Incidence and Predictors of Calf Morbidity and Mortality From Birth to 6-Months of Age in Dairy Farms of Northwestern Ethiopia

Calf Morbidity and Mortality: Critical Challenges for Smallholder Dairy Farmers in Northern Ethiopia

Calf morbidity and mortality pose significant economic challenges for smallholder dairy farms in Ethiopia, resulting in direct losses from calf deaths, replacement costs, treatment expenses, and reduced lifetime productivity. This study aimed to comprehensively investigate the magnitude and epidemiological characteristics of calf morbidity and mortality in Northern Ethiopia. A cross-sectional study with mixed approaches was carried out from December 2019 to September 2020. A total of 183 questionnaire survey, four focus group discussion (FGD), and 17 key informant interviews (KII) were included in the study. Furthermore, participatory epidemiological appraisals were incorporated to triangulate and strengthen survey evidences. Analysis of survey results revealed that 69.4% of the farmers have experienced calf morbidity, while 63.9% of them have encountered calf mortality. Similarly, results of proportional piling indicated that calf morbidity and mortality were estimated to occur in 75.5% and 55.9% of the farms, respectively. Moreover, all KIIs had encountered calf morbidity, while 88.2% of them had faced calf mortality. Ninety percent of KIIs, 66.2% of the participants of community-based epidemiology, and 27.87% of questionnaire survey respondents suggested that calf morbidity and mortality occur in less than one-week-aged calves. Regarding the potential risk factors, source of water, frequency of barn disinfection, breed types, health status of dams, using separate calf housing, amount of colostrum provided to calves, and cleaning frequency of barns had statistically significant association with the occurrence of calf morbidity and mortality (p < 0.05). Additionally, results of participatory appraisal, FGDs and KIIs showed that calf diarrhea, nutritional disorder, pneumonia, and navel ill were the leading causes of calf morbidity and mortality. Furthermore, observation assessment showed that most dairy farms were surrounded by dense human settlements, livestock markets, and municipal slaughtering houses. Hence, the farms had critical space limitation (for animals to exercise) as well as poor drainage systems and hygienic practices. Our assessment also showed that lack of veterinary services, shortage of water supply, and poor artificial insemination services were the major challenges of dairying in the area. In conclusion, the present study revealed that calf morbidity and mortality were critical challenges for dairying in Northern Ethiopia. Furthermore, the study highlighted the epidemiological characteristics and potential risk factors associated with calf morbidity and mortality, awareness gaps in calf management, as well as key bottlenecks in dairy farming. These findings underscore the need for a comprehensive study, continuous capacity building initiatives, improved infrastructure, and services to mitigate calf losses.

Incidence, risk factors, and control of Rabies in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Globally, rabies is found in several geographical areas, with tens of thousands of deaths annually, mainly in developing countries. However, though Ethiopia is highly endemic for rabies, the overall risk of rabies has not yet been estimated. Hence, this systematic review and meta-analysis aimed at estimating a pooled incidence rate of human exposure to suspected rabid animals as well as the incidence rates of rabies in humans and other domestic animals.

METHODS

Published articles search was systematically performed through PubMed, Scopus, Embase, and Web of Science databases to identify the available studies on rabies until October 2023. The Joanna Brigg's Institute (JBI) critical appraisal checklists were used for assessing the quality of the studies. The PRISMA 2020 guideline was followed. A qualitative synthesis was made describing the characteristics of the included studies. The quantitative synthesis was performed with a random effects model using Comprehensive Meta-Analysis (CMA) version 3.0 software. The Q statistic quantified by I2 was used to check for heterogeneity among the included studies. To explain the source of heterogeneity, subgroup analysis was performed. Egger's regression test was used to evaluate publication biases. This study is registered with PROSPERO, CRD42023468791.

RESULTS

For this study, a total of 439 articles were retrieved; of which fifteen studies were included in the final review. The annual pooled incidence rate of human exposure to suspected rabid animals was 33.65 (95% CI: 31.82 to 35.49) per 100,000 humans. The suspected rabies deaths in humans were also estimated to be 4.57 (95% CI: 2.93 to 6.21) per one million humans annually. In both cases, considerable heterogeneities were presented across the included studies, and obvious publication biases were detected using Egger's regression test. Among animals, the highest combined estimate per 100,000 population was recorded in dogs, 120.99 (95% CI: 46.29 to 195.69), followed by equines and cattle, with pooled incidence rates of 19.57 (95% CI: -1.85 to 40.98) and 18.08 (95% CI: 1 to 35.15), respectively. It was also described that human exposure to rabid animals and human rabies deaths were more common among children.

CONCLUSIONS

The current study showed a high pooled incidence rate of human exposure to rabid animals. Significant overall incidence rates of rabies in humans and animals were also indicated. Therefore, strengthening intersectoral and transdisciplinary collaborations through one health approach are key components for rabies prevention and control.

Review: Opportunities and challenges for the genetic selection of dairy calf disease traits

Interest in dairy cow health continues to grow as we better understand health's relationship with production potential and animal welfare. Over the past decade, efforts have been made to incorporate health traits into national genetic evaluations. However, they have focused on the mature cow, with calf health largely being neglected. Diarrhoea and respiratory disease comprise the main illnesses with regard to calf health. Conventional methods to control calf disease involve early separation of calves from the dam and housing calves individually. However, public concern regarding these methods, and growing evidence that these methods may negatively impact calf development, mean the dairy industry may move away from these practices. Genetic selection may be a promising tool to address these major disease issues. In this review, we examined current literature for enhancing calf health through genetics and discussed alternative approaches to improve calf health via the use of epidemiological modelling approaches, and the potential of indirectly selecting for improved calf health through improving colostrum quality. Heritability estimates on the observed scale for diarrhoea ranged from 0.03 to 0.20, while for respiratory disease, estimates ranged from 0.02 to 0.24. The breadth in these ranges is due, at least in part, to differences in disease prevalence, population structure, data editing and models, as well as data collection practices, which should be all considered when comparing literature values. Incorporation of epidemiological theory into quantitative genetics provides an opportunity to better determine the level of genetic variation in disease traits, as it accounts for disease transmission among contemporaries. Colostrum intake is a major determinant of whether a calf develops either respiratory disease or diarrhoea. Colostrum traits have the advantage of being measured and reported on a continuous scale, which removes the issues classically associated with binary disease traits. Overall, genetic selection for improved calf health is feasible. However, to ensure the maximum response, first steps by any industry members should focus efforts on standardising recording practices and encouragement of uploading information to genetic evaluation centres through herd management software, as high-quality phenotypes are the backbone of any successful breeding programme.

Multidrug-Resistant Staphylococcus aureus Strains Thrive in Dairy and Beef Production, Processing, and Supply Lines in Five Geographical Areas in Ethiopia

Livestock, farms, abattoirs, and food supply systems can become the source of foodborne pathogens, including S. aureus, in the absence of monitoring, general hygienic practices, and control. Studies are scarce on reservoirs (hiding places) and routes of entry of S. aureus into the food supply chain in Ethiopia. To fill these gaps, we evaluated the role of cows (milk), meat, equipment, and food handlers on the abundance and AMR of S. aureus in five geographical areas in central Oromia, Ethiopia. We isolated S. aureus from 10 different ecologies per area in 5 areas and tested their sensitivity to 14 antimicrobials of 9 different classes. We ranked the 5 areas and 10 ecologies by computing their multiple AMR index (MARI) at a cut-off value of 0.2 to determine 'high-risk' ecologies for AMR. We recorded as MDR if an isolate had resistance to ≥3 antimicrobial classes. We used a circos diagram to analyze if isolates with identical AMR patterns were shared between different ecologies. S. aureus is prevalent in central Oromia (16.1-18.3%), higher in dairy farms than in abattoirs, and varied among 10 ecologies (p < 0.001) but not among 5 areas (p > 0.05). Of the 92 isolates, 94.6% were penicillin-resistant. Their AMR prevalence was above 40% for 9 of 14 antimicrobials. All isolates (100%) had AMR in at least one antimicrobial class (range = 1-9; median = 5), indicating MDR was prevalent. The prevalence of MDR S. aureus varied (p < 0.05) among areas and 10 ecologies; the highest was in slaughter lines. All isolates had a MARI of >0.2, indicating drug overuse, and S. aureus's AMR burden is high in central Oromia. Dairy farms had higher MARI values (0.44) than abattoirs (0.39). Of 10 ecologies, the highest and lowest MARI values were in the beef supply chain, i.e., slaughter line (0.67) and butcher's hand (0.25). Of the 68 different AMR patterns by 92 isolates against 14 antimicrobials, 53 patterns (77.9%) were unique to individual isolates, indicating they were phenotypically dissimilar. MDR S. aureus was widespread in central Oromia in dairy and meat supply chains, contaminating milk, meat, equipment, and workers in farm and abattoir settings. In the absence of strict regulations and interventions, MDR S. aureus can be disseminated from these epicenters to the public.

Dairy farmer's perception on feeding, conservation, and constraints of brewery by-products utilization in selected districts of Ethiopia

A survey was conducted in Ada'a, Sululta, and Debre Birhan districts. The districts are located in the vicinity of brewery factories. A semi-structured questionnaire was used to collect data from purposively selected dairy farmers (160). Data were analyzed with a statistical package for social sciences (Version 21). The majority of farmers (69.4%) used wet brewery-spent grain (WBSG), whereas 30% of them used both WBSG and wet brewery spent yeast (WBSY). Farmers obtained WBSG and WBSY only in fresh form from the distributors. The majority of farmers (66.67%) blended WBSG and WBSY with concentrate and roughage feed before feeding it to their animals, while 14.47% fed the by-products alone to their animals. Several farmers (60.1%) responded that the key reason for providing WBSG and WBSY to their livestock was higher production (increased milk and growth rates). The majority (82.78%) of farmers used common salt to extend the shelf life of WBSG and WBSY. Out of 128 (80%) farmers who reported spoilage in WBSG, 49 (38.28%) farmers observed sever mold development, while the remaining 12 (9.38%) and 28 (21.88%) saw change in colour and unpleasant odor. According to 68 (53.13%) of the farmers who experienced in WBSG spoiling, the amount of spoilt was less than 9% and 10-20% of the total purchased. The majority of farmers (87.8%) reported that storage time and storage conditions (temperature, moisture, and humidity) were the primary reasons of WBSG spoilage, whereas 12.2% of the farmers reported that inadequate sanitation of feeding troughs, transportation, and storage facilities were the primary causes of spoilage. The key restrictions of brewery by-product utilization were found as scarcity and high purchasing costs. Farmers (44.38% and 41.86%) believed that feeding WBSG and WBSY to dairy cattle have negative health effect, respectively. In conclusion, insufficient and irregular supply, rising cost of material and transport, spoilage, and health-related hazards are the main constraints of WBSG and WBSY usage. It is suggested that there is a dire need for consistent supply, staying away from the brokers, and preserving the brewery by-products through sun drying, and ensiling. Additionally, more research is required to determine the negative health impact of feeding brewer by-products for dairy cattle.