感染IBDV雏鸡血液激素水平和ANAE阳性淋巴细胞动态变化

为探讨内分泌活动及细胞免疫反应在鸡抗传染性法氏囊病毒（ＩＢＤＶ）感染中的调节作用机制而进行了本研究。结果表明,攻毒后１～５ｄ内,未免疫攻毒鸡（Ａ组）、免疫攻毒鸡（Ｂ组）血浆皮质酮均明显上升,而未免疫未攻毒鸡（Ｃ组）则否。Ａ、Ｂ、Ｃ３组血浆Ｔ４水平攻毒前后无明显变化,Ｔ３除在攻毒后第３天Ａ组明显高于Ｂ、Ｃ组外,其他时间无明显差异性变化。血液ＡＮＡＥ阳性淋巴细胞（％）在攻毒后的１～５ｄ内,Ａ组和Ｂ组明显下降,以后回升,至２８ｄ回复到攻毒前水平,并接近于Ｃ组。Ａ组的ＡＮＡＥ阳性淋巴细胞（％）与皮质酮呈显著负相关,与Ｔ３和Ｔ４无明显相关性。     

鸡阿奇霉素中毒的病理学和血液生物化学研究

以大发乌骨鸡为研究对象,用1/5LD50固定剂量连续染毒,进行阿奇霉素的蓄积毒性实验.试验结果显示阿奇霉素的蓄积系数为2.79,蓄积作用分级为明显蓄积.中毒雏鸡临床症状表现为精神萎靡,呼吸困难,食欲减退.尸体剖检主要见肝脏肿大,呈黄色,胆囊肿大,胆汁淤滞;肠系膜点状出血.组织学变化以肝脏、肾脏、肠黏膜等组织器官的实质性细胞变性甚至坏死为特征.血液学变化主要是血清总蛋白、白蛋白含量和A/G值降低;球蛋白含量、总胆固醇含量、丙氨酸氨基转移酶活性、天门冬氨酸氨基转移酶活性、乳酸脱氢酶活性、碱性磷酸酶活性以及血糖含量增高.     

新扬州鸡IGF-1基因5′调控区PstI位点多态性与繁殖性状关系的研究

采用PCR-RFLP技术,对207只新扬州鸡的胰岛素样生长因子-1(IGF-1)基因的5'端调控区进行遗传多态性研究,发现该调控区的扩增产物经PstI酶切后出现AA、AB和BB3种基因型。χ2检验的结果表明:新扬州鸡在IGF-1基因PstI位点上均处于Hardy-Weinberg平衡状态(P>0.05)。分析基因型与产蛋性状的关系时,发现基因型对新扬州鸡开产蛋重、第30周和40周蛋重以及40周产蛋量有显著影响(P<0.05),而对新扬州鸡30、40、50和60周产蛋数、开产体重、开产日龄、开产胸骨长、开产胫长和蛋壳重影响不显著(P>0.05)。在所研究的指标中,新扬州鸡的BB基因型效应均大于AB和AA基因型。     

典型作物Logistic模型生长参数空间分布及其地区水热相关性

为明确作物生长模型——Logistic模型参数的空间变异特征,本文以冬小麦、夏玉米、水稻和新疆棉花作为典型作物,以作物株高、叶面积指数和干物质积累量作为生长指标,研究各生长指标的全相对化Logistic模型参数的空间分布情况,进一步分析该模型参数与地区多年平均降雨量、多年平均活动积温的相关关系.结果表明,4种典型作物全...     

Retrospective and prospective studies of transmissible viral proventriculitis in broiler chickens in Brazil

We investigated the occurrence and pathologic findings of transmissible viral proventriculitis (TVP) associated with the chicken proventricular necrosis virus (CPNV) in commercial broiler chickens in southeastern Brazil. Seventy-three broilers, 25–36 d old, with a history of reduced growth, were referred to our veterinary pathology services from 2013 to 2017. Broilers were clinically examined, weighed, and euthanized for postmortem examination. Broilers of different ages with proventricular histologic lesions were positive for CPNV by RT-PCR; however, the intensity of histologic lesions was higher among 33-d-old animals, and viral RNA detection was more frequent among those that were 28 d old. In the proventriculi of 35 of 73 (48%) broilers, lesions were characterized by glandular epithelial necrosis, lymphoplasmacytic and histiocytic infiltrates, and metaplasia of glandular epithelium to ductal epithelium. In 24 of 73 (36%) broilers with histologic TVP-compatible lesions, CPNV was detected by RT-PCR for the viral protein 1 (VP1) gene. Broilers with histologic lesions were lighter than expected compared to the Cobb 500 standard weight. TVP has not been reported previously in broiler chickens in Brazil, to our knowledge.     

Age-related intestinal monosaccharides transporters expression and villus surface area increase in broiler and layer chickens

In the chicken small intestine, glucose is mainly transported by the apically located sodium/glucose cotransporter 1 (SGLT1) and the basolaterally located glucose transporter 2 (GLUT2). Fructose is transported by the apically located glucose transporter 5 (GLUT5) and similarly by GLUT2. During the early post-hatching period, the intestinal villus surface area (VSA) should be considered as an important factor related to the monosaccharide absorption capacity. Our objective here was to study intestinal monosaccharide absorption by analyzing the effects of age, diet, and breed on monosaccharide transporters and the VSA. The mRNA expression patterns of SGLT1, GLUT2 and GLUT5 genes in broiler and layer chickens were measured from the day of hatching to day 28 using the absolute quantitative real-time PCR. Both the intestinal mRNA expression levels of these genes and the VSA were affected by age. The mRNA expression levels of SGLT1 and GLUT2 were significantly increased from day 1 to day 3 and then decreased from day 3 to day 28. The expression levels of GLUT5 decreased from day 1 to day 7. The broiler chickens VSAs were significantly larger than those of the layer chickens from days 7 to 28. The effect of diet on the gene expression patterns of these monosaccharide transporters and the VSA were not significant. Our results suggest that the expression levels of these monosaccharide transporters are increased rapidly at the beginning of intestinal growth to meet the demands for monosaccharides to support the fast growth of the chick before day 7. As intestinal maturation and VSA increased, the expression levels of these monosaccharide genes decreased to a certain expression level to maintain the intestinal transport capacity and the absorption balance of all other nutrients.     

Changes in tissue free amino acid pools in growing chickens fed thermally treated vetch diets

A three‐day assay was developed to evaluate the effect of autoclaving on protein quality of vetch as an alternative to classical growth methods. Male chickens (n = 10/diet) were given approximately isonitrogenous diets based on raw or autoclaved vetch for 3 days. Samples of plasma, muscle and liver were obtained for free amino acid analysis. Heating vetch depressed growth (11.9 vs. 23.2 g/d; p < 0.05). Plasma methionine and histidine increased (0.05 < p < 0.06), while gluconeogenic amino acids tended to decrease (p < 0.10) after heating. Muscle free amino acids did not change except for a trend to increased methionine (p = 0.06) in birds fed autoclaved vetch. In liver, most essential amino acids, glycine, proline and tyrosine increased markedly with heated vetch diet. Correlations between plasma and muscle free amino acids were poor compared with those between plasma and liver free amino acids. Liver free amino acid pool was more sensitive than muscle or plasma pool to amino acid inflow modifications after vetch heating.     

Efficacy of a Litter Amendment to Reduce Pododermatitis in Broiler Chickens

Broiler house environment, especially volatile NH₃ content, has a significant effect on pododermatitis in chickens. The efficacy of NaHSO₄ in reducing pododermatitis in broiler chickens was investigated in this study. A total of 960 straight-run 1-d-old chicks were randomly assigned to 16 environmental chambers with 4 different levels of NaHSO₄ (4 chambers/treatment). The treatments (TRT) comprised of TRT 1 (control), TRT 2 with NaHSO₄ applied at 1 × rate (0.22 kg/m²) on the day of placement of chicks, TRT 3 with NaHSO₄ applied at 2 × rate on the day of placement of chicks, and TRT 4 with NaHSO₄ applied at 1 × rate on the day of placement of chicks and at 1 × rate on 21 d. Birds were raised to 49 d of age on a 4-stage feeding program with diets formulated to contain high protein levels and all-vegetable ingredients. At 35 d of age, the litter was moistened artificially to see the effect of NaHSO₄ on NH₃ volatilization. In addition to assessing live performance, feet were scored on 42 and 49 d of age for incidence and severity of pododermatitis. Ammonia concentration (ppm) in the chambers was measured before placement of chicks and on a weekly basis throughout the experiment. No differences in live performance of the birds were observed throughout the study (P > 0.05). Sex had significant effects on incidence of pododermatitis (P < 0.05), with females showing higher incidence of pododermatitis than males. The NaHSO₄ had a significant effect on NH₃ volatilization in the chambers (P < 0.05). Ammonia concentration was significantly reduced in all TRT except the control (TRT 1). Sodium bisulfate had no significant effect on NH₃ levels after 35 d upon addition of moisture to the litter. Although not significant (P > 0.05), using NaHSO₄ as a litter amendment numerically reduced the incidence of pododermatitis by 10 or more percentage points.     

鸡胚胎干细胞单细胞克隆制备方法的比较

提取鸡X期胚盘细胞,体外培养传至第3代,采用口吸管法、细胞稀释法及克隆环法将细胞集落分离成单个细胞,并将其接种至96孔板上,每孔1个细胞,采用细胞化学法和免疫荧光法检测细胞表面标志物,探讨鸡胚胎干细胞单细胞克隆制备的实际操作的可行性,并对其生物学特性进行鉴定.结果表明:口吸管法、克隆环法、细胞稀释法克隆率分别为0、1.0%、4.2%.3种方法相比较,细胞稀释法具有操作简单易行、实验时间短、对细胞伤害小等优点,经碱性磷酸酶活性和阶段特异性表面抗原1免疫荧光鉴定均呈阳性,扩增出的克隆能稳定增殖且不分化.     

Fulvic acid displaces manure to improve soil in vegetable greenhouse

Acid soil has led to a significant decrease in vegetable yield in high-yield greenhouse vegetable production system. Chicken manure and fulvic acid (FA) application experiment was conducted to evaluate the effects on chemical properties of soil in vegetable greenhouse so as to confirm whether FA could replace chicken manure in acid soil amelioration under the same addition levels of nutrient, when compared to the effect of chemical fertilizers application alone on acid soil improvement. The results showed that the pH of soil added with chicken manure and FA, respectively, increased from the original value of 5.4 to 5.99 and 6.32 at the end of the experiment, while soil pH applied only with chemical fertilizers decreased to 5.43. Correlation analysis indicated that cation exchange capacity (CEC) of soil was positively correlated with soil pH buffering capacity. The peak values of soil CEC and pH buffering capacity occurred in April each year and subsequently tended to decrease in August and December throughout the experiment. Data demonstrated that chicken manure and FA in combination with soil contributed to soil base saturation that increased from 26.5%, 33.8% to 36.7%, 45.9% in chicken manure and FA treated soil during December 2011 to December 2012, respectively; however, chemical fertilizers displayed an adverse effect on soil base saturation that decreased from 17.1% to 5.6% on the same time period. Exchangeable aluminum (Al) concentration showed a weak but significant increase by 5.2% on August 2012 in comparison to April 2012, as chemical fertilizers were added into soil alone. Unlike to chemical fertilizer, chicken manure and FA significantly decreased soil exchangeable Al concentration from the original value of 5.37 cmol kg^?1 to 4.56 and 4.22 cmol kg^?1 at the end of experiment respectively. Compared to total yield treated solely with chemical fertilizers, chemical fertilizers combination with chicken manure or FA resulted in an increase in total yield in 2011 and 2012. Although chicken manure and FA possessed the same trend of improving acidic soil in vegetable greenhouse, a greater contribution was attributed to FA due to its lower mineralization rate of organic matter. Therefore, it was suggested that FA could completely displace chicken manure in improvement in acidic soil in vegetable greenhouse.