Features of intensive farming can seriously threaten pig homeostasis, well-being and productivity. Disease tolerance of an organism is the adaptive ability in preserving homeostasis and at the same time limiting the detrimental impact that infection can inflict on its health and performance without affecting pathogen burden per se. While disease resistance (DRs) can be assessed measuring appropriately the pathogen burden within the host, the tolerance cannot be quantified easily. Indeed, it requires the assessment of the changes in performance as well as the changes in pathogen burden. In this paper, special attention is given to criteria required to standardize methodologies for assessing disease tolerance (DT) in respect of infectious diseases in pigs. The concept is applied to different areas of expertise and specific examples are given. The basic physiological mechanisms of DT are reviewed. Disease tolerance pathways, genetics of the tolerance-related traits, stress and disease tolerance, and role of metabolic stress in DT are described. In addition, methodologies based on monitoring of growth and reproductive performance, welfare, emotional affective states, sickness behavior for assessment of disease tolerance, and methodologies based on the relationship between environmental challenges and disease tolerance are considered. Automated Precision Livestock Farming technologies available for monitoring performance, health and welfare-related measures in pig farms, and their limitations regarding DT in pigs are also presented. Since defining standardized methodologies for assessing DT is a serious challenge for biologists, animal scientists and veterinarians, this work should contribute to improvement of health, welfare and production in pigs.

Heat stress in dairy cows is caused by a combination of environmental factors (temperature, relative humidity, solar radiation and air movement). Continual genetic selectin for greater performance results to increased sensitivity to heat stress. It was one of the reasons why lactation curve during summer has decreasing trend compared to spring in which lactation curve maintained within high levels. The trial was conducted in spring (April-May) and summer period (June-July) on total of 40 dairy cows of Holstein-Friesian breed in early lactation period (first 60 days of lactation). Milking capacity in cows and milk chemical ingredients (milk fat and proteins) were statistically significantly higher in the spring period compared to summer, while higher values of lactose were not statistically significant. Total average milk production per cow was significantly higher in spring period (42.74±4.98l) than in summer (39.60±5.09l) at the level of P<0.05. A higher rate of milk fat was recorded in spring in relation to summer period the level of significance being P<0.01. The content of proteins in milk in spring period was 13% higher than in summer. The established difference was highly statistically significant (P<0.001). Obtained values for percentage of lactose varied slightly (4.45±0.54% in spring versus 4.03±0.24% in summer period; P>0.05).

This study was conducted in five dairy farms with different capacity (farms A with 47, B 12, C 10, D 14 and E 24 Simmental cows, aged between 4 and 5 years and body weight about 600 kg) in order to determine a relationship between rearing system, Animal Needs Index (ANI) and milk traits. Loose system of cow rearing was used in open stalls in farms A and C, while in other farms cows were tied in closed stalls. In two farms, there were outdoor pens, permanently available to cows on farm A, and during daytime on farm D. Rations for dairy cows were equal in all five farms and suitable for daily milk production about 20 kg with 4.0 % milk fat and 3.5 % milk protein. It was established that total ANI scores for farms were A 35.5, B 9.5, C 24.5, D 26.5 and E 10.5. The welfare levels in farms B and E were not sufficient, in farms C and D were very good, while in farm A it was excellent. A very significant influence of rearing system on cow welfare was found (p<0.001). A significant influence of rearing system (p<0.01) on average daily milk yield, milk yield in standard lactation, milk fat (kg), yield of 4 % fat corrected milk and yield of proteins (kg) were noticed. The influence of the rearing system on milk fat content (%), dry matter (%), protein (%) and lactose (%) was not statistically significant. Differences between ANI score, daily and standard lactation milk yield were very significant (p<0.001), as well as differences between ANI and the amount of milk fat (kg), protein (kg) and amount of 4 % fat corrected milk.

In this paper are described the most important stressors in intensive sheep production on farms and pastures. Stressors on farms and pastures mostly originate from adverse housing conditions, improper zootechnical procedures, veterinary procedures (treatment, vaccinations, blood tests, surgery), animal husbandry procedures (labeling, weaning, grouping, shearing, shortening the tail, hoof care), unsuitable weather conditions (extreme heat and cold) and insufficient nutrition. The paper puts out special emphasis on the consideration of period of life in which sheep were subjected to additional loads and susceptible to effects of these stressors, such as birth, juvenile period, puberty, oestrus, advanced pregnancy, parturition and the puerperal period. [Projekat Ministarstva nauke Republike Srbije, br. TR 31086 i br. TR 31053]

The most significant welfare problems in dairy calves in intensive rearing conditions have been investigated in this paper. These problems mainly result from inadequate intake of colostrum (separation from the dam), inadequate ventilation (resulting in inappropriate airflow, low or high temperatures, high humidity and poor air quality), poor floor conditions (wet floor, without bedding), inadequate monitoring of health, exposure to pathogens causing respiratory and gastrointestinal disorders and occurrence of iron deficiency. In addition, on cattle farms in our country welfare problems in calves originate from continuous restocking (no "all in - all out") and mixing calves from different sources, as well as insufficiently balanced solid food, insufficient access to water and generally poor response of farmer to health problems, especially necessary dietary changes. A special welfare problem is insufficient floor space allowance which results in calf?s discomfort.

The effects of general and special biosecurity measures to prevent introduction of infectious agents in a dairy farm or its spreading from farm were analyzed in details in this paper. Investigations were conducted on five different dairy farm production with different technology and capacity using a questionnaire method (Hristov and Stankovic, 2009), as well as scrutinizing their positions in relation to possible sources bio-risks from the near and far away environment. Test results showed that there are serious shortcomings on all observed farms, regarding the possibility of introduction of infectious agents in the production herd, and its possible spread to the environment. Although all fenced and a position of the most of the farms mostly favourable, there are some serious threats to the herd health and farm production, regarding open space and lack of green belt, the uncontrolled presence of wild birds and rodents in facilities and even in feed storage, as well as contact of the employees with other cows not belonging to the farm.

Three farms of dairy cows (A, B and C) were observed for health disorders of dairy cows and suckling calves. Farm A is farm with tied system of rearing, with 1100 cows, while farms B and C have 400 and 600 cows kept loose with outdoor pens, respectively. Data regarding welfare criteria of dairy cows (health, feeding, housing and behaviour) were collected and analysed through Protocol of Welfare Quality (2009). Health disorders of dairy cows and suckling calves were collected and statistically analysed by chi-square test (?2 test). Welfare of all of three dairy farms were assessed as acceptable, meaning that provided welfare conditions meet the minimum requirements of animals. Principle of provision of good health was rated as acceptable (?20 points) on farm A, while on farms with loose system (B and C) overall health rated as excellent (?80 points). Occurrence rate of reproductive, locomotor, skin and claws disorders and digestive and systemic disorders of dairy cows and calves up to 4 months old were very different between three farms (A, B, C) with ?2-values of 2901.71, 252.02, 204.08, 1152.31 and 184.23 respectively; ?<0.01). According presented data, it is obvious that the majority health problems were observed in tied system of rearing, on farm A, such as reproductive disorders and mastitis, as well as injuries and bad body score and lame cows. The most serious health problems of the calves were diarrhea and bronchopneumonia of different etiology. [Projekat Ministarstva nauke Republike Srbije, br. TR 31086]

The aim of this study was to investigate changes of serum testosterone, scrotal circumference, body weight, and semen characteristics in a Meat Institute Sheep (MIS) population during their developing period (between 3 and 17 months). Correlative relationships among parameters were also tested. Body weight and scrotal circumference were measured monthly, blood samples for testosterone levels were taken bimonthly (3-17 months), and semen samples were collected by an electroejaculator between the ages of 9 and 17 months. The analysis showed that the average serum testosterone levels ranged from 1.83 to 13.28 ng/mL and significantly depended on the age of the lambs (P < 0.05). The trend in the level of serum testosterone was characterized by pronounced variability throughout the study period. Changes in scrotal circumference and body weight were significantly dependent on age. Ejaculate volume, sperm motility, and the percentage of live spermatozoa increased with age, except for the percentage of abnormal spermatozoa, which decreased with age. Correlations among serum testosterone, scrotal circumference, and body weight were moderately to highly positive and highly significant. All parameters of semen quality were poorly correlated with testosterone and body weight, while scrotal circumference was in moderate correlation only with ejaculate volume and live sperm count (P < 0.05).