does not mean she will in subsequent years; many variables come into play every year.
What do you do if colostrum quality is too low? You can supplement the IgG content by adding colostrum replacer or supplement powder until the proper concentration is reached. Lower-quality colostrum can also be fed to two- or three-day-old calves that have already received high-quality colostrum on Day One. A cow’s very first colostrum in a new lactation is the most concentrated in IgG because when milk production starts, it dilutes colostrum.
Figure 1 below depicts data from the NAHMS study and shows that 77% of calves are receiving high quality colostrum, but 23% are not, leaving them at increased risk of disease. Unfortunately, only 53% of farms use any type of method to determine colostrum quality and only 15% use accurate methods (colostrometer or Brix refractometer). We can and should do better than this.
Q #2 pertains to HOW MUCH. The goal (BMP) is to feed 10% of a calf’s weight in high-quality colostrum to each calf within four hours of birth and repeat this feeding so each calf receives a total of 20% of body weight of colostrum in its first 24 hours. For many calves, this amounts to one gallon of colostrum fed ASAP and repeated 12 hours later.
Milk feeding rates are similar: 20% of the calf’s body weight in milk or milk replacer per day, divided into two to four meals. Learn how to measure calf weights accurately to avoid over- or under-feeding.
The NAHMS data tells us we could be doing better in this regard: the amount of colostrum fed at first feeding averaged 3.1 quarts and the total fed in 24 hours averaged 4.7 quarts; we need to increase these amounts to the BMP recommendations for optimal calf health.
As stated before, the goal is to give newborn calves four quarts (or 10% of body weight) of high-quality colostrum within its first four hours (the sooner the better!) and repeat in 12 hours or so for a total of eight quarts (or 20% of body weight) within first 24 hours.
How are we doing with regard to Q #3? Pretty well! The NAHMS study data show us the national average for all farms is 2.8 hours until the first feeding—well within the BMP goal.
Dr. Gooden calls Q #4 “sQueeky Clean”. Calves are babies; we need to feed them clean food. Cleanliness goals include minimizing bacterial loads (Total Plate Count <100,000 colony forming units/ml) and minimizing fecal-origin bacteria (Total Coliform Colonies <10,000 cfu/ml).
It may seem counter-intuitive, but the NAHMS data show larger operations practiced better sanitation practices than smaller farms. The majority of small dairies rinsed milk feeding equipment after each feeding, but the majority of large farms rinsed and disinfected equipment after each feeding. Rinsing alone can leave a milk film on equipment and this is an excellent place for bacteria to grow, endangering the health of young calves.
Successful passive transfer happens when we give enough quality and quantity of colostrum so a calf absorbs a protective amount of IgG antibodies. This form of immunity is immediate but temporary. Eventually, the absorbed antibody levels will decrease to below threshold levels of protection. Fortunately, the calf has been developing active immunity since birth using its own immune system so when maternal protection ceases, the calf will have its own fully-functional system. Indicated vaccinations given at appropriate times will also help calves weather disease risks; consult your veterinarian regarding vaccinations needed.
How do we measure successful passive transfer? We can draw a blood sample on a calf that is 24 to 60 hours old, let the blood coagulate (clot) for 24 hours, and use a pipette to draw off and place a few drops of the serum (see Photo 1) into a refractometer. If using a Serum Total Protein refractometer, the goal is >5.2 g/dl of total protein, which correlates with a protective amount of IgG in the bloodstream. If using a Brix refractometer, the goal is >8.4%. Even higher readings are better, except if they are very high, which could indicate dehydration. Your veterinarian could perform this task for you or help you gain the skills needed. Table 1 shows NAHMS data reporting more routine monitoring of serum protein on large farms vs. small.
Table 1. Percentage of operations that routinely monitored serum proteins as a measure of passive transfer status of newborn heifer calves, and percentage of heifer calves tested on those operations, by herd size.
|Average, all farms|
Failure of Passive Transfer (FPT) is a common underlying cause of poor-doing young calves that fall prey to diseases early in life and never catch up. Identifying >10% of calves with FPT indicates there is a system-wide colostrum problem, usually with either quality, quantity, or timing. Record keeping helps: document date and time of birth for every calf; source of colostrum given; time and amount given; method (bottle or tube); and name of person who fed.
To minimize the risk of colostrum-related diseases:
- Do not feed pooled colostrum to calves. Pooled colostrum is colostrum from multiple cows that has been mixed together; it is a good way to spread disease from one cow to numerous calves.
- Collect colostrum from clean udders using standard sanitary milking protocol. Cool to ≤40°F ASAP if feeding within 3 days; if not, freeze for up to one year.
- Do not borrow trouble, i.e. do not borrow colostrum from a neighboring farm or you may import serious diseases. Thaw frozen colostrum from your own farm using a water bath or use commercial colostrum replacer (not supplement)
- Heat treat all colostrum. This is similar to pateurization, but at a lower temperature to preserve antibodies. To kill pathogens, heat colostrum to between 133 and 135°F for 60 minutes, stirring often and thoroughly.
Odds and Ends
Other actions significantly differed between large and small farms and affected calf health. Only 26% of large dairies fed unpasteurized milk to calves, but 73 % of very small dairies performed this high-risk activity. Large farms fed more milk, fed more often, and fed higher protein milk replacers than smaller farms. Lastly, weaning ages differed greatly: average weaning age on very small farms was 11.6 weeks (37% of very small farms had average weaning ages above 13 weeks) and 8.9 weeks on large farms. As long as calves are healthy, gaining well, and consuming at least two pounds of calf starter grain for several days, earlier weaning decreases labor and feeding costs, which could be more important aggregated costs on larger vs. smaller farms
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