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排序方式: 共有1612条查询结果,搜索用时 15 毫秒
931.
Bruce E Anderson 《Veterinary Clinics of North America: Food Animal Practice》2006,22(2):357-372
Successful grazing management of stockers requires knowledge of plant growth characteristics. Maintaining abundant leaf area is critical to support photosynthesis and plant growth as well as to provide nutritious grazing for the animals. Controlling stocking rate, stock density, and lengths of grazing and recovery periods can optimize individual animal rates of gain and gain per acre while maintaining pasture productivity. Various plant resources, perennial and annual, can be used strategically to provide the quantity and quality of forage needed by stockers throughout the year. 相似文献
932.
Geoffrey K Saunders Bruce V Thomsen 《Journal of veterinary diagnostic investigation》2006,18(5):513-515
A 6-year-old, neutered male ferret presented with weight loss. Radiography revealed an enlarged liver and other abdominal masses. The ferret was euthanized, and at necropsy, the stomach wall was thickened, mesenteric lymph nodes were enlarged, and the liver contained multifocal tan nodules. Histopathology confirmed lymphoma and granulomatous inflammation in all affected organs. Acid-fast bacilli were present in the lesions and were confirmed to be Mycobacterium avium by PCR. 相似文献
933.
934.
Bruce K Johnson Terrance McCoy Christopher O Kochanny Rachel C Cook 《Journal of zoo and wildlife medicine》2006,37(3):301-305
The effects of vaginal implant transmitters for tissue damage after 11 wk in 13 captive adult elk (Cervus elaphus nelsoni) and subsequent reproductive performance in 38 free-ranging elk were evaluated. Vaginal implant transmitters are designed to be shed at parturition and are used to locate birth sites of wild ungulates; however, potential adverse effects of these transmitters on tissues associated with the vaginal walls or subsequent reproductive performance have not been assessed. Vaginal implant transmitters consist of a transmitter encased in inert acrylic with an antenna trailing out the distal end and wings at the proximal end to hold the transmitter in place. Using a laparoscope on sedated captive elk, necrosis or measurable differences in tissue trauma between designs with wing spans of 80 versus 150 mm over an 11-wk trial were not observed. After the captive elk trial, vaginal implant transmitters with 80-mm wings were placed into 38 pregnant wild elk, and 31 live births were documented. Fates of seven calves were not determined, because their transmitters were not shed at the birth site. We recaptured 36 of these cow elk again in fall 2003 or spring 2004, and 32 were pregnant. This study was unable to document any short- or long-term effects of vaginal implant transmitters on reproductive performance of cow elk in captive and free-range environments. 相似文献
935.
The Illinois soybean crop was monitored in 1965, 1966, 1967, 1971, and 1974 for dieldrin residues resulting from aldrin applied to corn in the years before soybean cultivation. Residue levels of dieldrin in soybeans increased between 1965 and 1974. The percent of fields which had soybeans with a dieldrin level above 0.03 ppm increased between 1965 and 1974. Dieldrin residue levels in soybeans grown in Illinois are expected to decline now that the use of aldrin has diminished and will soon cease. No significant correlation was evident between the dieldrin levels in soybeans and the area of the State where they had grown, the date of planting, or the variety. 相似文献
936.
937.
Sutherland MA Stafford KJ Mellor DJ Gregory NG Bruce RA Ward RN 《Australian veterinary journal》2000,78(6):402-405
OBJECTIVE: To test whether the cortisol response to ring castration plus docking is reduced by additional application of a castration clamp across the full width of the scrotum distal to the ring. DESIGN: A physiological study with controls. PROCEDURE: Lambs, 3 to 6 weeks of age, were castrated using a ring or ring plus castration clamp applied for 6 or 10 s and docked using a ring. Blood samples were taken before and regularly for about 4 h after treatment and analysed for plasma cortisol concentrations. The healing of the scrotal wounds was monitored for 6 weeks after castration. RESULTS: The plasma cortisol concentrations were lower only at 60 min after treatment in lambs castrated with a clamp placed on the scrotum for 10 s after ring castration and docking than in lambs castrated and docked by ring alone. Scrotal wounds healed more quickly after ring plus clamp than after ring only castration. CONCLUSIONS: The castration clamp had at most a marginal effect on the cortisol response to ring castration and docking of 3- to 6-week-old lambs, but it did seem to improve the rate of healing. 相似文献
938.
W J Bruce A Rose J Tuke G M Robins 《Veterinary and comparative orthopaedics and traumatology》2007,20(3):159-168
The triple tibial osteotomy (TTO) is a technique which combines the features of tibial tuberosity advancement and wedge osteotomy for the treatment of complete and partial cruciate ligament injuries in dogs. In this paper, the technique is described and the results of a prospective study of 64 consecutive cases are presented. TTO provided a satisfactory clinical outcome in a very high percentage of cases. The technique is relatively easy to learn and has a low post-operative complication rate. 相似文献
939.
Net efflux of CO(2) from attached avocado (Persea americana Mill.) fruit was measured periodically from three weeks after anthesis to fruit maturity. Net CO(2) exchange was determined in daylight (light respiration, R(l)) at a photosynthetic photon flux (PPF) greater than 600 micromol m(-1) s(-1), and in the dark (dark respiration, R(d)). Dark respiration and R(l) were highest during the early cell division stage of fruit growth (about 25 and 22 nmol CO(2) g(dw) (-1) s(-1), respectively) and decreased gradually until fruit maturity to about 1 and 0.5 nmol CO(2) nmol CO(2) g(dw) (-1) s(-1), respectively. Fruit photosynthesis, calculated from the difference between R(d) and R(l), ranged from 0.5 to 3.1 nmol CO(2) g(dw) (-1) s(-1). Net rate of CO(2) assimilation on a fruit dry weight basis was highest during the early stages of fruit growth and reached the lowest rate at fruit maturity. Net rate of CO(2) assimilation of fruit exposed to light was 0.4 to 2.5% of that for fully expanded leaves. Although the relative amount of carbon assimilated by the fruit was small compared with the total amount of carbon assimilated by the leaves, the data indicate that avocado fruit contribute to their own carbon requirement by means of CO(2) assimilated in the light. 相似文献
940.
Optimum ages for early combined-trait selection were derived for a breeding objective of reducing the total cost of unbleached eucalypt kraft pulp, assuming typical heritabilities and age-age genetic correlations for basic density and growth. The optimum biological selection age, the selection age where average annual gain is maximised, was four years for an assumed rotation age of 15 years. The optimum economic selection age, the selection age where the present value of all future gains is maximised, was three years. These conclusions were relatively robust to changes in assumptions used in analysis. 相似文献