单细胞蛋白在家禽营养中的应用

在一些阿拉伯国家,单细胞蛋白（SCP）被用于解决常规蛋白来源的缺乏和高成本问题,估计年产量17万吨,其中大部分来自石油,少数从其他培养基中制得。包括农副产品,纤维素产品,禽畜粪便,石油和天然气等工业产品。在这些培养基中,通过加入碳、氮、糖、矿物质和维生素等发酵刺激物,微生物得以生长,并产生高质量的单细胞蛋白。1。影响单细胞蛋自生产的因素1．1一旦选择了合适的微生物丛和适当的培养基,微生物即能有效利用养分在短时间内产生大量的单细胞蛋白。1．2单细胞蛋白的生产过程非常经济,较之常规的蛋白来源,需要的劳力和投…     

单细胞蛋白取代鱼粉饲喂蛋鸡试验

当前在蛋白饲料紧缺的情况下,开辟新的饲料,特别是蛋白饲料资源实感重要,而且甚为紧迫。我们与新疆生物发酵工程设计研究所合     

单细胞蛋白对家禽的营养作用

单细胞蛋白(SCP)为畜禽提供了一种廉价的蛋白源。在阿拉伯国家,SCP也用于缓解常规蛋白源缺乏的矛盾。据估计,阿拉伯国家每年SCP的总产量约17万吨。其中大部分是通过原油培养获得的,仅有少部分是用其它培养基产生的。 能用于产生SCP的培养物很多,如农副产品,纤维、家禽下脚料、牛粪以及石油天然气工业的废弃物。当在这些培养物中加入适宜微生物发酵的物质如碳、氮、糖、矿物元素和维生素后,微生物即     

单细胞蛋白简介

蛋白质是家畜必须的营养成份。解决饲料中蛋白质的途径,现在主要靠动植物供给。但是,动植物生长周期长,受自然条件和耕地面积的限制,单纯依靠动植物供给源来解决蛋白质的途径,不能适应人类和畜牧业发展的需要。因此,寻找新的、能摆脱自然条件控制的蛋白质来源,已成为各国研究的重要课题。其中单细胞蛋白引起了各国科学家的重视和研究,并取得了很大的进展。单细胞蛋白(Single cell Protein.简称SCP)是指细菌、酵母、藻类等单细胞生物的细胞蛋白质。60年代初首先由美国麻省理工学院研究并提出的。其突出的优点     

单细胞蛋白生产技术及其应用研究进展

单细胞蛋白(SCP)作为蛋白质的替代品,是高附加值的生物产品。使用温室气体和废弃生物质等不同的有机氮源,并利用环境中的无机氮源生产单细胞蛋白,进而转化为动物饲料产品,具有良好的发展前景。文章对单细胞蛋白生产菌种及产量提高技术、生产单细胞蛋白原料和单细胞蛋白应用进行详细综述,以期为单细胞蛋白在饲料行业中的应用和发展提供参考。     

单细胞蛋白质在家禽营养中的应用

生产和利用单细胞蛋白质,是世界各国为畜禽提供廉价蛋白质源的多种努力之一。单细胞蛋白质也一直为若干阿拉伯国家用以解决传统蛋白质源短缺和成本高昂的问题。据估计,如今单细胞蛋白质在阿拉伯国家的年产量约为１７万吨,其中大部分都是用石油制取的,仅极小一部分用其...     

单细胞蛋白质饲料的开发及在动物生产中的应用

单细胞蛋白质饲料是运用微生物发酵技术,使菌体大量生长繁殖并生产单细胞蛋白质得以用于饲料工业上,可替代一部分蛋白质原料(豆粕、鱼粉等)。本文主要对单细胞蛋白质饲料的营养特性、生产工艺及其在动物生产中的应用加以综述。     

Evaluation of amino-acid supplemented diets varying in protein levels for laying hens

The ideal amino acid concept is increasing by being applied to laying hens. However, understanding the responses of modern laying hens to decreasing levels of dietary protein balanced with crystalline amino acids has yet to be examined. In this study, 5 dietary treatments varying in CP content (18.0, 17.5, 17.0, 16.5, and 16.0%) were formulated at a fixed dietary energy concentration of 2,825 kcal of ME/kg of feed. The crystalline amino acids, including Met, Thr, Ile, Val, Trp, and Lys, were supplemented according to an assumed ideal AA profile, and all diets contained 0.831% ileal digestible Lys. Irrespective of the CP levels, the ratio of Lys and the profile of different essential amino acids in relation to Lys remained similar in all the diets. A total of 540 21-week-old Hy-Line W36 hens were used with 6 replicates per treatment group. This trial was conducted for a period of 14 wk, ranging from wk 21 to 34. Egg production, daily egg mass, feed intake, and FCR were not affected in the low-protein groups. Egg weight and N excretion declined, whereas egg yolk color increased in the low-protein groups. Decreasing dietary CP was found to have no effect on blood ammonia and plasma uric acid. The application of the assumed ideal AA profile can lead to reduced dietary protein level, from 18 to 16%, without affecting the production performance of laying hens during 21 to 34 wk of age. The ratios of standardized ileal digestible Met, Met + Cys, Thr, Trp, Arg, Ile, and Val to standardized ileal digestible Lys were 50, 91, 70, 21, 104, 80, and 88%, respectively, in the assumed ideal AA profile. Excretion of nitrogen was significantly decreased from hens fed the protein-reduced diet without impairing BW.     

Use of field beans (Vicia faba L) in diets for laying hens

1. Most samples of field bean, irrespective of their genetic origin, induced a decrease in the mean egg weight when included in the diet at a rate of 300 g/kg: the relative sizes of yolk, albumen and shell were unchanged.

2. Lipoxygenase was not involved in this phenomenon since addition of linoleic acid to the diets containing field beans did not improve egg weight.

3. The depressing effect of the field beans was proportional to the proanthocyanidine content of the seed extracted with absolute methanol.

4. In a longer trial (252d) field beans rich in these kinds of tannin decreased laying rate, efficiency of food utilisation and tended to increase mortality.

5. The removal of the hulls from the field beans did not prevent the reduction in egg weight.     

单细胞蛋白饲料的开发与利用

文章概述了单细胞蛋白生产原理,生产单细胞蛋白的微生物种类,以及单细胞蛋白的营养成分,介绍了单细胞蛋白生产的一般工艺,探讨了单细胞蛋白饲料的应用效果及应用中存在的问题及解决办法,最后展望了单细胞蛋白在饲料加工中的应用前景。     

The performance of laying hens fed on rearing and laying diets containing urea

In an experiment using 2880 light hybrid pullets the effect of urea on laying performance has been assessed. Birds received one of three low‐protein rearing diets from 7–20 weeks of age. The control rearing diet, containing 11.5% crude protein, was compared with two diets containing 13.2% crude protein, one in which the protein was from conventional sources and the other containing 11.5% conventional protein and urea equivalent to 1.7% crude protein. At 20 weeks birds were allocated to one of two laying diets formulated to meet essential amino acid requirements. Half the birds from each rearing treatment received a low‐protein diet (14.7%) and the remaining birds received a 16.4% protein diet which included urea equivalent to 1.7% crude protein. Laying performance was recorded for the next 30 weeks.

Body weights of birds fed on the urea‐containing rearing diet were similar to those of birds fed on the control diet (1.22 kg) and less than those on the 13.2% protein diet (1.29 kg). Urea in the laying diet caused a 2% increase in egg production and tended to cause an improved food conversion efficiency. In contrast, a 3.5% less efficient food conversion was found during laying in birds which had received urea during rearing, compared with birds which had received the low‐protein rearing diet. Birds receiving the 13.2% protein diet, containing no urea, during rearing laid smaller eggs than birds fed on the 11.2% protein rearing diet. A high mortality rate occurred during laying due to lymphoid leucosis but no differences between treatments were found.     

Development of furnished cages for laying hens

1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had two nest hollows at the side, one in front of the other. They were compared with conventional cages 2500 cm2 in area and 38 cm high at the rear. 2. Cages were stocked with from 4 to 8 ISA Brown hens per cage, resulting in varied allowances of area, feeder and perch per bird. No birds were beak trimmed. In F and FD cages two further treatments were applied: nests and dust baths were sometimes fitted with gates to exclude birds from dust baths in the morning and from both at night; elevated food troughs, with a lip 33 cm above the cage floor, were compared with standard troughs. 3. Management of the house was generally highly successful, with temperature control achieved by ventilation. Egg production was above breeders' standards and not significantly affected by cage design. More eggs per bird were collected when there were fewer birds per cage but food consumption also then tended to be higher. 4. The number of downgraded eggs was variable, with some tendency for more in furnished cages. Eggs laid in dust baths were often downgraded. Those laid at the back of the cage were frequently dirty because of accumulation of droppings. H nests were unsuccessful, with less than 50% of eggs laid in the nest hollows. However, up to 93% of eggs were laid in front rollaways, and few of these were downgraded. 5. Feather and foot damage were generally less in furnished than in conventional cages, greater where there were more birds per cage. With an elevated food trough there was less feather damage but more overgrowth of claws. In year 2, mortality was greater in cages with more birds. 6. Pre-laying behaviour was mostly settled in front rollaway nests. Dust baths were used more for pecking and scratching than for dust bathing. Comfort behaviour was more frequent in furnished cages than conventional, although still not frequent. Locomotion was strongly affected by number of birds per cage or by space per bird, being reduced by crowding. Most birds perched at night except in one treatment providing only 10.7 cm perch per bird. 7. Behaviour was more unrestricted and varied, and physical condition was better, in furnished than in conventional cages. However, egg production will cost more in furnished cages, partly because more eggs are downgraded. Dust baths must be fitted with gates that the birds cannot open from outside, but gates for nest boxes were found unnecessary. If a low perch is fitted it must be far enough from the back of the cage for birds to walk there. 8. Where there was less space per bird (more birds per cage) than the requirements in the 1999 European Commission Directive on laying hens, there were: fewer eggs per hen, but still above the breeders' target; lower food consumption; more feather and foot damage, but less than in conventional cages; higher mortality in one trial out of three; less freedom of movement. However, the results were still very good even with 8 birds per cage, and support the principle that furnished cages provide an acceptable way of protecting the welfare of laying hens.     

干番茄渣在蛋鸡饲料中的应用

本文旨在研究用干番茄渣（DTP）部分或全部替代大豆、玉米、小麦、麦麸饲料时，对蛋鸡生产性能、蛋品质的影响。将288只试验鸡（27—38周龄）随机分成4组，每组72只．分别为：DTP0（对照组）、DTP50、DTP100、DTP150（每吨饲料中分别含0、50、100、150kg DTP）。与对照组相比．DTP100组使其产蛋量、产蛋总重分别增加2．7％、4．1％．而鸡的体重、蛋重、日消耗饲料量、蛋壳重、蛋壳厚、哈夫单位、蛋黄颜色均与对照组相似。DTP150组使产蛋量、产蛋总重分别降低3．6％、3．0％，但饲料转化率增加2．9％。结果表明．DTP可以作为蛋鸡的饲料原料。     

蛋鸡产蛋期蛋白质需要量的研究及数学模型的应用

针对产蛋鸡蛋白质和氨基酸需要量的研究现状及相关数学模型的应用作一综述。     

Astaxanthin Z-isomer-rich diets enhance egg yolk pigmentation in laying hens compared to that in all-E-isomer-rich diets

The effects of feeding diets containing astaxanthin with different Z-isomer ratios to laying hens on egg qualities, such as astaxanthin concentration in egg yolk and yolk color, were investigated. As the astaxanthin source, a natural microorganism Paracoccus carotinifaciens was used. Astaxanthin with different Z-isomer ratios was prepared by thermal treatment with different conditions and then added to the basal diet at a final astaxanthin concentration of 8 mg/kg. We found that, as the Z-isomer ratios of astaxanthin in the diet increased, the astaxanthin concentration in egg yolk and the yolk color fan score also increased significantly. Importantly, feeding a 50.6% Z-isomer ratio diet increased astaxanthin concentration in egg yolk by approximately fivefold and the color fan score by approximately 2 compared to that in hens fed an all-E-isomer-rich diet. Moreover, we showed that feeding Z-isomer-rich astaxanthin to laying hens increased plasma astaxanthin concentration by more than five times in comparison to that in hens fed an all-E-isomer-rich diet. These results indicate that Z-isomers of astaxanthin have higher bioavailability than that of the all-E-isomer and thus they exhibit greater egg yolk-accumulation efficiency.