Influence of Heat Stress on the Cortisol and Oxidant‐Antioxidants Balance During Oestrous Phase in Buffalo‐Cows (Bubalus bubalis): Thermo‐protective Role of Antioxidant Treatment     

GA Megahed  MM Anwar  SI Wasfy  ME Hammadeh 《Reproduction in domestic animals》2008,43(6):672-677

In the present study, the effect of heat stress, which is commonly observed in the animals of Upper Egypt area in summer, as well as the effect of antioxidant treatment as a thermo‐protective was examined. In this study, the animals (n = 120) were divided into winter group (n = 40, bred during winter) and summer group (n = 80, bred during summer) as well as, animals in the summer group were divided into first subgroup animals (n = 40) and injected with Viteselen intramuscularly (15 ml) twice weekly for 10 weeks and second subgroup animals (n = 40) were not treated (as control). Serum levels of progesterone (P4), oestradiol (E2), cortisol, superoxide dismutase (SOD), lipid peroxidase (LPO) and nitric oxide (NO) were measured. The pregnancy rate of all animals was detected rectally. The levels of oestradiol and the activity of the antioxidant SOD were decreased in serum of animals in behavioural oestrus during summer as compared with those in winter. During the same time period the levels of oxidants such as LPO and NO were increased in the serum of animals again in the phase of oestrus. In another group of animals treated by intramuscular injection with 15 ml viteselen (antioxidant) twice weekly for 6 weeks during hot months, the activities of serum SOD showed an increase and the levels of oxidants and cortisol decreased. Moreover, the levels of oestradiol were increased during the oestrous behaviour. The pregnancy rate was decreased in animals under heat stress and the pregnancy rate was enhanced dramatically when these animals received antioxidants during the heat stress. This means that the heat‐stress in Upper Egypt may affect the fertility of animals and pregnancy rate and this effect may be through an increased production of free radicals and decreased production of antioxidants as well as increased levels of cortisol. Treatment of animals or supplementation with antioxidants before the beginning of months of heat‐stress and also during the stress period may correct the infertility due to heat‐stress through the decrease in cortisol secretion and a decrease in the oxidative stress. These results resulted in an increase in pregnancy rate in treated animals.  相似文献   

益生菌Lactobacillus casei|Zhang 高密度发酵中试工艺及动力学研究   总被引：1，自引：0，他引：1  

李妍  高鹏飞  赵文静  麻士卫  周琦  潘向辉  张和平 《中国农业科技导报》2008,10(5):59-65

在益生菌L.caseiZhang高密度培养小试（3L）基础上,进行30L到150L逐级放大中试生产工艺的研究以确定规模化生产工艺。在优化的发酵工艺下,150L规模发酵菌体密度可达2.9×10^10cfu/mL,与小试水平无差异。采用origin7.5软件在logistic equation基础上建立L.caseiZhang的生长和葡萄糖代谢动力学模型,模型与试验值拟合良好,平均误差小于10%,能够较好地反应发酵过程。初步探讨发酵后菌体的离心和冷冻干燥过程对菌体的影响,虽然发酵液经离心收集菌体后冷冻干燥可得到平均活菌数2.65×10^11cfu/g的菌粉,能够满足益生菌制剂和发酵剂对高活菌数的要求,但冻干前后活菌得率仅49.97%。有必要针对L.casei Zhang的冻干保护剂和冻干工艺进一步优化,以提高菌体存活率得到更高菌体浓度的益生菌粉。  相似文献   

SCN-AVP release of <Emphasis Type="Italic">mPer1/mPer2</Emphasis> double-mutant mice in vitro     

Daan R van der Veen  Ellis GA Mulder  Henrik Oster  Menno P Gerkema  Roelof A Hut 《Journal of circadian rhythms》2008,6(1):5

  相似文献   

Pregnancy loss in dairy cattle in the Waikato region of New Zealand     

S McDougall  FM Rhodes  GA Verkerk 《New Zealand veterinary journal》2013,61(5):279-287

AIM: To define the incidence rate of pregnancy loss and risk factors for those losses in pasture-fed dairy cattle in the Waikato region of New Zealand.

METHODS: Cows (n=2,004) from 10 pasture-fed, spring-calving dairy herds in the Waikato were enrolled following confirmation of pregnancy 29–45 days after insemination, for inseminations that occurred within the first 16 days of the seasonal breeding period. Transrectal ultrasonographic examinations for pregnancy were conducted at approximately 6, 8, 10, 14 and 22 weeks gestation, and subsequent calving data were recovered. Pregnancy loss was defined as having occurred when a confirmed pregnancy was not rediagnosed, when gross abortion was detected, or when a cow calved <265 days after the confirmed conception date. Data were analysed using reverse stepwise logistic regression and Cox's proportional hazards analysis.

RESULTS: A total of 128 (6.4%) pregnancy losses were detected. The incidence rate was higher in early compared to late gestation (10.9 vs 2.8 losses/10,000 cow-days between Weeks 6–10 vs Weeks 10–14, respectively; p<0.001). Higher rates of loss were associated with the occurrence of clinical mastitis (Hazards ratio (HR)=1.57; p=0.071), being treated for anoestrus (HR=1.69; p=0.007), and in cows that had calving-to-conception intervals ≤63 days compared with those that had calving-to-conception intervals >92 days (HR=2.49; p=0.06). In addition, the rate of pregnancy loss differed between herds (p=0.05).

CONCLUSIONS: The highest rate of pregnancy loss occurred in early gestation. Clinical mastitis, anoestrus and calving late in the calving season were risk factors for pregnancy loss.

CLINICAL RELEVANCE: Pregnancy diagnosis using ultrasonography can be undertaken from 28 days post-insemination. However, due to the high rate of pregnancy loss at this stage of gestation, herdowners need to be warned of possible losses, and cows should be re-examined to confirm pregnancy before certification of pregnancy status is given.  相似文献   

阿克苏引种面包小麦济南17号超高产栽培初探     

张卫东  秦勇  赛买提  古拉音  张巨松 《新疆农业科学》2005,42(Z1):22-24

阿克苏地区2000-2001年从山东省农科院引进强筋面包小麦新品种济南17号,在地区农业试验站进行品种区域适应性比较试验,并对其生育和植株性状进行了观测,在参试的8个品种中,济南17号平均产量6804kg/hm2,位居第三,较对照邯5316(地区小麦主栽品种)增产840kg/hm2,增产率14%。2001-2002年又在地区农业试验站对该品种示范种植800.04m2,产量8550kg/hm2,首次实现本地区引种面包小麦单产超8250kg/hm2的产量水平,两年试验示范结果表明,该品种在阿克苏地区具有较强的适应性和丰产性,同时取得了实现强筋小麦济南17号高产栽培的实践经验。  相似文献   

THE VITAMIN C CONTENT OF SPRING GREENS     

Burrell RC  Miller HA 《Science (New York, N.Y.)》1939,90(2329):164-165

  相似文献   

Risk factors for Merino ewe mortality on the Northern Tablelands of New South Wales,Australia     

GA Kelly  LP Kahn  SW Walkden‐Brown 《Australian veterinary journal》2014,92(3):58-61

  相似文献   

Field trials of foliar sprays of 3,5-dichlorophenoxyacetic acid (3,5-D) against common scab on potatoes     

A. H. McIntosh  M. M. Burrell  J. H. Hawkins 《Potato Research》1982,25(4):347-350

Summary Foliar sprays of 3,5-dichlorophenoxyacetic acid (3,5-D) in June or early July decreased the incidence of common scab by about 30% in four field trials on cv. Maris Piper and cv. Désirée; however, significant decreases in yield and in mean tuber weight were also common. The effects of 3,5-D on potatoes resembled those of the growth retardant daminozide in some ways, but 3,5-D was not persistent enough to have a useful effect on scab in the field.  相似文献   

Efficacy of a novel copper-based footbath preparation for the treatment of ovine footrot during the spread period     

GA REED  DU ALLEY 《Australian veterinary journal》1996,74(5):375-382

Objective: To determine the efficacy of a novel copper based footbath preparation (CHF-1020) for treatment of ovine footrot during the spread period.
Design: A series of field trials with treated and control groups run together.
Animals: Mobs of at least 125 sheep on each of six properties in southern New South Wales with equal numbers of controls.
Procedure: Sheep of group A were treated after minimal paring by making them stand in CHF-1020 for 15 minutes. Treatment was undertaken at intervals throughout the period of the trials (14 September to 17 December 1993). Group A sheep were run on the same pasture as those from group B (untreated sheep).
Results: The percentage of sheep exhibiting clinical signs of ovine footrot at the start of the trial ranged from 35 to 88% at score 3 or higher, using a 0 to 5 footscoring system. During the trial, the percentage of infected sheep (greater or equal to score 2) in group B increased and ranged from 40 to 90%. The level of infected sheep in group A on each property was reduced progressively to 1 to 16%. Cure rates of 45 to 94% were achieved, with the lowest rate being on a property with a metal footbath. The next lowest cure rate was 73%. Results indicated that treatment should be undertaken at 2-weekly intervals while spread continues. Treated sheep can be returned to contaminated pastures.
Conclusion: CHF-1020 is effective during the spread period and can be used for the progressive eradication of ovine footrot.  相似文献   

论琵琶演奏音乐语言表现力的多元性     

高微 《湖南农业大学学报(自然科学版)》2009,(2)

从音乐本身出发,从琵琶音乐语言和琵琶音乐表达的技术手段两方面对琵琶音乐语言的表现力作出作者自身的理解.琵琶音乐语言的表现力是多元性的,可以从琵琶音乐语言特性的界定以及琵琶音乐表达的技术手段来了解.  相似文献