Field studies investigating anthelmintic resistance in young cattle on five farms in New Zealand

AIM: To investigate the efficacy of pour-on anthelmintics against field strains of parasitic nematodes in young cattle on five farms in New Zealand.

METHODS: Faecal nematode egg count (FEC) reduction (FECR) tests were carried out on five calf-rearing farms using pour-on formulations of levamisole, ivermectin, eprinomectin, and the simultaneous administration of levamisole and ivermec- tin. Faecal samples were collected per rectum before treatment and about 7, 14, 21 and 28 days after treatment, for FEC and faecal nematode larval culture.

RESULTS: Resistance (i.e. <95% reduction in FEC) of Cooperia oncophora to ivermectin and eprinomectin was identified on all five farms. There was limited evidence of possible emerging resistance in Ostertagia spp to ivermectin but not eprinomectin, in short-tailed larvae of Cooperia spp to ivermectin and eprinomec- tin, and in Trichostrongylus spp to ivermectin, eprinomectin and levamisole used separately. Levamisole was effective against C. oncophora, but had variable efficacy against Ostertagia spp in the calves in this study. Simultaneous treatment with levamisole and ivermectin pour-on formulations were effective against all genera on all farms.

CONCLUSIONS: To effectively manage roundworm parasites in their calves farmers need to be aware of the resistance status of the parasites on their farms. Levamisole is likely to be an effective anthelmintic on most farms at times of the year when the impact of Ostertagia spp is not high. Simultaneous administration of levamisole and ivermectin pour-on anthelmintics to cattle is likely to control both ML-resistant C. oncophora and stages of Ostertagia spp that are not controlled by levamisole alone.     

Nitrogen rhizodeposition in agricultural crops: Methods,estimates and future prospects

The objective of the present review was to present the current knowledge on nitrogen (N) rhizodeposition, including techniques for ¹⁵N labelling of agricultural plants, amounts of N rhizodeposition and its fate in soil. Rhizodeposition is the process of release of organic and inorganic compounds from living plant roots. It is often quantified in terms of carbon (C) and less often as N derived from rhizodeposition (NdfR). Rhizodeposition of N can be estimated by labelling plants with ¹⁵N and following its fate in soil. Most methods used for labelling plants with ¹⁵N can only be applied after appearance of the first leaf and only allow pulse or multiple pulse labelling. Only the split-root technique and the application of gaseous ¹⁵N allow continuous labelling. All methods available at present have their flaccidities mostly due to the fact that the application of N is not following its physiological pathway of assimilation or by using artificial conditions. In the studies reviewed, amounts of N rhizodeposits ranged from 4% to 71% of total assimilated plant N. In legumes the median was 16% and in cereals it was 14%. Rhizodeposits were 15–96% of the below-ground plant biomass (BGP). In legumes the median was 73% and in cereal it was 57%. The high variability of these results shows the need for more investigations on N rhizodeposition looking especially on the factors influencing the amounts released in different plant species under field conditions.     

Nutritional and mineral content of prickly pear cactus: A highly water‐use efficient forage,fodder and food species

Increased demand for food requires us to investigate livestock forage and fodder crops that can be grown over a wide range of locations where their cultivation will not compete with that of the food supply. A large portion of the southwestern United States consists of underutilized semi‐arid land. Crops typically used for livestock fodder or forage have high‐water demands that make them uneconomical or unsustainable for semi‐arid and arid regions. The growth rate and low‐input requirements of prickly pear cactus (Opuntia ficus‐indica) make it an excellent candidate for forage or fodder supplementation or replacement in these regions. Previous reports about forage quality data on Opuntia have been scattered across multiple locations, growing conditions and cultivars. Here, we report on the forage quality and mineral content of Opuntia ficus‐indica grown under both field and greenhouse conditions. Crude protein was 71 and 264 g/kg of dry mass for field and greenhouse conditions, respectively. Field‐grown plants showed higher acid and neutral detergent fibre content than greenhouse‐grown plants reflecting higher cellulose, hemicellulose and lignin accumulation. Nutritional values were also compared to requirements of cattle to determine what deficiencies might need to be addressed through supplementation. These data suggest that Opuntia can be used in combination with other feed sources to reduce the demand of resource‐intensive forage crops for raising livestock in dryland areas.     

A dog with squamous cell carcinoma in the middle ear

An 8-year-old, castrated male golden retriever was referred for lethargy and inappetance. Severe pain was elicited on palpation of the left temporomandibular joint region. Computed tomography revealed aggressive bone destruction of the left bulla. Squamous cell carcinoma was diagnosed. Malignant tumor in the canine middle ear is rare.     

Deep‐water cirripedes colonizing dead shells of the cephalopod Nautilus macromphalus from New Caledonian waters

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post‐mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post‐mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post‐mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.     

铁路路堑边坡植被恢复调查研究

植被在边坡生态系统中有着非常重要的作用,具有涵养水源、保持水土的功能.选择四川省成昆铁路沿线不同坡向的土质路堑边坡和岩质路堑边坡,对边坡植物群落的植被类型及其结构特征、边坡植被恢复物种组成及其特征进行了调查研究.结果表明:铁路边坡自然定居物种共103种,隶属48科,全部植物中,常绿灌木2种,落叶灌木9种,藤本植物7种,1 a生草本20种,2 a或2 a以上草本植物49种;蕨类植物15种.群落物种的丰富度虽然较高,但是主要由草本植物构成,结构层次简单,应该适当的在边坡上栽植灌木或小乔木,形成坡面上乔、灌、草或草、灌相互映的群落景观.     

Use of personal protective equipment in a radiology room at a veterinary teaching hospital

The use of personal protective equipment by veterinary workers during radiographic imaging is inconsistent. While the self‐reported use of leaded aprons and thyroid shields approaches 100% in some studies, the use of leaded gloves and eyeglasses is much lower. Previous studies describing personal protective equipment use are based on self‐reporting. Objectives of this prospective, observational study were to describe use of leaded personal protective equipment during radiographic imaging by veterinary workers, and to compare observed use with self‐reported use. Use of leaded personal protective equipment during radiographic imaging by veterinary workers was observed over a 10 week period using two motion‐triggered video cameras, and a questionnaire was then completed by workers on their use of personal protective equipment. Workers restrained the animal during 91.8% (753/820) of exposures. An apron and a securely closed thyroid shield were worn for >99% of studies. Gloves were used correctly for 43.6% (156/358) of radiographic studies. Leaded eyeglasses were worn for 1.7% (6/358) of studies. Correct glove use was more frequent during regular working hours than after‐hours for both veterinarians (odds ratio 32.7, P = 0.001) and veterinary students (odds ratio 75.1, P < 0.001). The number of workers in the room was lower when animals were sedated (P = 0.002) or anesthetized (P = 0.017). Workers overestimated their frequency of glove use (P <0.001). In conclusion, workers use personal protective equipment less frequently in an unsupervised environment, and overestimate their use of personal protective equipment. Use of sedation or anesthesia decreases worker exposure to ionizing radiation.     

Diagnoses and clinical outcomes associated with surgically amputated feline digits submitted to multiple veterinary diagnostic laboratories

Amputation is commonly performed in an attempt to both treat and diagnose conditions affecting the digits of cats. The records of multiple veterinary diagnostic laboratories were searched to identify submissions of amputated digits from cats. Eighty-five separate submissions were reviewed for diagnosis, age, sex, limb of origin, and digits affected; and the original submitting clinics were surveyed to determine clinical outcome. The Kaplan-Meier product-limit method was used to determine the disease-free interval and survival time. Neoplastic disease was identified in 63 of 85 submissions, with exclusively inflammatory lesions composing the other 22 cases. In 60 (95.2%) of the neoplastic cases, a malignant tumor was identified. Squamous cell carcinoma was the most commonly identified malignant tumor (n = 15; 23.8%) and was associated with a median survival time of 73 days. Other diagnoses included fibrosarcoma (n = 14; 22.2%); adenocarcinoma, likely metastases of a primary pulmonary neoplasm (n = 13; 20.6%); osteosarcoma (n = 5; 7.9%); mast cell tumor (n = 4; 6.3%); hemangiosarcoma (n = 5; 7.9%); malignant fibrous histiocytoma (n = 2; 3.2%); giant cell tumor of bone (n = 2; 3.2%); and hemangioma (n = 2; 3.2%). Giant cell tumor of bone has not been previously described in the digits of cats. Various neoplasms can occur in the digits of cats, and submission of the amputated digit for histopathologic diagnosis is essential to determine the histogenesis and predict the clinical outcome.     

Reproductive performance and milk production of Israeli-Holstein cows with different supplementation during the dry period]

In three field trials comprising 602 Israeli-Holstein dairy cows, the effect of the dry period ration on reproductive performance, culling rate and milk production was investigated. The cows were fed in groups. The basic dry period rations consisted for two herds of medium quality cereal hay and for one herd of corn straw, which were fed ad libitum. In each herd dry cows were assigned to an experimental and control group. Cows of the experimental group were supplemented with 1.5 to 3 kg of lactating cows mixed ration (LMR), whereas in the control group the amount of supplement was increased by the factor two or 3.3. In the experimental group the amount of the supplement was calculated to achieve levels of net energy and of crude protein close to NRC requirements; in the control group the level of net energy and protein was 12 to 18% higher as compared to the experimental group. The amount of LMR supplement in the experimental group of herds A, B, C were 1.5 kg, 1.9 kg, and 3 kg, respectively. In the control groups these amounts were 5 kg, 3.8 kg, and 6 kg, respectively. The groups fed moderate amounts of LMR supplement had a higher conception rate at first insemination, a higher percentage of cows conceiving and fewer cows culled in the consecutive lactation than cows fed increased amounts of LMR supplement. The lactational incidence of reproductive disorders and the milk production were not affected by the differences in feeding during the dry period. Reproductive performance and culling rate appeared to be more favorable for cows fed moderate amounts of supplement during the entire dry period or during the last 3 to 4 weeks of the dry period.     

Ubiquitin gene expression and ubiquitin conjugation in chicken muscle do not reflect differences in growth rate between broiler and layer birds.

Previous work has shown that chicken strains selected for growth (broilers) degrade muscle proteins less rapidly than those selected for egg laying. They also have decreased calpain and increased calpastatin content in breast muscle. This study aimed to test the hypothesis that these differences correlate with changes in the ATP- and ubiquitin-dependent proteolytic system. Chickens of a broiler strain (Ross 1) and a layer strain (ISABrown) were reared to the age of 4 wk under identical conditions with ad libitum access to feed and water. Mean fractional growth rates were 10.4%/d for broilers and 7.4%/d for layers. Feed intake measured in the last week of the trial was slightly greater in layer birds (.11 and .12 g x g body weight(-1) x d(-1) for broilers and layers respectively; P < .006). Polyubiquitin (UbI) messenger RNA was abundant in the muscles of these well-fed birds, but it showed little difference between strains. Muscle did not significantly express the UbII polyubiquitin gene. The ATP-dependent system conjugating ubiquitin to endogenous proteins had greatest activity in the gastrocnemius muscle of broiler birds but was not significantly different between breeds. Proteins cross-reactive with antisera to recombinant human proteasome regulatory subunits MSS1 (multicopy suppressor of SUG 1; S7) and TBP1 (tat binding protein 1; S6') were present in muscle homogenates from both strains of bird. The chick equivalent of TBP1 was more abundant in breast muscle of broiler birds than in leg muscle, or in either muscle of layers. Antiserum to recombinant yeast subunit mts2 (mitosis temperature sensitive gene 2; S4) did not react with any protein of the expected size but detected a 30-kDa peptide that was not associated with the 26S proteasome; this was found only in muscle from the layer strain. Hence, during normal growth of chickens, rates of protein degradation are not controlled by the expression of ubiquitin mRNA or the conjugation of ubiquitin. However, the composition of the 26S proteasome may be a regulatory factor.