五种添加剂用于蛋鸡生产排污减量效果对比试验研究

目的筛选出既能提高蛋鸡生产性能,又能降低粪便粗蛋白的理想添加剂。方法选取540只日龄450 d的鸡,随机分成5个试验组和1个对照组。试验组分别添加中草药、枯草芽孢杆菌、地衣芽孢杆菌、禽专用复合酶SFQ-081和复合益生素,对照组不加任何添加剂。统计产蛋量、沙皮蛋数和病死鸡数量,测定粪便粗蛋白。结果5个试验组产蛋率比对照组分别提高4.43%、6.28%、5.59%、2.34%、5.50%;试验5组和对照组沙皮蛋率分别为0.041%和0.089%、病死率分别为1.11%和5.56%,其他试验组没有沙皮蛋和死淘鸡;试验组粪便粗蛋白相比对照组分别降低17.57%、40.3%、7.36%、8.79%和8.79%。结论综合生产性能、粪便粗蛋白、淘汰率和沙皮蛋率4个因素,试验表明,枯草芽孢杆菌是5种添加剂中最理想的添加剂。

Effects of salinity on egg and fecal pellet production, development and survival, adult sex ratio and total life span in the calanoid copepod, A cartia tonsa:a laboratory study

The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.

Analysis of Metabolic Products by Response Surface Methodology for Production of Human-like Collagen II

Recombinant Escherichia coli BL21 is used to produce human-like collagen. The key constituents of media are optimized using response surface methodology (RSM). Before thermal induction, the highest biomass production and the lowest production of some hazardous by-products, especially acetic acid, were obtained in the media containing 0.085 mol·L-1 glucose and 0.019 mol·L-1 nitrogen (carbon-nitrogen ratio, 4.47:1). After thermal induction, when the concentrations of glucose and nitrogen in the media were 0.065 mol·L-1 and 0.017 mol·L-1 , respectively (carbon-nitrogen ratio, 3.82:1), the productivity of human-like collagen per cell was the highest while that of acetic acid was the lowest. The extended analysis showed that the production of lactic acid and propionic acid increased while that of some intermediate acids of the tricarboxylic acid cycle decreased if the dose of glucose increased.

Effect of the Entomopathogenic Fungus, Paceilomyces farinosus （Dicks ex fr.） on the Reproductive Potential of Melasoma populi L.

The effect of the Entomopathogenic fungus, Paceilomyces farinosus on reproductive potential of female survivors, egg viability and total egg production of poplar leaf beetle Melasoma populi L. was investigated in Plant Protection Department laboratories, School of Plant Production, Faculty of Agriculture and Forestry, Duhok University in Spring 2011. Prepupae, pupae and newly emerged adults were treated with spore suspension of P.farinosus （1 ~ 10s conidia/mL）. Another group of adults were reared on sprayed poplar leaves with a same concentration of conidial suspension. Eggs production and hatching percentage were monitored daily over a 7-wk period. Overall reproductive capacity was significantly lower as compared with control. The total number of eggs per surviving female was 85.50, 149.50, 123.43 and 280.24 eggs for pre-pupa, pupa, adult and leaves treated, respectively as compared with 299.75 in control after fourth week. Pre-oviposition, ovipostion, post-oviposition days and the longevity of females and males were shorter in treated individuals compared with control. The lowest percentage hatching was 75.12% in eggs deposited by adults feed on treated leaves as compared with 98.42% in control.

Effects of Condensed Tannins from Quebracho Extract on the Kinetic of in vitro Gas Production on Trifofium repens, Lotus corniculatus and Lofium perenne

The aim of this work was to study the effect of condensed tannins （CT） on the kinetic of gas production in vitro, on the three main species of Azorean pasture： Trifolium repens, Lotus corniculatus and Lolium perenne, using Quebracho extract as the source of CT, and also to calculate total tannins and condensed tannins on the species studied. Lotus corniculatus, Lolium perenne and Trifolium repens were tested in vitro with the inclusion of Quebracho extract in doses of 0%, 2.5% and 5% DM. The total content in tannins was determined in the 3 species. We have found, in comparison with standard tannic acid, that tannins exist in the flower of T. repens （0.81 equivalents of tannic acid） and in L .corniculatus （1.07 equivalents of tannic acid） but not in L .perenne （0 equivalents of tannic acid）. The concentration of condensed tannins in the 3 species was： 0.34 mg/mL for T. repens; 0.83 mg/mL for L. corniculatus and 0 mg/ml for L. perenne. We verified that a significant reduction （P 〈 0.05） of gas production happened for doses of 5% of CT in comparison with the other two concentrations： 0% and 2.5% of CT. The results of this study express a reduction of the fermentation rate, which implies a reduction of gas production, so, a reduction of methane emission to the atmosphere and an increase of exploitation of the protein by ruminants.

Influence of Artificial Light on Laying Hens Production of Heat, Moisture and Carbon Dioxide in a Floor Housing System

Investigations about laying hens reactions on artificial light conditions were carried out in a climate chamber equipped with a floor housing system for laying hens. The release of moisture increased during light periods probably due to increased activity which increased respiration rate but also on increased scratching which increased evaporation of moisture from bedding material. The daily average was 6.29 g henl h＂l at 4 lux and 5.97 g henl hl, at 93 lux which corresponds to a difference of 5%. The level of light intensity seemed to have little influence on the release of moisture. The total release of heat was slightly higher during light periods compared to dark periods. Explanations can be increased activity but also feed intake increasing the metabolic rate during light periods. The daily average of total heat production was 17.0 W per hen at 4 lux and 14.7 at 93 lux which corresponds to a difference of 16%. The release of carbon dioxide increased during light periods probably due to increased activity and respiration.