The metabolism of labelled progesterone in the laying hen

Eight hours after administering 4–14C‐progesterone to laying hens four radioactive metabolites could be detected in the droppings. Excretion of labelled steroid products was still continuing 192 h after the injection. In blood a relatively high level of labelled progesterone was found 8 to 24 h after application. The last traces disappeared from blood after 72 h. Compared with mammals the hen metabolises progesterone at a slower rate.

Certain tissues were also examined 24 h after treatment. The adrenals showed a high level of labelled progesterone metabolites. The liver contained similar steroids as were found in the droppings. In the ovary, pituitary and skeletal muscle low or trace amounts of radioactive steroids were detected.     

植酸酶对产蛋鸡生产性能和代谢的影响

磷酸氢钙是饲料中最主要的磷来源之一 ,无机磷资源不仅在我国 ,就是在全世界范围内 ,已经处于匮乏状态 ,磷资源的匮乏使饲用磷产品价格上升 ,增加了饲料成本。植物性饲料中有 65 %～86 %的磷以植酸磷的形式存在 ,这些磷源不仅不能为单胃动物有效利用 ,而且会对环境造成严重的污染。如果能将植酸磷中的磷释放出来供动物利用 ,减少磷酸氢钙的用量 ,可缓解供求矛盾 ,并减轻粪磷污染。本试验旨在应用植酸酶迈特 -5 0 0 0以减少产蛋鸡日粮中的磷酸氢钙用量 ,观察其对产蛋鸡生产性能和代谢的影响。1　材料与方法试验在南京市青龙山养鸡场进行 ,选…     

Voluntary food and calcium intake by the laying hen

Two experiments, each of 40 d duration, are described in which a diet rich in calcium (3.5% Ca) or one deficient in calcium (1% Ca), but with oyster shell offered separately, were fed ad libitum to four laying hens. The voluntary consumption of food and oyster shell was automatically recorded every 2 h. The hourly consumption of the high Ga diet increased during the afternoon while the daily pattern of consumption was modified by the position of the egg in the clutch.

When the low Ca diet was fed with oyster shell, the daily consumption was increased but the effect of the position of the egg in the clutch was reduced. The ingestion of oyster shell was very high between 16.00 and 20.00 h when egg calcification was in progress; after the last oviposition of the clutch this elevated level of intake remained though to a lesser degree. In relation to the stage of egg formation, the voluntary intake of oyster shell increased sharply between 4 and 12 h after the former oviposition.

These results confirm that the laying hen can discriminate between food and calcium intake. It seems that appetite for calcium is firstly related to light‐dark cycles with a modulation of the afternoon peak by ovulation and then egg shell calcification.     

The effects of exogenous oestrogen and progesterone on laying and nesting behaviour in the hen.

1. It has been shown that if oestrogen and progesterone are given to ovariectomised hens nesting behaviour will occur. Thus if these hormones are given to normal hens the excessive pacing found in some hens before laying might be reduced. 2. Experiments showed that oestrogen produced no noticeable effects and progesterone caused a high incidence of delayed oviposition and abnormal behaviour.     

Regulation of plasma oestrogen by dietary fats in the laying hen: Relationships with egg weight

1. Feeding a diet supplemented with maize oil was found to elevate plasma oestradiol concentration in laying hens.

2. In a larger‐scale experiment, isoenergetic and isonitrogenous diets containing 10, 20, 40 or 60 g/kg supplemental maize oil, tallow, coconut oil or fish oil were fed for 5 weeks.

3. Egg weights showed very different responses to the different fats. The responses could be described by quadratic functions that all gave optimum responses with supplemental dietary fat concentrations of about 40 g/kg. Egg weight increased the most with maize oil and was decreased with fish oil at the highest inclusion rate.

4. Measurements of egg components showed a relatively larger increase in albumen weights with maize oil than with other fats.

5. Across treatments, mean plasma oestradiol concentrations were very highly correlated (r = 0.96) with the changes in egg weights over the experimental period.

6. It is concluded that oestrogen is important in controlling egg weight and that the effect of dietary fats in influencing egg weight is mediated by an effect of the fats on oestrogen metabolism.     

Effects of vitamin or mineral deficiency on the morphology of medullary bone in laying hens.

Adult laying hens were fed diets deficient in phosphorus, calcium, calcium and phosphorus, and vitamin D3 to determine their effects on bone histology and parathyroid gland size. The phosphorus deficient diet caused an insignificant decrease in parathyroid size while the other diets caused significant increases. A considerable amount of individual variation in medullary bone volume and osteoid seam width was observed in all groups but, despite this, the calcium, calcium and phosphorus and vitamin D3 deficient diets clearly resulted in increased osteoid. Birds receiving diets deficient in calcium and phosphorus, and in vitamin D3 for longer periods were observed to have partially or completely resorbed medullary bone. Osteodystrophia fibrosa was noted in vitamin D3 deficient birds which had no follicular activity.     

光照与蛋鸡饲养的关系

1 光照的意义 光照是一门科学,要想养好鸡,就必须要懂得这门学问.在蛋鸡饲养上,光照与雏鸡发育、青年鸡生长、成年鸡产蛋等都有着极密切的关系.实践证明,光照的时数与强弱、光照的颜色与波长、光照刺激的起止时间、黑暗期是否连续或间断,都会对蛋鸡的成活率、生长发育、体成熟、性成熟、产蛋率以及繁衍后代的公母交配活动等方面,产生重要的影响.光照是蛋鸡饲养的重要的环境条件之一.换句话说,没有光照条件的环境,是不能进行蛋鸡饲养活动的.     

Evaluation of the dietary interaction of calcium and phosphorus in the high producing laying hen

1. In a 6 x 7 factorial experiment using 2688 22-week-old laying hens of the Lohmann-SL strain kept in cages (4 birds/cage), diets containing six calcium (20, 25, 30, 35, 40, 45 g calcium/kg) and seven phosphorus concentrations (3.2, 4.2, 5.2, 6.2, 7.2, 8.2, 16.2 g total phosphorus/kg (Pt)) were combined orthogonally. The resulting 42 treatments were replicated 8 times so that a replicate consisted of a double cage of 2 x 4 hens. The experiment lasted 40 weeks (10 x 28 days). 2. The experimental diets, based on maize and soyabean meals contained 11.5 MJ metabolisable energy/kg and 175 g/kg protein. Different dietary calcium and phosphorus contents were obtained by substituting oat hulls with limestone and dicalcium phosphate. 3. Mortality, egg production, egg weight, egg mass, food intake and food conversion efficiency were determined as well as the breaking strength, thickness of shells and the percentage of eggs with defective shells. 4. All responses measured were significantly influenced by the variance sources (calcium, phosphorus, interaction). Most of the production traits responded asymptotically to increasing dietary phosphorus concentration, the greatest increases or decreases generally being seen between 3.2 and 5.2 g Pt/kg. Further but weaker increases were seen between 5.2 and 8.2 or 16.2 g Pt/kg. 5. Increases in dietary calcium content always resulted in curvilinear responses. In all cases optimal effects were obtained with diets containing 25 g calcium/kg and the worst values at 45 g calcium/kg. The interaction between calcium and phosphorus was recognised by strong performance depressions and a high mortality at combinations of the lowest phosphorus concentration (3.2 g/kg) with high calcium contents (35 to 45 g/kg). These were largely offset by increasing dietary phosphorus. Thus, between 7.2 and 16.2 g Pt/kg and 25 and 45 g Ca/kg a plateau was formed where only small differences in egg production were observed. 6. From the three egg shell characteristics measured, breaking strength and shell thickness responded differently to the percentage of eggs with defective shells. While breaking strength and shell thickness were respectively negatively and positively influenced by increasing dietary phosphorus and calcium contents, both elements affected the proportion of eggs with defective shells.(ABSTRACT TRUNCATED AT 400 WORDS)     

微生态制剂和异麦芽低聚糖对产蛋鸡产蛋性能和免疫力的影响

324只36周龄蛋鸡按3×3二因子完全随机设计分成9组,每组6个重复。微生态制剂添加水平为0%、1%和2%,异麦芽低聚糖的添加水平为0%、0.1%和0.2%。结果表明,添加1%或2%微生态制剂组蛋鸡平均日产蛋量均显著高于未添加组(P<0.10)。添加0.2%异麦芽低聚糖组蛋鸡日产蛋量显著高于未添加异麦芽低聚糖组和添加0.1%异麦芽低聚糖组(P<0.10)。添加0.1%或0.2%异麦芽低聚糖组料蛋比均低于未添加异麦芽低聚糖组(P<0.10)。添加2%微生态制剂组血清总SOD显著高于未添加微生态制剂组或添加1%微生态制剂组(P<0.10)。添加0.1%或0.2%异麦芽低聚糖组血清总SOD显著高于未添加组(P<0.10)。随微生态制剂和异麦芽低聚糖添加水平的提高,血清中IgA、IgM、IgG、C_3、C_4含量均有提高的趋势。     

槲皮素对蛋鸡胆固醇代谢的影响

采用单因素试验设计,选体重和产蛋率相近的29周龄蛋鸡240只,随机分为4组,每组6个重复,每重复10只鸡。在玉米-豆粕型饲粮基础上添加0、0.02%、0.04%和0.06%槲皮素,进行8周的饲养试验。研究槲皮素对蛋鸡的血脂、鸡蛋胆固醇和甘油三酯、肝脏胆固醇和甘油三酯、血清雌激素和胰岛素的影响。结果表明,与对照组相比,0.04%槲皮素可显著降低血清甘油三酯含量(P<0.05);0.02%、0.04%槲皮素极显著降低蛋黄胆固醇含量(P<0.01),三个剂量槲皮素均可显著降低肝脏胆固醇含量(P<0.05),但对肝脏和蛋黄甘油三酯含量无显著影响(P>0.05);0.04%槲皮素可显著提高血清胰岛素和雌二醇含量(P<0.05)。由此可见,一定剂量槲皮素能降低鸡蛋中胆固醇含量,最适添加量为0.04%。     

微生态益生菌粉在蛋鸡日粮中应用效果

在蛋鸡日粮中加入2～8％生物饲料添加剂——兹生态益生茵粉等量替代豆粕,以61周龄海兰褐鸡群为试验鸡群,通过7周的饲喂试验观察结果如下：饲料成本略有下降;鸡群料蛋比下降2．79～4．57％;能明显改善蛋鸡的产蛋性能,延迟蛋鸡产蛋后期产蛋率的下降速度,使只鸡每周可多盈利0．036～0．06元;能增加鸡蛋壳的颜色和硬度,加深鸡蛋黄的颜色和弹性;对去除鸡舍中的臭味有一定的效果。微生态益菌粉在蛋鸡饲料中的添加量以5～8％为宜。     

当归补血散对高龄蛋鸡生产性能及蛋品质的影响

120只390日龄海兰褐蛋鸡,随机分为4组。以日粮中分别添加0.5%、1%、1.5%剂量的当归补血散饲喂Ⅰ、Ⅱ、Ⅲ组鸡群,Ⅳ组为对照组。连续给药15 d。分别观察各组每天的产蛋率、日产蛋量等生产性能指标;于第8、15、22、30天各组随机收集10枚蛋测蛋品质指标。结果:试验组Ⅱ、Ⅲ的产蛋率比对照组提高了8.80%(P<0.01)、4.99%(P<0.05);日产蛋量均与对照组差异极显著(P<0.01),分别提高了12.12%、6.82%;料蛋比与对照组相比降低了12.46%(P<0.01)、11.42%(P<0.05)。Ⅱ组的蛋形指数与对照组有显著提高(P<0.05);Ⅰ和Ⅱ组的蛋壳厚度与对照组有显著提高(P<0.05)。其余指标与对照组差异不大(P>0.05)。结论:1%剂量可以明显提高高龄蛋鸡的生产性能和蛋品质。     

产蛋鸡卵母细胞卵黄生成受体(OVR)的研究进展

OVR介导大量的血浆蛋白被产蛋鸡吸收到生长的卵母细胞中,是卵黄前体进入卵母细胞的瓶颈。到目前为止发现它不仅与最丰富、最重要的卵黄前体极低密度脂蛋白(VLDL)、卵黄蛋白原(VTG)结合,还结合丛生蛋白、α2-巨球蛋白(α2-M)、受体相关蛋白(RAP)、乳铁蛋白、核黄素结合蛋白(ribBP)等,这些成分占蛋黄干物质的绝大部分。OVR发生突变的蛋鸡,不能繁殖,并且具有严重的高脂血症。它所内吞的VLDL的数量是蛋黄胆固醇含量的决定因素,因此期望通过调控OVR来控制蛋黄胆固醇的含量。     

Influence of dietary calcium and phosphorus on metabolism and production in laying hens

1. The effects of different dietary concentrations of calcium (24 to 56.9 g/kg) and phosphorus (4.5 to 14.2 g/kg) on production and some aspects of metabolism were studied in laying hens.

2. Treatments did not affect egg numbers, food consumption, conversion efficiency of food to egg, bodyweight gain or mortality.

3. Increasing dietary calcium (Ca) significantly increased plasma Ca and inorganic phosphorus (P), breaking strength at the radius and egg specific gravity and significantly decreased plasma alkaline phosphatase and egg weight.

4. Increasing dietary phosphorus increased plasma P and decreased egg specific gravity significantly.

5. Plasma Ca, P and alkaline phosphatase and radius breaking strength were suitable indices of the Ca status of the hens.     

蛋鸡应激综合征的分析与应对

2006年7月份丹东市动物疫病预防控制中心接到一养殖大户蛋鸡死亡病例的报告,经现场观察和实验室检验、诊断,确诊为蛋鸡猝死性应激综合征。现将情况报告如下。     

Effects of changes in photoperiod and feeding opportunity on the performance of two breeds of laying hen

1. ISA Brown and Shaver 288 hens, fed ad libitum, were given a 5‐h increase or a 2, 5 or 10‐h decrease in photoperiod at 215 d of age. Hens of both breeds were also maintained on constant 10, 13 or 18 h photoperiods. Other groups had their photoperiod increased from 8 to 13 h, or were held on constant days but had their access to food limited to 8 h per day.

2. Both breeds on ad libitum feeding exhibited curvilinear rate of lay and egg output, and linear food intake, responses to photoperiod change. Shaver hens reduced their egg output and rate of lay to a greater extent than ISA Brown hens when photoperiod was decreased.

3. In both breeds the beneficial effect on egg production of the 5‐h increase in photoperiod was less than the adverse effect of the 5‐h decrease.

4. The influence of light change per se generally had a greater effect on performance than the influence of feeding opportunity, but significant effects of changing feeding opportunity were demonstrated.

5. The reduction in mean rate of lay and egg output following a reduction in photoperiod was partly caused by some birds ceasing lay, but all birds showed some decrease in both variates     

Effects on egg production of including high residual lipid copra meal in laying hen diets

1. The effects on egg production of including copra meals of 220.9 (Copra‐1) and 205.0 (Copra‐2) g residual lipids/kg, in laying hen diets at up to 400 g/kg, were examined in two feeding trials. In a separate experiment, the dry matter retention and ME of a 400 g Copra‐2/kg diet were determined between 6 to 9, 9 to 12 and 12 to 15 d of feeding.

2. Food intakes, egg output and efficiencies of food utilisation (g eggs/g food) of hens fed on Copra‐1 at 100 and 200 g/kg diet were not significantly different from controls; while food intakes at 400 g Copra‐1/kg diet were similar to controls, egg output (6.0% lower), efficiency of food utilisation and body weights of hens were significantly reduced. Hens fed Copra‐2 at 400 g/kg diet had 5.0 and 6.9% lower food intakes and egg output, respectively, and lost body weight compared to controls; however, egg output increased to that of the control group by the 11th week of feeding.

3. Initially, dry matter retention of the 400 g Copra‐2/kg diet was similar to, and ME slightly higher than the control diet; however, both were reduced significantly in the second and third collection periods. The water content of excreta from hens fed on 400 g Copra‐2/kg diet was significantly higher than that from controls.

4. Complete replacement of dietary maize, mainly with copra (experiment 1) led to an increase in pale yolks, with the 400 g Copra‐1/kg diet producing cream‐coloured yolks. Inclusion of maize at 180.6 g/kg of the 400 g Copra‐2/kg diet (experiment 2) resulted in eggs with slightly golden‐yellow yolks.     

高钙高蛋白日粮对海兰褐蛋鸡肾脏结构与功能的影响

旨在探讨高钙高蛋白日粮对海兰褐蛋鸡肾脏结构和功能的影响。将80只40日龄海兰褐蛋鸡随机均分为4组,对照组(组1)饲喂基础日粮(钙1.0%、粗蛋白17.5%),组2饲喂高钙(钙4.5%),组3饲喂高蛋白(粗蛋白27.0%),组4饲喂高钙高蛋白(钙4.5%、粗蛋白27.0%)饲料,试验期95天。第95 d各组随机抽取6羽,采集血清用全自动生化分析仪检测血清尿酸(UA)、尿素氮(BUN)和肌酐(CR)。采血后扑杀,解剖并观察肾的病理变化及组织学变化,ELISA法检测肾脏中炎性因子白细胞介素1(IL-1)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)的水平。结果在试验第95天,组2和组3鸡的体重显著低于对照组(P0.05),血清BUN值极显著高于对照组(P0.01);组4鸡血清UA和BUN显著高于对照组(P0.05),血清CR极显著高于对照组(P0.01)。部分试验组鸡肾脏肿胀,内有白色糊状物。组织学观察发现肾小球炎性肿胀或萎缩,肾小管上皮细胞变性、坏死并脱离基底膜。3个试验组肾组织中的IL-1均极显著高于对照组(P0.01)、IL-6显著高于对照组(P0.05);组2、4肾组织中的TNF-α显著高于对照组(P0.05),组3TNF-α极显著高于对照组(P0.01)。结论:饲喂高钙高蛋白饲料会对鸡肾的结构和功能产生不同程度损伤。