Why Do Dairy Cows Die ? What Can Be Done To Decrease Dairy Cow Deaths ?
Mortality includes that die on farm , either an unassisted death or by euthanasia , but not cows that have the farm to be slaughtered . Mortality is one form of culling , as culling refers to cows exiting the herd for such reasons as sale , slaughter , unassisted death or euthanasia ( Fetrow et al 2006 ) . Mortality rates in the dairy industry are much higher than those in the cow/calf or feedlot industries . Death losses have not been studied very intensively in the dairy industry . Estimates of these death losses are quite variable , unless they are focused on monitoring cow deaths , dairy producers may underestimate the amount of adult cow death loss on their operations . The USDA; APHIS;VS National Animal Health Monitoring System ( NAHMS) , Dairy 2007 survey reported that 5.7% of dairy cows die on - farm across the country each year , an increase from 4.8% of the January 2002 inventory and 3.8% of the January 1996 inventory . These rising mortality levels represent a problem both in terms of financial losses and compromised animal welfare . Adult cow death losses appear to be attributable to reasons similar to those for culling cows . A recent literature review identified 19 studies between the years 1965 and 2006 that focused on dairy cow mortality in countries with relatively intensive dairy production . While 10 of 19 studies provided information about cause of death none of the diagnoses were founded on necropsy evaluation . Only a single study discriminated between cows that were euthanized or died unassisted .
Recorded causes of death were relatively uniform across studies and were categorized as : accidents , calving disorders , digestive disorders , locomotor disorders , metabolic disorders udder/ teat disorders other known reasons and unknown reasons . Most dairy veterinarians focus considerable effort on dairy reproduction , but little time on mortality evaluation . This presents a very significant liability to the dairy industry because efforts to effectively decrease mortality losses are hampered by a lack of monitoring and information that provide accurate assessment of the problem .
Dairy workers could be trained to more effectively monitor death losses ad to perform on - farm necropsyexaminations in consultation with veterinarians when the veterinarian can not be present to perform the examination on a freshly dead carecasses , necropsy information needs to be combined with other historical information about the affected animals to help direct management changes . Some studies suggest that at least 50% of cow death losses are attributable to causes that could be mitigated with proper management . Because of the complex nature of dairy management systems a variety of causes are responsible for high disease and mortality rates with different rates of occurrence on different operations .
To adequately address such as complex problem ( Metritis , Mastitis , Lameness etc......) requires more accurate information about current losses followed by management alterations that address the underlying problems . This will require changing the nature of information used in dairy management systems , for example : ( Mastitis Prevalence ) . ( Franklyn Garry Colorado State University - ExtenSion 2011 ) . Recently published studied showed increasing trends in dairy cow mortality in the United State and in other countries . Mortality is the primary reason of cows leaving the herd various herd and cow level factors have been associated to the rise in mortality over the last couple of decades .Two common measures are used in describing mortality 9 thrusfield 1999) . Mortality Rate : The number of deaths ( ie. unassisted death and euthanasia ) in a population per unit of animal - time during a given period . Mortality risk : The number of deaths during a given time period divided by the population of risk at the beginning of the period .
Risk Factors of Dairy Cow Mortality : Most of the studies focusing on dairy cow mortality , mainly described on - farm mortality relative to population characteristics and only few studies investigated the risk factors of dairy cow mortality ( Raboisson et al 2011) . Similarly , Alvason et al 2012 ) reported that the associations between on - farm mortality and herd level characteristics have been extensively studied The factors influencing the on - farm cow mortality can be categorized into two groups : Herd Level Risk Factor: ( Indicative of management Style ) and Cows Level Risk Factors: ( Cow's own characteristics ) . Herd level risk factors : Increasing herd size has been consistently reported as one of the risk factor for increased mortality ( Norgaard et al 1999 - Thomsen et al 2006 - Alvasen et al 2012 ) . Increased length in herd calving interval has been associated with increased mortality among dairy cows . Alvasen et al ( 2012) observed that the risk of mortality was 22% higher in herds with relatively larger calving interval ( average calving interval > 422 days compared with herds with smaller calving interval ( average calving interval = 389.3 days ) . Likewise , Raboisson et al -2011 - reported a +1% change in cow mortality for every 10 days increase in calving interval . Access to pasture for grazing has been associated with decreased dairy cow mortality ( Thomsen et al 2006 - Alvasen et al 2012 ) . Lower annual live culling rate and culling fewer cows in early lactation has also been associated with increased mortality ( Mc Connel et al 2008 - Pinedo et a 2010 - Raboisson et al 2011 ) .
In consistent association have been reported between mortality and housing systems . In a large Danish study ( n= 6.839 herds ), Thomsen et al 2006 - documented that the risk of mortality was lower in loose housing barns with deep litter than barns with free - stalls or tie - stall . Increasing herd level somatic cell score has been associated with increased on farm mortality ( Thomsen et al 2006 - Burow et al 2011 ) .
Thomsen et al reported (2006) a 16% increase in the risk of mortality for every 100.000 cell/ml increase in herds average somatic cell count . Some other management factors have also been associated with increased mortality . A couple of studies indicated that cow mortality was lower in organic herds compared to conventional herds (Thomsen et al 2006- Alvason et al 2012 ) . The herds with higher proportion of family labor ( 100% ) had lower mean mortality rate ( 4.0 %) compared to herds with lower proportion of family labor ( < 66%) with a mortality rate of 5.6% ( Dechow et al 2011 ) . The herds with higher prevalence of lameness , respiratory problems and with more antibiotic use had higher mortality ( McConnel et al 2008 ) . Regional differences in dairy cow mortality have also been observed ( Smith et al 2000 - Alvasen 2012 ) . Indicating that local physical environment , nutrition and management could play a role in dairy cow mortality ( McConnel et al 2008 ) .
Cow Level Risk Factors : Cows producing more milk than their herd's mate seemed to have lower mortality . Pinedo et al 2010 reported that the annualized mortality rate was lower ( 2.7% ) in cows with cow - relative 305 ME Milk Yield > 2.187 kg than the cows with cow relative 305 ME Milk Yield < 2.313kg with annual mortality rate of 9.9% . The early lactation period has been reported the highest risk period for mortality in dairy cows . The period before and after calving ( Transition Period ) in a high - risk period for many disease (Shanks et al 1981- Markusfeld 1993) . The study indicate that the mortality rates differ between the breeds . Alvasen et al 2012 - reported that herd's with Swedish Holstein had 22% and 10% higher risk of mortality compared to herds with Swedish Red and with mixed breeds ( crossbred , Swedish polled and Swedish Jersey ) respectively . Heins et al 2012 - reported that Holstein cows had higher mortality ( 5.3% ) compared to crossbred cows ( 17% ) during the first 305 Days of the first lactation ( M .Q Shahid _ University of Minnesota - 2013) .
Recent studies presented at the 2008 annual American Dairy Science Association meeting or published in the Journal of Dairy Science investigated risk factors associated with dairy cow mortality in the United States Penn State University researchers summarized the association of mortality and 60 - day culling rates with various housing and management systems . Mortality rate was lower in Tie - Stall Herds ( 3.3% ) than in Freestall Herds ( 4.9% ) . The most optimal herd environment in their study - Tie - stall , component feeding with pasture access - had mortality rate of 5.3% whereas the least optimal environment - freestall use of TMR no outdoor access - had 6.3% and 9.1 % respectively . Regarding a cow as an individual rather than only focusing on groups could help reduce some of the problems leading to high mortality in our dairy operations . Look at and see each animal , and treat them early . ( Marcia - Endres - Associated Professor Dairy Science University of Minnesota 2011 -DeLaval) .
Nowadays Farmers , Veterinarians remember Morbidity and Mortality outbreak of Cattle Plague Disease ( Rinderpest ) on 1900's AD . The World Organization for Animal Health ( OIE ) was formed in response to Rinderpest and in October 2010 the FAO announced that it was confident the disease has been
eradicated .Numerous contagious disease with high mortality have been eradicated and controlled by veterinary officers and veterinarians such as Tuberculosis , Brucellosis , FMD Clostridial Disease such as Blackleg , Anthrax , Tetanus , Malignant Oedema , Red Water Disease , Sudden Death &.......... by vaccinations , hygiene condition , management etc ..... But unfortunately some of nature disasters are now a cause of cows death in the world .
(A) = 50 Head of cattle die from mysterious disease in one week ( Bulawayo 15.Dec .2013 ) .(B) = Lightning kills 32 cows , leaving them " Piled on top of each other " ( USA To DAY - May .1 . 2017 ) ( Jackie Rehwold Springfield ) .
A Veterinarian confirmed the cows had been struck by lightning .(C) = Dehydration suspected after 200 cattle found dead in SouthWest Saskatchewan : About 200 cattle have been found dead on pasture in Southwest
Saskatchewan , the dead cows and calves were on Crown pasture land south of the community of Chaplin , which was operated and leasted out by 31 patrons , the animals were discovered Friday , Saskatchewan Chief Veterinary Officer , Dr . Betty . Althouse says preliminary necropolis and test results show the animals died of Dehydration and possibily salt toxicity . One water source on the pasture is a dugout , which may have become unsuitable for livestock due to evaporation and increased concentration of salt in the water . ( The Canadian Press , CTV NEWS , Monday July .10 . 2017 ) .
(D) = Up to 1.00.000 cattle dead in South Dakota Blizzard Tens of Thousands of Cattle Feared Dead after South Dakota Storm . The Storm was just so sudden , South Dakota cattle rancher Kathy Jabgen remembers . A freezing rain , followed by an avalanche of four feet of snow and winds of the 70 miles an hour , hit thousands of cattle still grazing on " Summer pastures " at a time when the animals had not yet grown their protective winter coats were ill prepared for the harsh conditions .
