儿童营养酸奶的研制

本文介绍了儿童酸奶的生产工艺,针对儿童生理特点及营养需要添加了各种营养强化剂。根据中国营养学会推荐的每日膳食营养素中钙、铁、锌和维生素的供给量,确定AD钙粉添加量为0.05%,铁锌粉为0.05%,VC为0.005%。另外原料中还添加了低聚糖、牛璜酸、麦片作为营养强化剂,添加量分别为1%、0.0025%、1.5%。为增强儿童免疫力,原料乳中适量加入了牛初乳粉,添加量为0.2%。最后通过正交实验确定配方中脱脂乳粉1.5%,稳定剂0.5%,蔗糖6%为最佳配比。实验采用Rhodia900直投型菌种,经43℃,4小时发酵,发酵酸度为68°T～72°T时终止发酵。置于0℃～5℃的冰箱中贮藏24小时,检验酸度为75°T～77°T时,即为成品。     

缓释氢氧化钙和缓释盐酸对家兔营养物质消化吸收的影响

本试验选用体重为(2.0±0.5)kg的家兔为试验动物,分别采用缓释氢氧化钙和缓释盐酸调节家兔的消化吸收,测定其对营养物质消化吸收的影响。结果表明:缓释氢氧化钙能促进营养物质特别是钙和粗蛋白质的消化吸收,其消化率分别从41.0%和65.2%增加到89.8%和93.8%;缓释盐酸对营养物质特别是钙和粗蛋白质的消化吸收不利,其消化率分别从55.5%和84.9%下降为28.4%和68.7%;此外,缓释氢氧化钙的促进消化吸收效果可维持3~4 d。由此可知,缓释氢氧化钙对钙以及蛋白质的消化吸收具有促进作用,而脂肪的消化吸收无论状态如何都具有良好的效果,因此增加脂肪的摄入容易产生营养过剩。然而,服用缓释盐酸会降低营养物质的消化吸收效果。     

玉米秸秆的复合处理

试验旨在探讨玉米秸秆的氨化-碱化-盐化复合处理对其营养价值的影响。试验采用3因素2水平完全交叉实验设计,即尿素的添加量分别为2%和4%,氢氧化钙的添加量为2%和4%,泌乳奶牛生长所必需的7种微量元素添加与不添加。结果表明:与未添加任何物质的对照组相比,复合处理玉米秸秆的NDF和ADF分别下降9～18和8～14个百分点,粗蛋白含量平均提高了一倍,钙、磷含量也有升高的趋势;微量元素对秸秆营养价值无明显影响,但添加微量元素有防止霉变的作用。     

以废弃花蛤贝壳制备柠檬酸钙的工艺优化研究

本试验以花蛤软体生产加工过程中的废弃贝壳为钙源,利用直接法生产柠檬酸钙。在确定了花蛤贝壳最适粉碎目数为60目的基础上,通过单因素试验研究了钙酸比、固液比、反应时间和反应温度对柠檬酸钙产率的影响;并通过正交试验对花蛤贝壳直接制备柠檬酸钙的工艺进行了优化。结果表明,最适宜的工艺条件为:钙酸比为0.80,固液比为35%,反应时间为2.5 h,反应温度为35℃,在此条件下的柠檬酸钙产率为92.13%。纯度及工艺放大检测结果显示利用该优化工艺制备的柠檬酸钙产品质量好且稳定,故本研究结果具有一定的实用价值。     

动物体内钙、磷代谢及其饲料补充物

1在体内的含量与分布钙、磷主要以无机盐的形式存在于体内。成年动物体内钙总量约占体重的1.5%,即700~1 400克;磷总量约为400~800克。约99.7%以上的钙与87.6%以上的磷以羟磷石灰、氢氧化钙的形式存在于骨骼和牙齿中。每100毫升血浆中的钙仅为8.5~11.5毫克,     

影响鸡对钙需要的因素

钙是鸡营养不可缺少的元素之一 ,但在不同生长期对钙的需要量是不同的。根据我国 1 986年公布的标准 ,蛋鸡 0～ 6周需钙量为 0 .8% ,7～ 1 4周龄需钙量为 0 .7% ,1 5～ 2 0周龄需钙量为 0 .6%。而进入产蛋期 ,对钙的需要量较多 ,根据产蛋率的高低 ,需要量为 3.2 %～ 3.5 %左右。饲料中矿物元素的含量及状态均能影响钙的吸收。磷是影响钙利用的主要元素 ,据试验证明 ,雏鸡和生长鸡的钙磷比例以 1 .5～ 1∶1为适宜 ,特别是在钙、磷水平都较低的情况下应该注意这两者的比例关系。到产蛋期 ,根据产蛋率的高低和生产情况要求钙、磷比应达到 5～ 7…     

不同水平尿素、氢氧化钙对玉米秸纤维含量的影响

为探讨不同水平尿素、氢氧化钙对玉米秸纤维含量的影响,本试验将尿素和氢氧化钙均按玉米秸风干重0%、2%、3%和4%的量分别添加,共16组,其中原玉米秸组为对照组,通过测定各组玉米秸的中性洗涤纤维和酸性洗涤纤维含量来确定尿素和氢氧化钙最适宜的添加水平。结果表明,试验组在中性洗涤纤维和酸性洗涤纤维含量上均极显著低于对照组(P<0.01),大部分试验组间也存在极显著或显著的差异(P<0.01或P<0.05)。在本试验设计条件下,尿素和氢氧化钙处理玉米秸时最适宜的添加水平分别为玉米秸风干重的4%和2%。     

氢氧化钙与2%尿素复合处理提高小麦秸营养价值的研究

通过化学成分分析、活体外消化率测定和绵羊饲养试验,研究了2%尿素与氢氧化钙复合处理对小麦秸营养价值的影响。结果表明:氢氧化钙大于6%时,氮保留率可达到98%;氢氧化钙为6%时,提高营养价值效果与4%NaOH处理相当;氢氧化钙为4%时,效果与单纯6%尿素处理相当。羊的饲养试验结果显示,2%尿素和6%氢氧化钙复合处理小麦秸效果最好。     

氢氧化钙与食盐结合处理稻草效果更好

我们于2000年6～10月在中国农业科学院畜牧所进行了试验,分别用0%(A)、4%氢氧化钙(B)、4%氢氧化钙加1%食盐(C)、4%氢氧化钙加2%食盐(D)处理稻草,水分调至45%,填紧压实,密封保存于贮罐内1个月,然后用瘤胃尼龙袋法测定稻草有效降解率,分析相关营养指标。试验结果表明,复合处理效果优于单独用氢氧化钙处理稻草的效果,有效降解率随着食盐添加量的提高而提高,表明食盐对提高稻草营养价值有重要作用。4%的氢氧化钙是处理秸秆比较理想的浓度,所以本试验未设碱化处理梯度。提高干物质有效降解率36.80%,提高中性洗涤纤维降解率7.54%。氢氧化钙与食…     

饲料添加剂碘酸钙的研制

用碘为原料，在盐酸介质中经氯酸钾氧化后，用氢氧化钙中和制得饲料级碘酸钙。本法具有工艺简单、操作方便、产品收率高、纯度高、生产成本低等特点。     

Faecal calcium excretion does not decrease during long‐term feeding of a low‐calcium diet in adult dogs

According to a previous meta‐analysis, adult dogs do not notably increase calcium absorption from the gastrointestinal tract when calcium intake is decreased. This results in a negative calcium balance even with a moderate calcium reduction. In this study we wanted to verify (i) whether a negative calcium balance occurs at a calcium intake equivalent to NRC (2006) (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC) minimal requirements, and if so (ii) whether the negative calcium balance will persist for up to 6 months on a low‐calcium diet. After a pre‐feeding period of at least 18 weeks with calcium intake slightly exceeding maintenance requirements (200 mg/kg body weight^0.75), 12 dogs (6 Beagles, 6 Foxhound crossbreds) were fed a low‐calcium diet for 28 weeks. One dog was removed from the trial for reasons unrelated to the study at week 23. Calcium intake amounted to 60 mg/kg body weight^0.75 corresponding to the minimal requirement for maintenance in dogs (NRC, 2006 (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC)). Digestion trials were carried out at week 7, 14, 21 and 28 of the low calcium feeding period. At these time points, and at week 18 of the pre‐trial, blood samples were taken and analysed for calcium, ionised calcium, phosphorus, parathyroid hormone, vitamin D, serum crosslaps and bone alkaline phosphatase. Apparent calcium digestibility was negative throughout the study, suggesting a negative calcium balance. There was no systematic decrease in faecal calcium excretion. Serum calcium, ionised calcium and phosphorus remained within the reference range. Serum crosslaps increased continuously from baseline to week 28 of trial, with averages increasing from 0.102 ng/ml to 0.279 ng/ml, suggesting osteoclastic activity, indicative of calcium mobilisation from the skeleton. The study supports the theory of a lack of adaptation of intestinal calcium absorption from diets with relatively low calcium content in dogs. This agrees with clinical findings in dogs eating low‐calcium diet.     

接种丛枝菌根真菌对柑橘不同钙剂吸收及苗木生长效应的影响

以柑橘苗为试材,分别对未接种植株、接种摩西球囊霉和幼套球囊霉的植株外施5nmol/L硝酸钙和醋酸钙,比较了三种处理下植株茎粗、株高、侵染率、根系活力和植株根系、叶片中钙和氮含量。结果表明,接种丛植菌根真菌促进植株的生长,其根系和叶片中钙元素和氮元素含量均比未接种的植株的高;施用硝酸钙的植株根系和叶片中钙、氮元素含量比施用醋酸钙的植株高。     

Vitamin D Status and Hypocalcemic Response to Protamine in Exercised and Non-exercised Dairy Cows

Bone resorption was studied in post parturient cows using intravenous injection of protamine. Protamine inhibits bone resorption and the protamine-induced hypocalcemia can be taken as a measure of this process. The studies were performed in a herd where half of the cows had been tied indoors for 21/2 years, the other half had been given daily exercise during the same period. All animals were fed in the same way.The hypocalcémie response to protamine was the same in both groups, which indicates that exercise did not change bone resorption.The serum levels of calcium, inorganic phosphorus and magnesium around parturition did not differ. The daily exposure to daylight increased the serum level of 25-(OH)-chole-calciferol in late summer in the exercised group.     

杜洛克杂种仔猪四项血清钙指标的研究

对青海省湟中县多巴镇猪场的20头杜洛克(父本)杂种仔猪的四项血清钙指标进行了测定。结果为:杜洛克二元杂交仔猪,血清总钙,2.40±0.12mmol/L;血清结合钙,1.57±0.20mmol/L;血清游离钙,0.85±0.19 mmol/血清游离钙百分率,35.27±7.64%。杜洛克三元杂交仔猪,血清总钙,2.45 0.24mmol/L;血清结合钙,1.66±0.13mmol/L;血清游离钙,0.80±0.22mmol/L;血清游离钙百分率,32.12±6.64%。且公、母仔猪间四项钙指标差异不显著(P>0.05)。     

野仔猪血清钙指标的测定

对青海省多巴镇猪场的12头野仔猪的4项血清钙指标进行了测定。结果表明:血清总钙,2.26±0.29 mmol/L;血清结合钙,1.71±0.15 mmol/L;血清游离钙,0.55±0.21 mmol/L;血清游离钙百分率,23.69%±6.89%。且公、母仔猪间4项钙指标差异不显著(P>0.05)。40日龄仔猪血清总钙、结合钙均显著高于60日龄仔猪(P<0.05)。     

Effects of excess calcium as a different form on mineral metabolism in rats

Excess calcium is known to affect the metabolism of other minerals. Calcium carbonate is the main source of calcium used in previous experiments that investigated excess calcium. Thus, it remains to be clarified whether other forms of calcium also have the same adverse effects. The effects of a high‐calcium carbonate diet or a high‐calcium citrate diet on mineral concentration in several tissues of rats were examined. Male rats aged 5 weeks were fed one of the experimental diets for 4 weeks. The control diet contained calcium as calcium carbonate at the requirement level. High‐calcium diets contained calcium carbonate or calcium citrate at a level of fivefold greater than the requirement level. In rats fed the high‐calcium diets, a similar decrease in phosphorus (in the plasma) and iron (in the testis, liver and femur) was observed. Hepatic copper increased in rats fed the high‐calcium diets, whereas renal copper decreased. Therefore, excess calcium affects these mineral metabolisms regardless of its form. In contrast, the high‐calcium carbonate diet increased femoral zinc and decreased femoral magnesium, but the high‐calcium citrate diet did not affect these minerals in the femur, which suggests that the effect of excess calcium on minerals partly depends on its form.     

青海省湟源县本地黄牛四项血清钙指标的测定

对30头湟源县本地黄牛的4项血清钙指标进行了测定。结果表明：犊牛的血清总钙、血清结合钙和血清游离钙含量均显著高于成年牛（P＜0．01），而两者的血清游离钙百分率相似（P＞0．05）。     

火焰原子吸收光谱法测定泛酸钙中的钙含量

用火焰原子吸收光谱法测定泛酸钙中的钙含量。以氯化钾溶液（0．1％，m／V）配制泛酸钙检测液，可消除空气-乙炔火焰的电离干扰作用。方法的线性范围为0．50～4．00μg／mL（r=0．9992），加标平均回收率为98．7％，RSD为0．46％（n=9）。