Seroprevalence of Chlamydia abortus infection in sheep and goats in Iran

Chlamydia abortus is a zoonotic bacterium that commonly causes abortions in ruminants. This microor-ganism is one of the most important infectious agents causing abortion and major economic losses in sheep and goats worldwide. The objective of this study was investigating the status of C. abortus infection among small ruminant flocks of some regions in Iran. A total of 1440 sera samples from sheep and goats were collected from 113 flocks of 7 provinces and tested with CHEKIT-ELISA for antibodies against C.abortus. The study detected overall se-roprevalence levels of 25.6% for the individual animals, and 81.4% flocks had at least one positive animal. Analysis of different sheep groups based on their age revealed that the highest numbers of infected animals were registered in the 2 years age group [p<0.05]. These results indicate that the seroprevalence of C. abortus infection in sheep and goats is very high in Iran. Therefore, it is necessary that Iran's veterinary organization set up appropriate surveillance and control programs to reduce economic losses of this disease

[ study of oocyst shedding pattern and weight changes in neonatal calves experimentally infected with Cryptosporidium parvum]

Background: Cryptosporidium parvum is a protozoan parasite which belongs to apicomplexa phylum. The parasite infects both wild and domesticated animals and human beings as wellOBJECTIVES: The purpose of the present study was to detect oocyst shedding and diarrhea pattern in experimental cryptosporidiosis and their correlation with weight loss in neonatal calves

Methods: Twelve Holstein calves of both sexes were obtained at birth from dairy farm and randomly divided into two groups of 6 calves. Six calves were orally infected with 10[7] C.Parvum oocysts at the 12h post parturition. The control group was not infected. Clinical signs were examined and fecal samples were collected by the rectal examination twice a day. All calves were weighed from day 0 to day 30 with 3 days intervals to determine effects of cryptosporidiosis on weight gain

Results: All infected calves were noticeably depressed and had a decreased appetite from 3 days post inoculation [DPI] while they received colostrum. Subsequently, watery diarrhea with clumps of mucus and yellow or pale changes of feces color were observed. The infected calves have had diarrhea for 5-8 days that remarkably had got dehydrated. The most severity of diarrhea was 4-6 DPI. Oocyst excretion started 4 DPI, peaked at 6 DPI [60.48×10[6] +/- 9.03oocysts/g feces] and continued until 11 DPI. Control calves had no diarrhea and other clinical signs during the whole period of the trial. The mean weight gain of control group was significantly higher than inoculated group during experiment [p<0.001]. The Weight of the infected calves was retarded until 9 days old and then risen subsequently

Conclusions: Present study showed the role of C.Parvum as the primary cause of diarrhea and weight loss among neonatal calves

[Control and eradication program for bovine brucellosis in Iran: an epidemiological survey]

Brucellosis is a zoonotic disease that is widely distributed throughout the developing countries. The status of bovine brucellosis combating program in Iran from beginning to now was reviewed. The information of 59 year combating against bovine brucellosis were obtained from Iran Veterinary Organization. Bovine brucellosis was first recognized in 1944 in Iran and is now endemic. In 1949, a bovine brucellosis combating program was setup which included vaccination of female calves with strain S19/RB51, infection diagnostic testing and slaughtering the infected cattle. Prevalence of brucellosis among industrial and semi-industrial dairy cattle calculated as 0.3%. Controlling and prevention of bovine brucellosis is far more complex than vaccination, testing and slaughtering the infected livestock. A financially well- supported control and eradication program and joint efforts between the farmers and governmental authorities are needed as a mean to prevent the spreading of disease. Without these, even a very good strategy will fail

Relationship between in vitro antimicrobial sensitivity of bovine subclinical mastitis isolates and treatment outcome in lactating dairy cows

The objective of the present study was to determine whether there was an association between in the in vitro antimicrobial sensitivity test results of subclinical mastitis pathogens and bacteriological cure following intramammary treatment using a combination of nafcillin, penicillin, and streptomycin [NPS]. Eighty-six intramammary pathogens from 43 cows were examined in this study. Most intramammary infections were due to coagulase-negative staphylococci, coliforms, and environmental streptococci. The antibiotic sensitivity to NPS was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for sensitive, intermediate, and resistant isolates in the standard treatment group [3 intramammary infusions of NPS once daily] were 84.44, 88.9, and 100%, respectively. These figures in the extended treatment group [6 intramammary infusions of NPS once daily] were 100% for the 3 categories. Bacteriological cure was not associated with the sensitivity test result. Based on this study, Kirby-Bauer sensitivity test results were not useful as predictors of the bacteriological outcome of subclinical mastitis treated with intramammary NPS

Conventional and extended intramammary therapy of persistent subclinical mastitis using nafcillin-pencillin-dihydrostreptomycin in lactating dairy cattle

The objective of the present study was to compare the efficacy of conventional and extended intrammamary [IMM] therapy of persistent subclinical mastitis in lactating dairy cattle using nafcillin-penicillin-dihydrostreptomycin combination [NPD]. Sixty-five dairy cows with 126 infected quarters were enrolled in the study. Infected cows were allocated randomly to 1 of 3 different treatment regimens: [1] conventional group: NPD administered IMM 3 times at 24-h intervals [20 infected cows, 43 intramammary infections [IMI]], [2] extended group: NPD administered IMM 6 times at 24-h intervals [23 cows, 43 IMI], and [3] untreated control group [22 cows, 40 IMI]. The overall bacteriological cure [BC] rates for subclinical IMI were 86.04%, 100%, and 20% for the conventional, extended and the control groups, respectively; indicating a higher BC rate [P<0.0001] for the treated groups than the control group. Significant difference [P=0.029] concerning the BC rate was also observed between the extended and the conventional groups. Significant difference [P=0.0021] in somatic cell count [SCC] was detected between the extended and the conventional groups. Significant difference [P=0.0021] in somatic cell count [SCC] was detected between the extended and the control group. Fat percentage increased in the conventional [P=0.029] and in the extended [P<0.0001] groups, and protein percentage increased only in the extended group [P=0.0016]. There was no significant difference in posttreatment milk production between the groups [P>0.05]. Results of this study indicate that NPD therapy was effective in eliminating subclinical IMI in lactating dairy cows, and that extended therapy enhanced BC rate and reduced SCC

Relationship between in vitro susceptibility of bovine subclinical mastitis isolates and bacteriological outcome of intramammary treatment with cefquinome

The objective of the present study was to determine whether there was an association between the in vitro antimicrobial susceptibility test results of subclinical mastitis pathogens and bacteriological outcomes of intramammary treatments using cefquinome. A total of 110 intramammary pathogens from 51 cows were assessed in this study. Most intramammary infections were due to coagulase-negative staphylococci, environmental streptococci, and coliforms. The antimicrobial susceptibility to cefquinome was determined using the Kirby-Bauer disc diffusion method. Bacteriological cure rates for the sensitive, intermediate, and resistant isolates in the standard treatment group [three intramammary infusions of 75 mg cefquinome at 16 h intervals] were 82.4%, 90%, and 87.5%, respectively. These figures in the extended treatment group [six intramammary infusions of 75 mg cefquinome at 16 h intervals] were 83.3%, 100%, and 100%, respectively. Treatment outcomes were not associated with the results of sensitivity tests in the standard group. However, in the extended group, the probability of a bacteriological cure was lower in quarters from which cefquinome-sensitive pathogens were isolated than the quarters from which intermediate or resistant pathogens were isolated. Based on this study, the Kirby-Bauer susceptibility test result is a poor predictor for the bacteriological cure of subclinical mastitis treated with intramammary cefquinome

Serological study of Neospora caninum in pregnant dairy cattle in Tehran, Iran

Seven hundred and sixty-eight blood samples of pregnant cattle from four Holstein dairy herds that are farmed in the vicinity of Tehran were used to evaluate the seroprevalence of Neospora caninum infection by enzyme-linked immunosorbent assay [ELISA]. Two hundred and ninety-eight of the 768 blood samples [38.8%] were positive for this infection. The prevalence of infection in the herds varied from 18.7% to 65.1%. The abortion rate in seropositive and seronegative animals was 20.67% and 10.11%, respectively. Thus, the risk of abortion was approximately double the rate in seropositive cows [p<0.0005]. There was a high correlation between the infection rate and the age in one herd. In other three herds, no significant correlation was found between infection rate and age. This is the first extended study with regards to the rate of Neospora caninum infection in pregnant cattle in the vicinity of Tehran

Effect of systemic antibacterial administration during prepartum period on coagulase negative Staphylococcal intramammary infection in Holstein Heifers

A total of 183 coagulase negative Staphylococcal infected quarters and 64 uninfected quarters were randomly allotted to 4 experimental groups: infected quarters that did not receive any treatment [positive control group; n = 60]; infected quarters that received Tylosin [n = 61] or Cefquinome [n = 62] and also uninfected quarters that did not receive any treatment were considered as negative control group [n = 64]. Treated heifers received Tylosin or Cefquinome 10 to 14 days before the expected calving date. The bacteriological cure rate based on sampling obtained 3 days after calving was significantly higher [P<0.01] in mammary glands treated with systemic Tylosin [85.3%] than in the positive control group and mammary glands treated with systemic Cefquinome [69.4%]. At the same time Tylosin treated heifers had significantly lower [P<0.01] somatic cell count scores compared to the positive control and Cefquinome groups. With the exception of one heifer that calved 8 days earlier than the expected calving date, there was no detectable antibiotic residues in the milk of the treated heifers on the 3rd day of lactation

[ estimation of national average of milk somatic cell count and production losses due to subclinical mastitis in commercial dairy herds in Iran]

Using the database of the Animal Breeding Center of Iran and based on the eligible test-day data from 78969 cows in five provinces: Tehran [with 44129 cows], Ghazvin [6668], Zanjan [1767], Isfahan [7572], Khorasan-e-Razavi [14521] and others [4312] the averages of 426850 +/- 966840 and 473860 +/- 605330 cells/ml of milk somatic cell count [SCC] was calculated for individual cows and herds respectively. A Pearson's correlation coefficient of -0.174 revealed a highly significant negative correlation between test-day milk production and SCC [p<0.01]. The annual production losses of approximately 150000 tons of raw milk in the price of 420 billion Rials were estimated at the national level

Association between digital disorders and reproduction indices in dairycows:study on farm level

This prospective longitudinal study deals with the associations between digital disorders and reproduction indices in dairy cattle on a farm in the vicinity of Tehran. It was carried out on 225 postparturient Holstein heifers. The evaluation of lameness due to digital disorders on postpartum period of heifers were done and after diagnosis of lameness [based on a 5 points lameness scoring system], the digital lesions and reproduction data of lame cows were recorded in a pre-established questionnaire and comparison with reproduction indices of other healthy heifers were made statistically using Chi Square and Student "t" tests and the relative risk "R.R." for each of indices was calculated and 95% confidence interval was made. Seventy-six cows among 225 cows were diagnosed lame in the period of study [30 months]. Digital dermatitis [28.9%] and Sole ulcer [21.2%] were the most prevalent lesions. All reproduction indices in this study including Projected minimum average days open, Days to first service, Projected minimum calving interval, Days in milk, Services per pregnancy for all cows, Services per pregnancy for pregnant cows, Conception rate at first service and Overall conception rate were found significantly different between lame and control groups [p < 0.0005]. 95% confidence interval for R.R. indicated that in lame cows the relative risk of negative rates of reproduction indices are significantly higher than non lame cows. It was concluded that pain and stress due to digital lesions play a key role in suppressing observable behavioral estrus which follows to negative changes of reproduction indices and other undesired consequences. On the other hand, pain may also suppress feeding and ruminating functions, leading to negative energy and protein balances and a low Body Condition Score [BCS] specifically in postpartum period. Thus, in order to mitigate the undesired effects of lameness on reproductive system and reproduction performance, early diagnosis and treatment of digital lesions is needed to be established

Pregnancy rates of frozen embryos recovered during winter and summer in Sistani cows

During spring, summer and winter seasons, Sistani donor cows, with normal reproductive status, were superovulated and embryos were recovered non-surgically on day 7. Grade A blastocyst embryos were either transferred fresh [spring] or frozen [summer and winter]. Recovered embryos during summer and winter were exposed to glycerol and frozen using conventional method. During spring season, recipient females [n = 70] were synchronized using two consecutive injections of prostaglandin F[2alpha] analogue, 14 days apart. On day 7 after the ensuing cycle, the females were assigned into three groups to receive single embryo, either fresh [n = 14; control; recovered embryos in spring] or frozen blastocyst recovered and frozen in summer [n = 27] or winter [n = 29]. Pregnancies were diagnosed by ultrasound examination, 30 days after non-surgical embryo transfer. Pregnancy rates following transfer of fresh embryos [64.3%] were higher than those that received frozen-thawed embryos [17.86%; P<0.05]. There was not any significant difference between pregnancy rates of recipients receiving embryos frozen in summer [18,5%] or winter [17.2%; P>0.05]

report of an ovine holoacardius acephalic monster

Presentation of a very rare monster case in the sheep was highlighted. A monster lamb twinned to a normal lamb. Cesarean section, morphological examination and necropsy. At cesarean operation, a live male twin and a henotypically male monster were delivered. The monster was diagnosed as Holoacardius acephalus

[Effect of reducing dose of GnRH analogue used in heat-synch program on pregnancy rate and day open of dairy cows]

To reduce the cost of hormones used in Heat-synch protocol in dairy cows. Enpenimental study.144 Holstein cows, at 50 days postpartum. Cows randomly assigned into 3 groups: [1] 40 cows; 7.5micro g luliberin, IM. [2] 45 cows; 15 micro g luliberin, IM. Seven days later in both groups, 150 micro g D-cloprostenol, IM 25 hours later Img Estradiol Benzoate was injected. Cows olserved for 48 hours and inseminated based on standing heat. Cows that did not display estrus were inseminated at 48 hours after estradiol injection. [3]Control: group in=59, did not received any treatment and were inseminated 12 hours after displaying estrus. Pregnancy was diagnosed on day 42 after AI via rectal palpation.Days open and pregnancy rate were analyzed by One-way ANOVA and chi square tests, respectively.The number of days open did not differ among experimental groups [group one: 104.17 +/- 7.76 days, group two: 106.28 +/- 6.24 days and the third group: 111.86 +/- 2.33 days [P>0.05]. Pregnancy rate to the first service was not different among groups [group one: 47.5%, 19/40, group two: 48.88%, 22/45, third group: 32.20%, 19/59][P>0.05]. In conclusion, reducing the dose of GnRH analogue [Luliberin] to half of the full dose did not affect pregnancy rate and days open. Therefore the cost of Heat-synch program can be reduced by using half dose of Luliberin

[Effects of Dexamethasone injection at the end of diestrous period on the estrous cycle length in Holstein heifers]

Objectives: Evaluation of the effects of dexamethasone on estrous cycle length

Design: Clinical trial

Animals: A total of 12 Holstein heifers at 16 month of age, 340kgs mean body weight and the average estrous cycle length of 20 days were selected

Treatment: Dexamethasone [4mg, im, Colvasone, Placebo [4mg, im, injectable Water solution] and PGF2a . Procedurs: The estrous cycles of the heifers were synchronized with two injections of PGF2a fourteen days apart . Estrous period [day=0] was detected with observation of estrous behaviors and evaluation of grafian follicle and regressed corpus luteum with rectal pulpation.In the treatment group, dexamethasone was injected at 12h intervals on days 13 to 17 of the iduced estrous cycle in six synchronized heifers .Blood sample were collected on day 13 and 21 via coccygeal vein puncture. Presence of corpus luteum was evaluated with rectal pulpation, and estrous behaviors were detected with observation at mentioned period . In control group ; water solutiom was injected at 12h intervals on day 13 to 17 of the induced estrous cycle in six remained synchronized heifers and serum progesterone assay, rectal pulpation and estrous detecion were accomplished as the test group

Statistical analysis: Difference between serum progesterone levels on day 13 and day21 of estrous cycle were statistically analysed by student t- test and difference between the number of animals suffered from luteolysis on day 21 of estrous cycle were analysed by fisher exact [two tailed] test

Results: In the test group, corpus luteum regressed normally in 4 heifers [66.6%], showing behavioral estrous and serum progesterone levels less than 0.5ng/m1 . However, two treated animals [33.3%] did not show estrus on day 21 of the cycle, retaining their corpura lutea with the serum progesterone concentrations higher than 1 ng/ml, persisting high until day 27 of estrus in one, and day 34 in the other . All the heifers in the control group with high concentration of progesterone on day 13 of the cycle returned to estrus on day 21 [100%] and showied serum progestrone levels less than 0.5 ng/ml

Conclusion: Findings of present study shows that dexamethasone injection at diestrous could not significantly inhibit, the endogenous regression of corpus luteum in Holstein heifers, and/or the presence of new estrous cycle

[ effect of a mastitis control program onsome udder health and milk quality indices in a large dairy herd in Tehran province]

Objective: to evaluate the effect of a mastitis control program [based on the mastitis prevention, elimination and monitoring] on a herd udder health and milk quality status

Design: field trial

Animals: a large Holstein dairy herd of 1150 dairy cows

Procedure: 1] Evaluating the herd udder health status [by CMT and milk sampling born 19.34% of the milking cows for bacteriologic culture, 2] Canying out a control program [Consisted of: blitz treatment of Shep. ag., Post milking teat dipping by a 2.5% povidone Iodine solution with 5% glycerin, dry cow combination therapy, systemic antibiotic therapy of late pregnant heifers, bedding management, early detection, and good record keeping of clinical cases as well as continuous monitoring of udder health and milk quality by using bulk tank milk analysis], 3] Reevaluating the herd udder health status [by CMT and milk sampling from 13.2% of the milking cows for culture]. Statistical analysis: Chi-square test, Analysis of variance,Correlation coefficient, Fisher's exact test

Results: 1] Significant decrease in point prevalence, and incidence rates of clinical mastitis, relative 6equency of CMT-positive quarters, relative frequency of samples from which Strep. ag., Staph. Aureus and Coliforrns yielded and distribution of Strep. ag. and Staph. aureus in clinical cases, 2] Significant increase in relative frequency of samples from which C. bovis yielded, relative frequency of samples yielding no microorganism and dishibution of environmental Streptococci, C. bovis and no growth in clinical cases, 3] Significant decrease followed by an increase in BTSCC [with an average of 225080 cells/ml], significant decrease in staph. count [with an average of 2726 cfu/ml] being noticed at the beginning of monitoring only, and absence of significant differences in TBC, Coli. Count and Strep. count [with averages of 56996,17131 and 9948 cfu/ml, respectively]. In addition, in 76% of weekly bulk tank milk samples, Strep. ag. and Staph. aureus were not detected, 4] No correlation between the concentrations of major contagious pathogens and herd BTSCC and a significant positive correlation between staph. count and BTSCC were observed

Clinical implications: seemingly, the achievement of further improvement in mastitis status of the studied herd [i.e., eradication of Strep. ag. and effective control of Staph. aureus] would be subjected to: Continuous supervising of post milking teat disinfection and shifting from teat spraying to dipping, monthly measurement of individual cow SCC, washing and disinfecting teat cup liners between cows during milking and using more effective dry period intramarnrnary preparations as well. In addition to improve quality of herd milk, good udder preparation prior to milking is advised

[Abortion and infertility due to bovine venereal campylobacteriosis in Tehran province]

Bovine Venereal Comylobacteriosis is still a serious problem of dairy herds in Tehran province. Most of these herds use natural service to breed cows. However, artificial insemination is also used in some herds. In a herd of 184 Holstein cows, located in southern part of Tehran, compylobacter fetujs var. venereal is was isolated from an aborted fetus and classified in veterinary organization central laboratory. Further investigations revealed that eight bulls had been used for natural service for several years in the herd. Manipulating data from reproductive records of the herd showed that nineteen pregnant cows [10.3%], being at different stages of pregnancy, experienced abortion and/or stillbirth during the period of one year. Mean days open was estimated to be 141 days, indicating a severe infertility in the herd. A high percentage of repeat breeders [37.5%] were observed. Cows had also a high incidence of endometritis and cystic ovarian disease [25.7% and 11.6% respectively]. The reproductive status of the herd was improved rapidly following the removal of bulls from the herd and starting A.I. Thirty four problem cows suffering from reproductive disorders such as repeat breeding, endometritis and cystic ovaries, responded promptly to appropriate treatments and conceived either to the first or the second A.I. Abortions were also stopped following the establishment of artificial insemination in the herd