Digital dermatitis of the accessory digits of dairy cows

This report characterizes the digital dermatitis (DD) lesions in the accessory digits of dairy cows and presents data on the applied therapy. Fifteen Holstein cattle with DD affecting the accessory digits of the hindlimbs from four dairy farms with previous history of DD were evaluated. Lesions were excised, the wounds were sutured, and a topical application of oxytetracycline powder covered by bandaging was associated with a single parenteral administration of long acting oxytetracycline IM (20mg/kg). Tissue samples were obtained for histopathology and transmission electronic microscopy (TEM). Lesions from all the animals were recuperated 15 days after surgical procedure. Overal, most DD lesions were papillomatous epidermal projections or wartlike verrucous lesions. Histopathologically, samples revealed hyperplasia of epidermis with hyperkeratosis, several mitoses in the stratum basale and elongated rete ridges in the superficial and middle dermis. TEM revealed long, thin spirochete-like bacteria. Morphologic features of lesions and its response to therapy were comparable to those described for DD.

Impact of ivermectin-resistant gastrointestinal nematodes in feedlot cattle in Argentina

The aim was to evaluate for 75 days the impact on production of the remaining burden of ivermectin (IVM)-resistant parasites in naturally infected feedlot calves. The herds came from tick-infested areas of cattle breeding where the systematic use of IVM to control tick increases the gastrointestinal parasites resistant to this drug. This investigation was carried out in two commercial feedlots in Buenos Aires province. In feedlot A, two groups of 35 animal each received IVM 1% and the other received ricobendazole (RBZ) 10% respectively. The same was done in feedlot B. On day 0, two groups of 35 animals were made in feedlots A and B. Fecal samples were taken on days 0, 22, 54 and 75 pos-treatment (PT), and body weight was registered, from each animal. Fecal samples were processed for individual count of eggs per gram (EPG) and pooled fecal culture was carried out for identification of the parasite genus in each sampling. Fecal egg count reduction test (FECR) was calculated on day 22 PT. The study design used was a totally randomized block, with commercial feedlot and sex as block variables. For data analysis, a mixed model of the SAS statistical program was used. The FECR average on day 22 was 28.4% in the IVM group, and 94,2 % in the RBZ group . From this date on, significant differences in EPG were kept until day 54. EPG counts were only equal near the end of the trial, on day 75 (p=0.16). In both commercial feedlots, especially in the IVM group, Cooperia spp. was the most prevalent parasite in the fecal cultures. Significant differences in weight (P<0.01) on post-treatment day 75 was found between the average weight in the RBZ and the IVM group (246 vs. 238 kg respectively), what means a difference of 8.3% in gains. The importance for production in the antiparasite failure treatment in commercial feedlots was demonstrated, and the need of pos-treatment controls to evaluate the efficacy of the antiparasitic administered is emphasized.

Antibodies against Bovine herpesvirus 1 in dairy herds in the state of Espirito Santo, Brasil

Bovine herpesvirus 1 (BoHV-1) causes major losses in worldwide livestock, affecting the respiratory and reproductive tracts of bovine. In the past decades, the number of cases in Brazil has been gradually increasing. Therefore, it is important to assess the distribution of infection in different regions of the country. In the state of Espírito Santo (ES) the BoHV 1 infection rate in dairy cattle herds is unknown. Thus, the aim of this study was to detect neutralizing antibodies against BoHV-1 in serum samples from 1,161 non-vaccinated cows from 59 dairy cattle herds in 23 municipalities of the Metropolitan, North, Northwest and South macro-regions. The identification of seropositive cows was evaluated by the virus neutralization test. The results showed that of all serum samples evaluated 775 (66.75%) had neutralizing antibodies against BoHV-1. Moreover, all herds were found positive; however, the percentage of positive cows varied among regions; 49.06%, 62.15%, 67.21% and 80.04% for the Metropolitan, South, North and Northwest macro-regions, respectively. In this study, the results clearly indicate the dissemination of the viral agent in dairy cattle in the ES state, requiring the monitoring and control of diseases related to BoHV-1 infection.

Economic viability of the third milking in systems of production using closed-circuit mechanical milking

This study aimed to analyze the economic viability of the third milking in production systems using mechanical milking in a closed circuit, aiming to provide technicians and farmers with information to assist them in decision-making. Specifically, it intended: (a) to estimate the cost of one milking; (b) to estimate the cost of the third milking; (c) to develop a mathematical equation to estimate the minimum amount of milk produced with two milkings, from which it would be economically feasible to do the third milking. Data were collected from three dairy farms, from November 2010 to March 2011, keeping a twice-a-day milking frequency, with three data collections in each farm, totalizing nine collections. Considering the average data, it would be feasible to do the third milking if the average milk yield per day of lactating cows in a twice-a-day milking frequency was greater than or equal to 24.43 kg of milk.

Daily pattern of flight activity of Aedes albifasciatus in Central Argentina

Aedes albifasciatus is an important common mosquito in Central Argentina. Its a confirmed vector of the Western Equine Encephalitis and is responsible for loss of milk production in dairy cattle during peak populations. This paper reports the flight activity pattern of Ae. albifasciatus for different seasons, in the southern coast of the Mar Chiquita Lake (Central Argentina). Data were collected by sampling two sites between 1992 and 1993 with CDC traps and human-bait captures. Adult mosquito population density, estimated by CDC trapping and human-bait, were highly correlated. However, when compared to other species, the proportion of Ae. albifasciatus was higher in human-bait collections. Adult female populations were active only when temperature were higher than 6§C. Two daily biting peaks were observed (dusk and dawn) during the spring, summer and autumn, and only one peak during winter (around 15:00 pm). Adult abundance was significantly correlated (R²= 0.71; p<0.01) with temperature and illumination.

Association of bGH and Pit-1 gene variants with milk production traits in dairy Gyr bulls

The objective of this study was to obtain genetic marker information in the Gyr breed by analyzing bGH and Pit-1 gene polymorphisms and to verify their association with milk production traits. One sample including 40 Gyr bulls were genotyped at two bGH gene restriction sites (bGH- AluI and bGH-MspI) and at one restriction site in the Pit-1 gene (Pit-1 HinfI). The bGH-MspI(-) allele was favorable for fat milk percentage. The heterozigous Pit-1 HinfI (+/-) bulls were superior for fat milk production, in relation to homozigous Pit-1 HinfI (+/+). The Pit-1 and bGH genes are strong candidates in the dairy cattle QTL search, and zebuine populations are promising samples for this purpose.

Milk yield and reproductive performance of dairy heifers and cows supplemented with polyunsaturated fatty acids

The objective of this work was to determine productive and fertility responses of Holstein-Friesian heifers and cows to supplementation with extruded linseed and soybean as sources of polyunsaturated fatty acids (PUFAs). Supplementation had a positive effect on profitability, with significant increases in milk yield in supplemented cows, but not in heifers. Treatments had no effect on milk fat content, but higher milk protein contents were observed with supplementation. A higher conception rate was found for supplemented heifers, but not for cows. Fat sources containing PUFAs are recommended for dairy cattle supplementation, since they improve fertility in heifers and milk yield in cows.

Conception rate of artificially inseminated Holstein cows affected by cloudy vaginal mucus, under intense heat conditions

The objective of this work was to obtain prevalence estimates of cloudy vaginal mucus in artificially inseminated Holstein cows raised under intense heat, in order to assess the effect of meteorological conditions on its occurrence during estrus and to determine its effect on conception rate. In a first study, an association was established between the occurrence of cloudy vaginal mucus during estrus and the conception rate of inseminated cows (18,620 services), raised under intense heat (mean annual temperature of 22°C), at highly technified farms, in the arid region of northern Mexico. In a second study, data from these large dairy operations were used to assess the effect of meteorological conditions throughout the year on the occurrence of cloudy vaginal mucus during artificial insemination (76,899 estruses). The overall rate of estruses with cloudy vaginal mucus was 21.4% (16,470/76,899; 95% confidence interval = 21.1-21.7%). The conception rate of cows with clean vaginal mucus was higher than that of cows with abnormal mucus (30.6 vs. 22%). Prevalence of estruses with cloudy vaginal mucus was strongly dependent on high ambient temperature and markedly higher in May and June. Acceptable conception rates in high milk-yielding Holstein cows can only be obtained with cows showing clear and translucid mucus at artificial insemination.

Prediction of free-stall occupancy rate in dairycattle barns through fuzzy sets

The goal of this study was to develop a fuzzy model to predict the occupancy rate of free-stalls facilities of dairy cattle, aiding to optimize the design of projects. The following input variables were defined for the development of the fuzzy system: dry bulb temperature (Tdb, °C), wet bulb temperature (Twb, °C) and black globe temperature (Tbg, °C). Based on the input variables, the fuzzy system predicts the occupancy rate (OR, %) of dairy cattle in free-stall barns. For the model validation, data collecting were conducted on the facilities of the Intensive System of Milk Production (SIPL), in the Dairy Cattle National Research Center (CNPGL) of Embrapa. The OR values, estimated by the fuzzy system, presented values of average standard deviation of 3.93%, indicating low rate of errors in the simulation. Simulated and measured results were statistically equal (P>0.05, t Test). After validating the proposed model, the average percentage of correct answers for the simulated data was 89.7%. Therefore, the fuzzy system developed for the occupancy rate prediction of free-stalls facilities for dairy cattle allowed a realistic prediction of stalls occupancy rate, allowing the planning and design of free-stall barns.

Fireweed (Senecio madagascariensis) poisoning in cattle

In a dairy cattle herd in southern Brazil, 7 out of 554 cattle were affected and died due to Senecio madagascariensis poisoning. Clinical, pathological, and epidemiological findings in the affected cattle were indistinguishable from those usually seen in poisoning caused by other Senecio species. The plant invaded extensive areas in heavily stocked paddocks. Senecio madagascariensis had been spreading in this farm for the last three years, with no control strategy, because neither the farmers nor the local veterinarian knew about the potential risks of this Sernecio species.

Metabolic evaluation of dairy cows submitted to three different strategies to decrease the effects of negative energy balance in early postpartum

In early lactation dairy cattle suffer metabolic alterations caused by negative energy balance, which predisposes to fatty liver and ketosis. The aim of this study was to evaluate the metabolic condition of high yielding dairy cows subjected to three treatments for preventing severe lipomobilization and ketosis in early lactation. Fifty four multiparous Holstein cows yielding >30 L/day were divided into four groups: control (CN= no treatment), glucose precursor (PG= propylene-glycol), hepatic protector (Mp= Mercepton®), and energy supplement with salts of linolenic and linoleic faty acids (Mg-E= Megalac-E®). Treatments were administrated randomly at moment of calving until 8 weeks postpartum. Blood samples were collected on days 1, 7, 14, 21, 28, 35, 42 and 49 postpartum. Body condition score (BCS) was evaluated at the same periods and milk yield was recorded at 2nd, 4th, 5th, 6th, 7th, and 8th weeks of lactation. Concentrations of non-esterified fatty acids (NEFA), albumin, AST, ß-hydroxybutyrate (BHBA), cholesterol, glucose, total protein, urea and triglycerides were analyzed in blood samples. Cut-off points for subclinical ketosis were defined when BHBA >1.4 mmol/L and NEFA >0.7 mmol/L. General occurrence of subclinical ketosis was 24% during the period. An ascendant curve of cholesterol and glucose was observed from the 1st to the 8th week of lactation, while any tendency was observed with BHBA and NEFA, although differences among treatments were detected (p<0.05). BCS decreased from a mean of 3.85 at 1st week to 2.53 at 8th week of lactation (p=0.001). Milk yield was higher in the Mg-E group compared with the other treatment groups (p<0.05) Compared with the CN group, the treatments with Mp and PG did not show significant differences in blood biochemistry and milk yield. Cows receiving PG and Mg-E showed higher values of BHBA and NEFA (P<0.05), indicating accentuated lipomobilization. Supplementation with Mg-E also resulted in significant higher concentrations of cholesterol, BHBA, urea, AST and lower values of glycemia. This performance may be explained by the highest milk yield observed with this treatment. Treatments with PG and Mp did not improve milk yield, compared with control cows, but did not show metabolic evidence of ketosis, fat mobilization or fatty liver. These results suggest that treatment with Mg-E improves milk production but induces a higher negative energy balance leading to moderated lipomobilization and ketone bodies production, increasing the risk of fatty liver.

Molecular epidemiology and extended-spectrum β-lactamases production of Klebsiella pneumoniae isolated from three dairy herds

The objectives of this study were to isolate Klebsiella pneumoniae from different sources in three dairy cattle herds, to use the pulsed-field gel electrophoresis (PFGE) to measure genotypic similarities between isolates within a dairy herd, to verify the production of extended-spectrum β-lactamases (ESBLs) by the double-disk synergy test (DDST), and to use the PCR to detect the main ESBLs subgroups genes. Three dairy farms were selected based on previous mastitis outbreaks caused by K. pneumoniae. Milk samples were collected from lactating cows and from the bulk tank. Swabs were performed in different locations, including milking parlors, waiting room, soil, animal's hind limbs and rectum. K. pneumoniae was isolated from 27 cases of intramammary infections (IMI) and from 41 swabs. For farm A isolates from IMI and bulk tank were considered of the same PGFE subtype. One isolate from a bulk tank, three from IMI cases and four from environmental samples were positive in the DDST test. All eight DDST positive isolates harbored the bla shv gene, one harbored the bla tem gene, and three harbored the bla ctx-m gene, including the bulk tank isolate. Our study confirms that ESBL producing bacteria is present in different locations in dairy farms, and may be responsible for IMI. The detection of ESBLs on dairy herds could be a major concern for both public and animal health.

A new species of Culex (Melanoconion) from Southern Brazil (Diptera: Culicidae)

A new species from Southern Brazil, named Culex (Melanoconion) ribeirensis is described. The description includes adults, pupal and larval stages, illustrating the morphological aspects and a picture of a breeding place. Some data about known distribution and bionomics are presented.

Studies on some species of Culex (Melanoconion), with the description of a new one from Southern Brazil (Diptera: Culicidae)

Redescription of Culex (Melanoconion) oedipus Root and of Cx. (Mel.) plectoporpe Root, as well as the description of a new one, named Cx. (Mel.) rabelloi, are made. The material was collected in S.Paulo State, Southern Brazil. The descriptions include adults, pupal and larval stages, illustrating the morphological aspects and with pictures of breeding places. Some data about known distribution and bionomics are presented, remarking that all the three species seem to be closely associated with artificial manmade enviroments.

Risk of drug interaction: combination of antidepressants and other drugs

OBJECTIVE: To assess the frequency of combination of antidepressants with other drugs and risk of drug interactions in the setting public hospital units in Brazil. METHODS: Prescriptions of all patients admitted to a public hospital from November 1996 to February 1997 were surveyed from the hospital's data processing center in São Paulo, Brazil. A manual search of case notes of all patients admitted to the psychiatric unit from January 1993 to December 1995 and all patients registered in the affective disorders outpatient clinic in December 1996 was carried out. Patients taking any antidepressant were identified and concomitant use of drugs was checked. By means of a software program (Micromedex®) drug interactions were identified. RESULTS: Out of 6,844 patients admitted to the hospital, 63 (0.9%) used antidepressants and 16 (25.3%) were at risk of drug interaction. Out of 311 patients in the psychiatric unit, 63 (20.2%) used antidepressants and 13 of them (20.6%) were at risk. Out of 87 patients in the affective disorders outpatient clinic, 43 (49.4%) took antidepressants and 7 (16.2%) were at risk. In general, the use of antidepressants was recorded in 169 patients and 36 (21.3%) were at risk of drug interactions. Twenty different forms of combinations at risk of drug interactions were identified: four were classified as mild, 15 moderate and one severe interaction. CONCLUSION: In the hospital general units the number of drug interactions per patient was higher than in the psychiatric unit; and prescription for depression was lower than expected.