畜禽某些疾病的遗传控制与抗病育种

提高畜禽的抗病性与健康水平已成为当今提高畜牧生产的重要途径。本文从抗病遗传机制出发 ,叙述了单基因与多基因遗传病研究进展 ,探讨了抗病育种的可能途径。     

抗鸡新城病毒高免卵黄IgG的研制与应用

本文报导了抗鸡新城病毒高免卵黄IgG的研制方法:选用健康母鸡数只,用新城Ⅰ系经基础免疫、强化免疫和超强化免疫后获得高效价的鸡蛋,从卵黄中粗提卵黄IgG,进一步纯化。卵黄IgG对人工发病的鸡新城疫和自然发病的鸡进行治疗,收到了显著的疗效,治愈率为77—91.2％,在治疗家禽病毒性传染病方面提供了一种新的生物制剂。特异性卵黄IgG来源广泛,制备简单,成本低廉,给治疗家禽病毒性传染病开辟了广阔的前景。     

鸡粪再生饲料饲喂生长兔试验

本试验分别以10％、20％和30％的鸡粪饲料代替等量精計,探讨对肉兔生产性能的影响。三种补充水平的日增重分别为31.25、31.82知28.90克,而对照组为29.27克。试验结果表明,肉免饲料中用鸡粪饲料作为蛋白饲料补充是可行的,从日增直、料肉比及生产成本分析认为,用10～20％的鸡粪饲料代替基础精料有较大的经济效益,且弥补了农村肉兔饲料蛋白质之不足,也充分利用了鸡粪蛋白饲料资源,因而具有较大的推广价值。     

畜禽微量元素营养与疾病的研究 Ⅰ.湖南省猪肝中七种微量元素的含量

1986～1988年,在湖南省有代表性的20个县(市)的屠宰场,采集了健康成年猪肝样品1040份,分析测定了Cu,Fe,Mn,Zn,Se,Co和Mo元素的含量。结果表明,上述7种微量元素的平均含量(干重)分别为:Cu13.59±2.45PPm;Fe1122.97±153.97ppm;Mn8.93±2.36ppm;Zn168.75±45.37ppm.Se0.62±0.57ppm;Co0.24±0.09ppm;Mo2.35±0.40ppm;除Fe以外,其余6种元素的平均含量各地区之间的差再均达极显著水平(p<0.01)。     

灭幼脲Ⅰ号胶悬剂对家禽安全性的试验

使用灭幼脲Ⅰ号防治森林害虫,必须考虑到它对家禽以至鸟类的影响。其试验方法是,将灭幼脲Ⅰ号混入家禽饲料中,每只鸡每日饲喂药量为每公斤体重1—2g,试鸡为成鸡,连续饲喂14—15天,通过体重、羽毛、冠色和产蛋等观察、检验,均无影响。对血清白蛋白、总蛋白、胆碱酯酶、谷丙转氨酶和血液葡萄糖等生理指标进行测定均无改变。由此可见,灭幼脲Ⅰ号在防治生产中,对家禽是安全的。     

The insensitive mechanism of poultry to zearalenone: A review

Zearalenone (ZEN) is one of the most common contaminating mycotoxins and is mainly produced by Fusarium graminearum. ZEN and its metabolites can interfere with estrogen function and affect animals' reproductive ability. Pigs are most susceptible to ZEN, and ZEN is less harmful to poultry than to pigs. The exact mechanism for the difference in susceptibility remains unclear. In this review, we summarized some possible reasons for the relative insensitivity of poultry to ZEN, such as the lower total amount of α-zearalenol (α-ZOL) and the α-ZOL-to-β-ZOL ratio which reduce the toxicity of ZEN to poultry. The faster hepatic and enteric circulation, and excretion capacity in poultry can excrete more ZEN and its metabolites. There are other possible factors such as the transformation of intestinal microorganisms, differences in hydroxysteroid dehydrogenases' activity, high estrogen levels, and low estrogen receptors affinity which can also cause poultry to be relatively insensitive to ZEN. In this review, we summarized the hazards, pollution status, metabolic pathways, and some measures to mitigate ZEN's harmfulness. Specifically, we discussed the possible mechanisms of low reproductive toxicity by ZEN in poultry.     

Line-scan hyperspectral imaging system for real-time inspection of poultry carcasses with fecal material and ingesta

In poultry processing plants, fecal material and ingesta are the primary source of carcass contamination with microbial pathogens. The current practice of the poultry inspection in the United States is primarily human visual observations. Since the visual inspection is becoming more challenging in poultry processing plants adopting high-speed lines, a rapid sorting system could significantly improve the detection and monitoring of carcasses with surface fecal material and ingesta. As a result, we developed a prototype line-scan hyperspectral imaging system configured as a real-time multispectral imaging subsystem for online detection of surface fecal material and ingesta. Specifically, we integrated a commercially available off-the-shelf hyperspectral image camera into the system with two line lights and a custom software program for real-time multispectral imaging. The bottleneck of the imaging system was the data acquisition. For that reason, a multithreaded software architecture was designed and implemented not only to meet the application requirements such as speed and detection accuracy, but also to be customizable to different imaging applications such as systemic disease detection in the future. The image acquisition and processing speed tests confirmed the system could operate to scan poultry carcasses in commercial poultry processing plants. The fecal detection algorithm was based on the previous research using different hyperspectral imaging systems. A new carcass detection and image formation algorithm was developed to allow existing image processing and detection algorithms reusable without any modifications. Sixteen chicken carcasses and four different types of fecal and ingesta samples were used in a study to test the imaging system at two different speeds (140 birds per minute and 180 birds per minute) in a pilot-scale poultry processing facility. The study found that the system could grab and process three waveband images of carcasses moving up to 180 birds per minute (a line-scan rate 286 Hz) and detect fecal material and ingesta on their surfaces. The detection accuracy of the system varied between 89% and 98% with minimum false positive errors (less than 1%), depending on tested detection algorithms. Therefore, these findings provide the basis of not only a commercially viable imaging platform for fecal detection but also a single poultry inspection system for multiple tasks such as systemic disease detection and quality sorting.     

高职《养禽与禽病防治》课程的教学形式改革

[目的]适应新时期高职《养禽与禽病防治》课程改革的需要。[方法]从理论知识、实践能力和素质培养着手,根据学科发展和人才培养的趋势,对该课程教学内容、教学形式及实践性教学环节进行探讨和研究。[结果]该课程教学形式改革提高了教学效果,调动了学生的学习积极性、主动性,提高了学生的学习兴趣和解决实际问题的能力。[结论]该课程改革获得了成功。     

Macronutrient concentration in plant parts of cotton fertilized with broiler litter in a marginal upland soil

Effectiveness of surface-applied unincorporated broiler litter as a fertilizer relative to conventional inorganic fertilizers under no-till or conventional-till cotton (Gossypium hirsutum L.) production systems in the upland soils of the southern and southeastern USA is not well documented. The objectives of this research were to (1) test if broiler litter improves plant macronutrient (N, P, K, and Mg) nutrition of cotton above that of cotton fertilized with conventional inorganic fertilizers and (2) determine if lack of incorporating litter into the soil reduces macronutrient concentration in cotton plant parts in an upland soil considered marginal for cotton. Six treatments consisting of an unfertilized control, a fertilized standard (STD), two litter-only, and two litter plus inorganic N as urea–ammonium nitrate solution (UAN) were tested in two adjacent fields, one under no-till (NT) and the other under conventional-till (CT) systems. Litter alone, UAN, or a combination of litter plus UAN were applied to supply 101 kg ha⁻¹ plant available N assuming nearly all of the UAN-N and 50% of the total litter N becomes plant available during the cotton growing season. Concentration of N, P, K, and Mg were measured in leaves, stems, and reproductive parts on three or four dates between early flowering and maturity. Cotton fertilized with the litter-only treatments always had less N concentration but greater P and K concentration in leaves, stems, and reproductive parts than cotton that received the STD treatment. Leaf and stem Mg concentration seems to depend on the N concentration in these plant parts. Lack of incorporating litter into the soil reduced N concentration in nearly all plant parts at all growth stages, suggesting some amount of the litter-derived N is lost due to lack of incorporation. Lack of incorporation also reduced leaf and stem Mg concentration, which seemed to be due to its reducing effect on N concentration. Unlike N and Mg, lack of incorporation did not consistently affect concentrations of P and K in all plant parts. Regardless of the incorporation treatment, fertilization with the litter-only treatments increased tissue P and K concentration and supported lint yield exceeding that of the STD without increasing tissue N concentration.     

Nitrous oxide emissions from a bermudagrass pasture: Interseeded winter rye and poultry litter

Adequate use of manure in grasslands may constitute an economical means of manure disposal and an abundant source of nutrients for plants; however, excessive nitrogen (N) additions to these soils could create new environmental risks such as increasing nitrous oxide (N₂O) emissions. These potentially adverse effects in grasslands may be mitigated by improved management practices. In pasture systems, the combined effects of poultry litter applications and interseeded rye (Secale cereale L.) on N₂O emissions are still not well established. This study was conducted to estimate the magnitude of soil surface N₂O fluxes as affected by interseeded winter rye forage, annually spring-applied composted turkey litter as well as by weather and soil parameters. Fluxes were measured by vented chambers during 2 yr in a bermudagrass (Cynodon dactylon [L.] Pers.) pasture in moderately well-drained Tonti gravelly silt loam (fine-loamy, active, mesic Typic Fragiudault) located in northwestern Arkansas, USA. During the 60 d following turkey litter applications, N₂O fluxes were frequently well correlated with soil nitrate (NO₃⁻; r: up to 0.82, P's < 0.05) implying substrate stimulation on soil N₂O production. Likewise, rainfall patterns strongly influenced N₂O fluxes. Large rainfalls of 91 and 32 mm occurred within 6 d prior to the maximum N₂O flux means (263 and 290 μg N m⁻² h⁻¹, respectively). Treatment effects on N₂O emissions were significant only in spring periods following manure addition, particularly in the second year of our study. In the spring of 2000, additions of composted turkey litter resulted in 1.5-fold increase in seasonal cumulative N₂O emissions (P = 0.04) which was directly associated to a numerically greater soil NO₃⁻. In the spring of 2001, soils planted to rye exhibited a pronounced significant effect on mitigating N₂O emissions (30 vs. 112 mg N m⁻²; P = 0.04). During the winter and early spring, rye growth also decreased quantities of both soil NO₃⁻ and water-filled pore space (WFPS) partly accounting for the lower N₂O emissions in these fields. These results suggest that because poultry litter additions increased and interseeded rye diminished N₂O emissions, the combined implementation of both management practices can produce environmental benefits while sustaining productivity in temperate pasture systems.