BACKGROUND: Urea is a non-proteinaceous nitrogen source, often used as a substitute for raw ration protein in order to reduce the feeding cost of livestock. OBJECTIVES: The purpose of this study was to investigate the effects of substitution of different levels of slow-release urea with soybean  meal on feed intake, milk production and composition, and blood parameters of lactating cows in early lactation. METHODS: Twelve Holstein cows were selected at the third birthday, milk production of more than 30 kg per day, and from 10 to 100 days after birth, with four diets, the treatments included 0, 23, 0.46 and 0.69  % of slow-release urea was replaced by soybean meal. Feed intake was measured daily. The milk sample was taken on the day of the start of the experiment and was taken at intervals of 14 days. To measure glucose, urea, cholesterol, triglycerides, high density lipoprotein, and low blood levels, were determined  from the start of the test to the end of the test every two weeks. RESULTS: Consumption of feed, milk production and composition did not differ from experimental treatments. Glucose concentration and blood parameters (cholesterol, high and low density lipoprotein) did not differ between experimental treatments, but triglyceride and lipoprotein showed a very low density at zero (P <0.05). CONCLUSIONS: The results of this study showed that adding slow-release urea to the level of 0.69% had no negative effect on feed consumption, milk production and composition, and blood parameters.

BACKGROUND: Aflatoxin B1 (AFB1) is a secondary toxic metabolite produced by some Aspergillus species, particularly Aspergillus flavus (A. flavus) and A. parasiticus that contaminate feedstuffs. OBJECTIVES: The aim of this study was to evaluate the contamination of the concentrate and corn silage samples to toxigenic fungi and aflatoxin B1 in cattle farms of Yazd province in Iran. METHODS: A total of 80 samples of concentrated feeds and 80 samples of silage feeds were collected from cattle breeding farms of 4 cities in Yazd province in winter and spring seasons (40 samples in each season and one sample from each cattle farm). The samples were cultured on mycological media in order to isolate and determine the amount of the toxigenic fungi. Concurrently, the content of AFB1 was measured in feedstuff samples using ELISA technique. RESULTS: The results indicated that the most frequent fungi isolated were Aspergillus spp. (49.3%), Penicillium spp. (23%), Mucor spp. (22.3%) and Fusarium spp. (4.8%) in winter and Aspergillus spp. (46.9%), Penicillium spp. (21.8%), Mucor spp. (28.5%) and Fusarium spp. (2.8%) in spring from all understudy feedstuffs. The mean of AFB1 in feedstuffs were 0.25 and 0.21 µg/kg in winter and spring, respectively. According to statistical analysis of the results, significant differences were observed between the frequency of Aspergillus isolates and other fungal species (p<0.05) and also between toxigenic fungi, such as Aspergillus, Fusarium and Penicillium, with other isolated fungi (p<0.05). Among toxigenic fungi, significant differences were observed between Aspergillus and Penicillium species, Aspergillus and Fusarium species and Penicillium and Fusarium species (p<0.05). Significant relationship was observed between the amount of toxigenic fungi and AFB1 in feedstuffs (p<0.05). CONCLUSIONS: The results obtained by this study show that rapid and specific detection of aflatoxigenic fungi is essential to ensure the mycological safety of animal feedstuffs.

Background: Candidiasis is a fungal infection that is often caused by Candida albicans (C. albicans) and in a few cases caused by other Candida species. Infection of gastrointestinal tracts including mouth, esophagus and stomach, as well as enteritis and diarrhea are the most common form of the disease in cattle. Clinical findings: In January 2015 reduction in milk production and severe watery diarrhea were observed in a dairy farm located in Varamin city Tehran, Iran. So that 57.1% of cows with high milk production efficiency and 40% of cows with low milk production efficiency involved severe watery diarrhea. Laboratory tests: in clinical examination of affected animals vital signs such as number of breathing, heart rate, as well as the quality and number of ruminal movements were quite normal. No unusual sings were seen in CBC pattern of affected animals. In stool samples of affected animals no viruses or bacteria were detected while specimens were positive for yeast contamination RapID commercial kits used to identify the genus and species of yeast and C. famata was diagnosed as the cause of diarrhea. Final evaluation: Reports of diarrhea caused by fungal pathogens in animals is very low and Candida species, especially C. albicans and C. glabrata are known as the main causes of fungal diarrhea in animals .This study is the first repot about occurrence of C. famata diarrhea in adult cattle. So that C.famata could be considered as one of the potential causes of diarrhea in cattle.

BACKGROUND: Eimeria infection is an important part of protozoal infection in ruminants which causes economic lost in animal husbandry of Iran and worldwide. Therefore it is important to implement effective control programs on the prevalence and diversity of Eimeria species in livestocks. OBJECTIVES: This study was aimed to determine prevalence and Eimeria species diversity in dairy cattle with different age groups under industrial management. METHODS: The present study was carried out in industrial cattle husbandry of Kangavar suburban of Kermanshah province, Iran, from spring 2011 to 2012. A total of 307 fresh fecal samples were randomly collected from the rectum of examined animals. The fecal specimens were subjected for flotation technique and collect Eimeria oocysts. The intensity of infection was determined using McMater method. Eimeria species diversity and frequency was also determined by using oocyst sporulation technique in 2.5% potassium dichromate. RESULTS: The overall prevalence was 31.92% (98 out of 307). The highest prevalence was found in dairy cattle (37%) with 1-3 years old. There was no significant difference between prevalence and different age groups. The highest frequency was significantly in spring (41.66%). The intensity was variable in examined animals which ranged from 3.18×103 to 2.71×105. There was no significant difference between the prevalence and intensity in all age groups. Fecal consistency findings revealed that the highest infection was significantly in dairy cattle with normal fecal consistency in all age groups. According to Laboratory identification, a number of seven Eimeria species were detected in all infected animals. The most common specie was E. zuernii (28.25%) in 5% dairy cattle (1-3 years-old) in spring (30%) and summer (30%). There was significant association between frequency of Eimeria infection and each season during the course of the study. All infected cattle had mixed infections with two (42.85%) and three (3.15%) species of Eimeria. CONCLUSIONS: The results of this study indicated that cattle Eimeria infection was a problem in dairy cattle of industrial farms in the region. Attention should be paid within seasonal infection in young cattle to avoid probable clinical coccidiosis, particularly in farms with poor hygienic conditions and no prophylactic treatments.

BACKGROUND: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).

BACKGROUND: Neospora caninum is one of the most important pathogenic protozoan parasites causing bovine abortion around the world. Objectives: The aim of this study was to detect the presence of Neospora caninum in the brain, cerebellum and medulla oblongata of aborted fetuses in cattle in Arak by means of molecular method. Methods: 38 samples of brain, cerebellum and medulla oblongata from aborted fetuses in dairy cattle of Arak were tested for the presence of Neospora with nested-PCR. Results: Survey findings indicated the presence of DNA in 26.3 % of aborted fetal brains. In the cerebellum and medulla oblongata samples no Neospora caninum  DNA was detected. There was a significant relationship between neosporosis and maternal age (number of calvings), abortion history and the presence of dogs in the herd. Conclusions: The results showed a significant association between the infection and the number of abortions in the examined cows; As a result it seems that neosporosis could be an important factor in epidemic abortions in Arak city’s dairy farms which requires continuous monitoring and implementation of prevention programs in the dairy industry.

A study was conducted to develop valid estimates of lymphocyte count (LC; cells per microliter) of individual, clinically normal dairy cattle. Estimated weighted regression was used on repeated measures of individual LC to examine 6 models predicting LC as a function of age in cattle not infected with bovine leukemia virus. The generalized growth curve model of analysis of variance was used to estimate intercepts, slopes, and prediction limits for the models and to compare the LC-to-age relationship between Holstein and Guernsey breeds. The best-fitting model (P = 0.0001) with the narrowest prediction interval was LC = 4,414.4 - 84.6X, where X = (age - 48) if age less than or equal to 48 months, and X = 0 if age > 48 months, and 163.6 and 8.1 are the SE of the estimates, respectively. Upper one-sided 95%-predicted normal LC tended to be higher than estimates derived from traditional hematologic keys that use confidence limits of mean LC. Difference was not found in the LC-to-age relationship between the Holstein and Guernsey cattle (P = 0.67). Results of this study provided estimates of normal LC that are more specific in diagnosing lymphocytosis in individual cattle.

Six primiparous Holstein cows were fed a Se-deficient diet, beginning at least 90 days before their first calving, and 6 other primiparous cows were given the same diet plus a supplement of 2 mg of Se/cow/d as sodium selenite. All cows were fed their diets for the duration of the experimental period. One uninfected quarter of each cow was injected with 25 microgram of Escherichia coli endotoxin at postpartum week 5. Leukocytes were isolated by centrifugation from milk collected at postinjection hour 16. Isolated cells were 92 +/- 3% neutrophils and were incubated with Staphylococcus aureus or E coli in a 1:300 ratio. Phagocytosis and intracellular killing by neutrophils were assessed after 0, 30, 60, and 90 minutes by a fluorochrome assay, using acridine orange. Viability of neutrophils was assessed by use of trypan blue. Superoxide anion production and hydrogen peroxide production by neutrophils also were determined. Cows fed Se-deficient diets had significantly (P < 0.05) lower blood Se concentration and blood glutathione peroxidase activity than cows fed Se-supplemented diets. Selenium status had no effect on the phagocytic capacity of neutrophils. Neutrophils obtained from cows fed Se-supplemented diets killed a significantly (P < 0.05) higher percentage of ingested bacteria than did neutrophils from cows fed the Se-deficient diet. Viability was significantly (P < 0.05) reduced by incubation with S aureus in neutrophils from both groups of cows, with neutrophils from Se-deficient cows having lower viability. Superoxide anion production did not differ significantly between neutrophils from the 2 groups, but extracellular hydrogen peroxide concentration was significantly (P < 0.05) higher in neutrophils harvested from milk of cows fed the Se-deficient diet.

Bovine mammary glands were inoculated intracisternally with a streptomycin-resistant (SR) strain of Corynebacterium bovis to determine the number of colony-forming units (CFU) required to induce colonization and to maintain persistence of C bovis colonization throughout lactation and involution. Streptomycin resistance was used as a strain marker. Uninfected quarters in cows during midlactation were challenge exposed with successively higher numbers of SR C bovis until all quarters became colonized. Inoculum containing 790 CFU of SR C bovis established colonization in only 7 of 38 quarters. Colonization persisted in only 4 of these quarters by 23 days after inoculation. Eleven quarters were reinoculated with higher numbers of SR C bovis, and all became colonized by the time challenge-exposure inoculum contained 8 X 10(4) CFU. Colonization persisted throughout the 93-day experimental period. Somatic cell counts were significantly (P less than 0.01) higher in SR C bovis-colonized quarters after inoculation than before. Sixteen additional quarters were inoculated with a mean number of 8 X 10(4) CFU of SR C bovis 7 days before suppression of lactation. All quarters became colonized, and SR C bovis was shed during the experimental period; throughout the nonlactating and peripartum periods, high numbers of SR C bovis in pure culture were shed from 13 of 16 quarters.