PCR方法鉴别肉骨粉中的动物成份种类

为防范疯牛病传入我国,有必要鉴别肉骨粉中动物成份的种类。针对牛、羊、猪和鸡四种动物的特异性核苷酸序列,分别选用和设计了四对特异性引物,用试剂盒提取四种动物的肉骨粉或者处理过的肉组织中的DNA,然后进行PCR扩增,所扩增的目的片断大小分别为271bp、199bp、196bp、148bp,运用PCR技术建立了鉴定这四种动物源性成分的方法。结果分别扩增出四种动物的特异性条带,证明该PCR方法具有很高的特异性和敏感性,而且成本低廉,简便易行,因此可以作为鉴别肉骨粉种类的常规方法。     

蓝山灰鹅生态之研究

对湖南省蓝山县的地方良种灰鹅进行了研究,测定了体重、体尺、体温、脉搏、呼吸次数、血液学参数、产蛋性能、屠宰率、羽绒产量等。经对该县不同生态环境中的灰鹅进行比较,发现山区灰鹅在体形外貌、成年体尺、体重、体温、脉搏、呼吸及血液学指数等方面与平原地区灰鹅没有明显差异,但生长发育较慢(P<0.05)、开产迟(p<0.05)、产蛋率低,但羽绒产量和孵化率皆显著高于平原地区(P<0.01和P<0.05),母鹅利用年限也较长(P<0.05)。     

用BLUE法评定猪繁殖性能的杂交效果

用BLUE法分析了青海省养猪繁育体系中母本互助猪,父本杜洛克、长白、汉普夏、大约克、巴克夏、苏白猪和二、三元杂交猪的繁殖效果。结果表明:不同品种和不同杂交组合的繁殖性状之间有明显差异(P<0.05或P<0.01);三元杂交组合的多数繁殖性状极显著的优于纯种亲本,显著优于二元杂交组合,而二元杂交组合也显著优于纯亲本;互助猪产仔数显著高于瘦肉型父本,而瘦肉型父本在改良仔猪生长发育方面则有明显优势。说明我省以三元杂交为主建立养猪繁育体系是适当的,但应注意提高互助猪早期生长发育性能,才能表现出更大的杂种优势。     

姜曲海母猪发情周期性腺激素及其子宫受体含量的变化规律

以长白猪为对照,测定了姜曲海母猪发情周期血浆中雌二醇和孕酮及其子宫受体含量。发现发情期血浆雌二醇的峰值为58.3±3.9pg/ml,与长白猪比差异不显著。间情期孕酮的最高水平和平均水平均比长白猪高(23.25±1.36对14.28±1.42ng/ml和18.56±1.42对11.76±0.57ng/ml,P<0.01)。发情期和间情期的细胞质雌二醇受体(CER)分别为 410±30.3和367±14.2fmol/mgDNA,其kd值分别为4.8±0.65和4.0±0.8nmol;细胞核雌二醇受体(NER)分别为1390±195.3和620±28.9fmol/mgDNA,其kd值为6.6±2.1和4.4±1.3nmol;细胞质孕酮受体(CPR)分别为364±56.0和147±46.0 fmol/mgDNA;细胞核孕酮受体(NPR)分别为337±51.8和184±67.0fmol/mgDNA。发情期和间情期子宫NER含量较长白猪高(P<0.05),说明此时姜曲海母猪子宫对雌二醇具有较高的敏感性。     

雏鸭病毒性肝炎弱毒疫苗的研究——Ⅰ.弱毒疫苗的培育及实验室试验

水试验通过将鸭肝炎病毒(DNV)在鸡胚传代,培育出雏鸭用鸭病毒性肝炎(DVH)弱毒疫苗——鸭病毒性肝炎81代鸡胚化弱毒疫苗(简称BAU-1),并对该苗进行了实验室试验。 试验表明,BAU-1对雏鸭安全无毒性,稳定性好,在敏感鸭体内连传5代无毒力返强现象。经测定,BAU-1的免疫剂量为5×10~(9·4)ELD50/只(皮下免疫)。通过对免疫雏鸭的血清抗体滴度进行测定,证实该BAU-1疫苗对雏鸭的免疫保护期在6周以上。     

Expression of Perilipin 2 (PLIN2) in Porcine Oocytes During Maturation

Perilipins have been reported to limit the interaction of lipases with neutral lipids within the droplets, thereby regulating neutral lipid accumulation and utilization. This study aimed to identify the location and expression of PLIN1 and PLIN2 in porcine oocytes during maturation. Quantitative real‐time polymerase chain reaction (qRT‐PCR), immunostaining and Western blot methods were used to characterize the expression and distribution patterns of PLIN1 and PLIN2 in porcine oocytes. The results showed that PLIN1 was not detectable in porcine oocytes. PLIN2 and BODIPY 493/503‐detected neutral lipid droplets appeared identical distribution patterns and extensive colocalization in both GV and MII porcine oocytes. PLIN2 protein expression was higher in GV oocytes than that in MII oocytes (p < 0.05), although PLIN2 mRNA expression was similar in both groups. These findings suggested that PLIN2 was a major lipid droplet‐associated protein in porcine oocytes.     

A gene expression estimator of intramuscular fat percentage for use in both cattle and sheep

Background

The expression of genes encoding proteins involved in triacyglyceride and fatty acid synthesis and storage in cattle muscle are correlated with intramuscular fat (IMF)%. Are the same genes also correlated with IMF% in sheep muscle, and can the same set of genes be used to estimate IMF% in both species?

Results

The correlation between gene expression (microarray) and IMF% in the longissimus muscle (LM) of twenty sheep was calculated. An integrated analysis of this dataset with an equivalent cattle correlation dataset and a cattle differential expression dataset was undertaken. A total of 30 genes were identified to be strongly correlated with IMF% in both cattle and sheep. The overlap of genes was highly significant, 8 of the 13 genes in the TAG gene set and 8 of the 13 genes in the FA gene set were in the top 100 and 500 genes respectively most correlated with IMF% in sheep, P-value = 0. Of the 30 genes, CIDEA, THRSP, ACSM1, DGAT2 and FABP4 had the highest average rank in both species. Using the data from two small groups of Brahman cattle (control and Hormone growth promotant-treated [known to decrease IMF% in muscle]) and 22 animals in total, the utility of a direct measure and different estimators of IMF% (ultrasound and gene expression) to differentiate between the two groups were examined. Directly measured IMF% and IMF% estimated from ultrasound scanning could not discriminate between the two groups. However, using gene expression to estimate IMF% discriminated between the two groups. Increasing the number of genes used to estimate IMF% from one to five significantly increased the discrimination power; but increasing the number of genes to 15 resulted in little further improvement.

Conclusion

We have demonstrated the utility of a comparative approach to identify robust estimators of IMF% in the LM in cattle and sheep. We have also demonstrated a number of approaches (potentially applicable to much smaller groups of animals than conventional methods) to using gene expression to rank animals for IMF% within a single farm/treatment, or to estimate differences in IMF% between two farms/treatments.     

Effects of linseed oil and palm oil on growth performance,tibia fatty acid and biomarkers of bone metabolism in broilers

1. This study was conducted to determine the effects of different dietary fat sources on growth performance, tibia fatty acids and biomarkers of bone metabolism in broilers.

2. One-d-old commercial Arbor Acres broilers were fed with a maize–soya bean basal diet for 42 d, supplemented with oils according to the following 5 treatments: lard (lard group); linseed oil (linseed oil group); palm oil (palm oil group); linseed oil + palm oil (60:40 or 40:60 w/w, LP-1 group and LP-2 group, respectively).

3. No significant differences in weight gain, feed intake and gain/feed ratio were observed between the lard and linseed oil groups. Birds fed on palm oil had significantly greater weight gain and feed intake than those fed on lard or linseed oil. Growth performance in LP-1 and LP-2 was significantly greater than that of single-oil groups.

4. Tibia growth and bone characteristics were not influenced by supplementation with lard, linseed oil, or palm oil alone, but broilers fed on a mixture of fats had significantly greater tibia weight and length compared to broilers fed on linseed oil. Bone mineral density in tibia was significantly increased in LP-1 and LP-2 groups.

5. Supplementation of linseed oil alone or in combination with palm oil enhanced apparent digestibility of calcium, reduced serum calcium and increased tibia calcium concentrations. Moreover, supplementation with linseed oil alone or in combination with palm oil had a positive effect on biomarkers of bone growth.

6. The combination of linseed and palm oils was beneficial for growth performance, tibia growth and biomarkers of bone metabolism.     

Dietary copper supplementation improves pelt characteristics of female silver fox (Vulpes fulva) during the winter fur‐growing season

Copper has an essential role in normal fur pigmentation and fur quality. This study evaluated the effects of cupric citrate (CuCit) supplementation on growth, nutrients metabolism and pelt characteristics of the female silver fox (Vulpes fulva). Fifty age‐matched female silver foxes with similar body weights were randomly divided into five dietary groups for 58 days during the winter fur‐growing season. The basal diet contained 4.92 mg/kg copper. Groups I‐V were supplemented with 6, 30, 60, 90 or 150 mg Cu from CuCit per 1 kg dry matter basal diet. Serum alkaline phosphatase activity was significantly higher (P < 0.05) in those fed 90 mg/kg Cu than those fed 150 mg/kg Cu. Pelt total thickness was significantly higher (P < 0.05) in those fed 30 mg/kg Cu than foxes fed 6 mg/kg Cu supplemented diet, but were similar to the other groups. Length of guard hair was significantly lower (P < 0.05) in those fed 90 mg/kg Cu than fed 6 mg/kg Cu and 30 mg/kg Cu, but were similar to the other groups. Length of underhair was significantly higher (P < 0.05) in those fed 6 mg/kg Cu than those fed 90 mg/kg Cu, but was similar to the other groups. Considering decreasing environmental contamination and improving pelt performance, supplementing 30 mg/kg Cu from CuCit (actual copper 35 mg/kg dry matter) is appropriate for female silver fox.