Assessment of α-Cypermethrin Pour-On Application and Diminazene Aceturate for Treating Trypanosome-Related Diseases Caused by Tsetse Flies on Cattle in Mô, Togo

The effects of tsetse-transmitted trypanosomosis control in high tsetse flies (Glossina spp.) challenge and trypanocidal drug resistance settings remain poorly understood in Togo owing to poor data coverage on the current disease impact. From March 2014 to November 2017, a database of zoo-sanitary surveys integrating the evolution of disease incidence and intervention coverage made it possible to quantify the apparent effects attributable to the control effort, focused on all sedentary cattle breeds in the 1,000 km² area of Mô in Togo. The strategy involved an initial phase with cross-sectional entomological and parasitological. Then, three times a year, 20% of the bovine animals of the study area received α-cypermethrin pour-on, and infected cattle with poor health (798 cattle in 2014 and 358 in 2017) were individually given diminazene aceturate at 7 mg/kg of body weight. The tsetse density in the area decreased significantly, from 1.78 ± 0.37 in March 2014 before the α-cypermethrin application to 0.48 ± 0.07 in February 2017. The α-cypermethrin pour-on application and diminazene aceturate treatment of cattle led to the largest reduction in disease incidence, from 28.1% in 2014 to 7.8% in 2017, an improvement in hematocrit from 24.27 ± 4.9% to 27.5 ± 4.6%, and a reduction in calf mortality from 15.9 ± 11% to 5.9%. Improved access to these interventions for different types of livestock and maintaining their effectiveness, despite high tsetse (Diptera: Glossinidae) challenges, should be the primary focus of control strategies in many areas of Togo.

Prevalence of Calf Mortality in Ethiopia: A Systematic Review and Meta-Analysis

Background. Calf mortality has been a major cause of economic losses in the dairy industry in Ethiopia. The condition results in a significant drop in the number of replacing heifers and bulls for sustainable dairy business. Reports on calf mortality with a wide range of prevalence are rising in the country; however, a pooled prevalence of this condition has not been established. Thus, this systematic review and meta-analysis aimed to quantitatively estimate the pooled prevalence of calf mortality in Ethiopia. Methods. Meta-analysis was carried out to obtain the pooled prevalence of calf mortality in Ethiopia. A comprehensive literature search was carried out on PubMed, African Journals Online, CAB, Web of Science Direct, and Google Scholar. Eligible studies were selected based on predefined inclusion and exclusion criteria. Moderators such as the study area, breed of calf, study design, agroecology, and year of study article published were used as a milestone of data extraction. The random-effect model was used to estimate pooled prevalence. Publication bias and the variation in prevalence estimates attributed to heterogeneity were also assessed. Results. Twenty-five original research papers on the prevalence of calf mortality in various parts of Ethiopia were included. The reported prevalence of calf mortality was between 0.9% and 37%. The pooled prevalence of calf mortality in the country was 14.79%, and the pooled calf mortality estimate across studies for the entire period regarding 1991 to 2000, 2001 to 2010, 2011 to 2016, and 2017 to 2020 was 26.54%, 17.03%, 14.21%, and 11.23%, respectively. Analysis of study subgroups and location revealed significant variations in prevalence. High heterogeneity was observed in the pooled estimates and even after the subgroup meta-analysis. The funnel plots and Egger’s regression asymmetry coefficient (b = −1.0434) (95% CI = −1.49, −0.59; p value of 0.012) did suggest the presence of publication bias. There was also an indication of missing studies that could be incorporated by Duval and Tweedie’s trim and fill method where they might fall on a funnel plot and visualize them in an attempt to increase the plot’s symmetry. Analyses also suggest that calf breed, sample size, and study location are likely to be moderators of calf mortality prevalence in Ethiopia. Conclusion. This finding shows that calf mortality is widespread and could result in considerable economic losses for the dairy industry in Ethiopia. Inevitably, a significant reduction in calf mortality prevalence has been observed in recent years since 2010, but the reduction has not yet reached an economically tolerable level. Calf breed susceptibility contributed to the high prevalence. Therefore, interventions for increasing calf health and performance should be focused on minimizing calf mortality on farm and animal levels.

Effect of Calving Difficulties and Calf Mortality on Functional Longevity in Polish Holstein-Friesian Cows

Longevity is one of the functional traits that considerably affect dairy herd profitability. A Weibull proportional hazards model was used to evaluate the impact of difficult calvings and calf stillbirths on cow functional longevity, defined as length of productive life corrected for milk production. The data for analysis comprised calving ease and calf mortality scores of 2,163,426 calvings, 34.4% of which came from primiparous cows. The percentage of male calves was 53.4%. Calving ease was scored as “without assistance” (34.44%), “with assistance” (62.03%), “difficult—hard pull” (3.39%), and “very difficult, including caesarean section” (0.14%). Calf mortality scores were “live born” (94.21%) and “stillborn or died within 24 h” (5.79%). The Weibull proportional hazards model included classes of calving ease or calf mortality scores × parity (1, ≥2) × sex of calf as time-dependent fixed effect. The model also included time-dependent fixed effects of year × season, parity × stage of lactation, annual change in herd size, fat yield and protein yield, time-independent fixed effect of age at first calving, and time dependent random herd × year × season. In first-parity cows, very difficult birth of a bull or heifer increased the relative risk of culling, respectively, 2.18 or 1.26 times as compared with calving without assistance. In later parities, the relative risk of culling related to very difficult calving was 2.0 times (for male calves) and 1.33 times (for female calves) higher than the relative risk of culling associated with calving without assistance. Calf mortality showed a negative impact on longevity in both heifers and cows. First-parity stillbirth increased the relative risk of culling depending on sex of calf by 18% in females and by 15% in males; in later parities the increase of the relative risk of culling was lower (by 7% for females, 9% for males). Difficult calvings and their consequences, especially in primiparous cows, may negatively influence dairy herd profitability by reducing the length of cows’ productive life.

Longitudinal study of calf morbidity and mortality on smallholder farms in southern Ethiopia

Calf morbidity and mortality are serious constraints in the success of dairy calf production. Thus, the current study was carried out with the objective to estimate the incidence of calf morbidity and mortality and associated risk factors in milk-shed districts of Gamo Zone, Southern Ethiopia. A prospective cohort and cross-sectional survey were employed from November 2019 to April 2020. A total of 196 calves were recruited by simple random sampling. Recruitment of calves was deployed by both the concurrent and prospective cohorts in calves aged below three months in study herds. The crude incidence of calf morbidity and mortality was 30.9% and 8.64%, respectively. The most frequently encountered disorder was calf diarrhea (10.17%), followed by pneumonia (6.5%). The other disorders were septicemia, omphalitis, arthritis, eye problem and miscellaneous cases. Multivariable Cox regression was revealed significant association for the calf vigor status, colostrum ingestion time, colostrum feeding status, dam parity, age at first calving, and related disorders were found risk factors of calf morbidity; likewise, calf vigor status at birth, time of colostrum ingestion and weaning were risk factors determining calf mortality. Calf morbidity and mortality rates recorded in this study were marginally higher than economically tolerable level, therefore, could affect the productivity of smallholder dairying by decreasing the obtainability of replacement heifers. Among significant explanatory factors investigated, colostrum ingestion time, method and amount were found important determinant factors of calf mortality and morbidity under the small-holder farming in the milk-shed districts of the Gamo zone. Therefore, rigorous calf husbandry practice is a need to manipulate the aforementioned calf determinants with subsequent application of tailor-made interventions.

Mobile Veterinary Clinic: an innovative approach to promote calf health

Background: Calf morbidity and mortality are of great concern for dairyman all over the world including Bangladesh. A mobile Veterinary Clinic (MVC) was established to identify the diseases associated with morbidity and mortality and provide veterinary services at farmers’ door step to promote calf health. Methods: A MVC was established and run from October 2011 to October 2014 to promote calf health. A total of 500 farmers from small and large holder private farms having at least two crossbred cattle were selected. A motorcycle and a mobile phone were provided to each research assistant (RA). The farmers were linked with RAs through mobile number. The ULO/VS were linked with the RA of the respective upazila for immediate treatment of the affected animal(s). The farms were under routine surveillance of the RA. In case of sickness or mortality, RA immediately contacted with ULO/VS and project coordinator/principal investigator at Bangladesh Agricultural University. Necessary advices were given by ULO/VS/consultants to solve the problem as required. Health cards were distributed to the selected farmers for recording the health status of cattle. Diseases were confirmed by clinical and laboratory methods. Farmers were trained on better calf health management. Early disease diagnosis and treatment, routine de-worming and vaccination of cows and calves were performed regularly. Results: Before implementing MVC services, the overall mortality at herd level was 11.5% which was 8.2% and 14.7% in Muktagacha and Shahjadpur respectively. The overall morbidity was 48.5% which was higher in Shahjadpur (57.94%) than Muktagacha (33.81%). The most common causes of calf mortality were pneumonia (66.2%), unknown (17.4%), adverse drug effect (5.3%), FMD (2.6%) and sudden death (2.4%). Due to MVC at farmers’ door step, the overall herd level mortality reduced significantly from 11.5 to 2.9% which were 8.2 to 2.3% in Muktagacha and 14.7 to 3.6% in Shahjadpur. Conclusion: Measures to control pneumonia and FMD in calves should be undertaken. The unknown etiology of mortality should be explored. Cautions should be taken before administering drugs in calves. As MVC was successful in reducing calf mortality, we recommend replicating in other parts of the country.

Review on Common Infectious Diseases of Neonatal Calves

Neonatal calf mortality is one of the important problems of calf rearing in dairy farms worldwide. A successful dairy farm operation requires that a large percentage of cows wean a live healthy calf every year. However, in many developing countries, a large number of calves die during the early neonatal life, this causing heavy economic loss. This is due to several infectious (bacterial, viral, and protozoal) and non-infectious factors (management around birth, colostrum management, calf housing, feeding system, hygiene, and pathogens) play an important role in calf rearing. This paper aims to review major infectious causes of neonatal calf mortality. Numerous studies have been conducted in the past from many parts of the world using both retrospective and prospective data sources to document the major causes of calf mortality. Of the infectious diseases of calves, neonatal diarrhea is a matter of major concern, and multiple etiological agents from viruses (Bovine rotavirus, Bovine coronavirus, Bovine viral diarrhea virus) from bacteria (Salmonella spp, Escherichia-coli, and Clostridium perfringens) from protozoal (Cryptosporidium-parvum) have been identified as major causes of neonatal calf mortality. Among the infectious agents, rotavirus and E. coli are mainly involved in the causation of neonatal calf diarrhea which leads to high mortality and morbidity in young calves. E. coli mainly plays its role up to the second week of life whereas, rotavirus up to the third week. Generally, early calf mortality leading to economic losses due to the cost of treatment, prophylaxis, increased susceptibility to other infections, reduced growth rates, and death of calves. Keywords: Calf Mortality; Infectious Diseases; Diarrhea

Seasonal and Age-Associated Pathogen Distribution in Newborn Calves with Diarrhea Admitted to ICU

Calf mortality constitutes a substantial loss for agriculture economy-based countries and is also a significant herd problem in developed countries. However, the occurrence and frequency of responsible gastro-intestinal (GI) pathogens in severe newborn diarrhea is still not well known. We aimed to determine the seasonal and age-associated pathogen distribution of severe diarrhea in newborn calves admitted to the intensive care unit (ICU) of Erciyes University animal hospital over a year. Fecal samples were collected during the ICU admissions, and specimens were subjected to a diarrheal pathogen screening panel that included bovine coronavirus (BCoV), Cryptosporidium spp., ETEC K99+, and bovine rotavirus, using RT-PCR and conventional PCR methods. Further isolation experiments were performed with permissive cell cultures and bacterial enrichment methods to identify the clinical importance of infectious pathogen shedding in the ICU. Among the hospitalized calves aged less than 45 days old, the majority of calves originated from small farms (85.9%). The pathogen that most frequently occurred was Cryptosporidium spp. (61.5%) followed by rotavirus (56.4%). The frequency of animal admission to ICU and GI pathogen identification was higher during the winter season (44.9%) when compared to other seasons. Most calves included in the study were 1–6 days old (44.9%). Lastly, co-infection with rotavirus and Cryptosporidium spp. occurred more frequently than other dual or multi-infection events. This study was the first to define severe diarrhea—causing GI pathogens from ICU admitted newborn calves in Turkey.

Elevated Calf Mortality and Long-Term Responses of Wild Bottlenose Dolphins to Extreme Climate Events: Impacts of Foraging Specialization and Provisioning

As demands for wildlife tourism increase, provisioning has become a popular means of providing up-close viewing to the public. At Monkey Mia, Shark Bay, Australia, up to five adult female Indo-Pacific bottlenose dolphins (Tursiops aduncus) visit a 100 m stretch of beach daily to receive fish handouts. In 2011, a severe marine heatwave (MHW) devastated seagrass and fish populations in Shark Bay. Offspring survival declined precipitously among seagrass specialists (dolphins that forage disproportionately in seagrass habitat). As all provisioned dolphins at the site are seagrass specialists, we examined how provisioned and non-provisioned seagrass specialists responded to the MHW. Using 27 years of data we compare habitat use, home range size, calf mortality, and predation risk between provisioned and non-provisioned females and their offspring before and after the MHW. Our results show that provisioned females have extremely small home ranges compared to non-provisioned females, a pattern attributable to their efforts to remain near the site of fish handouts. However, weaned offspring (juveniles) born to provisioned females who are not provisioned themselves also had much smaller home ranges, suggesting a persistent maternal effect on their behavior. After the MHW, adult females increased their use of seagrass habitats, but not their home range size. Provisioned females had significantly lower calf mortality than non-provisioned females, a pattern most evident pre-MHW, and, in the first 5 years after the MHW (peri-MHW, 2011–2015), calf mortality did not significantly increase for either group. However, the ecosystem did not recover, and post-MHW (2016–2020), calf mortality was substantially higher, regardless of provisioning status. With few survivors, the impact of the MHW on juvenile mortality post-weaning is not known. However, over three decades, juvenile mortality among offspring of provisioned vs. non-provisioned females did not statistically differ. Thus, the survival benefits accrued to calves in the provisioned group likely cease after weaning. Finally, although shark attack rates on seagrass specialists did not change over time, elevated predation on calves cannot be ruled out as a cause of death post-MHW. We discuss our results as they relate to anthropogenic influences on dolphin behavioral plasticity and responses to extreme climate events.