Calf morbidity, mortality, and management practices in dairy farms in Jimma City, Southwestern Ethiopia

BACKGROUND

This research aims to determine the incidence of calf morbidity, mortality and its potential predisposing factors in the first six months of life. Morbidity and mortality of dairy calves are persistent problems for dairy farmers worldwide. For effective control and prevention programs on calf health, it is imperative to estimate the extent of calf morbidity and mortality, and associated risk factors. Although few studies have investigated the epidemiology of calf morbidity and mortality in Ethiopia, comprehensive information is scarce in this area.

METHODS

Data were collected through a cross-sectional survey and longitudinal follow-up on purposively selected dairy farms. A longitudinal study was conducted on 235 calves from birth to 6 months of age. Survival analysis methods using the Kaplan-Meier (K-M) method, and mixed effect Cox proportional hazard regression were employed to compute the life-to-event data on morbidity and mortality.

RESULTS

From the 235 calves studied, 53 morbidity and 15 mortality events were recorded. This gives an overall morbidity and mortality incidence rate of 55 per 100-calf 6-months at risk (risk rate of 42.07%) and 14 per 100-calf 6-months at risk (risk rate of 12.97%), respectively. Diarrhea (13.84%) followed by pneumonia (8.97%) were the most common diseases that occurred in calves, respectively. Similarly, diarrhea (33.3%) and pneumonia (26.7%) were the leading causes of death. Dam parity (p < 0.001) and pen cleaning (p < 0.001) were significant predictors of calf morbidity. Dam parity (p = 0.007), calving status (p = 0.005), pen cleaning (p = 0.04), and floor type (p = 0.001) of houses were significantly associated with mortality. The hazard of diarrhea was significantly associated with sex (p = 0.003), first colostrum feeding time (p = 0.028), pen cleaning (p = 0.010), and breeding method (p = 0.013).

CONCLUSION

The rates of morbidity and mortality reported in the study were higher than the economically acceptable, also affecting the welfare of the animals. The risk factors found need due attention in the management practices of dairy calves in Ethiopia.

Outdoor access practices in the Canadian dairy industry

Dairy cows are highly motivated to access pasture and have a partial preference for alternative forms of outdoor access (e.g., deep-bedded outdoor sand or wood-chip packs). In addition, Canadians value the provision of outdoor access to dairy cows as they perceive it as important for good cow welfare. In contrast to Europe, Oceania, and the United States, little data exist on the use of outdoor access on Canadian dairy farms. Therefore, our objective was to assess current outdoor access practices for dairy cows in Canada. An online questionnaire was used to determine housing and outdoor access practices for lactating cows, dry cows, pregnant heifers, and weaned, nonpregnant heifers on Canadian dairy farms. The questionnaire was distributed by the 10 provincial milk boards between November 2020 and August 2021, resulting in an 8.9% response rate (n = 903 completed questionnaires). In total, 75% (n = 675) of respondents provided some form of outdoor access to at least 1 cattle class on their farm. Pasture was the most frequently used form of outdoor access for all cattle classes. Based on a weighted average, a total of 29% and 48% of Canadian dairy farms provided lactating and dry cows, respectively, access to pasture; for youngstock, these numbers were 48% and 27% for pregnant heifers and weaned, nonpregnant heifers, respectively. Herd size (for each cow class), indoor housing system, and region were all associated with the provision of pasture. Farms with larger lactating herds less often provided access to pasture; larger herd sizes in terms of weaned, nonpregnant heifers, pregnant heifers, and dry cows were also associated with a lower likelihood of access to pasture. Farms using indoor bedded pack housing for their lactating cows more often provided pasture to this cattle class than farms with freestall or tiestall housing; this likelihood did not differ between farms with tie or freestall housing for this cattle class. Dry cows or pregnant heifers housed in a tiestall were more often provided pasture than freestall-housed dry cows or pregnant heifers. Housing type for weaned, nonpregnant heifers was not associated with the likelihood of pasture provision. Farms in British Columbia or on Canada's East Coast (i.e., Nova Scotia, New Brunswick, and Prince Edward Island) more often provided lactating cows pasture compared with farms in other regions. For the other 3 cattle classes, farms on the East Coast of Canada more often provided pasture than farms in other parts of Canada. These results will inform future decisions regarding outdoor access for Canadian dairy cattle and may also aid in identifying future areas of research. For example, our results may aid in designing housing systems that facilitate outdoor access in larger herds and in areas that are subject to more extreme weather conditions.

Developing ‘Smart’ Dairy Farming Responsive to Farmers and Consumer-Citizens: A Review

Simple Summary

Dairy production has evolved over many generations to be an important source of high-quality nutrition for a significant proportion of the global population. However, it needs to evolve further to ensure it contributes to sustainable diets. Technological innovation can be a key enabler. It is also the case however that innovation brings about significant change, and can introduce unexpected, unintended and undesirable consequences, which are experienced differently by different actors on the ground. Thus, a major challenge is turning good science and technology into positive and innovative outcomes for society in an equitable way. Drawing on concepts from Responsible Research and Innovation (anticipation, inclusion, reflexivity and responsiveness) and Food Systems thinking, the authors reviewed the academic literature to consider the perspectives of different actors relating to technologies on dairy farms. It considers ‘smart’ on-farm technologies at three key stages of the dairy production cycle—breeding, feeding and milking—through the lens of two actor groups. It considers the farmers who may(not) adopt such innovations and the consumer-citizens who will(not) purchase/accept the resultant on-farm practices and foods. It highlights some differences between and within these actor groups, but also identifies commonalities, including tensions, faced by both groups. Dairy production in the future, thus, is not only challenged with embracing advanced technologies, the process by which such technologies are designed and selected must also be ‘smart’.

Abstract

Innovation has resulted in more dairy products being produced with less inputs than ever before. It has also affected how animals are raised, the structure of the sector and the nature of products produced. Not all impacts have been positive. As disruptive technologies—such as precision farming and robotics—herald significant change, it is timely to reflect on the perspectives of different actors on innovations within the sector. Drawing on a review of academic literature, this paper considers farmers’ and consumer-citizens’ perspectives; as expected, their diverse knowledge, interests and values surface a range of perspectives. To provide focus to the study, it examines technologies across three stages of the dairy production cycle: breeding, feeding and milking. It finds that consumer-citizen and farmer perspectives have been examined by researchers in several countries, using a variety of methods, across a range of technologies. It finds both areas of agreement and tension within and between consumer-citizen and producer cohorts. While differences in knowledge account for some variation, differences in values are also significant. The extent to which efforts can and should be put into addressing differences is raised as a point for reflection.

Effect of GnRH administered at the time of artificial insemination for cows detected in estrus by conventional estrus detection or an automated activity-monitoring system

The objectives of this study were to determine the effects of GnRH at the time of artificial insemination (AI) on ovulation, progesterone 7 d post-AI, and pregnancy in cows detected in estrus using traditional methods (tail chalk removal and mount acceptance visualization) or an automated activity-monitoring (AAM) system. We hypothesized that administration of GnRH at the time of AI would increase ovulation rate, plasma progesterone post-AI, and pregnancy per AI (P/AI) in cows detected in estrus. In experiment 1, Holstein cows (n = 398) were blocked by parity and randomly assigned to receive an injection of GnRH at the time of estrus detection/AI (GnRH, n = 197) or to remain untreated (control, n = 201) on 4 farms. The GnRH was administered as 100 µg of gonadorelin acetate. Ovarian structures and plasma progesterone were assessed in a subset of cows (GnRH, n = 52; control, n = 55) in experiment 1 at the time of AI and 7 d later. In experiment 2, a group of 409 cows in an AAM farm were enrolled as described for experiment 1 (GnRH, n = 207; control, n = 202). Data were categorized for parity (primiparous vs. multiparous), season (cool vs. warm), number of services (first vs. > first), DIM (>150 DIM vs. ≤150 DIM), and for AAM cows in experiment 2 for activity level (high: 90-100 index vs. low: 35-89 index). Pregnancy diagnosis was performed between 32 and 45 d post-AI (P1) and 60 to 115 d post-AI (P2). In experiment 1, there was no difference in plasma progesterone at day of estrus detection (control = 0.09 ng/mL vs. GnRH = 0.16 ng/mL), 7 d later (control = 2.03 ng/mL vs. GnRH = 2.18 ng/mL), and ovulation rate (GnRH = 83.2% vs. control = 77.9%) between treatments. There were no effects of GnRH in experiment 1 for P/AI at P1 (control = 43.3% vs. GnRH = 38.6%), P2 (control = 38.4% vs. GnRH = 34.5%), and for pregnancy loss (control = 9.8% vs. GnRH = 8.2%). In experiment 2, there were no effects of GnRH for P/AI at P1 (control = 39.6% vs. GnRH = 40.1%), P2 (control = 35.0% vs. GnRH = 37.4%), and for pregnancy loss (control = 9.5% vs. GnRH = 6.2%). There was a tendency for a parity effect on P/AI for P1, but not P2 or for pregnancy loss. High-activity cows had greater P/AI in P1 (low activity = 27.9% vs. high activity = 44.1%), P2 (low activity = 21.8% vs. high activity = 41.2%), and lower pregnancy loss (low activity = 20.7% vs. high activity = 5.1%), but there were no interactions between treatment and activity level. The current study did not support the use of GnRH at estrus detection to improve ovulatory response, progesterone 1 wk post-AI, and P/AI. More research is needed to investigate the relationship between GnRH at the time of AI and activity level in herds using AAM systems.

Symposium review: Linking activity-sensor data and physiology to improve dairy cow fertility

Several studies have demonstrated that the intensity of estrous expression is associated with ovulation, ovarian and uterine function, and fertility, and is dependent on social hierarchy and the housing system used. Data from recent studies involving spontaneous and induced estrus have shown that a greater relative increase and longer estrus (captured by different automated activity monitors; AAM) are both associated with improved pregnancy per artificial insemination (AI; around 10 to 14% increase) and decreased pregnancy losses. Intensity and duration of estrus were surprisingly weakly associated with preovulatory follicle diameter and concentrations of plasma estradiol at estrus, whereas ovulation failure was associated with low estrus intensity. Studies have also shown that the display of estrous behavior near AI was associated with the modification of expression of genes related to the immune system, adhesion molecules, and prostaglandin synthesis in the endometrium. Transcripts in leukocytes and in the conceptus tissue associated with maternal recognition of pregnancy as well as conceptus elongation were all associated with differences in the intensity of estrous expression. Most recently, studies from the United States and Canada have demonstrated that reproductive programs emphasizing detection of estrus using AAM can be successful and comparable to intensive timed AI protocol-based programs that incorporate GnRH and PGF_2α treatments. Further, one study concluded that the administration of GnRH at AI for spontaneous estrus events greatly improved pregnancy per AI, but only for cows with reduced intensity of estrous expression, showing the potential to use AAM data as a tool in targeted reproductive programs. Quantitative information from estrus events could be used to improve estrus detection and develop decision-making strategies at the farm level. Future studies in this field should aim to better understand ovarian, conceptus, and endometrial mechanisms associated with either the expression or the intensity of estrus, and to refine the identification of phenotypes related to estrus (relative increase, absolute increase, baseline levels, duration, and repeatability within cow) to improve data usage, estrus detection, and possibly genetic selection.

Comparison of behavioral patterns of dairy cows with natural estrus and induced ovulation detected by an ear-tag based accelerometer

Dairy farms face many challenges and changes. With increasing herd sizes and fewer farmers or employees per cow, new strategies to maintain or improve reproductive management are required. One of the major challenges is to detect cows in estrus and to estimate the perfect time for artificial insemination (AI). Several estrus and ovulation synchronization programs with timed AI as well as estrus detection aids, e.g., tail-paint, pedometer, accelerometer, and others are available. A combination of ovulation synchronization programs and technical solutions, however, has rarely been tested. This study was designed to gain insights into behavioral patterns of cows subjected to an Ovsynch program and to test if behavioral data could be used to optimize the timing of insemination within an Ovsynch program. In this study, we used an ear-tag based 3D-accelerometer system (SMARTBOW, Smartbow GmbH, Weibern, Austria) to generate data of behavioral patterns, i.e., rumination and activity. In Part 1 of this study, behavioral patterns during the peri-estrus period were compared between cows with physiological estrus and cows subjected to an Ovsynch protocol. On the day before estrus and on the day of estrus/AI, cows with natural estrus showed a clear drop in rumination and "inactivity" and an increase in "high activity", based on an algorithm of the accelerometer system, whereas, cows in the Ovsynch protocol showed only minor changes in behavioral patterns. In Part 2, we analyzed behavioral patterns between synchronized cows that became pregnant after AI and synchronized cows that remained open. As a result, no differences were detected between these two Ovsynch groups before AI. Thus, in this study we found no evidence that behavioral patterns can be used to improve conception rates within an Ovsynch protocol.

Evaluation of an ear-attached accelerometer for detecting estrus events in indoor housed dairy cows

Precision dairy farming technologies have tremendous potential to improve and support farmers in herd management decisions, particularly in reproductive management. Nowadays, estrus detection in cows is challenging and several supporting tools are available. In this study, a 3D-accelerometer integrated into an ear-tag (SMARTBOW, Smartbow GmbH, Weibern, Austria) was used for the detection of cows in estrus. Movement pattern based on accelerometer data were analyzed and processed by algorithms and machine learning, resulting in estrus alerts. For the evaluation of the system, reproductive performance data of 579 estrus events of multiparous cows were used to retrospectively evaluate the accuracy of estrus alerts generated by the accelerometer-based system and the overall performance of the system. Estrus events were classified as 'gold standard' events, if an estrus followed by AI resulted in pregnancy, and as 'recorded estrus' events, if two estrus events with an interval of 18-25 d were in the herd records, independent of whether estrus was followed by AI or pregnancy. In total, 316 'gold standard' events were matched with estrus alerts generated by the accelerometer-based system, resulting in a sensitivity of 97%. Furthermore, 263 'recorded estrus' events were compared with correct or incorrect estrus alerts by the system. Sensitivity, specificity, positive and negative predictive values, accuracy, and error rate for 'recorded estrus' events were 97%, 98%, 96%, 94%, 96%, and 2%, respectively. In summary, the SMARTBOW system is suitable for an automated detection of estrus events of multiparous cows in indoor housed dairy cows.

Evaluation and Countermeasures of the Implementation of the Lake Protection and Governance System in Wuhan City, Middle China

The protection and management of lakes is closely related to people’s quality of life and the rapid development of urban economy, and it is also an important aspect of realizing ecological sustainability. Hubei Province has over 1000 lakes, so the importance of the protection and governance of lakes is self-evident. Since the Lake Protection Regulations of Hubei Province came into being, Hubei Province has achieved the gradual extension and improvement of the system of responsibility for the protection of the lake. In order to understand the development of the system of responsibility for the protection of the lake and to explore the shortcomings in the implementation of the lake management system, this paper takes Wuhan city, capital of Hubei Province, as an example, as the object of research and evaluates the implementation effect of the lake protection mechanism and system after the promulgation of Hubei Province Lake Protection Regulations. According to the evaluation results, since the implementation of the regulations, the formal protection of lakes in Wuhan city has been promoted step by step, and the effect of lake management has also been remarkable. The government attaches great importance to lake protection, and the enthusiasm of government staff participating in this is increasing. However, the evaluation results also reveal some weaknesses of the current system of lake protection and governance, including the protection of lake quality, the perfection of the annual appraisal system and the administrative responsibility system, and the optimization of the lake garbage disposal system. On the basis of the results, this paper puts forward countermeasures and ideas to perfect the mechanism and system of lake protection and management in Wuhan city, in order to provide reference for the lake protection and management in other areas.