Cow Mortality Research Articles

Embryonic and Fetal Mortality in Dairy Cows: Incidence, Relevance, and Diagnosis Approach in Field Conditions

Pregnancy loss (PL) in dairy cattle results in animal health and welfare disruption and has a great economic impact on farms, with decreases in fertility and increased culling. It can occur at any stage of embryonic or fetal development. Abortion occurring from the second half of pregnancy has a more negative impact on dairy farms. There are several infectious and non-infectious factors that can lead to PL and vary according embryonic or fetal stages. As this is a multifactorial or multi-etiological occurrence, it is important to identify the risk factors and the best diagnostic tools to approach these reproductive losses that can occur sporadically or by outbreaks. Reaching a final diagnosis can be challenging, especially when it occurs at a very early stage of pregnancy, where losses may not be detected and neonatal deaths may be related to alterations in the fetus in utero. Also, laboratorial results from animal samples should be interpreted according to the full clinical approach. This review aimed to highlight all these essential aspects, identifying the main infectious and non-infectious causes leading to PL, as well as the best veterinary practices for diagnosing it, mainly through transrectal palpation, ultrasound, and laboratory methods, in bovine dairy farms.

A first insight into seropositivity of Neospora caninum and associated risk factors in free-roaming dogs from Ecuador

Neosporosis is a worldwide parasitic disease caused by the protozoan Neospora caninum. It can cause economic losses to farmers due to its relationship with abortions and neonatal mortality in cows. Dogs play a key role in its spread as they are considered definitive hosts. In this study, we determined for the first time the seropositivity of N. caninum infection in dogs from Ecuador and evaluated potential risk factors. A total number of 339 free-roaming dogs from the three main regions of Ecuador (Coastal, Andean, and Amazonian regions) were included in the study and classified either as urban or rural dogs. Serum samples were collected from November 2018 to May 2019, and analyzed with a commercial ELISA test. An overall seropositivity of 6.8 % (CI: 95 %, 2.8 % – 11.7 %) was found in N. caninum infection with no statistical differences among regions or urban/rural dogs. This is the first surveillance of N. caninum in Ecuador, confirming a country-wide distribution of this pathogen. Considering the large populations of free-roaming dogs in Ecuador, a One Health approach for surveillance and managing N. caninum in dogs is needed to protect either livestock or wildlife.

Financial Performance of Dairy Cooveratives in West Java-Indonesia During the Covid-19 Pandemic and Foot-and-Mouth Disease Outbreak

Dairy cooperatives play an important role to collect milk production from dairy farmers, distribution of milk to the milk processing industry, concentrate supply services, credit guarantees, artificial insemination and animal health services, savings and loan services, and various other services carried out by cooperatives. This condition causes the dependence of dairy farmers on cooperatives to be quite high. External factors can influence cooperative resilience, such as the Covid-19 pandemic and Foot-and-Mouth Disease (FMD). Therefore, the purpose of this study was to analyze the performance of cooperative milk production, and to the financial performance of cooperatives in the post-pandem Covid-19 period and during FMD. The method used in this study was a survey method to KPBS Pangalengan which represents large cooperatives, KSU Tandangsari which represents medium-sized cooperatives, and KPS Bogor which represents small cooperatives. The analysis method used standard cooperative performance methods through regulations of the Deputy for Supervision of the Ministry of Cooperatives and Small and Medium Enterprises (KUKM) of the Republic of Indonesia Number 06/Per/Dep.6/IV/2016 and key perfomance index to assess the financial performance of cooperatives. The results of the study showed that the performance of cooperative milk production decreased by 19.45% during the Covid-19 pandemic to the FMD as a result of the dairy cow mortality rate of 20.14%. The financial performance of dairy cow cooperatives was in the adequate category, both during the Covid-19 pandemic and FMD, but there was a decline in the ratio in all aspects of financial performance during the FMD. Thus, the performance of milk production and the financial performance of dairy cooperatives was better during the Covid-19 pandemic than during the FMD period. Therefore, strengthening milk production by providing new dairy cows and strengthening finances is very important

Invited Review: Increasing Milk Yield and Negative Energy Balance: A Gordian Knot for Dairy Cows?

The continued increase in milk production during the last century has not been accompanied by an adequate dry matter intake (DMI) by cows, which therefore experience a negative energy balance (NEB). NEB is low and of minor importance at low milk yield (MY), such as for the nutrition of one calf, and under these circumstances is considered "natural". MY and low DMI around parturition are correlated and are the reason for the genetic correlation between increasing MY and increasing NEB up to 2000 MJ or more for 2-3 months postpartum in high-genetic-merit dairy cows. The extension and duration of NEB in high-producing cows cannot be judged as "natural" and are compensated by the mobilization of nutrients, particularly of fat. The released non-esterified fatty acids (NEFAs) overwhelm the metabolic capacity of the cow and lead to the ectopic deposition of NEFAs as triglycerides (TGs) in the liver. The subsequent lipidosis and the concomitant hampered liver functions cause subclinical and clinical ketosis, both of which are associated with "production diseases", including oxidative and endoplasmatic stress, inflammation and immunosuppression. These metabolic alterations are regulated by homeorhesis, with the priority of the physiological function of milk production. The prioritization of one function, namely, milk yield, possibly results in restrictions in other physiological (health) functions under conditions of limited resources (NEB). The hormonal framework for this metabolic environment is the high concentration of growth hormone (GH), the low concentration of insulin in connection with GH-dependent insulin resistance and the low concentration of IGF-1, the so-called GH-IGF-1 axis. The fine tuning of the GH-IGF-1 axis is uncoupled because the expression of the growth hormone receptor (GHR-1A) in the liver is reduced with increasing MY. The uncoupled GH-IGF-1 axis is a serious impairment for the GH-dependent stimulation of gluconeogenesis in the liver with continued increased lipolysis in fat tissue. It facilitates the pathogenesis of lipidosis with ketosis and, secondarily, "production diseases". Unfortunately, MY is still increasing at inadequate DMI with increasing NEB and elevated NEFA and beta-hydroxybutyric acid concentrations under conditions of low glucose, thereby adding health risks. The high incidences of diseases and of early culling and mortality in dairy cows are well documented and cause severe economic problems with a waste of resources and a challenge to the environment. Moreover, the growing public concerns about such production conditions in agriculture can no longer be ignored.

Genetic parameters and evaluation of mortality and slaughter rate in Holstein and Jersey cows

The longevity of dairy cattle has economic, animal welfare, and health implications and is influenced by the frequency of mortality on the farm and sale for slaughter. In this study cows removed from the herd due to death or slaughter during the lactation were coded 1 and cows that were not terminated were coded 0. Genetic parameters for mortality rates (MR) and slaughter rates (SR) were estimated for Holstein (H) and Jersey (J) breeds by applying both linear (LM) and threshold (TM) sire models using about 1.2 million H and 2,860,000 J cows. Estimated breeding values (EBV) for MR and SR were predicted using animal models to assess the opportunity for selection and genetic trends. Cow termination data, recorded between 1990 and 2020 on a voluntary basis by Australian dairy farmers, were analyzed. Cow MR has increased from below 1% in the 1990s to 4.1% and 3.6% in H and J cows, respectively. Most dead cows (~36%) left the herd before 120 d of lactation, while cows that were slaughtered left the herd toward the end of the lactation. Using the LM, heritability (h2) estimates for MR were lower (1%) than those for SR (2%-3.5%). When h2 were estimated using a TM, the estimates for both traits varied between 4% and 20%, suggesting that the difference in incidence level is one of the reasons for the difference in the h2 values between MR and SR. Early test-day milk yield (MY) and 305-d MY (305-d MY) have unfavorable genetic correlations (0.32-0.41) with MR in both breeds. The genetic correlations of calving interval with MR were stronger (0.54 to 0.68) than with SR (0.28-0.45) suggesting that poor fertility can serve as an early indicator of poor cow health that may lead to increased risk of death. High early test-day somatic cell count is genetically associated with increased likelihood of slaughter (0.24-0.46), but not with increased likelihood of death. In H, 305-d protein yield (PY) had the strongest genetic correlation (-0.34--0.40) with SR whereas in J, both 305-d PY and Fat yield showed high genetic (-0.64--0.70) and moderate environmental (-0.35--0.37) correlations with SR. The genetic correlation of removal from the herd due to death and slaughter was negative (-0.3) in J and zero in H. Strong selection for improved fertility and survival and less selection emphasis for MY, has led to an improvement in the genetic trend for cow MR in H and the trend in J has stabilized. Although genetic evaluations for cow MR are feasible, the reliabilities of the EBV are low and the level of cow MR in Australia are relatively low compared with similar countries. Therefore, genetic evaluation for survival based on mortality and slaughter data could be sufficient in the current selection circumstances where breeding objectives are broadly defined. Nevertheless, all Australian farmers should be encouraged to continue recording mortality and slaughter data for monitoring of the trends and for future development of genetic evaluations.

High risk of dairy cow mortality in early lactation.

On-farm mortality among dairy cows constitutes a major problem in modern dairy production. Detailed knowledge about when cows die may help guide the prevention of future deaths. Data from 46,927 on-farm dairy cow deaths reported to the Danish Cattle Database were analysed to evaluate the distribution of deaths in relation to time after calving and the effect of parity and breed. Of all on-farm deaths, 15.2% occurred within 7 days after calving, 32.2% within 30 days and 49.4% within 90 days. Older cows generally died sooner after calving compared to younger cows, and Jersey cows died later than other breeds. The results are based on a large and reliable dataset but include only data from Danish dairy cows. The distribution of on-farm deaths was very uneven, with a large proportion of deaths occurring during the first few weeks after calving, especially in older cows.

Case report on an outbreak of theileriosis in a dairy herd: Could it be a co-infection of a virulent strain of Theileria mutans with Theileria parva?

This case report aimed to alert veterinarians of the possibility of simultaneous infections with more than one Theileria species in cattle herds in Zimbabwe. Cows (N=7) and a postmortem specimen from a dairy farm located in Chivhu, Mashonaland East province, Zimbabwe were presented for clinical and postmortem examination, respectively. On history taking, the herd had a decrease in milk yield and high cow mortalities. The presented live animals had a heavy tick burden and were febrile and lethargic. Post-mortem findings revealed strong evidence suggestive of theileriosis. Theileria schizonts and piroplasms were identified in stained lymph node aspirate, impression, and blood smears. The herd was managed using tetracyclines and buparvaquone together with an intensive dipping protocol until deaths had stopped. Both the clinical and postmortem findings were strongly suggestive of the possibility of a simultaneous infection with more than one Theileria species in this herd. Thus, these finding highlight the need to characterise the Theileria species profile in Zimbabwe.

Late embryo mortality in Holstein cows inseminated with Holstein or Limousine frozen semen.

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO × HO) or Limousine semen (HO × LM), to compare pregnancy loss from 28 to 35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO × HO embryo vs. HO × LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO × HO embryos had greater LEM (15.16%) than HO × LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; yet, within no-summertime, LEM (%) was higher in HO × HO than HO × LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO × HO than in the HO × LM (p= .023) group; yet, the concentration of P4 was not different between groups (p> .05).

Necropsy-based study on dairy cow mortality—Underlying causes of death

The worldwide problem of increasing dairy cow mortality is widespread in modern production systems, it causes economic losses, and indicates problems with herd health and welfare. Most studies on causes of dairy cow mortality are limited as they are based on secondary register data, or questionnaires for producers or veterinarians, and neither necropsies nor histopathologic analyses are usually performed. For this reason, no definite causes for dairy cow deaths have been determined making it difficult or impossible to implement effective preventive measures. The objectives of this study were to (1) determine the causes of on-farm mortality of Finnish dairy cows, (2) determine the usefulness of routine histopathologic analysis in bovine necropsies, and (3) assess how reliable producers' perception about the cause of death is. Underlying diagnoses of on-farm deaths were determined through necropsy of 319 dairy cows at an incineration plant. The necropsy data were combined with background information obtained from online questionnaires covering cow and herd records. Mastitis was the most common underlying diagnosis of death (26.6%), followed by digestive disorders (15.4%), other known disorders (13.8%), calving-associated disorders (12.2%), and locomotion disorders (11.9%). The underlying diagnoses of death varied during different stages of lactation and with parity. A large proportion of the study cows (46.7%) died during the first 30 d after calving, and of those, 63.6% died during the first 5 d. A routine histopathologic analysis was performed in every necropsy, and it changed the preliminary gross diagnosis in 18.2% of the cases. Producers' perception about the cause of death agreed with the necropsy-based underlying diagnosis of death in 42.8% of the cases. It was most consistent for mastitis, calving disorders, locomotion diseases, and accidents. In cases where producers had no insights about the cause of death, necropsy revealed the final underlying diagnosis in 88.2% of cases, demonstrating the usefulness of necropsy. Based on our findings, necropsies provide useful and reliable information to develop control programs for cow mortality. Including routine histopathologic analysis in necropsies, more accurate information may be obtained. Furthermore, targeting preventive measures on transitional cows may be most effective, as the number of deaths was highest at this time.

Genetic and Genomic Analysis of Cow Mortality in the Israeli Holstein Population

"Livability" was defined as the inverse of the probability of death. The objectives of this study were to estimate the heritability, genetic and phenotypic trends for the livability of Israeli Holstein cows; estimate the genetic and environmental correlations between livability and the nine traits included in the Israeli breeding index; estimate the effect of the inclusion of livability in the Israeli breeding index on expected genetic gains; and compute a genome-wide association study (GWAS) for livability. Seven data sets were analyzed. All data were derived from the database of the Israeli dairy cattle herd-book. The mean livability for the complete data set of 523,954 cows born from 2000 through 2016 was 89.6%. Pregnancy reduced livability by 15%. Livability generally increased with parity and days in milk within parity. Heritability of livability was 0.0082. Phenotypic and genetic trends over the 14-year period from 2000 through 2013 were -0.42% and -0.22% per year. If livability is included in the Israeli breeding index, accounting for 9% of the index, livability would increase by 1.3% and protein production would decrease by 11 kg over the next decade, as compared to the current index. A marker in proximity to the oxytocin-vasopressin locus had the greatest effect in the GWAS. Oxytocin activity in cattle affects calving-associated pathologies and maternal death. Inclusion of livability in the Israeli breeding index is not recommended.

An investigation into potential genetic predictors of birth weight in tropically adapted beef cattle in northern Australia

Context Birth weight can be an important trait in beef cattle through its association with dystocia and increased likelihood of calf and cow mortality. Recording large numbers of birth weights in beef cattle to obtain a suitable genetic evaluation has often been hard to achieve. Aims We assess if coronet circumference measurements taken at birth and weights and coronet circumference measured post-birth are suitable predictors of birth weight for use in genetic evaluation in northern Australian tropically adapted beef breeds. Methods Animals were recorded at birth for weight (N = 5352) and coronet circumference (N = 2552), at 3 months of age for the liveweight (N = 2848) and coronet circumference (N = 2855) and liveweight at 6 months (N = 4929). Data were from three tropically adapted beef cattle breeds (viz. Brahman, Droughtmaster and Santa Gertrudis) recorded in two northern Australia herds. Genetic parameters were estimated from a pooled dataset containing all three breeds. Results Birth weight had an estimated direct and maternal heritability of 0.51 (0.04) and 0.14 (0.02) respectively. Coronet circumference also had high heritabilities, with estimates at birth and 3 months of 0.50 (0.07) and 0.55 (0.06) respectively. The estimated genetic correlation between birth weight and coronet circumference measured at birth was 0.86 (0.03). Birth weight genetic correlations were 0.75 (0.05) with 3-month weight, 0.69 (0.05) with weaning weight and 0.62 (0.05) with coronet circumference at 3 months. Conclusions Coronet measurements could be used in genetic evaluation as a proxy for birth weight. However, the most useful coronet measure was when it was recorded at birth. This would still require catching the calf at birth, thus greatly reducing the benefit of having an alternative measure. Coronet circumference recorded in the branding cradle at 3 months of age was also a useful predictor of birth weight but added little if post-birth weights were available. Importantly, all post-birth indirect measures of birth weight require adjustment for animal age and, therefore, would need recording of the individual calf’s date of birth. Implications Coronet circumference recorded at birth and 3 months of age does not appear to be a suitable proxy for genetic evaluation of birth weight.

Mortality and culling of adult dairy cows in Jordan: A 3-year study (2016-2018) based on a single intensively managed dairy farm.

Dairy cow mortality and culling are important parameters reflecting on cow health, productivity, and welfare as well as important determinants of herd sustainability, growth, and profitability. There are no published reports on the causes and rates of mortality and culling of dairy cows in Jordan. Therefore, the objectives of this study were to determine the most common causes and rates of mortality and culling of adult dairy cows in Jordan using a single well-managed dairy farm as a model over 3 years. Data extracted from the farm management record software over 3 years (January 2016-December 2018) were used in this study. Cow-specific data included the date and month of sale, death or euthanasia, age, parity, reproductive status, and daily milk yield. Cow health-specific data included physical examination findings, presumptive diagnosis, medical or surgical treatments, postmortem findings, and any available laboratory findings. Descriptive analysis was performed to determine means (± standard deviation) and frequencies of various variables using Excel Spreadsheets of Microsoft Word 10. The 3-year rolling cow population in the farm used in the study was 500 ± 35. The overall mortality and culling rates were 5.9% and 28.5%, respectively. The mean age of died and culled cows was 3 ± 1.2 and 4 ± 1.5 years, respectively. The mortality rates were highest in the colder months (January through April). The most frequent causes of mortality were infectious diseases (28%), followed by non-infectious gastrointestinal diseases (25%), udder and teat diseases (mastitis 22%), and other diseases/accidents (25%). Of the infectious diseases, the most frequently diagnosed were enterotoxemia (12%), tuberculosis (TB) (8%), enteric salmonellosis (7%), and paratuberculosis (1%). The most frequently diagnosed non-infectious gastrointestinal diseases were traumatic reticulitis (11%), vagal indigestion (9%), and abomasal ulcer (5%). The most frequently diagnosed diseases causing mortality involving other body systems were reproductive diseases (acute puerperal metritis 6%), respiratory diseases (pneumonia 5% and pulmonary embolism 1%), metabolic diseases (fatty liver 3%), musculoskeletal diseases (septic arthritis 3% and downer cow syndrome 4%), neurologic diseases (unspecified causes 2%), and finally accidents (electrocution 1%). The most frequent causes of culling were old age/low milk production (39%), followed by the poor reproductive performance (31%), diseases/accidents (24%), and unidentified causes (6%). The most frequent diseases/accidents causing culling were udder diseases (mastitis 32%), followed by non-infectious gastrointestinal diseases (28%) (vagal indigestion [15%], rumen tympany [7%], and abomasal ulcer [6%]), musculoskeletal diseases (23%) (foot and claw diseases [7%], downer cow syndrome [7%], hip luxation [5%], septic arthritis [2%], and gastrocnemius rupture [2%]), respiratory diseases (pneumonia 10%), and finally infectious diseases (9%) (paratuberculosis [3%], hemorrhagic bowel syndrome [2%], and TB [2%]). Results of this study showed that the majority of deaths and culling of dairy cows in Jordan are due to infectious diseases followed by non-infectious gastrointestinal diseases and mastitis. More efforts aiming at improving biosecurity standards, nutritional management, and mastitis prevention measures are required to limit the impact of disease on farm economy, animal health and productivity, and animal welfare in Jordan.

Longevity and the association with cattle health in Dutch dairy farms

Longevity of a herd is defined as the average age of all cattle over two years old at the moment of death (either natural, by euthanasia or by slaughter), and is increasing since 2018. The aim of this study was to evaluate the association between longevity and cattle health indicators in Dutch dairy herds. Anonymized census data were available for 16,200 Dutch dairy herds (∼98 % of the dairy herds) between 2016 and 2020. All herds were categorized into one of six longevity groups: herds with a high longevity (>seven years old), increasing longevity (mean increase of one year and two months between 2017 and 2020), median longevity (∼five years and eight months, without major fluctuations in longevity), decreasing longevity (mean decrease eight months), low longevity (<four years and ten months) and a varying longevity of ∼five years and eight months, with fluctuation in longevity throughout the study period. Data were aggregated to herd and quarter of the year level. Cattle health parameters were analysed with multivariable population-averaged models with health indicators as dependent variables, and longevity and other management and herd level factors as explanatory variables. Belonging to the group of herds with a high longevity was associated with lower calf- and cow mortality, a higher percentage of cows with a high somatic cell count (HSCC), fewer inseminations per pregnancy for heifers and more inseminations for cows, a higher antibiotic use in adult dairy cows and a lower antibiotic use in calves compared to the average Dutch dairy herd. Further analysis showed that the higher percentage of cows with a HSCC could be explained by the higher share of older cows. Herds with a low longevity had a higher calf- and cow mortality, a lower percentage of cows with a HSCC, more inseminations for heifers and fewer for cows, lower antibiotic use in cows and higher antibiotic use in calves compared to the average Dutch dairy herd. To conclude, there were differences in cattle health between groups of herds with a different longevity.

Culling and mortality of dairy cows: why it happens and how it can be mitigated

The United Nations estimates that the global population will total 9.7 billion in 2050. Rapid population growth pose a significant obstacle to achieving the Sustainable Development Goals, particularly eradicating hunger and poverty. In view of the expanding population growth, food production ideally should triple to prevent massive food shortages. Sustainable food and nutrition security is the focal point of the dairy industry. Dairy production plays a pivotal role in addressing and advancing global food and nutrition security. It serves as a major source of protein, calcium, and phosphorus in many families in developing countries with a fast-growing population. Consequently, the dairy industry is expected to grow by approximately 26% in the next 10 years and produce an estimated 1077 million tonnes of milk by 2050. However, the growth and distribution of the dairy industry is limited by many factors such as culling and mortality of dairy cows. Several studies highlight reproduction failures, old age, poor milk yield, diseases (mastitis, lameness, and dystocia), and heat stress as some reasons for culling of dairy cows. Hence, this review highlights the factors influencing culling and mortality in dairy production farms, and discusses mitigating measures to limit culling.

Impact of Veterinary Herd Health Management on German Dairy Farms: Effect of Participation on Farm Performance

German dairy farming has intensified markedly in recent years, and the demand for Veterinary Herd Health Management (VHHM) is rising. To protect farms from epidemics, ensure food safety, and prevent developing of antibiotic resistance, VHHM has been anchored in EU law since April 2021. Via an online survey, distributed by different farmers' organizations, dairy farmers were asked about the cooperation with their veterinarian. The aim was to evaluate farm performance as a function of participation in VHHM. From 216 analyzed questionnaires, 106 respondents participated in VHHM. Results showed that farmers who make use of VHHM and consult their veterinarian in decision-making frequently have the highest 305-day milk yield (305dMY), the lowest bulk tank somatic cell counts, and the lowest age at first calving (AFC). However, these farmers tended to have higher replacement rates and a higher mortality of cows in the period up to 60 days in milk (MORT60DIM). Furthermore, respondents who defined VHHM as “evaluation of herd data, strategic planning” had the highest 305dMY compared with those who defined VHHM through one of the different options given (“pregnancy checks and support in reproduction”/“problem solving”). In the multifactorial regression model, VHHM participating farms had a 660-kg higher 305dMY and 1 month less in AFC, compared with farms not participating in VHHM. However, within the VHHM participants, no association between VHHM practices and performance parameters was found. Further research is needed, to find out if tailored advice of the VHHM approach may show effect herein.

Reproductive performance of northern Australia beef herds. 7. Risk factors affecting mortality rates of pregnant cows

Context There are multiple reports of high annual cow mortality rates in northern Australia, but no reports clearly indicating the overall rates and the impact of primary risk factors. Aims The research aimed to determine which measured region-, property-, management group- and animal-level risk factors are associated with missing pregnant females. Methods Risk factors for the annual rate of pregnant-cow mortality were investigated in an epidemiological study using outcomes for 21 554 cows from 52 beef herds in 2009 and 2010 in four primary country types within the mostly-dry tropical north Australian environment. Modelling of 2001–2011 Australian beef-herd statistics was used to corroborate and further quantify findings. Key results In the epidemiological study, the overall predicted annual mean incidence of missing pregnant cows, a surrogate for mortality, was 10.9%, including lost tags and unrecorded cow movement that were estimated to constitute up to 9% missing cows. Risk factors associated with higher pregnant-cow mortality were as follows: not having follow-up rainfall more than 30 days after the first wet-season storms (4 percentage point increase); &lt;2 t/ha of available pasture biomass in the early dry season (2–6 percentage point increase); pasture dry-season biomass &lt;2 t/ha interacting with less than moderate mid-dry-season body condition score (3–10 percentage point increase); and, calving between April and September (non-significant trend for a 1–2 percentage point increase). Feed-quality measures did not affect mortality rate. Population modelling of Australian beef herd statistics suggested an average annual cow mortality rate in the Northern Forest region of ~7% compared with 2% in more nutritionally endowed regions. Conclusions The major risk factor for cow mortality is under-nutrition, related either to generally-low soil fertility, seasonally-dry conditions, or management that exposes animals to poor nutrition. Annual mortality of pregnant cows appears 6–9 percentage points higher in the low-fertility Northern Forest region than elsewhere. Implications Beef cow mortality is a major business cost in northern Australia. The efficacy of targeted management to achieve high cow performance was demonstrated by losses in a third of studied businesses in the Northern Forest being kept to the same or lower levels as median loss in endowed regions.

Breeding goals for conservation and active Polish dairy cattle breeds derived with a bio-economic model

The aim of the study was to calculate economic values (EV) of breeding traits (production, reproduction, direct health, calving and survival traits) for the Polish dairy cattle breeds Polish Holstein (PH) and Polish Red (PR). EV are key elements in setting up economically based breeding goals for dairy cattle and they are crucial for optimizing breeding schemes. For deriving EV, a stochastic bio-economic model was used, which estimates EVs based on population-specific biological and economic characteristics. Because the bio-economic model considers correlations between different traits, a multiple regression approach was used to correct for any double counting of effects. The results showed that EVs for direct health traits and fertility differed between breeds. The biggest difference was observed for lameness (PH -1.44 €, PR -1.09 € per cow-year), ketosis (PH -0.94 €, PR -0.58 € per cow-year) and for cow conception rate (PH 1.94 €, PR 0.84 € per cow-year). The relative economic weights for production traits were estimated as 37.00 % (PH) and 34.30 % for (PR) and for fertility traits 15.10 % (PH and for 16.10 % (PR). Major economic differences between the relative weights were observed for cow mortality (22.70 % PH, 16.90 % PR). The results of our study showed that breeding the PH brings higher economic profit than breeding the PR. Total income per PR cow was equal to 1,623 € and for PH 2,970 €.

A Review on Prevalence of Bovine Mastitis and Antibiotic Residual Effects in Raw Milk and Its Human Health Significance

This paper has reviewed researches and paper reviews obtained from peer-reviewed literature published between 1950 to 2014 on the prevalence of bovine mastitis and antibiotic residual effects in raw milk and its human health significance in dairy sectors. A dairy is a development tool because it widens and sustains pathways out of poverty through securing assets of the poor, improving smallholder productivity, and increasing market participation by the poor. Hence, the development of the dairy sector in different parts of the countries can contribute significantly to poverty alleviation, improved nutrition, and household income. But, the dairy sector has not been fully exploited and promoted due to inflammation of the mammary gland called mastitis. Mastitis remains one of the most significant causes of morbidity and mortality of adult dairy cows and results in reduced profitability for the dairy industry. Generally, mastitis is one of the most devastating disease conditions leading to significant economic losses globally because of reduced milk production, treatment costs, increased labor, milk withholding following treatment, death, and premature culling. in addition to these, samples of raw milk produced and/or transported to consumers in different parts of the country showed that almost all microbiological counts were above the international accepted standard level (&gt;105cfu/ml and &gt;102cfu/ml for AMBC and Enterobacteriaceae/coliform counts, respectively) and different pathogenic (spoilage) bacteria have identified, it is probably because of problem-related with the health of milking cows, poor production and handling practices, contaminants from milking environment and administration of antibiotic drug rule. Therefore, awareness creation about quality milk production and good handling practices produced, transported until consumption is necessary; the concerned body shall control the quality of milk by prevention of the prevalence of mastitis regularly and also set the standard for bacterial quality. Keywords: Antibiotic; bovine; mastitis; prevalence; quality milk DOI: 10.7176/JBAH/11-24-01 Publication date: December 31 st 2021

Culling and mortality of dairy cows: why it happens and how it can be mitigated.

The United Nations estimates that the global population will total 9.7 billion in 2050. Rapid population growth pose a significant obstacle to achieving the Sustainable Development Goals, particularly eradicating hunger and poverty. In view of the expanding population growth, food production ideally should triple to prevent massive food shortages. Sustainable food and nutrition security is the focal point of the dairy industry. Dairy production plays a pivotal role in addressing and advancing global food and nutrition security. It serves as a major source of protein, calcium, and phosphorus in many families in developing countries with a fast-growing population. Consequently, the dairy industry is expected to grow by approximately 26% in the next 10 years and produce an estimated 1077 million tonnes of milk by 2050. However, the growth and distribution of the dairy industry is limited by many factors such as culling and mortality of dairy cows. Several studies highlight reproduction failures, old age, poor milk yield, diseases (mastitis, lameness, and dystocia), and heat stress as some reasons for culling of dairy cows. Hence, this review highlights the factors influencing culling and mortality in dairy production farms, and discusses mitigating measures to limit culling.

​Color Doppler Ultrasonographic Characteristics of Embryonic Development and Mortality in Dairy Cows

Background: Embryonic mortality is one of the major factors leading to reproductive failure, decreased fertility and delayed pregnancy in cattle. Method: The study was aimed for investigating the incidence of embryonic mortality(EM), differentiate embryonic development and mortality based on color Doppler ultrasonographic characteristics. Different characteristics correlated were corpus luteum(CL) vascularity, embryonic development and EM features, monitored on day 21 post-insemination. Result: The overall incidence of EM was recorded to be 25%, with 15% and 10% mortality occurred between days 21-28 and 28-35 of gestation. Color Doppler analysis stated that, the CL in pregnant cows had a higher percentage of luteal tissue with positive Doppler signals on initial examination (day 21) differing significantly (P less than 0.01) from non-pregnant and consistently increased till the end of the examination. However, cows with EM had a significantly lower CL vascularity than pregnant (P less than 0.05) but significantly higher (P less than 0.05) than non-pregnant cows on day 21. Embryos from pregnant cows (detected by 28 days) increased in size along the days of examination. However, cows diagnosed with EM showed signs (day 28), which included reduced intra-uterine allantoic fluid, absence of embryo proper with an embryonic heartbeat, hyperechoic free-floating embryonic debris in the uterus and distorted allanto-chorionic membrane. In conclusion, the present study firmly supports color Doppler ultrasonography in diagnosis of pregnant cows based on CL vascularity, visualizing the different characteristics signs of EM, and detecting non-pregnant animals undergoing EM as early as day 21.