By Michal Lunak
Replacing dairy cows in the dairy herd is a major cost for the operation. The 2018 USDA/NAHMS Health and Management Practices on U.S. Dairy Operations reported that the average cow removal rate in the Northeastern U.S. was 31.4 percent plus a 6.2 percent cow death rate for a total of 37.6 percent cows permanently removed from herds per year.
Cows removed from the dairy herd for biological reasons comprised 73.2 percent of the total removal rate (2018 USDA/NAHMS Report). Considering the cows population of 9.4 million (ERS/USDA, 2021), average removal rate, and incidence of diseases, over 2.3 million cows were removed from dairy herds annually due to management diseases that can be largely prevented or reduced.
The most common management diseases that occur during the cow’s transition period on US dairies are lameness, mastitis, retained placenta, metritis, ketosis, hypocalcemia, and left-displaced abomasum. Some of these diseases have a small effect on the biological removal rate or are not reasons for removal from the herd at all. Although these cows are kept in the herd, they incur costs for the treatment and their future performance is diminished.
The following table summarizes financial losses per incidence for the most common transition period diseases on US dairies that are discussed in this article.
Table 1. Financial loses per incidence caused by common transition period diseases in dairy cows.
Transition period disease | Losses per case ($) |
---|
Left-displaced abomasum (LDA) | 432 - 639 |
Mastitis | 325 - 457 |
Retained placenta (RP) | 150 - 389 |
Metritis | 171 - 386 |
Lameness | 120 - 333 |
Hypocalcemia | 246 – 300 |
Ketosis | 111 - 232 |
The losses estimated in Table 1 consist of direct and indirect costs. The direct costs are expenditures including veterinarian's and manager's labor, medications, and supplies. The indirect costs or losses that occur include non-saleable milk, reduced milk production, reduced reproductive performance, increased risk of culling, incidence of other diseases, and reduced animal welfare.
Left-Displaced Abomasum (LDA) - appears when the abomasum is filled with gas and subsequently trapped by the descending rumen to the left side of the abdominal cavity.
Left-displaced abomasum is the predominant type of displaced abomasum in the US. Most of the LDAs occur within 30 days after calving (80 to 90 percent), and 52 to 86 percent within two weeks after calving (Shaver, 2019).
Even though relatively small number of cows are removed from the herd (1-3 percent, depending on the herd size) due to LDA, in the Northeast it was the most expensive management disease per incidence (Table 1.)
Two decades ago, the costs of LDA were estimated at a range of $250 to $400, depending on whether surgery was needed (Geishauser et al., 2000). Recent research indicates that the cost of a clinical case increased about 50 percent, ranging between $432 for primiparous and $639 for multiparous cows (Liang et al., 2017)
Prevention and control should start in previous lactation when cows enter dry off period. Proper body condition score monitoring, prevention of other metabolic diseases, sufficient feed bunk space, dry matter intake, and proper particle size length are all important for prevention of LDAs.
Mastitis - or inflammation of the mammary gland, is the most common management disease on dairy farms. In fact, it is the top biological reason to remove cows from the herd. On average, 18.6 percent of cows leave the herd annually due to udder infection making it the second most costly management disease (Table 1.)
Rollin at al. (2015) estimated the direct cost of mastitis of $100 for primiparous cows and $146 for multiparous cows, and the indirect cost of $333 and $305 for primiparous and multiparous cows, respectively.
Liang at al. (2017) reported the total cost of clinical case of mastitis was $325 for primiparous, and $426 for multiparous cows. The largest indirect cost was decreased milk production, $162 and $165 per primiparous and multiparous cows, respectively. Of the total costs, veterinary ($77) and costs of discarded milk ($53 and $65 for primiparous and multiparous cows, respectively) were the largest direct cost.
Prevention and control of mastitis includes following correct milking procedures, using dry cow treatment, and a clean, stress-free environment for cows. Consult nutritionists regarding micronutrient supplements to boost the cow’s immune system.
Retained Placenta (RP) – is a condition where all or part of the placenta or membranes are left behind in the uterus 24 hours or later after parturition. It is widely considered to be a predisposing factor for metritis. The prevalence among dairy cows ranges from 5 to 15 percent (Gilbert, 2015).
Recently, Gohary (2018) estimated the cost of a single case of RP at $389. The largest portion of the estimate was reduction in milk yield, $287, increased time until pregnancy, $73 and increased disease risk, $25. Another research study showed the difference of RP costs between primiparous ($150) and multiparous ($313) cows (Liang, 2017).
Prevention and control of RP includes proper nutrition during the transition period, including adequate intake of selenium, and vitamin E. Retained placenta is commonly associated with hypocalcemia.
Metritis - is an inflammation of the uterus caused by a bacterial infection. LeBlanc et al. (2011 estimated that 10 to 20 percent of dairy cows are affected by metritis, but Duboc et al. (2011) reported that dairy herds can experience prevalence of up to 47 percent. The costs of metritis to the dairy industry were estimated from $665 to $900 million (Jeon, 2018; Overton and Fetrow 2008), primarily from declines in fertility (Overton and Fetrow, 2008).
Overton and Fetrow (2008) reported that a case of metritis costs between $330 and $386 depending on the therapy used and discarded milk. This estimate also includes extra breedings. Liang et al. (2017) estimated that a single clinical case of metritis costs $171 and $262 for primiparous and multiparous cows, respectively.
Prevention and control of metritis includes maintaining cleanliness of the calving area as well as working with your nutritionist to ensure proper rations for adequate intake of nutrients and good feeding management on the farm.
Cleanliness of the calving area is critically important. The exposure to bacteria of both the cow and the calf in the calving environment will affect the health of both.
Lameness - is a foot or leg condition caused by laminitis, claw disease, digital dermatitis, or foot rot. It is one of the top reasons cows are removed for biological reasons from dairy herds. The 2018 USDA/NAHMS reported that 9.1 percent cows left the herd due to lameness - the third highest cause for removal after infertility and udder infections. Several studies reported the prevalence of lameness on US dairies as low as 13 percent and as high as 55 percent (Adams et al. 2017, Von Keyserlingk, 2012).
Cha et al. (2010) used dynamic programming to estimate the mean cost per case of lameness at $177 with a range of $120 to $216 for different lameness types. Another researcher reported the cost of lameness at $185 and $333 per primiparous and multiparous cows, respectively, (Liang et al. 2017)
Prevention and control of lameness includes good herd hygiene and management, prevention of infectious and non-infectious lesions, regular use of footbaths, consistent hoof trimming, elimination of slippery walking surfaces, and good nutrition.
Hypocalcemia - or milk fever, is low plasma calcium shortly after parturition and is a result of clinical hypocalcemia. Hypocalcemia was not major reason for removal of cows from the herd - 0.1 to 0.4 percent of cows (USDA/NAHMS, 2018).
However, hypocalcemia is widely spread among dairies. It affects 25 to 40 percent of primiparous and 45 to 80 percent multiparous cows (Brown, 2018). Such a high prevalence would suggest that there is a lot of lost opportunity and a lot of additional cost in treatment.
Financial losses for a clinical case of hypocalcemia for multiparous cows were estimated from $246 (Liang et al. 2017) and up to $300 (Brown, 2018). Treatment for subclinical hypocalcemia was estimated at $125 per case (Brooks, 2020).
Prevention and control of hypocalcemia generally occurs through modifications to the pre-fresh or close-up diet. Consult with your nutritionist about incorporating low calcium or potassium diets or feeding anionic salts for 21 days pre-fresh.
Ketosis - also known as acetonemia or ketonemia, is a metabolic disorder caused by negative energy balance typically within a few weeks of calving. Ketosis was not the top reason for cow removal from the herd (1.1 percent), and it was the least costly disorder (Table 1); however, ketosis can result in higher incidence of other metabolic disorder increasing the costs considerably.
Guard (2008) estimated the total ketosis cost at $232 per case, including $5 for the treatment.
McArt et al. (2015) reported that the cost per case of ketosis was $134 and $111 for primiparous and multiparous cows, respectively; with the average cost per case of $117.
Most of the costs were attributed to future reproductive losses (34 percent), death losses (26 percent), and future milk production losses (26 percent). However, when the costs related to ketosis-attributable displaced abomasum and metritis cases were accounted for, the total cost estimate per case of ketosis more than doubled to $375 and $256 for primiparous and multiparous animals, respectively; with the average total cost per case of $289.
Gohary et al. (2015) reported the cost of $203 per a case of subclinical ketosis in Canadian dairy herds. Liang et al. (2017) reported $77.00 for primiparous and $180.91 for multiparous cows per clinical case of ketosis.
Prevention and control of ketosis includes maintaining good management practices such as: feeding good quality forage and balanced diets, minimizing stress, monitoring body condition at dry off and calving, and eliminating factors that reduce dry matter intake. Some feed additives, including niacin, calcium propionate, sodium propionate, propylene glycol, and rumen-protected choline, may help prevent and manage ketosis
Why is Prevention Important?
Prevention is much cheaper than treatment. Cows diagnosed and successfully treated for transition disorders still have decreased performance for current and future lactations. Cow treatment is expensive, but the indirect costs associated with these disorders are often higher than the treatment itself.
For example, veterinary and labor cost for a single incident of ketosis was $64, which is 35 percent of the total cost per incidence for multiparous cows. Similarly for a single case of RP, where veterinary and labor costs were 31 percent of total costs ($96 of $313) for multiparous cows (Liang, et all. 2017).
Those indirect costs negatively affect future performance of the cow, including reproduction, milk production, animal welfare, and biological removal from the herd. As a result, they slowly and silently reduce farm profits.
These disorders occur during the transition period – three weeks before and three weeks after parturition which is a critical time in the cows’ life.
Often, one disorder increases the risk for another one, and good management practices can help to prevent these costly diseases. For example, cows with a single incidence of hypocalcemia also have a chance of increase incidence of retained placentas and metritis, LDA, and ketosis (Brown, 2018).
When reviewing your monthly DHI herd summary, check the 'Yearly Summary of Cows Entered and Left the Herd' table for how many cows were removed for biological reasons from the herd related to these management disorders. If those numbers are high, check your records to determine the reason for biological removal. Contact your nutritionist, veterinarian, and/or Penn State Extension Educator to review some of the herd’s management practices. Spending time preventing these costly transition diseases will have a long-term economic benefit.
Source : psu.edu