Rearing conditions and health status of calves on small rural farms

Good rearing conditions are the key factor for health and welfare of calves. Diarrhea, respiratory and navel infections are commonly referred to as the most common health problems in calves. The aim of this study was an observation of rearing conditions and the occurrence of the most common health problems in calves on small rural farms in Danube Region of Serbia. Data were colected from 30 farms by surveying the farmers. The questionary consisted of 75 questions pertaining to the following: general information on the farm, and on calving, nutrition, weaning, housing, hygiene of space for cows and calves, on calf diseases and diseases prevention measures. According to the answers, the average number of all categories of cattle at the fams is 18 heads. Calves are separated from their mothers immediately after birth at 67% farms. They receive colostrum up to two hours after birth at 47% of the farms and immediately after birth at 20% of the farms. Average age of calves at weaning is 13 weeks. Calves begin to use hay usually between the 1 and 2 week of life, and a concentrated feed in 2 week. They are held in different types of pens. Farmers specified diarrhea and respiratory diseases as the most common health problems in calves. Rearing conditions at the farms often do not meet the recommendations and the breeders do not implement all of the necessary preventive measures. Corrections in this regard could contribute to better health of calves.

Smederevska Palanka. The data were collected by questioning the owner of the farm, and in cooperation with the competent veterinary service, during the regular actions of the vaccination of animals.
The survey consisted of a total of 75 questions related to the following: general information on the farm, and on calving, feeding, weaning, nutrition, housing, hygiene of space for cows and calves, on calf diseases and diseases prevention measures. The collected data have been summarized and processed by the Microsoft Office Excel 2010 package. The results are displayed as integers, and due to the amount of data, except tables and charts, they are also shown in the text.

General data
According to results from the questionnaire, the dominant type of livestock production in Danube region is cattle breeding (50% farms). All of the farms are of conventional type (100%), the most often with combined production of milk and meat (58%). The most common is Simmental type of cattle (63%) and, on average, the farms own 18 heads of all categories of cattle (Table 1). This is approximately the same as data by Popović (2014), according to which family farms with up to 19 heads of cattle account for 97% of households in the Republic of Serbia.
Data shows that breeders mostly do not know the reason of calf's death. Secondly, they mentioned respiratory diseases and diarrhea as the cause of mortality in calves. As reasons for loss due to accidents, the breeders mentioned the unprofessional aiding during the difficult calving and some inadequate rearing conditions, which resulted in injuries to calves with a fatal outcome. The occurrence of death due to such reasons indicates that on some farms calves are not kept and treated according to the regulations, such as the Regulation on animal welfare conditions (Anon., 2010). Inappropriate care of the animals may be related to insufficient manpower, motivation and personal traits of breeders (Samolovac, 2016). On the examined farms is a small number of working-age population and the highest percentage of breeders have only a high school completed (Table 1). Similar to the previous, ignorance of the cause of death may be related to the lack of experience, training or interest from the breeders in the study. The situation is similar in other countries. For example, for breeders in Brazil, the world's fifth milk producer, the reason for about 38% of calves' death cases is unknown. The fact that farmers struggled to identify the cause of death highlights the lack of knowledge of signs that could aid them to tackle disease on time and apply preventive measures (Fruscalso et al., 2017).

Managing and housing of cows and calves
In 80% of the farms bed for expecting cow is cleaned (i.e. dirty straw is replaced by fresh) two or more times a day; in 10% is cleaned once a day and in 10% more times a week. For cows in the phase of transition, wich is usually defined as the period of 3 weeks before and 3 weeks after parturition, a clean and comfortable space is needed. Disturbed rest and uncomfortable resting areas in this period may result in a physiological stress response increasing the susceptibility to disease. Furthermore, during the calving, cows are agitated and often change their position, so special attention should be placed on cow comfort in the maternity i.e. calving pen, particularly to aspects of stall surface known to affect comfort when changing positions (Huzzey et al., 2005). However, according to the survey results, none of the farms has a pen for calving and at the calving time the cow remains tethered in place (93%) or is moved to a separate stall bed that is in the same facility (7%).
During calving, the most breeders always provide help to the cow (57%), while others help only in the case of distocia (27%), occasionally (13%), or they call a veterinarian for help (3%). Mainly farmers with a higher number of cows provide assistance from time to time, due to the lack of adequate manpower, which would enable the timely performance of all jobs on the farm.
The breeders usually separate the calf from the mother immediately after birth (67%), which is in line with the usual technology on commercial farms; in 26% farms calves stay longer with their mother, usually all the period until they suck, and in 7% they remain until mother dries them after birth. The cow should be allowed to lick the calf after birth. If the cow does not lick the calf, the newborn should be dried with clean cloths. This practice not only dries the calf but stimulates the calf's blood circulation (Amaral-Phillips et al., 2006).

Chart 1. Providing assistance to newborn calf (*multiple answers)
Data from the Chart 1 indicate that breeders do not give enough necessary care to the newborn calves. This is also supported by the fact that 7% of breeders never wash the pen for newborn calf; 46% of them wash the pen after each calf, and 47% of breeders wash it several times a year. Regular cleaning and desinfection of all surfaces in the stall, especially the floor of the pen is significant for reduction of the infectious pressure and the occurrence of conditional diseases, as is described by Hristov (2002).
The calves are housed in different types of pens, whose average surface is in accordance with the recommended values (Anon., 2010). They are most often together with adult cattle (73%). In others, baby calves are housed separately (13%), or together with older calves (7%), or tied outside the stall (7%). According to the Regulations (Anon., 2010), calves should not be tied.
The straw in the calf pen is completely changed in different intervals, depending on the farm: every day (22%); every two days, with adding the fresh in the meantime (38%); and once a week (33%) or once in two weeks (7%), with adding fresh straw every day.
Ventilation in buildings is mostly natural (60% of farms) and is carried out by opening windows and doors; 17% of the farms also have a fan, while on other farms, calves are kept in semi-open structures (20%) or outside (3%).

Calf feeding and weaning
Nenad Stojiljković et al. 424 On most of the farms (60%) breeders do not let calves suck their mothers but use buckets with a nipple to feed the calves; 55% of them use one bucket for more calves, and 45% have a separate bucket for each calf. The buckets are washed after each use (50%) or at least once a day (50%), but only 15% of the breeders use the detergent when washing.
Of the remaining 40% farms where the calves suck, most breeders wash the cow's udder only if it is dirty (23%), some of them always do udder washing before the calf begins to suck (14%), and some do not wash it at all (3% ). Failure to implement adequate hygiene measures before sucking and feeding calves in a large extent leads to more frequent occurrence of diseases in calves (Samolovac, 2016).
Hygiene measures contribute the calf is less exposed to pathogenic microorganisms from the environment. Beside that, the two most important factors in newborn calf survival are warmth and colostrum. Time after birth at which colostrums is first fed is critical to determining if the calf will acquire an adequate passive immunity and its ability to defend against disease. Calves that don't nurse within 2 to 4 hours after birth often die or become weak and unable to nurse and starve .
According to the responses, the average amount of colostrum that breeders offered to the calf at the first feed is 2 liters, which is in accordance with the capacity of abomasum in the first hours of life. More than half of them know that timely provision of colostrum is very important for calves' health, and mostly they allow calves to consume it within 2 hours of birth (Table 2).
In calves which do not sucking, the temperature of the colostrum, and later the milk (or milk replacer) should be as close as possible to the calf's body temperature, but not below 37 ºC (Romčević et al., 2007;Lang, 2008). Given that quite a high percentage of breeders do not check the temperature, and of those who do it, more than two thirds use hand to determine the temperature, it is not certain that the temperature of colostrum/milk is in accordance with the recommendations. There are also a worryingly high percentage of breeders that can not provide additional heating of the milk prior to the administration, as well as those who do not carry out quality checks prior to the administration of colostrum (Table 2). On the other hand, it is positive that most breeders freeze the colostrum. Freezing and storing surplus colostrum of healthy cows allow appropriate feeding the calves even if there is insufficient quantity of fresh colostrum . However, thawing colostrum at the room temperature is not reccomended, as bacteria double every 20-30 minutes at room temperature (Lang, 2008). On 40% of farms weaning of the calves is rapidly (today they get milk, tomorrow not), and on the remaining 60% it is done gradually, within a week. The average age of calves at weaning is 13 weeks. Calves are weaned when they reach an average 159 kg and when they are able to eat 550 g of concentrate per day. These parameters indicate that full milk and/or milk replacer probably have a significant part in the diet, given that the calves in the mentioned period usually have a lower weight (Romčević et al., 2007;Stojanović et al., 2007).

Diseases and preventive measures
During the day, the breeders most often monitor the calves for about 15 minutes (37%) or up to 30 minutes (37%), but also between 30 and 60 minutes (13%) or longer than 60 minutes (13%), which is usually enough to notice health problem, if any. However, answers on the prevention, appearance and treatment of some calves diseases (Table 3) indicate that breeders give insufficient attention to the health of calves or they do not know enough of the signs of these diseases or about the consequences to the animal (e.g. the weakening of resistance to other diseases, slower waight gain or death). In raising calves, succes or failure depends to a great extent on the breeder's attitude to the calves and the ability to react promptly to the calves'signals (Moran, 2002). The breeders'attitude can best be seen from the following data on diarrhea and respiratory diseases, as the most frequent calf diseases in our study and generally in cattle breeding (Samolovac, 2016;Fruscalso et al., 2017).
In the past year, at almost all of the farms (97%) have been cases of diarrhea i.e. stool that is more liquid than normal and lasts longer than two days. Almost a half of calves at the farm gets sick (46%), but less than half of them is treated (41%). This indicates that breeders do not call often a vet for calves that have diarrhea, and reasons for calling can be found in Chart 2.

Chart 2. Reasons for calling a veterinarian for calf having diarrhea (*multiple)
Most farmers (52%) measure the temperature of sick calf if they estimate it is necessary due to poor condition of the animal, and 10% do it always (as soon as they notice the signs of illness); 38% breeders never measure the temperature. If a calf with diarrhea can still stand, it should continue to receive sufficient quality of milk and a mixture of electrolytes. In calves that can not stand up electrolyte must be compensated by intravenous infusion (Smith, 2010). Another common opinion among breeders is that deprivation of water in the calf with diarrhea can accelerate the healing (Relić et al., 2017a). Calves with diarrhea lose large amounts of fluid and electrolytes, with attendant dehydration and acidosis (Groutides and Michell, 1990). That is the reason that in calves suffering from diarrhea ad libitum availability of water is strictly required (Wenge et al., 2014). In Table 4 is shown that calves of 34% breeders have no permanent access to the water. It is recommended to give calves access to water directly after birth, what also stimulates food intake and growth (Martyn, 2017).
Occurrence of respiratory diseases in the last year has been reported by 33% of the breeders, while the rest did not notice the signs (difficulty breathing, coughing, wheezing and/or discharge from eyes or nose). An average incidence is 26% of calves per farm. Veterinary intervention was necessary for 80% of them. The reasons for calling veterinarian (Chart 3) are in line with determined in study by Samolovac (2016).

Chart 3. Reasons for calling a veterinarian for calf having respiratory disease (*multiple answers)
On 20% of the farm, the breeder never measures body temperature of the sick calves, and the remaining 80% of the farms it is measured as is needed (according to subjective assessment of the farmer).
In addition to the already mentioned measures that are directly related to the specific disease, as general biosecurity i.e. preventive measures the breeders usually carry out control of flies (35%) and rodents (28%) in the stalls. Some consider that for this purpose it is sufficient to keep only one species of animals in the stall (12%), and the least of them have a disinfection barrier at the entrance of the stall (2%). At 17% of the farms any measure aimed at the prevention of diseases is not implemented.
Successful disease prevention requires the simultaneous, regular and proper application of several hygienic-sanitary and veterinary measures (Hristov, 2002;Relić, 2014). According to data in this survey, the breeders implement even less preventive measures than in the similar study by . On small farms where different species of animals are present and where traditional methods of breeding are applied, it is very difficult but it is not impossible to implement certain measures, such as isolation of animals and control of movement. Factors that can influence the application of preventive measures on any farm, regardless of its capacity and the species that are breeding, primarily include knowledge, awareness and economic opportunities of the breeder (Relić, 2014).