Cytogenetic survey of Holstein bulls at a commercial artificial insemination company to determine prevalence of bulls with centric fusion and chimeric anomalies

OBJECTIVE: To determine prevalence of Holstein bulls with chromosomal anomalies, particularly the 1/21 centric fusion (CF), at a commercial artificial insemination (AI) company in the United States. DESIGN: Cross-sectional cytogenetic prevalence study. ANIMALS: All 606 Holstein bulls at a commercial AI company were cytogenetically screened to detect CF, chimerism, and other chromosomal abnormalities. PROCEDURE: Lymphocytes from heparinized blood samples were cultured by standard cytogenetic techniques, and chromosome spreads were prepared for microscopic examination. Chromosomal abnormalities were detected by examining 10 chromosome spreads per bull. Pedigree analysis was performed. RESULTS: None of the bulls had any type of CF. However, 6 bulls were identified as chimeras (i.e., contained lymphocytes with male [XY] and female [XX] chromosomes). One bull was sire or maternal grandsire to 85 of the bulls tested, and 739 of 1,212 (61%) sire and maternal-grandsire possibilities were accounted for by just 18 bulls. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of these results supports previous indications that CF is extremely rare in Holstein bloodlines available commercially via AI in the United States. However, chimeric bulls are more common, and they reportedly have decreased reproductive performance. Therefore, identification of chimeric sires in the AI facility reported here and the possibility of de novo onset of CF at any time indicates that early cytogenetic screening should be encouraged for prospective bulls intended for use in AI programs.     

Historical landscape ecology of an urbanized California valley: wetlands and woodlands in the Santa Clara Valley

Historical records provide information to land managers and landscape ecologists attempting to understand current trajectories in altered landscapes. In this study, we synthesized a heterogeneous array of historical sources to reconstruct historical land cover in California’s Santa Clara Valley (a.k.a. “Silicon Valley”). To increase and assess accuracy, we used the triangulation of overlapping, independent data sources and the application of certainty level standards. The region has been subject to extensive urbanization, so we also evaluated the applicability of historical landscape reconstructions to the altered landscape. We found evidence for five major land cover types prior to significant Euro–American modification. Valley freshwater marsh, wet meadow, alkali meadow, willow grove, and valley oak savanna have all experienced extreme decline (85–100%) since Euro–American settlement. However, comparison of historical land cover patterns to contemporary land use suggested several new strategies for environmental recovery, despite the limitations of surrounding urbanization. We also observed a temporal shift in riparian habitat along the mainstem of Coyote Creek, from a relatively open mixture of riparian scrub, sycamore woodland, and unvegetated gravel bars to dense riparian forest, likely resulting from stream flow regulation. By identifying former land cover patterns we provide a basis for evaluating local landscape change and setting restoration targets, including the identification of residual features and under-recognized land cover types. These findings suggest that reliable historical landscape reconstructions can be developed in the absence of standardized historical data sources and can be of value even in highly modified regions.     

Adaptation and evaluation of the National Cancer Institute's Diet History Questionnaire and nutrient database for Canadian populations

BACKGROUND AND OBJECTIVE: Despite assumed similarities in Canadian and US dietary habits, some differences in food availability and nutrient fortification exist. Food-frequency questionnaires designed for the USA may therefore not provide the most accurate estimates of dietary intake in Canadian populations. Hence, we undertook to evaluate and modify the National Cancer Institute's Diet History Questionnaire (DHQ) and nutrient database. METHODS: Of the foods queried on the DHQ, those most likely to differ in nutrient composition were identified. Where possible these foods were matched to comparable foods in the Canadian Nutrient File. Nutrient values were examined and modified to reflect the Canadian content of minerals (calcium, iron, zinc) and vitamins (A, C, D, thiamin, riboflavin, niacin, B6, folate and B12). DHQs completed by 13 181 Alberta Cohort Study participants aged 35-69 years were analysed to estimate nutrient intakes using the original US and modified versions of the DHQ databases. Misclassification of intake for meeting the Dietary Reference Intake (DRI) was determined following analysis with the US nutrient database. RESULTS: Twenty-five per cent of 2411 foods deemed most likely to differ in nutrient profile were subsequently modified for folate, 11% for vitamin D, 10% for calcium and riboflavin, and between 7 and 10% for the remaining nutrients of interest. Misclassification with respect to meeting the DRI varied but was highest for folate (7%) and vitamin A (7%) among men, and for vitamin D (7%) among women over 50 years of age. CONCLUSIOn: Errors in nutrient intake estimates owing to differences in food fortification between the USA and Canada can be reduced in Canadian populations by using nutrient databases that reflect Canadian fortification practices.     

Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

Agroforestry Systems - Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage...     

Impact of temperature and nutrition on the toxicity of the insecticide λ-cyhalothrin in full-lifecycle tests with the target mosquito species Aedes albopictus and Culex pipiens

The global spread of the Asian tiger mosquito Aedes albopictus, an urban pest as well as a vector for arboviruses, is a threat for public health. As control measures include the use of insecticides such as the pyrethroid λ-cyhalothrin, it is crucial to assess their efficiency and their potential impact on the biodiversity especially under climate change conditions. To evaluate the environmental risk, biotests are well established for non-target organisms but not yet for mosquitoes. We therefore developed a full-lifecycle biotest for mosquitoes kept under quarantine conditions based on the OECD guideline 219. Therewith we tested the effect of temperature and nutrition on the ecotoxicological response to λ-cyhalothrin on the mosquitoes Ae. albopictus and Culex pipiens by assessing sublethal and life history parameters. The efficiency of λ-cyhalothrin decreased in both mosquito species with increasing temperature and changed with feeding protocol. At effective concentrations for potential mosquito control in surface waters, λ-cyhalothrin poses a high risk for indigenous aquatic key role species inhabiting the same microhabitats. Those aspects should to be taken into account in vector control strategies.     

Replacement of live food with a microbound diet in feeding Litopenaeus setiferus (Burkenroad) larvae

Microbound feeds have been well accepted by shrimps and farmers in many penaeid shrimp hatcheries. The present study focused on an adequate level of replacement of Artemia nauplii and microalgae by a microbound diet for rearing Litopenaeus setiferus (Burkenroad) larvae. A microbound diet (MBD) consisting of fishmeal, squid meal, shrimp meal, yeast meal and soybean meal was used. The first experiment was designed to obtain the optimum level of MBD to complete the live feeding schedule, from Protozoea (PZ_III) to Mysis (M_III). The experimental levels of the microbound diet tested were 2, 4, 6 and 8 mg MBD L^?1 day^?1. The next step was to determine the Artemia nauplii replacement level from PZ_I to M_III by MBD. These experiments were carried out either in the presence (Experiment 2) or in the absence of algae (Experiment 3). Four replacement levels were tested: 0% (4 mg MBD L^?1 day^?1: 1 Artemia nauplii mL^?1), 40% (5.5 mg MBD L^?1 day^?1: 0.6 Artemia nauplii), 60% (6.5 mg MBD L^?1 day^?1: 0.4 Artemia nauplii) and 100% (8 mg MBD L^?1 day^?1: 0 Artemia nauplii). In all experiments growth, survival, development, quality index (QI) and performance index (PI), were used to determine the optimum concentration of microbound diet. Results showed that 6 mg MBD L^?1 day^?1 can be recommended as a complement to live food for L. setiferus larvae from PZ_III to M_III. In the presence of algae, maximum growth and survival may be obtained in 40–60% (5.5–6.5 mg MBD L^?1 day^?1) of Artemia nauplii replacement levels. In the absence of algae, the Artemia nauplii replacement resulted in slower development, less salinity resistance, lower growth and lower survival than was obtained in larvae fed with algae.     

Effects of four egg desticking procedures on hatching rate and further survival and growth of larvae in the tench (Tinca tinca L.)

Four desticking procedures for tench eggs (A: tannic acid solution (1 g L⁻¹) for 15 s; B: alcalase enzyme solution (8 mL L⁻¹) for 60 s; C: alcalase enzyme solution (15 mL L⁻¹) for 120 s; D: Woynarovich and Woynarovich (1980) solution for 58 min followed by tannic acid solution (1 g L⁻¹) for 15 s) were tested to obtain data about influence on embryo survival to hatching stage and further survival and growth of the larvae. In the tannic acid and Woynarovich and Woynarovich (1980) treatment (A and D) few eggs stuck together and some were adhered to the incubator walls, whereas in the alcalase treatments (B and C) eggs neither stuck together nor adhered to the incubator walls. Percentages of hatched larvae did not show significant differences (mean values ranged between 47.4% in treatment A to 37.0% in treatment C). Larvae deformities observed were <0.5% in all cases. There were no significant differences among survival and growth rates of the larvae from different egg desticking origin, reaching, after 30 days, mean survival values around 90% and total length and weight of 12.5 mm and 19 mg respectively.     

IMAGING DIAGNOSIS ‐ SPONTANEOUS SUBPERIOSTEAL VERTEBRAL HEMORRHAGE IN A GREYHOUND

A 4‐year‐old, spayed female greyhound dog was presented with an acute onset of paraplegia. There was no known history of trauma or coagulopathy. Spinal cord compression was identified on MRI. Intra‐operative evaluation revealed the presence of a large subperiosteal hematoma and a smaller epidural hematoma. To the authors’ knowledge, this is the first report of a spinal subperiosteal hematoma diagnosed antemortem through MRI, with surgical exploration and successful treatment in a dog.