DiscussionTop

Structure of farms and farmers

Official data show a similar ratio between total numbers of cattle and dairy cows per farm in Slovenia and Serbia (Cvijanović et al., 2014; SURS, 2018) as in our study. In Slovenia, the average age of the owner of a family farm is 57 years (SURS, 2018), and in Serbia it is 65 years or more (RZS, 2018). That is not consistent with our results from Table 1 and points that mostly younger population took part in our survey. Medium level of education is common for farmers in both countries (Eurostat, 2017; RZS, 2018), which is in accordance with our results.

Calf diseases

Morbidity and mortality rates are useful in assessing poor welfare associated with disease and lack of care (Ortiz-Pelaez et al., 2008; Colditz et al., 2014), wherefore they should be as low as possible. The mortality rates in Slovenian and Serbian farms are in accordance with data by Gulliksen et al. (2009) and Santman-Berends et al. (2014).

Two major causes of calf mortality in the first 180 days of life are diarrhea and respiratory diseases (Gulliksen et al., 2009; Lorenz et al., 2011a). They are also the main diseases in pre-weaned dairy calves: diarrhea during the f irst three weeks of life, and viral or bacterial pneumonia in calves over four weeks old (Lorenz et al., 2011a). Weaning is considered a predisposing factor of pneumonia in recently weaned suckler calves (Lorenz et al., 2011c). Common time reported by all responders on diarrhea appearance is consistent with data by Lorenz et al. (2011a). Our results show that diarrhea more frequently occurs (or breeder detects it easier) than respiratory diseases. Lorenz et al. (2011c) also stated that the cases of calf pneumonia are more likely to be missed than misdiagnosed indicating that breeders pay less attention to the signs such as coughing, wheezing, and especially the appearance of discharge from the eyes and nose, which are early signs of respiratory disease. The last claim is supported also by our findings that the most frequent reason for calling a veterinarian to help is only when the calf is breathing heavily.

Traditional cattle breeding in both countries implies tied housing in closed facilities with solid walls and using seasonal pasture from spring until late autumn. However, in some Serbian farms, cattle spend most of the time housed because everyday releasing, re-attaching and keeping animals on the pasture are not feasible operations for small families or elderly people if they are alone in the household and, in both cases, if there are no funds for extra workers. Spending time outdoors in the fresh air is beneficial in reducing the prevalence of respiratory diseases in pre-weaned calves, while poor air and hygienic conditions in a stall may facilitate the emergence and extend the duration of diseases (Lorenz et al., 2011c). According to farmers’ responses in the survey, an average length of both diseases in Slovenia and diarrhea in Serbia is in line with data by Donovan et al. (1998).

Navel infection and joint ill are also conditions related to young calf exposure to pathogenic bacteria from the environment. Preventive measures for umbilical infection include maternity pen hygiene, decreasing the time a newborn calf spends in the maternity pen, adequate passive immunity transfer, and antiseptic umbilical cord care (Mee, 2008). Regular implementation of navel disinfection in both countries is much lower than in the study by Vasseur et al. (2010) but similar to data by Renaud et al. (2017). Among farmers who never or irregularly use the navel-dip is likely to be those who allow the cow to dry off her newborn calf by licking. Calves with joint ill may have history and symptoms of other diseases, such as pneumonia, umbilical cord infection and diarrhea (Goodarzi et al., 2015). The incidence of navel infections reported in our study is in accordance with data by Wieland et al. (2017) and the incidence of joint ill is lower than reported by Klein-Jöbstl et al. (2015). Trichophytia is a dermatomycosis (ringworm) common in calves housed together, in poor hygienic and hot and humid conditions. Poor nutrition, biosecurity, and livestock management, as well as lack of sanitation routines, facilitate the spreading of T. verrucosum, the causative agent of this disease. The prevalence rate in a herd can be higher than 70% (Papini et al., 2009; Agnetti et al., 2014), which was not the case in our study.

Rearing techniques

Monitoring calves for signs of disease is of special importance in the first weeks of life when they are most sensitive to pathogens. Farmers must continue to check all housed calves at least twice a day and calves kept outside at least once a day, irrespective of the milk feeding systems used in the first months of life (FAWC, 2015). In small farms, up to 30 minutes of observing per day may be enough but not on larger farms with more calves. On dairy farms, calves are kept separately from their mothers. Breeders usually check the calves during feeding time, which could explain the significant inf luence of farm specialization on the answer chosen for this parameter in Serbia. Furthermore, Serbian breeders with better education consider monitoring of calves important for successful rearing, but we did not examine what exactly this implies.

Our survey results show that farmers in Serbia more regularly use ecto- and endoparasitic treatments than Slovenian farmers. In farms where cattle graze they have more problems with parasites and are more likely to use the means to control parasites. In the study by Schnieder et al. (1999), farmers did not use strategic control regimes for the control of helminths but preferred to use treatments after clinical signs were observed in animals, which is similar to our results. Diarrhea and respiratory infections may be related to the presence of internal parasites (Göz et al., 2006; Panciera & Confer, 2010); so irregular endoparasite control may contribute to a greater incidence of these diseases.

Details on appropriate colostrum management and its importance in the prevention of common calf diseases have been described by Vasseur et al. (2010), Lorenz et al. (2011a,b) and Hötzel et al. (2014). In our research, the time of first consumption and the quantity of consumed colostrum are in accordance with the recommendations. However, in both countries, it is common practice to use colostrum without any kind of quality control (visual, by colostrometer or by refractometer), which is a risk factor for failure of passive immunity transfer in calves. It is interesting that the youngest population of breeders in Slovenia and the lowest educated in Serbia said they were checking, possibly because young farmers have more knowledge and enthusiasm to apply recommended practices but less educated have enough experience in cattle breeding to know the importance of colostrum. Milk for feeding calves should have the temperature as close as possible to the calf's body temperature, and values obtained in this study can be considered as appropriate in that sense. However, it is debatable if responders really know the value, or they just know how it should be, considering most of them assess the temperature of the milk by hand. According to the results, many farmers pay too little attention to ensuring adequate milk temperature for feeding calves that could be related to the high frequency of diarrhoea in some farms. The appropriate temperature of milk fed to the calves is necessary for optimal digestion. A too low temperature of milk impairs digestion in the abomasum (Mornet & Espinasse, 1990) and may cause diarrhoea, additionally, it is also a risk factor for abomasal bloat (Marshall, 2009).

Practices in the case of diarrhea and respiratory diseases

Calves with diarrhea require prompt replacement of lost fluid and electrolytes to prevent severe dehydration and death. In calves suffering from diarrhea, ad libitum availability of water is strictly required (Wenge et al., 2014). Still, there are many farms where diarrheic calves have limited access or no access to the water; the owners give them instead rehydration solution two or more times per day (Relić et al., 2017). Besides lack of information on the importance of free water-access, the reasons for limitation can be related to calves’ housing and feeding systems and the absence of automatic waterers in old stalls, and the specialization of production. Another traditional belief is that milk feeding should be stopped for calves with diarrhea, either for a defined period or for as long as diarrhea persists. However, starvation rapidly results in malnourishment and weight loss of the sick calf. Continued milk feeding provides the energy and nutrients that are necessary for the recovery of the intestinal mucosa (Lorenz et al., 2011b). In our results, it is noticeable that all respondents in Serbia stated they stop giving milk to the calves with diarrhea, but most of them give fluid for rehydration. In a study by Klein-Jöbstl et al. (2015), on 86.3% of examined farms in Austria, milk was fed restricted. On the other hand, less than a fifth of breeders in Slovenia stop giving milk that is probably the reason why they said to use rehydration solutions in a smaller percentage than farmers in Serbia.

Deviation of body temperature from the normal range is a sign that something may be wrong with a calf. When other signs of illness are poorly expressed or unclear, noticing the elevated temperature can contribute to timely treatment. In favor of the previous, early signs of pneumonia, include increased respiratory rate and fever, followed by depression (Lorenz et al., 2011c). Delayed diagnosis may result in a more severe disease that needs prolonged use of antibiotics, a high recurrence rate, and complications on the respiratory and other organs with worsening of the condition or even death of the calf. On the other hand, early detection and effective treatments minimize antibiotic use, disease recurrence, chronic respiratory disease cases, and endemic dairy calf pneumonia (McGuirk & Peek, 2014). In both countries, a greater number of breeders measure the calf temperature if a respiratory disease is suspected than in the case of diarrhea. However, no matter what the disease is, respondents from Serbia less often measure the body temperature of sick calves.

Pathogens causing diarrhea are usually transmitted via the fecal-oral route (McGuirk & Ruegg, 2019). Therefore, a high level of hygiene in the area where calves are housed has an important role in the prevention of diarrhea, as well as cleaning pens after sick calves. Isolation of a sick calf is necessary to prevent spreading pathogens to other animals, which is more often done in Serbia than in Slovenia. However, it is not clear if respondents under “isolation” mean the keeping of an animal individually in a box or tied somewhere in the stall, which can be found on many family farms in Serbia. Individual pens for isolating sick animals must have solid walls (Marce et al., 2010), but we did not specify that in the question in our survey.

Biosecurity measures

Results indicate that farmers in both countries are similarly implementing biosecurity measures. Rodents and f ly control were considered as the most important by the farmers. A worryingly small percentage of farmers in both countries practice quarantine of newly purchased animals; it looks like they are not fully aware of the importance of quarantine and other biosecurity measures in preventing diseases. Farmers partially or completely omit implementation of biosecurity measures also in other countries, as described by Sarrazin et al. (2014) and Ritter et al. (2017).

According to Velde et al. (2018), poor adoption of recommendations to reduce disease transmission or enhance biosecurity practices and low participation in voluntary disease prevention are related to the personal traits of the farmer. Sometimes, small family farmers cannot bear the management costs; even more frequently, they may lack the information, knowledge, and skills needed for modern environmental management (Davidova & Thomson, 2014). Ritter et al. (2017) listed some key recommendations to enhance farmers’ skills, disease problem and benefits awareness, as well as a sense of responsibility. These universal recommendations can be applied to breeders’ education in any country.

It can be concluded that rearing practices in Slovenia and Serbia mostly match, in positive and also in negative aspects. Breeders greatly rely on tradition and experience, and farm size and type of specialization most often showed the influence on rearing procedures. The most neglected biosecurity measure in both countries is the isolation of newly purchased animals. A very common practice is to use colostrum without checking the quality. Farmers devote too little attention to controlling milk temperature for feeding calves and to water provision. Farmers often inadequately supply diarrheic calves. They call a veterinarian for help when diarrhea does not improve in a few days and when heavy-breathing is noticed in case of respiratory disease, which poses a risk to worsens the health status of the calf. All these data may help in breeders’ education and in another kind of support in the areas to be improved on-farm, e.g. colostrum management and prevention strategies for common calf diseases. The findings may help to improve the health and welfare of calves, reduce the use of antibiotics and, consequently, facilitate more sustainable and effective cattle breeding on family farms.