A new approach in the prevention of gastrointestinal parasitic infections in cattle

The efficacy of a morantel long-acting device in preventing parasitic gastroenteric infections throughout a whole year was evaluated in heifers and steer calves in south central Québec. Thirty-two calves, comprising nine Hereford steers, one Hereford heifer, fourteen Holstein crossbred steers and eight Holstein crossbred heifers, were allotted into two treatment groups and maintained throughout the grazing season on adjacent pastures resulting from equivalently dividing one original pasture. One morantel long-acting device was administered to each animal in one group at the time of turnout onto the pasture in the spring while the calves in the other group remained as nonmedicated controls. The parasitic infections incurred during the pasture season were primarily Ostertagia, Trichostrongylus, Cooperia and Nematodirus.

The following fall, after twelve calves were necropsied for worm counts, the twenty remaining ones were brought into the barn where they were kept throughout the winter with access to an outside yard. They received good quality hay and rolled barley (1 kg/head/day) up until the following May, at which time they were weighed and had fecal samples taken for egg counts. In contrast to the results observed among controls, the morantel long-acting device treatment group had an 87% reduction in fecal worm egg excretion and a 67.3 kg per calf increased weight gain after one year.

     

Tick-borne parasitic diseases in cattle: current knowledge and prospective risk analysis related to the ongoing evolution in French cattle farming systems

Parasitic diseases, like babesiosis and theileriosis are transmitted by ticks: their occurrence is therefore linked to the size of the tick stock and the seasonality of the vectors. Babesia divergens bovine babesiosis transmitted by Ixodes ricinus is widespread and often reported in France. Serological prevalence is high, ranging from 20 to 80% according to the farms. Clinical incidence is low: around 0.4% for the whole cattle population. The endemic situation is unstable and clinical cases occur more frequently with farming system modifications. L. ricinus is a tick essentially found in woodlands and so, for the most part, is found in closed rural areas. The situation of the other bovine babesiosis (Babesia major) and theileriosis (Theileria orientalis) is not well documented in France. However, the epidemiology of parasitic diseases is changing, especially because of changes in the environmental characteristics, i.e. both farm and herd management conditions and also climatic conditions. These modifications can provoke an increase in the tick stocks, an increase in the contact rate between cattle and ticks, and an increase in the contact rate between cattle and the wild fauna, especially deer. This results in likely modifications of the endemic situation, with a higher risk of clinical babesiosis in the medium term.     

Unidentified parasitic cysts in cattle

Between February 18, 1995, and July 1, 1996, 38 cysts derived from New Zealand cattle were subjected to a diagnostic polymerase chain reaction (PCR) designed to identify genomic Taenia saginata DNA. No Tsaginata DNA was identified but an amplification product of 1078 bp was obtained consistently from several of the cysts. In Switzerland, suspect Tsaginata cysts are commonly positive for Tsaginata by PCR, but recently three cysts have also given a PCR fragment of 1078 bp, originating from a putatively unknown Taenia species.     

Covariate selection in multivariate spatial analysis of ovine parasitic infection

Gastrointestinal (GI) strongyle and fluke infections remain one of the main constraints on health and productivity in sheep dairy production. A cross-sectional survey was conducted in 2004-2005 on ovine farms in the Campania region of southern Italy in order to evaluate the prevalence of Haemonchus contortus, Fasciola hepatica, Dicrocoelium dendriticum and Calicophoron daubneyi from among other parasitic infections. In the present work, we focused on the role of the ecological characteristics of the pasture environment while accounting for the underlying long range geographical risk pattern. Bayesian multivariate spatial statistical analysis was used. A systematic grid (10 km×10 km) sampling approach was used. Laboratory procedures were based on the FLOTAC technique to detect and count eggs of helminths. A Geographical Information System (GIS) was constructed by using environmental data layers. Data on each of these layers were then extracted for pasturing areas that were previously digitalized aerial images of the ovine farms. Bayesian multivariate statistical analyses, including improper multivariate conditional autoregressive models, were used to select covariates on a multivariate spatially structured risk surface. Out of the 121 tested farms, 109 were positive for H. contortus, 81 for D. dendriticum, 17 for C. daubneyi and 15 for F. hepatica. The statistical analysis highlighted a north-south long range spatially structured pattern. This geographical pattern is treated here as a confounder, because the main interest was in the causal role of ecological covariates at the level of each pasturing area. A high percentage of pasture and impermeable soil were strong predictors of F. hepatica risk and a high percentage of wood was a strong predictor of C. daubneyi. A high percentage of wood, rocks and arable soil with sparse trees explained the spatial distribution of D. dendriticum. Sparse vegetation, river, mixed soil and permeable soil explained the spatial distribution of the H. contortus. Bayesian multivariate spatial analysis of parasitic infections with covariates from remote sensing at a very small geographical level allowed us to identify relevant risk predictors. All the covariates selected are consistent with the life cycles of the helminths investigated. This research showed the utility of appropriate GIS-driven surveillance systems. Moreover, spatial features can be used to tailor sampling design where the sampling fraction can be a function of remote sensing covariables.     

Isolation and sero-genomo-epidemiological studies on Brucella infection in dairy cattle in Meghalaya,India

In this study, we report the serological, bacteriological and whole genome sequencing data of a 6 years study of Brucella abortus in Meghalaya, India. Investigation of 3060 sera samples indicated overall prevalence of 6.4% by Rose Bengal Plate Test and 10.7% by ELISA. Considerably higher prevalence was observed among milk samples (17.5%, n = 362) and in blood samples (37.7%, n = 262) by direct PCR. Clinical samples (n = 94) from late abortion cases yielded 11 B. abortus isolates. Multi-locus sequence typing indicated circulation of single sequence type, ST1. Whole genome sequencing (n = 8) and phylogenomic analysis revealed close clustering of majority of isolates in two clusters alongwith genomes from other countries, indicating global relatedness among B. abortus. Taken together, the results of our study revealed the putative hotspot of infection in the dairy-dominant districts of the state and also calls for concerted One Health based action for prevention and control of this zoonotic disease.     

Ultrasonography in gastrointestinal disease in cattle

Ultrasonography is an ideal diagnostic tool for investigating gastrointestinal disorders in cattle. It is performed on standing non-sedated cattle using a 3.5 MHz linear transducer. In animals with traumatic reticuloperitonitis, inflammatory fibrinous changes, and abscesses can be imaged; however, magnets and foreign bodies are difficult to visualize because of the gas content of the reticulum. Ultrasonography can be used to assess the size, position and contents of the abomasum. Percutaneous ultrasound-guided abomasocentesis can be performed to evaluate the nature and chemical composition of its contents. In left displacement of the abomasum, the abomasum is seen between the left abdominal wall and the rumen. It contains fluid ingesta ventrally and a gas cap of varying size dorsally. Occasionally, the abomasal folds are seen in the ingesta. In cattle with right displacement of the abomasum, the liver is displaced medially from the right abdominal wall by the abomasum, which has an ultrasonographic appearance similar to that described for left displacement. Motility and diameter of the intestine are the most important criteria for ultrasonographic assessment of ileus. However, the cause of the ileus is rarely determined using ultrasonography. In cases with ileus of the small intestine, there is at least one region of dilatation of the intestine and motility is reduced or absent. In cattle with caecal dilatation, the caecum can always be imaged from the right lateral abdominal wall. The wall of the caecum closest to the transducer appears as a thick, echogenic, semi-circular line.     

Differences in susceptibility to gastrointestinal nematode infection between Angus and Brangus cattle in south Louisiana

Breed susceptibility to nematode infection was evaluated in Angus (Bos taurus) and Brangus (B. indicus crossbreed) cattle. A cow-calf herd and a yearling replacement heifer herd were monitored during one grazing season. Calves were born in March and were weaned in October. Individual rectal fecal samples were collected monthly from the two herds and processed for fecal egg counts (FEC) and coprocultures. Cow and calf FEC increased from April, reaching maximum values during the summer. Angus cows and calves had significantly (p<0.05) greater FEC than Brangus cows and calves, and Haemonchus and Cooperia were the predominant genera. Replacement heifer FEC showed a similar pattern with maximum levels during late summer/fall, and Haemonchus was the predominant genus. No significant differences were seen between breeds, however, infection levels were consistently lower in Brangus heifers. Ostertagia was present in cows and heifers only in fall/winter, which is consistent with summer inhibition. The data suggested that cows were an important source of pasture contamination for their susceptible calves and that the Brangus breed was relatively more resistant to infection. The use of B. indicus crossbreeds may help in alleviating reliance on chemical control by reducing the rate of pasture contamination and subsequent infection losses.     

Seroprevalence and risk factors of Coxiella burnetii infection in cattle in northeast Algeria

Tropical Animal Health and Production - A cross-sectional study was conducted to determine the seroprevalence and the risk factors associated with C. burnetii infection in cattle in the state of...     

新疆某肉牛养殖场不同架子牛育肥模式的经济效益分析

本研究通过对新疆某肉牛养殖场架子牛育肥经济效益的调研分析,旨在为新疆肉牛养殖从业者选择架子牛育肥模式提供理论参考。购入高、低初始重的新疆褐牛与本地土牛杂交架子牛各24头,分为高成本高初始重组(HH组)、低成本高初始重组(LH组)、高成本低初始重组(HL组)、低成本低初始重组(LL组),每组12头牛,育肥周期为7-9个月,每月称重并记录结果,并对数据进行分析。单因素方差分析结果显示,LL组末重极显著低于其它3组(P<0.01),HH组末重显著高于LH组和HL组(P＜0.05);育肥期平均日增重LL组显著低于其它3组(P＜0.05),HH组、LH组和HL组虽然差异不显著(P>0.05),但是HH组和HL组日增重大于LH组。经济效益分析结果显示,成本利润率HL组>HH组>LL组>LH组。相关性分析结果显示,成本利润率与平均日增重呈极显著正相关关系(P<0.01),与日饲喂成本呈现显著正相关关系(P<0.05)。本研究发现,在架子牛育肥过程中,高饲喂成本投入可以获得更高的经济效益,选择低初始重的架子牛进行短期高营养水平育肥,比选择高初始重的架子牛育肥经济效益更好。     

齐齐哈尔市牛寄生性蠕虫的区系调查

在齐齐哈尔市龙江县、富裕县、泰来县的3个肉牛饲养场随机选取改良成年肉牛52头，用蠕虫学剖检法进行寄生性蠕虫区系调查。结果，在牛体内共检获各类寄生性蠕虫13种，隶属于2门、3纲、10科、12属，其中以捻转血矛线虫、牛仰口线虫、前后盘吸虫、食道口线虫、肝片形吸虫、毛圆线虫和莫尼茨绦虫的感染率和感染强度高，分布广，为齐齐哈尔市牛寄生虫的优势虫种。     

Herd-level risk factors for bovine viral diarrhea infection in cattle of Tamil Nadu

A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12–65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P?<?0.05).