Industrial Dairy Farms Research Articles

Bovine brucellosis, associated risk factors and preventive measures in industrial cattle farms

Effective management of brucellosis in human populations is closely tied to controlling the disease in domestic livestock. This study focused on identifying determinants of brucellosis prevalence in mixed industrial dairy and beef cattle farms within Isfahan Province, Iran. Employing a case control design, we compared 32 ranches with documented brucellosis within the previous year (12 months) to 38 farms with no brucellosis during the same timeframe. The comparison examined the farms' adherence to health protocols for raising cattle. Utilizing multivariable logistic regression, the study identified several significant risk factors linked to brucellosis prevalence. These included cleaning milking accessories with a water and chlorine solution (OR 0.25, 95%CI 0.06 to 0.99), cleaning water troughs daily (OR 0.20, 95%CI 0.04 to 0.89), the cows' density per square meter (OR 0.14, 95%CI 0.03 to 0.75), being within 2000 m of another cattle ranch with brucellosis (OR 4.02, 95%CI 1.09 to 14.84) and ovine farms situated within a 500-m radius (OR 8.43, 95%CI 1.66 to 42.70). No meaningful difference was observed in vaccination frequency between infected and non-infected farms (P = 0.645). While vaccination is essential for preventing bovine brucellosis, robust biosecurity measures are crucial for effective disease management.

How control and eradication of BVDV at farm level influences the occurrence of calf diseases and antimicrobial usage during the first six months of calf rearing

BackgroundBovine viral diarrhoea (BVD) is one of the major cattle diseases causing economic losses worldwide. Nowadays the disease manifests mainly as virus-induced immunosuppression and early embryonic death, impacting overall herd performance and contributing to increased antibiotic usage in calf rearing.MethodsIn our study we investigated the effect of rapid BVDV control measures on calf diseases and antimicrobial usage after weaning on a large industrial dairy farm. Persistently infected (PI) animals were identified and removed from the herd within a short period of time, and all susceptible animals were vaccinated against BVDV. Recorded herd parameters and AB usage were monitored retrospectively and compared with data collected after starting the BVD control program.Results and discussionThe programme began in January 2023 with identifying and eliminating PI animals from the farm. Twenty-one PI animals were found by using RT-qPCR testing of blood sera out of the 1571 animals tested (1.33%). Subsequent testing (January and December 2023) identified further 28 PI animals amongst the 542 calves tested shortly after birth, and all were instantly removed from the farm. In parallel with the BVDV eradication measures, AB usage dropped by more than 50% compared to previous years. Calf mortality also decreased from 7.45 to 4.38% as the control program progressed. Correspondingly, both the number of respiratory and diarrhoea cases decreased dramatically on the farm while the eradication measures were in place.ConclusionOur study clearly demonstrated the positive effects of BVDV eradication on the improvement of calf health and importantly, a reduction of AB usage, contributing to the One Health perspective of farm animal production.

BoHV-1 affects abortion and progesterone in dairy cows Bovine alphaherpesvirus 1 (BoHV-1) seropositivity, progesterone levels and embryo loss of 30-day-old pregnant dairy cows in Zagros Industrial Dairy Farm in Shahrekord: Examination and analysis.

Bovine alphaherpesvirus 1 (BoHV-1) is a serious disease with severe negative economic effects on the global cattle sector, especially in Iran. This cross-sectional study was carried out to examine the seroprevalence and associated risk factors of BoHV-1 infection with progesterone levels and embryo death in 30-day pregnant dairy cattle at Zagros Industrial Dairy Farm in Shahrekord, Iran. Between December 2017 to February 2018, blood samples were obtained from 60 dairy cow herds. To determine whether BoHV-1 was present, serum samples were examined using the ELISA for serum antibodies. To find progesterone (P4) in blood, the progesterone ELISA test was used. 96.7 % of sera tested positive for BoHV-1 antibodies, according to the findings. Additionally, 60.34 % of blood samples that tested positive had an experience of abortion and significantly more inseminations that resulted in pregnancy, consistent with findings from other studies conducted in Iran and other nations. Since this study is the first to document the risk factor for BoHV-1 infection in Shahrekord, Iran, we could infer that the virus is extensively dispersed in this area.

EVALUATION THE DAIRY COWS’ WELFARE IN NORTHERN KAZAKHSTAN FARMS

In modern society animal welfare is an important attribute of the food quality general concept. Research purpose was to identify the dairy cows’ welfare problems in Kazakhstan. In 2022 and 2023, studies were organized at two industrial dairy farms in the central (Kamyshenka LLP) and northern (Ayna Dairy Farm LLP) zones of the Akmola region. Here, the welfare of 110 cows was measured in accordance with 33 parameters, 12 criteria and 4 principles (according to the Welfare Quality® protocol). On both farms, the main animal welfare indicators were approximately within the same limits. The criterion "Absence of prolonged thirst" was 60.0 scores. In both farms, such criteria indicators as “Absence of prolonged hunger", “Absence of diseases" had relatively low values in the range of 3.5-19.98 points. The criteria “Absence of injuries”, “Lameness”, "Integument alterations", "Positive emotional state" were also below 53.9 points. Scores of criteria “Comfort during rest”, “Absence of pain caused by management procedures”, “Manifestation of other forms of behavior”, “Good relations between man and animal” exceeded 55 points and reached a maximum value of 80.01 points at the Ayna Farm. Overall, farms scored from 20.1 to 50.4 points on the basic principles of welfare, with the exception of the principle of "Good Health", according to which Ayna Dairy Farm scored 64.4 points, but Kamyshenka Farm had a lower level – 38.2. Thus, both farms were classified by the Welfare Protocol as "Acceptable". The study has been shown that the housing of dairy cows needs to be improved for increasing the comfort of rest and reduce cow injuries.

Comparison of the effects of Presynch-Ovsynch, Presynch- Ovsynch+CIDR, and G6G protocols on the reproductive performance of lactating Holstein cows in the postpartum period

This study was performed on an industrial dairy farm near Tehran province, Iran, on 666 lactating Holstein cows from September 2019 to June 2020 in order to eliminate the harmful effects of heat stress on the reproductive performance of the cows. The hypothesis of the recent study was that by increasing the serum concentration of progesterone (P4) in the luteal phase before insemination in the form of Presynch-Ovsynch+CIDR (POC) and G6G protocols, the pregnancy rate of cows would be increased compared to the Presynch-Ovsynch (PO) protocol. The aim of the present study was to evaluate the effects of Presynch-Ovsynch (PGF2α-14d- PGF2α-12d-Ovsynch (OVS: GnRH(GnRH1)- 7d-PGF2α(PG)-2d-GnRH)-18h-Fixed-time artificial insemination (FTAI), n=212), Presynch-Ovsynch+CIDR (similar to the PO protocol, plus the use of a CIDR for 7 days, from the start of the OVS+FTAI protocol to the time of PG injection, n=230), and G6G (PGF2α- 2d-GnRH-6d-OVS+FTAI, n=224) protocols on the reproductive performance and pregnancy rate of lactating Holstein cows. The average body condition score (BCS) for the cows was about 2.5 at the time of the onset of the OVS+FTAI program. The average daily milk production for cows at the time of the start of the OVS+FTAI program was 38.3 kg/day. On average, the studied cows were inseminated 86 days postpartum. Implementation of the G6G protocol in comparison to the PO and POC protocols increased the serum concentration of P4 at GnRH1 (P=0.04). The cows that received the G6G protocol had a greater number of corpuses luteum (CL) on their ovaries at PG in comparison to the cows in the PO and POC protocols (P=0.03 and P=0.05, respectively). For all treatment protocols, the pregnancy rate of cows with >2 CLs on their ovaries at PG was significantly higher than for cows with ≤2 CLs on their ovaries at this time. The overall pregnancy rate for all cows studied was 42%. Separately, pregnancy rates for cows in PO, POC, and G6G protocols were calculated at 36.7%, 41.7%, and 47.3% respectively. The highest and the lowest pregnancy rates were obtained in the G6G and PO protocols, respectively (P=0.03). It can be concluded that the G6G protocol increased the pregnancy rate of cows in comparison to the PO but not to the POC protocol. This result can be attributed to the increase in serum concentration of P4 at GnRH1 and the greater number of CLs at PG following implementation of the G6G compared to the PO protocol. Although CIDR administration in the POC protocol led to an increase in the pregnancy rate of cows compared to the PO protocol, possibly by increasing the synchrony rate and the quality of the ovulatory follicle, this increase was not statistically significant (P=0.09).

The effect of ketones on estrogen, progesterone, ovulatory follicle size, estrus and fertility in Holstein cows

This study aimed to investigate the effect of hyperketonemia on estrogen, progesterone and ovarian follicle size during postpartum as well as on pregnancy rate at first insemination. Regarding this, 90 Holstein cows were selected from one of the industrial dairy farms in Isfahan province, Iran. Estrus synchronization was routinely applied to all cows using the Ovsynch method. The blood sample of the cows was taken two times. The first blood sample was taken in 7-14 days after calving; to measure betahydroxybutyrate (BHBA), and the second sample was taken at the first insemination to measure the 17-ß oestradiol and progesterone hormones. The pregnancy status was recorded at the first insemination. T-test analysis was used to evaluate the effects of hyperketonemia on the concentration of steroid hormones and pregnancy rate at first insemination. 4.4% of cows (4 of 90) had subclinical ketosis (SCK) (BHBA greater than 1000 μmol/L). Results showed that cows with BHBA levels greater than 600 μmol/L in 7-14 days of postpartum had lower 17-ß oestradiol levels (p = 0.04) and higher progesterone levels (p = 0.06) at the time of insemination. Pregnant cows also had significantly lower serum BHBA and higher 17-ß oestradiol levels than nonpregnant cows at first insemination. The levels of BHBA, oestradiol, and progesterone were not significantly different in cows with different ovulation follicle sizes (p > 0.05). However, the level of BHBA was lower in cows that exhibit symptoms of estrus at the time of insemination (p = 0.07). 17-ß oestradiol levels were higher and progesterone levels were lower in cows with estrus symptoms with p = 0.07 and p = 0.01, respectively. The present study confirms that higher ketone bodies have negative effects on 17-ß oestradiol level and fertility. Also it appears that postpartum return to estrus is associated with high concentrations of 17-ß oestradiol and a low concentration of BHBA in early lactation.

Industrial Dairy Cattle Farms in Hungary Source of Coxiella burnetii Infection in Humans.

Previous research has demonstrated a high prevalence of Coxiella burnetii in the bulk tank milk on large industrial dairy farms of the central and eastern European region. The aim of this survey was to estimate the prevalence of specific IgG antibodies to C. burnetii proving previous infection among dairy farm workers and to determine the possible risk factors. Serum samples from veterinarians, inseminators, animal caretakers, milking parlor workers, and herd managers working on dairy farms were tested for the presence of IgG to phase I and phase II of C. burnetii using an indirect microimmunofluorescence assay. Antibodies phase II to C. burnetii were detected in 59 out of 70 individuals tested (84.3%). All occupational groups are highly exposed to C. burnetii infection. Veterinarians, inseminators, and animal caretakers had 100% seropositivity rate of phase II, whereas the seropositivity rate found among herd managers and milking parlor workers was 71.4% and 47%, respectively. The findings of this survey suggest that the risk of C. burnetii infection is correlated with cattle density in the large dairy farms and also with occupational groups.

Isolation and Molecular Characterization of Enterotoxigenic Escherichia coli (ETEC) Strains From Industrial Dairy Farms of Hamedan, Iran

Background: Enterotoxigenic Escherichia coli (ETEC) is considered as one of the most common causes of infectious diarrhea in calves, infecting animals during the first week of age. The secretory diarrhea is attributed to the virulence factors of ETEC strains mainly including heat stable toxin (STa), as well as F5 (K99) and F41 fimbriae. Objectives: The present study was undertaken to investigate ETEC infection in neonatal calves of industrial dairy farms of Hamedan, Iran. Additionally, it was undertaken to investigate the genotypic screening of virulence genes in enterotoxigenic E. coli isolated from from dairy farms calves of Hamedan county. Materials and Methods: A total of 120 rectal swab samples were collected from healthy and diarrheic calves at one week of age belonging to eight farms. Conventional bacteriological methods, multiplex PCR, and antibiotic susceptibility test of the ETEC isolates were performed. Results: Nine E. coli isolates were found to be ETEC strains, carrying STa enterotoxin along with F5 and/or F41 fimbriae as the indicators of ETEC cells. Additionally, antibiotic susceptibility test of the ETEC isolates revealed that all of them were sensitive to trimethoprim-sulfamethoxazole, ciprofloxacin, and enrofloxacin, whereas complete resistance was observed against amoxicillin-clavulanic acid (100%) and polymyxin B (100%). The present study, conducted for the first time in Hamedan, indicated a prevalence of 7.5% for Enterotoxigenic Escherichia coli in the examined animals. Conclusion: Regarding economic losses of the infection in claves as well as the zoonotic nature of ETEC cells, it is recommended that measures should be taken, such as immunization of pregnant cows prior to the delivery, feeding of adequate colostrum to newborn calves at the right time, and adherence to hygiene practices on the farms to prevent and/or reduce the incidence of diarrhea cases caused by infection with these bacteria.

Identification of bovine leukemia virus in raw milk samples in North-West of Iran.

Bovine leukemia virus (BLV) is one of the most important carcinogenic viruses genetically related to the human T-cell lymphotropic viruses (HTLV-1 and HTLV-2). The virus infects type B lymphocytes and creates lymph glands tumors. Recently, the association between the presence of this virus and breast cancer has been addressed in humans. Here, we studied the prevalence of BLV in the samples of raw milk of native Iranian and Iranian-foreign cows in traditional, semi-industrial and industrial dairy farms in rural and urban areas of Zanjan province. Raw milk samples of cows were collected manually in sterile tubes. The samples were tested by nested-PCR method. Forty samples (9.93%) out of 403 samples showed BLV contamination. In this study, nested-PCR was successfully applied to determine the level of contamination in raw milk samples from cows infected with BLV. Furthermore, a relatively high rate of BLV infection was found in dairy cows in Zanjan province, northwestern of Iran.

NUTRIENT USE EFFICIENCY AND LOSSES OF INDUSTRIAL FARMS AND MIXED SMALLHOLDINGS: LESSONS FROM THE NORTH CHINA PLAIN

<List> <ListItem><ItemContent> • Degree of integration of crop and livestock was insufficient on mixed smallholdings. </ItemContent></ListItem> <ListItem><ItemContent> • Liquid manure discharges on industrial farms hamper the closing of nutrient loops. </ItemContent></ListItem> <ListItem><ItemContent> • Coupling with local crop farms is encouraged to achieve integration of crop-livestock systems. </ItemContent></ListItem></List> <fig><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="2095-7505-8-1-58/fase-20371-myf-tu1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="2095-7505-8-1-58/FASE-20371-MYF-tu1.tif"/></fig> The proportion of industrial livestock in China has increased over the past 30 years, which increases animal performance but causes the decoupling of crop and livestock production. Here, we aimed to quantify nutrient flows, nutrient use efficiency, and nutrient losses in different livestock systems in the North China Plain based on the NUFER-farm model. Activity data were collected by face-to-face surveys on pig and dairy (41 livestock farms) during 2016–2018. The two systems included industrial farms and mixed smallholdings. In mixed smallholdings, 4.0% and 9.6% of pig and dairy feed dry matter (DM) were derived from household farmland, but 4.8% and 9.3% of manure DM recycled to household farmland. Nutrient use efficiency in industrial farms was higher than in mixed smallholdings at animal level, herd level, and system level. To produce 1 kg N and P in animal products, nutrient losses in industrial pig farms (2.0 kg N and 1.3 kg P) were lower than in mixed pig smallholdings, nutrient losses in industrial dairy farms (2.7 kg N and 2.2 kg P) were slightly higher than in mixed dairy smallholdings. Liquid manure discharge in industrial farms was the main losses pathway in contrast to mixed smallholdings. This study suggests that feed localization can reduce nutrient surpluses at the district level. It is necessary to improve manure management and increase the degree of integrated crop-livestock in smallholdings. In industrial farms, it is desirable to increase the liquid manure recycling ratio through cooperating livestock and crop production at the district level.

Serological screening for Coxiella burnetii in the context of early pregnancy loss in dairy cows.

Q fever is one of the commonest infectious diseases worldwide. A Coxiella burnetii prevalence of 97.6% has been found by ELISA and PCR tests of the bulk tank milk in dairy cattle farms of Hungary. The herd- and individual-level seroprevalence rates of C. burnetii in the examined dairy cows and farms have dramatically increased over the past ten years. Three high-producing industrial dairy farms were studied which had previously been found ELISA and PCR positive for C. burnetii by bulk tank milk testing. Coxiella burnetii was detected in 52% of the 321 cows tested by ELISA. Pregnancy loss was detected in 18% of the cows between days 29-35 and days 60-70 of gestation. The study found a higher seropositivity rate (80.5%) in the cows that had lost their pregnancy and a seropositivity of 94.4% in the first-bred cows that had lost their pregnancy at an early stage. The ELISA-positive pregnant and aborted cows were further investigated by the complement fixation test (CFT). In dairy herds an average of 66.6% individual seropositivity was detected by the CFT (Phase II) in previously ELISA-positive animals that had lost their pregnancy and 64.5% in the pregnant animals. A higher (Phase I) seropositivity rate (50.0%) was found in the cows with pregnancy loss than in the pregnant animals (38.5%). The high prevalence of C. burnetii in dairy farms is a major risk factor related to pregnancy loss.

Reproducing the qualities of cows with different methods of synchronization of sexual hunting

Increasing the intensification of herd reproduction is one of the main ways of increasing the number of beef cattle, increasing beef production, and reducing its cost. The main task in the reproduction of the herd is the annual receipt of a viable calf from each cow and heifer. One of the methods to increase reproductive functions is the use of hormonal drugs, analogues of sex hormones. Synthetic hormonal preparations in dairy cattle breeding are used to synchronize sexual hunting, ovulation and calving, to intensify the sexual functions of uterus (inducing superovulation, shorten the service period, etc.) and to treat pathologies of the ovaries, endometritis, and other disorders of the sexual apparatus of cows and heifers. The article presents the results of applying two synchronization schemes of sexual hunting in Holstein cows in an industrial dairy farm. In the first group, the Pre-synch scheme was used, in the second – «Ovsynch». The schemes differed in that the «Pre-synch» is longer and more costly, but it begins to be used from 21 days after calving. According to the results of the synchronization of sexual hunting of both groups, results were obtained on milk productivity. In the first group, baseline fat milk was produced for 305 days of lactation, 9411.0 kg of milk, in the second - 7785.0 kg. Considering all the costs of synchronizing sexual hunting in Holstein cows, profitability in the control group was 24.8%, in the experimental group - 19.2%.

Biochemical and Molecular Identification of Listeria monocytogenes and Escherichia coli in the Raw Milk Samples Delivered to the Dairy Farms in Golestan Province, Iran

BackgroundMilk is an essential human nutrient, and the monitoring of its sanitation is vital during transportation and storage. The present study aimed to assess bacteriological contamination with Escherichia coli and Listeria monocytogenes in the raw milk samples of the dairy farms in Golestan province, Iran. MethodsIn total, 100 samples were collected from dairy farms in hot and cold seasons. The frequency of E. coli and L. monocytogenes was determined using biochemical tests and polymerase chain reaction (PCR). ResultsThe biochemical tests indicated that 28% and 27% of the samples were contaminated with E. coli and L. monocytogenes based on the culture-dependent methods, respectively. In addition, 35 and 40 samples were contaminated with E. coli and L. monocytogenes based on PCR, respectively. PCR had higher sensitivity compared to the biochemical tests (P ˂ 0.05). E. coli and L. monocytogenes contamination was significantly higher in traditional dairy farms than industrial dairy farms (P ˂ 0.05). However, seasonal sampling and geographical region had no significant effects on the contamination load.ConclusionAccording to the results, E. coli and L. monocytogenes were highly frequent in the raw milks samples. However, the microbial loads had no significant differences in hot seasons and traditional dairy farms.

The optimization of resilience and sustainability using mathematical programming models and metaheuristic algorithms

The present study attempts to posit a suitable strategy for the optimal production with the maximum resilience and sustainability in the industrial dairy farms. The resilience and sustainability indicator was designed by integrating 5 indexes; they include the environmental, economic, social, technology and policy indexes and were modeled using the non-linear mathematical programming. The status of the industrial dairy farms in Khorasan Razavi province, Iran, was evaluated in terms of resilience and sustainability with the utilization of this indicator during 2016. The results of the initial estimation indicated the low level of resilience and sustainability of the probed dairy farms. Therefore, in order to clarify the application of the proposed model, all variables were considered as passive; hence, an intelligent and automatic model was postulated to optimize the resilience and sustainability in the industrial dairy farms. In order to gain the best outcome, the model was gauged by both the genetic algorithm and particle swarm optimization. Although both algorithms produced the same results, the validation tests unveiled the superiority of the genetic algorithm. Based on the results, the proposed model can improve the resilience and sustainability of production in the dairy farms and can reduce the environmental degradation brought about from the production process. For instance, the resilience and sustainability indicator increased up to 0.5% and profitability to 0.23%. Moreover, the greenhouse gas emissions and the energy intensity decreased to 0.09% and 0.02%, respectively. Our model can be adopted in variegated contexts to enhance the resilience and sustainability of the dairy farms and other production systems.

High prevalence of Prototheca spp. and isolation of fungal species in milk samples from cows suffering from mastitis in Mashhad city, northeast Iran

The aim of this study was to investigate the fungi and algae isolated from milk samples in dairy cows with clinical and subclinical mastitis from dairy farms around Mashhad, Iran. A total of 503 milk samples were obtained from 10 industrial dairy farms. All samples were simultaneously cultured on the surface of Blood agar, Macconkey agar, and Sabouraud dextrose agar supplemented with chloramphenicol. Fungi and algae were identified using phenotypic characteristics. In the examined samples, the bacterial contamination (338 out of 503 samples; 67.20%) was the most dominant followed by algae (93 out of 503 samples; 18.5%), filamentous fungi (32 out of 503 samples; 6.4%) and yeast fungi (26 out of 503 samples; 5.2%).Penicillium spp. (2.8%), Aspergillus spp. (2.6%), Cladosporium spp. (1.2%), Geotrichum spp.(0.4%), Ulucaladium spp., Scopolariopsis spp. and Alternaria spp. (0.2% each), Cryptococcus neofermenes (3%), Candida spp. (1%), Trichosporon spp. (0.8%) and Rhodoturula spp. (0.4%) were the filamentous and yeast fungi isolated from milk samples. Of the 93 algae isolated from 503 milk samples (18.5%), 83 (16.5%) samples were positive for Prototheca zopfii and 10 (2%) samples for Prototheca wickerhamii. According to the results of this study, yeast fungi, filamentous fungi and algae, especially Prototheca spp. are important contaminant factors in milk and contribute to clinical and subclinical bovine mastitis. Therefore, proper sanitation practices and management of dairy herds and judicious use of antibiotics is essential to control the fungal and algal contamination both in the environment and the breast.

Farmworker Gardens and Food Sovereignty in the Northern Borderlands

First paragraph: For Maria, the small kitchen garden that she tends behind her house brings a sense of balance to her family and a sense of agency over the food that sustains them. As she explained to me, “The garden balances us. What we harvest from the garden is healthier for me and my kids and my family because it is fresher. My kids also help in the garden with preparing the soil, learning how to plant. And maybe in the future, they will continue doing it.” A mother of five from the southern Mexican state of Guerrero, Maria has lived in the United States for the past 13 years, supporting her husband who has worked on industrial dairy farms, first in New York and now in Vermont. While she raises her children and tends to her garden and free-range chickens, she acts as the primary caretaker and cook for their household during the long hours that her husband spends in the milking barn. Maria has some serious skills in the kitchen, and she loves to share dishes that remind her of Mexico with her children, whose only memories are of rural Vermont. And yet, despite having a relatively stable household income, Maria’s family still struggles with severe food insecurity. The vegetables and eggs that Maria harvests from her garden and chicken coop, along with support in the form of WIC benefits and free school meals, have been essential in keeping her children fed.

Investigating Optimal Scale in Industrial Dairy Farms and Estimation of Effective Factors (Case Study: Selective Counties of Mazandaran Province)

Investigating Optimal Scale in Industrial Dairy Farms and Estimation of Effective Factors (Case Study: Selective Counties of Mazandaran Province)

Molecular prevalence of bovine noroviruses and neboviruses in newborn calves in Iran.

In this study, bovine enteric caliciviruses (BECs) were detected in 49.4% of a total of 253 stool specimens for diarrheic calves collected from 42 industrial dairy farms from March 2010 to February 2012. Genogroup III norovirus (NoVsGIII) were more prevalent (39.5%) than neboviruses (NBs) (15%), and coinfections were observed in 5.1% of the samples tested. Sequence analysis of the partial polymerase gene from 13 NoVsGIII samples indicated the circulation of both genotype 1 and genotype 2 strains. Among the six NB strains sequenced, five were related to the Bo/Nebraska/80/US strain, while one was related to the Bo/Newbury1/76/UK strain.

The molecular epidemiology of bovine rotaviruses circulating in Iran: a two-year study.

Bovine group A rotavirus (bovine RVA) is recognized as a major cause of severe gastroenteritis in newborn calves. The purpose of this study was to estimate the prevalence and identify the genotypes of circulating bovine RVA in newborn diarrheic calves. Two hundred fifty-three stool samples of diarrheic calves up to 1 month old were collected from 42 industrial dairy farms in two Iranian provinces during March 2010 to February 2012. All collected samples were screened for the presence of bovine RVA by RT-PCR, and the G and P genotypes were determined by semi-nested multiplex RT-PCR assay. The results of RT-PCR indicated that 49.4% (125 out of 253) of the samples were positive for bovine RVA. The G and P genotyping of a subset of positive samples (n=85) by semi-nested multiplex RT-PCR revealed that G6 (55.3%) and G10 (43.5%) and P[5] (51.8%) and P[11] (27%) were the most prevalent G and P genotypes, respectively. G6P[5] was the dominant genotype (35.3%), followed by G10P[5], G10P[11] and G6P[11], with prevalence rates of 16.5%, 15.3% and 10.6%, respectively. Sequence analysis of 20 VP7 and four VP4 genes showed highest nucleotide sequence identity with the corresponding genes of strains RVA/Cow-tc/GBR/UK/1973/G6P7[5] and RVA/Cow-tc/USA/B223/XXXX/G10P[11]. The results of this study reveal the diversity of G and P genotypes in bovine RVA samples from diarrheic Iranian calves and expands our knowledge of bovine RVA infections in the Middle East. These results also highlight the importance of producing of an effective rotavirus vaccine and its inclusion in the national cattle immunization program.

Seasonal study of aflatoxin M1 contamination in milk of four dairy species in Yazd, Iran

This survey was conducted to determine the occurrence of aflatoxin M1 (AFM1) in samples of raw milk obtained from cow, sheep, goat, and camel herds in Yazd province during different seasons. Aflatoxin M1 was analyzed using the competitive enzyme-linked immunosorbent assay technique for screening and high-performance liquid chromatography with fluorescence detection for confirmatory purposes. The detection rates of AFM1 in cow, sheep, goat, and camel milk samples were 46.5%, 21.6%, 20.1%, and 4.03%, respectively. Levels of the toxin in 15.4% of cow milk, 11.5% of sheep milk, and 9.15% of goat milk samples exceeded the legal limit (0.050 μg/kg) recommended by the Institute of Standards and Industrial Research of Iran; while none of the camel milk samples exceeded the legal limit. The occurrence and levels of AFM1 in cow milk samples from industrial dairy farms was significantly lower (P ≤ 0.05) than those from traditional ones. Seasonal variations influenced the occurrence and levels of AFM1 in cow, sheep, and goat milk; however, no statistically significant seasonal effect was found for camel milk. This study indicates a high occurrence of AFM1 in cow milk especially those obtained from traditional dairy farms. Therefore, more supervision is required on these farms; and traditional dairy farms should be gradually replaced by industrial ones.