茼蒿的养生价值浅谈

在广泛文献检索基础上,对茼蒿的种属、成分、药理、养生价值、代表性膳食及食用注意事项等进行概述,为全民养生保健提供科学资料。     

紫薯养生保健价值分析

在广泛文献检索基础上,对紫薯的成分、养生和保健价值(治便秘、防癌、防衰老、抗氧化、降血压、抗紫外线、作为安全、无毒的食品添加剂等)及饮食注意事项进行了概述,以期为全民养生保健提供科学资料。     

Pregnancy impairs ketone body disposal in late gestating ewes: implications for onset of pregnancy toxaemia

The impact of pregnancy on ketone body disposal during a hyperketonaemic clamp was examined by tracer isotope dilution techniques in seven 12 h fasted sheep in three reproductive states, in the dry non-gestating period, late in gestation and during early lactation. After a sampling period of 60 min under basal conditions a DL-BHB racemate solution was continuously infused intravenously for 3 h at rates of 14.3-24.3 micromol/(kg min) to elevate the D-BHB concentration in blood plasma to values between 5 and 7 mmol/l. Two separate experiments were carried out with the same sheep in each of the three reproductive states. During pregnancy three ewes were pregnant with a single lamb and four ewes carried twins. Maximal D-BHB turnover rates fell significantly in late gestation by 26% relative to early lactation and by 22% when compared with the dry non-pregnant state. Reduction of maximal D-BHB disposal rate during late gestation was accompanied by a significant 297% (p<0.005) and a non-significant 49% increase in the basal BHB concentration in blood, a non-significant 10% and 4% decrease in the rate constant of D-BHB turnover and a non-significant 24% and 13% rise in the incremented increase of D-BHB concentration per unit D-BHB infusion, relative to the dry and the lactating period, respectively. Induction of hyperketonaemia significantly lowered NEFA and glycerol concentrations in blood by 67% and 57%, respectively, compared to the pre-infusional concentrations. The magnitude of this effect was the same in all reproductive states and was explained as a direct antilipolytic action of D-BHB on adipose tissue. It is concluded that the reduced ability of the late gestating ewe to utilize D-BHB promotes hyperketonaemia. Since hyperketonaemia exerts several adverse effects, e.g. on energy balance and glucose metabolism it appears that the impairment of ketone bodies disposal in late pregnancy facilitates development of pregnancy toxaemia, especially in ewes carrying twins.     

精液对母兔子宫免疫及孕向发育的影响

在结扎子宫颈的情况下,在同一子宫的两侧子宫角分别注入生理盐水（对照组）和精液（试验组）以研究精液对子宫免疫和孕向发育的影响。试验共用母兔8只。子宫注入后48 h处死试验用兔,取子宫进行测量,并制片染色,用图像采集分析系统进行研究。结果显示：1）与对照组相比,兔子宫注入精液后可以显著（P〈0.05）增加子宫的长度、直径和子宫角指数;可明显增加子宫壁（P〈0.05）、黏膜上皮层（P〈0.01）和黏膜层（P〈0.05）的厚度;可显著增加黏膜中腺管（P〈0.05）和血管（P〈0.05）数量,可明显增加腺上皮的厚度（P〈0.05）。2）子宫注入精液后,子宫冲洗液中的细胞数（53.3±4.03×109/L）较对照组极显著增加（P〈0.01）;单位面积子宫黏膜中肥大细胞的数量（2.85±0.05个/mm2）较对照组（3.72±0.04个/mm2）显著减少（P〈0.05）。子宫冲洗液涂片染色检查发现,子宫冲洗液中的细胞主要为嗜中性粒细胞。本研究表明,兔精液确实能够促进母兔子宫的孕向发育,能够改变子宫的免疫状态。     

Serum levels of stanniocalcin-1 in Holstein heifers and cows

Stanniocalcin-1 is a hormone that possesses both paracrine and endocrine functions and has recently been identified in mammals. While paracrine functions have been determined for several organs, the role of circulating stanniocalcin-1 in cattle is still unclear but, observations in mice and cows suggest that stanniocalcin-1 plays a role in both gestation and lactation. The changes in serum stanniocalcin-1 content in different physiological states have never been evaluated in ruminants. We measured stanniocalcin-1 levels in sera from cattle ranging in age from post-weaned calves to 17-month-old heifers and in sera from cows during lactation and pregnancy. Our results indicate that the blood concentration of stanniocalcin-1 is increased by pregnancy, but not by lactation. The highest levels of stanniocalcin-1 were found in young calves and during the non-lactating period preceding calving. This suggests that stanniocalcin-1 is important for gestation and the preparation of the mammary gland for lactation.     

Season and physiological status affects the circadian body temperature rhythm of dairy cows

The circadian body (vaginal) temperature rhythm was measured in 36 dairy cows: Holstein–Friesian (HF, n = 12), Jersey (J, n = 12) and their crossbreed, Holstein–Friesian × Jersey (HF × J, n = 12) at six different periods (5-7 days in duration) during the year that could potentially be a seasonal and physiological stressor. These were a) early winter (late pregnancy), (b) early spring (early lactation), (c) late spring (before mating at mid-lactation), (d) early summer (after mating at mid-lactation), (e) late summer (late lactation, early pregnancy) and, (f) early autumn (drying-off at the end of lactation, mid-pregnancy). Live weight and body condition score was recorded on the first day of each measurement period. Live weight differed (P < 0.001) with breed with HF cows heaviest and J cows lightest (HF: 525 ± 51, HF × J: 456 ± 56, J: 401 ± 30 kg). HF cows tended (P = 0.099) to have a higher body condition than either J or HF × J cows although the overall change in body condition during the experiment was similar (P = 0.961) amongst breeds. The circadian body temperature rhythm differed markedly between each measurement period, being flatter and having a less prominent morning nadir and afternoon peak during early winter compared to spring and summer. The timing of peak body temperature was 4-5 h earlier in early autumn in HF and HF × J cows relative to J cows. There was no breed difference (P ≥ 0.162) in daily mean body temperature except for a tendency (P = 0.075) for mean body temperature to be moderately higher in J cows (38.5 °C) during late summer compared to HF and HF × J cows (38.4 °C), primarily due to an increase (P = 0.001) in daily minimum body temperature (38.0 vs. 37.8 °C). The daily range of oscillation (maximum–minimum) in the body temperature rhythm was highest during late summer, particularly in HF and HF × J cows. Minimum body temperature was also higher (P = 0.033) for J cows than HF and HF × J cows during early autumn (37.9 vs. 37.8 °C). In conclusion, season and physiological status of cattle had a profound effect on the circadian body temperature rhythm but there was little difference between the breeds of dairy cows studied.     

影响转基因绵羊胚胎移植受胎率的因素

为了提高并稳定转基因胚胎移植受胎率,对可能影响受胎率的供受体同期化程度、移植胚胎数量、受体处理方式、胚胎发育速度、受体注射黄体酮、供体作受体等6个方面进行研究。结果表明,(1)供受体发情时间差在±12h以内,不影响受胎率(P>0.05);(2)每只受体移植2～3枚转基因胚胎的受胎率极显著高于移植1枚的受胎率(P<0.01);(3)在繁殖季节里,受体采用自然发情、肌肉注射PGF2α、肌肉注射PMSG+PGF2α等方式,三者受胎率间差异不显著(P>0.05);(4)发育迟缓的胚胎移植后,受胎率显著低于正常发育胚胎的受胎率(P<0.01);(5)移植后的受体注射2mg黄体酮,不能提高受胎率(P>0.05);(6)供体当作受体使用,不影响受胎率(P>0.05)。     

生物灭鼠新探索—制备芸香毒饵降低小鼠生育的实验研究

芸香（Rutag raveolens）是一种药用植物,有良好避孕效果,制成植物灭鼠剂,为植物灭鼠剂的大批量生产和应用提供理论基础。实验把芸香全草包煎制成水煎剂,制成毒饵,孕前和孕后分别饲喂小鼠,观察体重变化、怀孕率和流产率。统计分析结果,毒饵组与对照组比,体重变化差异不显著,怀孕率明显降低,流产率明显增高。结论：芸香毒饵可以有效的抑制小鼠繁殖速度。     

鄂西北马头山羊繁殖性能分析

湖北省 6个县、市农户饲养的马头山羊繁殖性能调查资料 ,表明马头山羊公、母羔的初情日龄分别为 14 0 4± 16 9和 10 8 4±19 1,母羊发情持续期为 5 8 6h± 15 9h ,发情周期为 19 7d± 1 5d。母羊妊娠 15 0d± 7 4d ,产羔数平均为 (2 14± 0 9)只 ,羔羊成活率平均为 90 8% ,公羔和母羔的初生重分别为 1 61kg± 0 45kg和 1 5 9kg± 0 68kg。妊娠期与胎次无关 ,但随窝产羔数的增加而延长。产羔数以头胎最低 ,第 4胎时达到最高峰 ,然后逐渐降低。羔羊成活率在第 1～ 5胎差异不明显 ,第 6和第 7胎显著降低 ,第 8胎以后又升高。窝产羔数为 1～ 4时 ,羔羊成活率最高 ,产羔数为 5时 ,成活率最低。羔羊初生重与性别有关 ,公羔显著大于母羔。公羔的初生重与胎次有关 ,但与窝产羔数相关关系不明显。头胎母羊所产公羔的初生重最低 ,随胎次的增加 ,初生重有增大的趋势 ,而母羔则没有这种趋势。比较发现马头山羊类似于多胎动物