Comparative investigations of immune response of calves at different intervals between primary and secondary immunization using inactivated bovine herpes virus 1 vaccine

Bovine herpesvirus 1 (BHV-1) is one of the most siginificant causes of infections of the respiratory tract of cattle and immunoprophylaxis has a key role in curbing this infection. The intensity of the immune response against BHV-1 following immunization using inactivated commercial vaccines varies depending on the type of vaccine, but it is generally believed that they provide good protection from the development of the clinical form of the infection, and that they are safe. The paper present the development of the humoral immune response in fattening calves that were immunized against bovine herpesvirus 1 (BHV-1) at different time intervals between the primary and the secondary immunization. Calves were administered a commercial vaccine, and then they were divided into two groups which were revaccinated on days 14 or 21. Over a course of the 120 days of the duration of the experiment, blood and nasal mucus were sampled 11 times. The blood serum samples were examined for antibodies to BHV-1 using the virus neutralization (VN) test, and the nasal mucus samples were analyzed using the VN test and the ELISA method. Following revaccination, it was established that there was an increase in the antibody titer in blood of all experimental animals, and it was maintained at a high level up until the very end of the experiment (day 120). In the blood serums, maximum mean values for the antibody titer were determined on day 30 in the group that was revaccinated on day 14, and on day 45 in the group of calves revaccinated on day 21. In nasal mucus, antibodies were established at the earliest, using the virus neutralization test, on day 14 following vaccination, and using the ELISA method only after revaccination. The highest antibody titer in nasal mucus was established on day 45 in the group revaccinated on day 21, and on day 120 in the group revaccinated on day 14. Based on the established antibody titer values, calves can be revaccinated using the inactivated BHV-1 vaccine already on day 14. [Projekat Ministarstva nauke Republike Srbije, br. 31084

Koncentracija laktoferina u mlijeku krava tijekom involucije mliječne žlijezde s različitim bakteriološkim nalazima.

Lactoferrin is an iron-binding glycoprotein of the transferrin family, present in high concentrations in secretions from the mammary glands during the involution period, and has antimicrobial ability. To determine lactoferrin concentrations in bovine milk with different bacteriological findings, 151 quarter milk samples were collected on a dairy farm of the Holstein-Friesian breed in Vojvodina, Republic of Serbia. Classical microbiological methods were used for bacteria isolation, and ELISA analysis was used for lactoferrin concentration quantification. The most common isolated bacteria in bovine milk samples were Corynebacterium spp. (32.45%) and coagulase-negative staphylococci (4.64%) with lactoferrin concentrations of 6.0497 ± 1.6774 mg/mL and 5.2961 ± 1.3633 mg/mL, respectively. The lowest mean value of lactoferrin concentration was observed in uninfected quarters and quarters infected with environmental pathogens, while the highest concentration of lactoferrin was in udder quarters infected with Streptococcus agalactiae. One in four milk samples where Staphylococcus aureus was isolated had much lower lactoferrin concentrations (1.1736 mg/mL) than the other three samples (6.2089 ± 0.5016 mg/mL), which requires further research.Laktoferin, glikoprotein koji veže željezo, pripadnik porodice bjelančevina transferin, prisutan je u visokoj koncentraciji u sekretu mliječne žlijezde tijekom involucije i posjeduje antimikrobnu sposobnost. Radi utvrđivanja koncentracije laktoferina u mlijeku krava s različitim bakteriološkim nalazima, prikupljen je 151 pojedinačni uzorak mlijeka na farmi holštajn-frizijske pasmine na području Autonomne pokrajine Vojvodine Republike Srbije. Za identifikaciju bakterija korištene su klasične mikrobiološke metode i ELISA za određivanje koncentracije laktoferina. Najčešće izdvojene bakterije u uzorcima mlijeka krava bile su Corynebacterium spp. (32,45%) s koncentracijom laktoferina 6,0497 ± 1,6774 mg/mL i koagulaza negativni stafilokoki (4,64%) s koncentracijom laktoferina 5,2961 ± 1,3633 mg/mL. Najniža srednja vrijednost koncentracije laktoferina zabilježena je u negativnim četvrtima vimena i četvrtima inficiranim bakterijama iz okoliša, dok je najviša koncentracija laktoferina bila u četvrtima vimena inficiranima vrstom Streptococcus agalactiae. Jedan od četiriju uzoraka mlijeka gdje je bio izdvojen Staphylococcus aureus imao je znatno nižu vrijednost laktoferina (1,1736 mg/mL) od ostala tri uzorka (6,2089 ± 0,5016 mg/mL), što zahtijeva daljnja istraživanja

Available control measures for Q fever in sheep

Q fever is a worldwide zoonosis caused by Gram-negative bacteria, Coxiella burnetii. This antropozoonosis is characterized by a wide spectrum of hosts and vectors. Primary role of domestic animals as reservoirs of human infections emphasizes the accurate prompt detection of Q fever in domestic animals. This microbe can survive for months and even years in dust or soil. Sanitation of endemic foci of Q fever is practically pretty close to impossible because of the high resistance of the causative agent, small infectious dose and various epidemiologies. Within the group of zooantroponoses, Q fever takes a leading position in the region of Vojvodina. This is why Q-fever is considered a specific problem of this province. Control programs against Q fever in sheep and cattle, most frequently recommend serological examination and vaccination of animals. In animals, the most effective vaccines are those composed of inactivated whole phase I bacteria. Bacterial shedding in placental tissue and milk was reduced in experimental infection or in natural C.burnetii infection of sheep and cows vaccinated by phase I vaccines. One of the recommended measures is excluding positive reactors from the flock followed by continuous monitoring and separation of seropositive animals. Milk from seropositive cows must be pasteurized. The aim of the vaccination after lambing season, is to prevent new infections until next lambing of young animals, which were not pregnant. Well-timed sequential vaccination before pregnancy reduces the risk of C.burnetii infection, highly prevents the abortions decreases the shedding rate of C.burnetii after the abortion

Influence of body condition score and ultrasound-determined thickness of body fat deposit in holstein-friesian cows on the risk of lameness developing

The aim of this study was to examine the correlations between ultrasound measurement of thickness of fat over the tuber ischiadicum (TFT), body condition scoring (BCS) and the risk of lameness developing in Holstein-Friesian dairy cows. The 100 cows were enrolled from a population of dry cows on one farm. TFT was measured with ultrasound, and BCS and locomotion score were determined during lactation. Of the 100 cows, 31% developed lameness during lactation. The highest proportion of lame cows was in cows with BCS≥4.25 (66.7%). The risk of lameness developing was higher in cows with BCS≥4.25 (OR=7) and ≤3.25 (OR=2) than in cows with optimal BCS=3.75. Cows in the lower TFT quartile had a higher proportion of lameness, but not those in the upper quartile. TFT may have some value as a predictor of lameness in thin cows. The best prediction of lameness in both fat and thin cows (ROCAUC=0.8725, P<0.01) occurred when both BCS and TFT values were used together. The risk of developing lameness was positively correlated with BCS, negatively correlated with TFT and negatively correlated with their interaction. For fat cows, BCS assessment is a suitably strong predictor of lameness. In normal or thin cows, lameness prediction required the combination of both BCS and TFT measurements

Electrical conductivity of milk and bacteriological findings in cows with subclinical mastitis

Intramammary infections change the composition of milk and increase electrical conductivity of milk and decrease milk electrical resistance. Electrical conductivity has been used to detect mastitis during last four decades. The aim of this research was to examine the reliability of the milk electrical conductivity measuring in detection of subclinical mastitis. The experiment was conducted on a dairy farm of Holstein-Friesian breed. A total of 113 quarter milk samples were examined, 55 samples from cows in first stage of lactation and 58 from cows in third stage of lactation. Electrical conductivity (EC) of milk samples was detected by Hand-held EC meter (Draminski mastitis detector). Quarter milk samples for bacteriological analysis were taken aseptically during the morning milking in sterile test tubes. Bacteria growth was not detected in 60 quarter milk samples (53.1%), while in the other 53 samples bacteria was found (46.9%). The most common isolated bacteria in first and third stage of lactation was Corynebacterium spp. (38.9%) and coagulase - negative staphylococci (3.54%). High quality and healthy milk with Draminski mastitis detector was observed in 59.29% of the samples (67/113). Cows with mastitis may not always show an increased EC of milk from the infected quarter. Electrical conductivity of milk can give useful informations about udder health status, but hand-held EC meters, such as Draminski mastitis detector, cannot be used alone in diagnosis of subclinical mastitis