Trenbolone acetate/estradiol combinations in feedlot steers: dose-response and implant carrier effects.     

S J Bartle  R L Preston  R E Brown  R J Grant 《Journal of animal science》1992,70(5):1326-1332

Two experiments were conducted at three locations to determine the correct dosage and carrier for trenbolone acetate (TBA) and estradiol (E2) implants in feedlot steers. In the dose-response experiment, 1,296 steers were allotted to six implant treatments (48 pens per location): control, 140 mg of TBA (140/0), 30 mg of E2 (0/30), 20 mg of TBA + 4 mg of E2(20/4), 80 mg of TBA + 16 mg of E2(80/16), and 140 mg of TBA + 28 mg of E2 (140/28). In the carrier experiment, 575 steers were allotted to five implant treatments (25 pens per location): control, 140 mg of TBA + 28 mg of E2 in lactose (140/28-LA), 140 mg of TBA + 28 mg of E2 in cholesterol (140/28-CH), 140 mg of TBA + 20 mg of E2 in LA (140/20-LA), and 200 mg of progesterone + 20 mg of E2 benzoate (SS, reimplanted). In both experiments steers were fed a finishing diet for 140 to 168 d. In the dose-response experiment, response to TBA alone (140/0) did not differ from control (P greater than .2). Estradiol alone (0/30) improved ADG by 7% (P less than .01) and tended to improve feed efficiency over control (3%, P = .17). The highest dosage (140/28) improved ADG by 18% (P less than .001) and feed efficiency by 10% (P less than .001) over control and 10% (P less than .001) and 7% (P less than .01) over E2 alone, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

普通小麦抗白粉病配合力及其与过氧化物酶的关系   总被引：5，自引：1，他引：4  

胡延吉  李晴祺 《华北农学报》1992,7(2):46-50

选用6个亲本组配成双列杂交设计,对普通小麦抗白粉病的配合力及基因效应进行了分析。结果表明,白粉病病情指数属于数量性状遗传,符合加性—显性遗传模型,由加性效应和非加性效应共同控制,且以加性效应为主。低病情指数为部分显性。不同亲本之间一般配合力效应及含有的有利显性基因数存在明显差别。因此,选配杂交组合应在一般配合力高的基础上,注重其特殊配合力的选择。研究还表明,感病品种过氧化物酶活性高。  相似文献   

Ostertagia ostertagi infection in the calf: effects of a trickle challenge on appetite, digestibility, rate of passage of digesta and liveweight gain     

M T Fox  D Gerrelli  S R Pitt  D E Jacobs  M Gill  D L Gale 《Research in veterinary science》1989,47(3):294-298

The effects of a trickle challenge with the equivalent of 10,000 infective Ostertagia ostertagi larvae per day on appetite, digestibility, rate of passage of digesta and liveweight gain were investigated in 12 calves assigned to infected, pair-fed control and ad libitum-fed control groups. Digestibility of cellulose, nitrogen, organic matter and dry matter was determined using insoluble acid detergent fibre as a marker on two occasions during the study: (i) Between days 31 and 38, when abomasal dysfunction was greatest; and (ii) between days 52 and 58, beginning approximately one week after anthelmintic treatment (day 46). Rate of passage of digesta was measured using chromium mordanted hay, fed to each calf after each digestibility study period. Voluntary feed intake of the infected group was significantly reduced from day 37 with the greatest depression (77 per cent) occurring just before anthelmintic treatment. The drop in appetite was responsible for nearly 73 per cent of the difference in liveweight gain between the infected and ad libitum fed control groups. The apparent digestibility coefficient of nitrogen was significantly depressed (22 per cent) in the infected group though was restored to control levels by anthelmintic treatment. The rate of passage of digesta was significantly reduced in both pair-fed control (50 per cent) and infected (74 per cent) groups. Anthelmintic treatment increased the latter though only to pair-fed control group levels. It is suggested that the marked hypergastrinaemia seen in the infected calves may have been in part responsible for the decreased rate of passage of digesta and in turn for the drop in appetite.  相似文献   

Lactate Kinetics in veterinary Critical Care: A Review   总被引：3，自引：0，他引：3  

Michael S. Lagutchik DVM  Gregory K. Ogilvie DVM  Wayne E. Wingfield MS  DVM  Timothy B. Hackett DVM  MS 《Journal of Veterinary Emergency and Critical Care》1996,6(2):81-95.

Elevation in blood lactate concentration, with or without accompanying metabolic acidosis, is a hallmark finding in patients with circulatory compromise, and is also consistently noted in other conditions affecting critically ill or injured individuals. Little is reported in a veterinary literature regarding lactate measurement in the emergency and critical care setting, despite impressive reports of the clinical usefulness of lactate measurement in people. The purpose of this article is to review lactate kinetics and the clinical utility of lactate measurement. Limitations to lactate evaluation will also be discussed.  相似文献   

干巴菌（Thelephoraganbajun Zang）的研究Ⅰ．干巴菌与其生境因子的关系     

朱启顺  杨大智  刘岵 《中国食用菌》1995,(4)

本文研究了干巴菌的分布及其在分布区内的植被类型，查清了干巴菌主要分布于针叶树林中，尤以云南松林内分布最多，但也分布于纯的栗树林中。通过对于巴菌生境中土壤微生物的分析，结果与宏观调查一致：其生长土壤较为贫瘠，是一种菌根菌。  相似文献   

Pathotypes of Synchytrium endobioticum in Germany     

E. LANGERFELD  H. STACHEWICZ  J. RINTELEN† 《EPPO Bulletin》1994,24(4):799-804

Results are given of a survey on the occurrence of pathotypes (races) of Synchytrium endobioticum (potato wart) in both parts of re-unified Germany. An assortment of six differential cultivars appears to be sufficient to distinguish between the seven presently important German wart pathotypes. A total of ten pathotypes was recorded. Two West and two East German pathotypes seem to be identical, based on the results obtained with presently available cultivars. In contrast to pathotype 1 (common race) which prior to 1945 was distributed over the whole German territory, the 'new' pathotypes seem to prefer the central and south German mountain areas.  相似文献   

Pharmacokinetic evaluation of ceftiofur in serum, tissue chamber fluid and bronchial secretions from healthy beef-bred calves.          下载免费PDF全文

S L Halstead  R D Walker  J C Baker  R E Holland  G E Stein    J G Hauptman 《Canadian journal of veterinary research》1992,56(4):269-274

Ceftiofur is a new broad spectrum cephalosporin marketed for the treatment of acute bovine respiratory disease. In this investigation ceftiofur was administered by intramuscular injection, at 24 h intervals, to healthy beef-bred calves for four days at dosages of 2.2 and 4.4 mg/kg of body weight, with 4 wk intervals between dosing regimens. Serum, tissue chamber fluid (TCF), and bronchial secretion (BS) concentrations of ceftiofur were measured by microbiological assay after the first and fourth dose of each dosing regimen. Peak serum concentrations (Cmax) of 8.8 micrograms/mL and 17.3 micrograms/mL were obtained approximately 2 h (Tmax), the time of mean peak concentration) after single injections of 2.2 mg/kg and 4.4 mg/kg, respectively. The Cmax was increased approximately twofold following multiple doses of 2.2 mg/kg (Cmax = 13.1 micrograms/mL) and 4.4 mg/kg (Cmax = 24.1 micrograms/mL). Ceftiofur accumulated slowly into TCF and peak concentrations were found to be approximately 14% of those observed in serum after the first dose and approximately 24% after multiple dosing. Concentrations of ceftiofur in BS were obtained rapidly with peak concentrations reaching 45% of the serum Cmax after the first dose. After multiple dosing the Cmax for BS was approximately 25% of the serum Cmax. This study found that both the 2.2 mg/kg and 4.4 mg/kg dosing regimens resulted in continuous serum, TCF and BS concentrations of ceftiofur that exceeded the minimal concentration required to inhibit the bacteria most frequently isolated from calves with acute bovine respiratory disease.  相似文献   

Management of Critical Care Facilities     

Thomas E. Catanzaro DVM  MHA 《Journal of Veterinary Emergency and Critical Care》1994,4(1):45-47

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Effects of 'Agri-SC' soil conditioner on soil structure and erodibility: some further observations     

M.A. Fullen  A.M. Tye  K.E. Cookson 《Soil Use and Management》1995,11(4):183-185

Abstract. In field and laboratory experiments the conditioner‘Agri-SC’has shown improvements in the structure of loamy sand soils in east Shropshire, UK. It resulted in statistically significant decreases in soil bulk density values and increases in soil porosity and aggregate stability. Further experiments are in progress on both loamy sand and silt loam soils.  相似文献   

Effect of porcine somatotropin on number of granulosa cell luteinizing hormone/human chorionic gonadotropin receptors, oocyte viability, and concentrations of steroids and insulin-like growth factors I and II in follicular fluid of lean and obese gilts.     

L J Spicer  J Klindt  F C Buonomo  R Maurer  J T Yen  S E Echternkamp 《Journal of animal science》1992,70(10):3149-3157

Prepubertal gilts of obese (n = 24) or lean (n = 24) genetic lines were injected (s.c.) daily with 0, 2, or 4 mg of porcine somatotropin (pST) for 6 wk starting at 160 d of age to determine whether pST affects follicular function. Blood and ovaries were collected at slaughter 24 h after the last injection. Surface follicles greater than or equal to 1.0 mm in diameter were counted, and pools of follicular fluid (FFL) and granulosa cells were collected from 1.0- to 3.9-mm (small) and 4.0- to 6.9-mm (medium) follicles. Oocytes were collected from small and medium follicles and evaluated for maturational stage and viability. Porcine somatotropin increased (P less than .08) the numbers of small but not the numbers of medium follicles per gilt (P greater than .10). Oocyte maturation and viability were not affected by pST or genetic line. Porcine somatotropin increased (P less than .05) concentrations of insulin-like growth factor I (IGF-I) in serum and FFL of both obese and lean gilts; IGF-I was lower (P less than .01) in lean gilts. Treatment with pST decreased (P less than .05) IGF-II in FFL of lean but not in that of obese gilts. Dose of pST and line had no effect on concentrations of progesterone in FFL of small or medium follicles or on concentrations of estradiol in FFL of small follicles.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献