– Detection of subclinical mastitis in five different breeds of cows were done on the territory of a municipality Ključ, through all four year seasons by using the California mastitis test, at the level of the udder’s quarter with a certificate of bacteriological findings in order to justify their application in the diagnosis of mastitis. In total, 2150 cows of different breed composition: Simmental 1090, red Holstein 322, Holstein-Friesian 340, montafon 108 and various crossbreeds of 290 in total. After 1978 tested cows, 56.02% of cases had positive reactions to the California mastitis test. The most common positive reaction we found in the milk was in one or two quarters with the intensity of the reaction of one and two plus. The most common causes of mastitis were staphylococci, streptococci and mixed infections. Continuing use of these methods it is possible to timely detect the presence of subclinical mastitis and get satisfactory results in the prevention and treatment of mastitis as well as increasing the quantity and improving the quality of milk.

Considering there are different and inconsistent results of the wider use of gonadotropin-releasing hormone or its analogs in cattle breeding and due to scarce research studies in the field of individual breeding, we decided to explore the influence of gonadorelin Fertagyl on the results of the blood serum progesterone levels and conception of cows in veterinary field practice. Examination of the progesterone levels involved 14 (fourteen) cows treated with gonadorelin (GnRH), Fertagyl, manufactured by Intervet, according to the manufacturer’s instructions dose of 2,5ml (250 micrograms), within five minutes after insemination. There are individual differences in progesteron concentrations according to days of sampling in treated cows, respectively individuality is manifested in all cows between days of blood sampling, except for period of luteolysis (18th day) in non-gravid cows. Our research results indicate that there is a tendency for progesterone concentration to increase in gravid cows treated with Fertagyl at the time of insemination. Progesteron concentrations in blood serum in gravid cows were higher for 0.21 ng/ml in first three days after insemination and at 6th day those concentrations were higher for 0.40 ng/ml compared to non-gravid cows.

Lameness in sheep, especially in semi-extensive breeding of Dubska pramenka, which starts in the interdigital region, was the motive of our morphological and histological research, in order to and in some way, bring the structure of the interdigital sinus in correlation with the appearance of this pathological state that causes extensive economical losses in the domestic sheep breeding,. The anatomical location of the interdigital diverticulum, its histological structure, which point to abundance of sebaceous glands around the hair follicles surrounding the interdigital opening and interdigital glands in deeper layers, point to the suggestion that their secretion increases due to poor hygienic keeping conditions. Pathogens - anaerobic microorganisms, which are most commonly causing the contagious lameness find the ideal conditions for their growth and reproduction because the secretion of these glands is likely "to close" the only "air" communication - interdigital opening.

Glandulla mammae is a secondary sexual characteristic. The composition and structure of the mammary gland depends on the functional state of the gland and is affected by hormones. The mammary gland reaches its full development during gestation and it becomes functional and secretory upon delivery. Lactocytes of the mammary gland may be squamous in shape, low or high prismatic, depending on the phase of the glandular cycle. Lactocytes are affected by LTH hormones due to which they are called prolactin. The function of the mammary gland is also affected by STH, and indirectly by TTH. Examined material was taken from Central Bosnia Canton, under field conditions of veterinary practice. The assay of histological features of the mammary gland of Dubska pramenka was conducted during the dry period as well as during lactation. The total number of animals was 16, eight (8) during the dry period and eight (8) during lactation period. Following the development of histological preparations, we conducted a descriptive overview - interpretation of the histological structures. The study of histological preparations of the mammary gland of Dubska pramenka during the dry period and lactation shows that the parenchyma is well developed, more or less, with reduced intersticium. Histological appereance of the lactocytes resembles that of the perifollicular tissue, the presence of different cells is higher during the lactation - the onset of glandural cycle. Well-developed lactiferous ducts with cavity, with or without secretion, but with preserved epithelium are the characteristics of both periods. The glandural tissue is well-developed and the secretion was present regardless of the examination period.

Success in cattle breeding is one of the most important goals in livestock farming and it requires particular attention when it is about securing unobstructed reproduction. Final goal in cattle breeding is to produce one live calf per year, which will likewise enhance milk production through successful pregnancy. The aim of our research was to monitor uterine involution speed with aid of ultrasound device and make records when cows are ready to be inseminated again, which cows need more time to complete involution and how many cows will have uterine disorders and require therapy. The experiment was carried out from October 2009 until the end of January 2010. In our experiment 50 cows were included and 412 transrectal ultrasound examinations were performed. Cows were transrectally examined, starting from 6th day postpartum until 52 days postpartum. Speed of uterine involution has been monitored through decrease of uterine horn diameter and wall thickness. Cows with normal puerperium have completed involution in the period from 38 - 45 days postpartum, while those with abnormal puerperium needed more time to complete it or required therapy of disturbed uterine status. In total 48% of cows had normal uterine involution, 52% of cows had some abnormalities in involution and 10% of cows in experiment required therapy. With continuous monitoring of reproductive tract in cattle with ultrasound it is possible to timely detect right time for first insemination postpartum, decrease period of open days or to detect abnormalities in uterine health status and treat it.

We have performed diagnostics of sub clinical mastitis in three different cow breeds with comparison of California mastitis test results, somatic cells count at quarter level and with bacteriological findings confirmation in order to justify their appliance in mastitis diagnostics. In total, 90 cows or 360 quarters of mammary gland have been examined. In 63.3 % of the examined cows, with different racial origin, positive reaction to California mastitis test have been established. Usually, positive reaction have been found in milk of one and two quarters, with reaction intensity of one and two plus. SSC higher than 200.000 in 1 ml is established in 60 % of cases and the most often causes of mastitis were staphylococcae, streptococcae and mixed infections. With continuous use of this methods it is possible to timely detect presence of sub clinical mastitis and so to obtain satisfactory results in prevention and therapy of mastitis, as well as improvement in amount and quality of milk.

With 268 heifers in farm breeding, udder examination has been performed for clinical mastitis during 14 days after calving. From each quarter we took secretion samples and performed bacteriological analysis. From total number of heifers, 56 of them had shown clinical signs of inflammation, and 12 were bacteriologicaly positive. By bacteriological analysis mastitis pathogens had been found, even in 14 heifers without inflammation signs, at least until the end of test period. From the total number of tested heifers in 3,35% of cases Streptococcus agalactiae have been found, 4,85% coagulase positive staphilococcae (CPS) and 1,49% Corynebacterium pyogenes. Because coagulasa positive staphilococci were the most present bacteries in the period of 14 days, we made opinion that the same are the most often mastitis pathogen. Heifers with intramammarian infections like these, represent source of infection fot other non-infected animals in herd.