The effects of large doses of soluble and insoluble forms of cobalt given at monthly intervals on cobalt deficiency disease in lambs     

E D Andrews  B J Stephenson  C E Isaacs  R H Register 《New Zealand veterinary journal》1966,14(11):191-196

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Seeking consensus on a new Veterinary Surgeons Act     

Stephenson R 《The Veterinary record》2008,162(16):527

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Influence of Precipitation on Plant Production at Different Topographic Positions in the Nebraska Sandhills     

Mitchell B. Stephenson  Jerry D. Volesky  Walter H. Schacht  Nevin C. Lawrence  Jon Soper  Jessica Milby 《Strength and Conditioning Journal》2019,72(1):103-111

Several studies have evaluated the spatial distribution of cool- and warm-season grasses across different topographic positions in the Nebraska Sandhills, but limited research has explored topographic differences in total plant production or production of plant functional groups in relation to variable amounts of precipitation. This study evaluated how spring and growing season precipitation influenced plant production at four topographic positions common in the eastern Nebraska Sandhills. Plant production data were collected from annually moved grazing exclosures in mid-June (peak cool-season grass production) and mid-August (peak warm-season grass production) during a 17-yr period from 2001 to 2017. Total plant production and precipitation use efficiency were 35 ? 58% greater on interdune positions, and precipitation marginal response for total plant production was more sensitive to increases in spring and growing season precipitation on interdune compared with dune positions in both mid-June and mid-August. The greater precipitation marginal response of total plant production on interdune positions was driven primarily by greater increases in cool-season grass production with increasing spring or growing season precipitation. Warm-season grass precipitation marginal response was not different among the topographic positions, but production was 23 ? 70% greater on interdune compared with dune topographic positions in mid-August. When differences in the amount of each topographic position at the study location were accounted for, growing season precipitation explained 49% of the variation for total plant production in mid-August, but spring precipitation only explained 23% of the variation for total plant production in mid-June. Because of the differential response of plant production at dune and interdune positions, incorporating the relative amount of each topographic position into estimates of plant production at the pasture or ranch scale will provide better information for adjusting stocking rates to more accurately match animal demand with forage availability.  相似文献   

Pathogenicity studies with the fungi Aphanomyces invadans, Achlya bisexualis, and Phialemonium dimorphosporum: induction of skin ulcers in striped mullet     

Sosa ER  Landsberg JH  Kiryu Y  Stephenson CM  Cody TT  Dukeman AK  Wolfe HP  Vandersea MW  Litaker RW 《Journal of aquatic animal health》2007,19(1):41-48

Based on isolations from naturally infected fish in Florida, we investigated the role of the fungi Aphanomyces invadans, Achlya bisexualis, and Phialemonium dimorphosporum in the etiology of ulcerative mycosis (UM) in striped mullet Mugil cephalus. We injected healthy striped mullet subcutaneously with secondary zoospores of four oomycete isolates: two concentrations (50 and 115 zoospores/mL) of SJR (an endemic isolate of Aphanomyces invadans in American shad Alosa sapidissima from the St. Johns River); two concentrations each of CAL (25 and 65 zoospores/mL) and ACH (1,400 and 2,000 zoospores/mL; endemic isolates of Aphanomyces invadans and Achlyva bisexualis, respectively, in striped mullet from the Caloosahatchee River); and two concentrations of the ascomycete culture MTZ (2,500 and 3,500 zoospores/mL; endemic isolate of P. dimorphosporum from whirligig mullet M. gyrans in the Matanzas Inlet). All fish injected with either concentration of SJR developed granulomatous ulcers after 8 d and died within 21 d. Eighty percent (8/10) of fish injected with the high dose of CAL developed ulcers after 13 d and died within 28 d, but only 30% (3/10) of fish injected with the low dose of CAL developed ulcers. Four of the ulcerated fish died within 28 d, and the remaining fish were terminated after 32 d. Fish injected with zoospores of Aphanomyces invadans developed ulcers that were grossly and histologically similar to those observed in naturally infected striped mullet with UM from several estuaries or rivers in Florida. These hemorrhagic skin ulcers were characterized by myonecrosis and the presence of mycotic granulomas. None of the fish injected with ACH, MTZ, or sterile water developed ulcers. This study fulfilled Koch's postulates and demonstrated that ulcers could be experimentally induced in striped mullet after exposure via injection to secondary zoospores of an endemic Florida strain of Aphanomyces invadans.  相似文献   

The potential of microsatellites for high throughput genetic diversity assessment in wheat and barley   总被引：5，自引：1，他引：4  

P. Donini  P. Stephenson  G.J. Bryan  R.M.D. Koebner 《Genetic Resources and Crop Evolution》1998,45(5):415-421

Microsatellite (SSR) profiles from 65 wheats and 135 barleys have been generated, involving 14 and 22 loci, respectively. The wheat and barley varieties were chosen to represent the bulk of the area sown to these crops in the UK over the past 70 years. The profiling identified genotypic mixtures in some seed samples. Null alleles were common in wheat, but rare in barley. We describe attempts to increase the efficiency of data acquisition. High resolution agarose gel electrophoresis was unable to satisfactorily resolve 1–2 repeat unit differences in the common size range for SSR loci, and was therefore unsuitable for mass screening of allelic variants. Multiplex PCR was very dependent on the choice of primer combinations and seldom produced amplifications as consistently as when primer pairs were used individually. Background (non-specific) amplification was common to many primer pairs, and this hindered the use of both multiplex PCR and multiple sample loading. Sequential sample loading was the most effective strategy, although this was the least time-efficient of the measures used.  相似文献   

Influence of body condition score on by-product yield and value from cull beef cows.     

J K Apple  J C Davis  J Stephenson 《Journal of animal science》1999,77(10):2670-2679

Mature beef cows (n = 122) representing British and Continental phenotypes were slaughtered to measure the influence of body condition score (BCS) on by-product yield and value. All cows were weighed and assigned BCS, based on a 9-point scale, 24 h before slaughter. By-product weights were obtained during the slaughter process and included blood, feet (with hooves attached), oxlips, tongue, gullet, trachea, cheek meat, head meat, skull, tripe, honeycomb tripe, large and small intestines, spleen, mesenteric fat, weasand meat, kidneys, heart, lungs, and oxtail. By-product yields were calculated as a percentage of the animal's live weight taken 24 h before slaughter. By-product values were computed by multiplying the weight of each piece removed during the slaughter process by the 1997 average price. Live weight increased linearly (P<.001) as BCS increased from 2 to 8, whereas Continental cows were approximately 86 kg heavier (P<.05) at slaughter than British cows. Cows assigned a BCS of 2 or 3 had greater (P<.05) skull, feet, tongue, tripe, honeycomb tripe, trachea, and lung yields than cows assigned a BCS of 4 or higher. On the other hand, BCS-7 and 8 cows had greater (P<.05) weights and yields of large intestines and mesenteric fat than cows given a BCS of 6 or lower. The feet, trachea, lungs, and bone meal from BCS-2 cows had the greatest (P<.05) value, whereas the value of the large intestine, oxtail, and mesenteric fat was highest (P<.05) for BCS-7 and 8 cows. Weight, yield, and value of the skull, head meat, and feet were greater (P<.05) for Continental cows than British cows. Total by-product value was quadratically (P<.001) related to BCS. Cows assigned a BCS of 5 had lower (P<.05) total by-product values than either BCS-2 or BCS-7 and 8 cows. Drop credit for BCS-2 cows was greater (P<.05) than BCS-3, 4, 5, and 6 cows, with cows assigned a BCS of 7 and 8 having intermediate drop credit values. Continental cows tended to have greater (P<.10) total by-product and drop credit values than British cows. Information from this study indicated that the BCS of cows at the time of slaughter had a profound influence on by-product yields and, more importantly, values of by-products that are credited back against the cost of production to the beef cattle producer.  相似文献   

Independent statistical validation of the New Zealand Seafloor Community Classification     

Fabrice Stephenson  Jordi Tablada  Ashley A. Rowden  Richard Bulmer  David A. Bowden  Shane W. Geange 《水产资源保护:海洋与淡水生态系统》2024,34(3):e4114

Wanted dead or alive: Polydora websteri recruit to both live oysters and empty shells of the eastern oyster,Crassostrea virginica          下载免费PDF全文

J C Clements  D Bourque  J McLaughlin  M Stephenson  L A Comeau 《Journal of fish diseases》2018,41(5):855-858

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Enhanced atrazine degradation is widespread across the United States          下载免费PDF全文

Thomas C Mueller  Ethan T Parker  Larry Steckel  Sharon A Clay  Micheal DK Owen  William S Curran  Randall Currie  Robert Scott  Christy Sprague  Daniel O Stephenson  Donnie K Miller  Eric P Prostko  W James Grichar  James Martin  L Jason Kruz  Kevin Bradley  Mark L Bernards  Peter Dotray  Stevan Knezevic  Vince Davis  Robert Klein 《Pest management science》2017,73(9):1953-1961

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Effect of Early Postpartum Ovulation on Fertility in Dairy Cows     

KN Galvo  M Frajblat  WR Butler  SB Brittin  CL Guard  RO Gilbert 《Reproduction in domestic animals》2010,45(5):e207-e211

Our objectives were to determine the effects of early ovulation on fertility and uterine health of dairy cows. Four hundred and forty‐five Holstein cows (185 primiparous and 260 multiparous) from five herds were used. Blood samples were collected at 21, 35 and 49 days in milk (DIM) and cows were considered to be cyclic at 21 DIM (Cyc21) if serum progesterone (P4) concentration was above 1 ng/ml, cyclic by 49 DIM (Cyc49) if P4 concentration was above 1 ng/ml at 35 or 49 DIM, or not cyclic (NotCyc) if P4 concentration was below 1 ng/ml at all sample times. Endometrial cytology for diagnosis of subclinical endometritis was examined at 49 DIM in a subset of 414 cows. Cows in the group Cyc21 had increased hazard of insemination, for the first service, compared with cows in Cyc49 [hazard ratio (HR) = 1.40; 95% CI = 1.10–1.79; p = 0.006] and NotCyc (HR = 2.07; 95% CI = 1.52–2.82; p < 0.001). Cows in the Cyc49 group also had increased hazard of insemination compared with cows in the NotCyc group (HR = 1.47; 95% CI = 1.13–1.93; p = 0.005). Median days to insemination were, respectively, 71, 76 and 96 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in Cyc21 had greater first service pregnancy per AI than Cyc49 [38.6 vs 28.1%; adjusted odds ratio (AOR) = 1.67; 95% CI = 1.01–2.75; p = 0.04] and NotCyc (38.6 vs 23.6%; AOR = 2.08; 95% CI = 1.08–4.00; p = 0.03). Pregnancy per AI was similar in Cyc49 and NotCyc cows (28.1 vs 23.6%; AOR = 1.25; 95% CI = 0.70–2.24; p = 0.45). Cows in Cyc21 had increased hazard of pregnancy up to 300 DIM compared with Cyc49 (HR = 1.52; 95% CI = 1.17–1.96; p = 0.002) and NotCyc (HR = 1.98; 95% CI = 1.41–2.78; p < 0.001). Cows in Cyc49 tended to have increased hazard of pregnancy compared with NotCyc (HR = 1.31; 95% CI = 0.96–1.77; p = 0.09). Median days to pregnancy were, respectively, 103, 147 and 173 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in the Cyc21 group had decreased prevalence of subclinical endometritis compared with cows in the NotCyc group (29.9 vs 43.7%; AOR = 0.53; 95% CI = 0.29–0.97; p = 0.04); however, the prevalence did not differ from the Cyc49 group (29.9 vs 39.1%; AOR = 0.68; 95% CI = 0.41–1.14; p = 0.15). Cyc49 cows had similar prevalence of subclinical endometritis compared with NotCyc cows (AOR = 0.77; 95% CI = 0.46–1.29; p = 0.32). Early postpartum ovulation was associated with improved uterine health and fertility.  相似文献