昆明翠湖越冬红嘴鸥数量变化及投食量调查分析

昆明翠湖公园是红嘴鸥进城越冬数量最集中的地方,其数量分布在昆明水域内具有一定的代表性,翠湖公园是红嘴鸥的主要投食点,每年冬季,有大量市民和游客前来观鸥、喂鸥、护鸥。每年11月至次年3月翠湖公园的红嘴鸥数量存在规律性的变化,游客每天投放多少饲料量,要结合红嘴鸥的日食量和数量,受节假日的影响,游客数量变动大,投食量依赖于游客数量,经常出现喂鸥过量或不足的情况,翠湖水体补给有限,过量投食会带来富营养化污染,投食不足则不利于红嘴鸥的保护。通过对2009年11月至2010年3月期间昆明翠湖越冬红嘴鸥的数量进行分期统计,得出2010年翠湖越冬红嘴鸥前、中、后期的数量变化,参照红嘴鸥的能量代谢标准,分析计算昆明翠湖红嘴鸥饲料的合理投放量,为科学喂鸥提供依据,便于红嘴鸥和翠湖水体的保护。     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

Determination of biogenic amines in aerobically stored beef using high-performance thin-layer chromatography densitometry

The aim of this study was to develop a high-performance thin-layer chromatography densitometry method to simultaneously evaluate levels of different biogenic amines (BAs) in beef stored aerobically at 4°C. Steaks from M. longissimus thoracis et lumborum muscles were overwrapped with polyvinyl chloride film and stored for 0, 4, 7, and 10 days. For this purpose, the solvent system and pH for the derivatization of BAs with dansyl chloride were optimized. Moreover, this method was also validated for linearity, limits of detection and quantification, precision, and recovery. As found using this method in beef samples, spermine content decreased significantly after 7 days of storage, and tyramine and cadaverine were not detected until day 10.     

Surveillance of Parapoxvirus Among Ruminants in Virginia and Connecticut

In 2008, two deer hunters in Virginia and Connecticut were infected with a unique strain of pseudocowpox virus, a parapoxvirus. To estimate the prevalence of this virus, and in an attempt to define the reservoir, Parapoxvirus surveillance was undertaken between November 2009 and January 2010. 125 samples from four ruminant species (cows, goat, sheep and white‐tailed deer) were collected in Virginia, and nine samples from white‐tailed deer were collected in Connecticut. We found no evidence that the parapoxvirus species that infected the deer hunters is circulating among domesticated ruminants or white‐tailed deer. However, parapoxvirus DNA of a different parapoxvirus species, bovine papular stomatitis virus (BPSV), was detected in 31 samples obtained from asymptomatic cattle in Virginia. Parapoxvirus DNA–positive cattle originated from the same counties indicating probable transmission among animals. Molecular analysis identified BPSV as the parapoxvirus affecting animals. Asymptomatic parapoxvirus infections in livestock, particularly young animals, may be common, and further investigation will inform our knowledge of virus transmission.     

柞蚕饲料转化效率的遗传模型与基因效应值的估算

利用2对柞蚕杂交组合8821×四青、8822×青6号的6个世代材料,对柞蚕茧重转化率和茧层生产率两个数量性状进行了遗传分析,结果表明:茧重转化率的基因作用复杂,不符合加-显性遗传模型,存在着基因互作,且显性互作大于显性效应,使茧重转化率增加;茧层生产率的基因作用符合简单的加-显性遗传模型,显性效应为正值,使茧层生产率增加。     

益生菌发酵饲料对猪的生长和肉质的影响

应用益生菌发酵饲料喂猪,能提高饲料中粗蛋白含量,明显降低猪粪臭味,促进生长、降低料肉比和提高猪肉品质。     

Pyruvate kinase is necessary for Brucella abortus full virulence in BALB/c mouse

Brucellosis, caused by a facultative intracellular pathogen Brucella, is one of the most prevalent zoonosis worldwide. Host infection relies on several uncanonical virulence factors. A recent research hotpot is the links between carbon metabolism and bacterial virulence. In this study, we found that a carbon metabolism-related pyruvate kinase (Pyk) encoded by pyk gene (locus tag BAB_RS24320) was associated with Brucella virulence. Determination of bacterial growth curves and resistance to environmental stress factors showed that Pyk plays an important role in B. abortus growth, especially under the conditions of nutrition deprivation, and resistance to oxidative stress. Additionally, cell infection assay showed that Pyk is necessary for B. abortus survival and evading fusion with lysosomes within RAW264.7 cells. Moreover, animal experiments exhibited that the Pyk deletion significantly reduced B. abortus virulence in a mouse infection model. Our results elucidated the role of the Pyk in B. abortus virulence and provided information for further investigation of Brucella virulence associated carbon metabolism.     

打击"两抢一盗"犯罪的特殊专业队

在深入开展打击“两抢一盗”犯罪专项斗争中,四川省乐山市活跃着一支鲜为人知的特殊专业队伍——乐山市公安局警犬队。据不完全统计,2005年1～11月,该队共直接和协助破获各类刑事案件22起,抓获犯罪嫌疑人16名,充分发挥了警犬在预防和打击犯罪中的特殊作用。     

统一着装

~~统一着装$第二炮兵军犬训练队@李保华 $第二炮兵军犬训练队@张春新~~     

Changes in growth performance, digestive enzyme activities and nutrient digestibility of cherry valley ducks in response to aflatoxin B1 levels

The objective of this study was to investigate toxic effects of aflatoxin B1(AFB₁) on growth performance, organs, hepatic enzyme activities, apparent digestibility of nutrients and digestive enzyme activities in ducks. Ninety 1-day-old Cherry Valley commercial ducks were designed to three treatment groups with three replicates of ten birds each. Group I (control) was fed conventional feed free of AFB₁, group II or III was fed the diets containing 20 μg/kg or 40 μg/kg AFB₁-contaminated rice respectively. The feeding trial lasted 6 weeks. The results were that decreased body weight gain and feed intake, increased feed to gain ratio and selected organ weights (liver, kidney and pancreas) were observed in AFB₁-treated groups. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in AFB₁-contamined groups. The apparent digestibility of crude protein (CP) was significantly lower while activities of digestive enzyme from duodenum contents including protease, chymotrypsin, trypsin and amylase were increased in AFB₁-treated group. These results indicated that AFB₁ of feed could decrease growth performance and apparent digestibility of nutrients, change digestive enzyme activities of duodenum contents in duck.