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21.
1. Light‐weight (Babcock B300) and medium‐weight (Warren‐SSL) hens were offered diets, containing 0, 100 or 200 g dried poultry manure (DPM) and 11.49, 11.12 or 10.83 MJ metabolisable energy/kg respectively, between 18 and 70 weeks of age. The true protein, metabolisable energy, calcium and phosphorus contents of the DPM, from caged layer hens, were used in the diet formulation.

2. The hen‐housed laying performance of hens offered the DPM‐containing diets was significantly better for number of eggs laid and total egg mass produced but the performance of the control groups was lower than would normally be expected of those stocks. The reason for the lower rate of lay and higher mortality of hens fed on the control diet was not identified. The amount of food consumed increased as the energy content of the diet decreased and the efficiency of food conversion (EFC) of the lightweight strain was reduced; there was no significant effect on the EFC of the medium‐weight hens.

3. The inclusion of DPM in the diets had no effect on albumen quality or on the incidence of hair‐cracked, cracked or broken eggs. However, with both strains of hens, shell weight and shell thickness were poorer when 100 or 200 g DPM/kg diets were fed.  相似文献   

22.
1. Treatment of rapeseed meal with calcium hydroxide suspension decreased the sinapine content by up to 90%. Smaller decreases were obtained by autolysis, steaming and treatment with ammonia.

2. When this treated meal was fed to susceptible ("tainting") hens the concentration of trimethylamine in the eggs was decreased to much less than that required to cause taint.  相似文献   

23.
小麦对条锈病的水平抗病性研究初报   总被引:4,自引:0,他引:4  
将小麦品种采用随机区组的田间设计种于小种病圃中,以鉴定和测定其水平抗性。根据各个“品种——小种”组合的相对病情指数的方差分析的结果,有些品种,如农大311、西农6028和丰产3号,其品种——小种互作高度显著,被鉴定为具有垂直抗性,另外一些品种,对试验所用的小种并无专化性,并且在大田生产中已显出20多年的持久的中度抗性,初步推测为属水平抗性。在后一类中,有些品种,如平原50,表现为中等反应型,其余则属于呈典型感病的迟锈慢锈类型。在迟锈慢锈品种的病指的对数矫正值(logits)和病圃的锈病强度(以感病对照品种的病指表之)的对数矫正值之间发现了直线回归。  相似文献   
24.
1. The growing embryo uses about 1% of the total protein available in the egg during the first week of incubation.

2. Injecting the growing embryo with amino acids equivalent to the amount of protein used resulted in higher weight of chicks at all stages up to 56 d.  相似文献   

25.
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27.
1. Under summer conditions in north Iraq, 2 000 chicks were reared for 56 d in two broiler houses. One house was provided with two air‐coolers. The birds were housed at densities of eight to 16 birds/m2.

2. Differences in weight gain between birds in cooled and uncooled houses ranged from 101.5 g at eight birds/m2 to 385 g at 16 birds/m2. Food consumption increased gradually with increasing bird density. Food conversion efficiency, meat yield and carcass conformation were much better in the cooled house than under conventional conditions.

3. The financial return/m2 ranged from 2.30 to 4.51 ID1 in the cooled house, compared with 2.01 to 2.77 ID in the uncooled house at different floor densities.  相似文献   

28.
1. Whole broilers and separated legs were stored at ‐12 ± 1 °C, —18 ± 1 °C and — 75 ±2 °C (reference group, whole carcasses only), for up to nine months.

2. Legs cut from the whole birds after removal from store, unpacking and thawing, and legs from the portions were compared in odour preference at four times of examination.

3. After only 1 d the odour of the legs stored as parts at —12 °C was less preferred than that of the reference group; this was also true for legs cut from whole birds after 3 months at the same temperature.

4. After 3 months at — 12 °C the odour of the legs stored as parts was less preferred than the odour of legs obtained from whole birds.

5. Storage of legs as parts at —18 °C resulted in a comparatively less preferred odour after 3 months, while the same was true after 9 months for legs cut from the carcasses.  相似文献   

29.
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The in vitro metabolism of the chiral isomers of fonofos and fonofos oxon in the presence of mouse liver mixed-function oxidase and serum esterase was investigated. The metabolism of 35S-labeled phenyl-(S)P-fonofos mediated by mixed-function oxidase took place stereoselectively, resulting predominantly in (R)P-fonofos oxon. Similarly, (R)P-fonofos was converted to (S)P-oxon. In each case, however, a significant amount of racemization occurred. Other products were diphenyl disulfide and diphenyl disulfide oxide. In addition to stereospecificity, the oxidative metabolism of (R)P-fonofos proceeded at a rate faster than that of (S)P-fonofos. Stereoselective rate differences also were observed in mouse or rat serum-catalzyed degradation of the fonofos oxon enantiomers, the (S)P isomer being degraded about twofold faster than its enantiomer. The differences in toxicities of the isomers of fonofos and fonofos oxon were consistent with the in vitro metabolism data.  相似文献   
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