The suitability of some blood gas and biochemical parameters as diagnostic tools or early indicators of ascites syndrome in broiler sire lines

In recent few years, there have been some attempts to find a reliable indicator trait as a selection criterion against susceptibility to ascites syndrome (AS). Blood parameters were of great interest as they could be measured in live animals without implementing an ascites‐inducing challenge (AIC). In this work, the suitability of some blood parameters was evaluated for diagnosing AS‐susceptible chicks in later steps of the disease in trial 1 as well as their early predictive ability in trial 2. In the first trial, one hundred 1‐day‐old chicks from two pure broiler lines namely S₁ and S₂ and, in the second trial, 226 1‐day‐old chicks from line S₂ were subjected to AIC. Saline drinking water (1200 mg/l) and lower‐than‐standard ambient temperatures were the implemented AICs in trials 1 and 2 respectively. The blood parameters including pH, partial pressure of O₂ (pO₂), partial pressure of CO₂ (pCO₂), bicarbonate ion concentration (BIC), percentage of haematocrit (HCT) and saturated haemoglobin (SaO₂) were measured twice per each bird at days 28 and 35 in trial 1 and once in trial 2 at day 21. The results of the first trial revealed that in line S₂ some of the blood parameters differed significantly between the ascitic and non‐ascitic groups following exposure to AIC. In this line, the incidence of AS was accompanied by a lower pO₂, SaO₂ and BIC, while with higher pCO₂ and HCT values. In the second trial, however, although almost all of the parameters showed meaningful differences between the ascitic and non‐ascitic broilers, only mean difference of BIC parameter was statistically significant. The general conclusion of this study is that the blood parameters can somewhat have diagnostic ability in the condition in which the AIC is already present, whereas the results did not approve their usefulness as early predictors of AS.     

Structure and diversification of the bovine immunoglobulin repertoire

Our understanding of the basis to immunoglobulin formation in cattle has benefited substantially from the application of molecular biology over the past decade. It is now established that both the lambda light chain and heavy chain repertoires are founded upon the frequent expression of single gene families and subgroups of segments which are of conserved sequence. It is likely that a functional kappa locus exists in the bovine genome but this isotype comprises as few as 5% of bovine light chains. Similarly, alternative but non-expressed V(H) gene families are present posing intriguing but unresolved questions about the regulation of immunoglobulin synthesis. The heavy chain frequently bears a third complementarity-determining region which is atypically long but the processes which expand this region of the reading frame and its contribution to the interaction with antigen remain matters of speculation. Opportunities exist to map the major immunoglobulin loci and to define the membership and sequence diversity of the gene families which dominate each repertoire. However, it is already evident that cattle cannot generate significant diversity from rearrangement and junctional imprecision alone. Elucidation of the mechanism(s), dynamics and tissue distribution of immunoglobulin diversification in cattle, thus, remain key challenges in this branch of veterinary immunology.     

若干家蚕品种的复壮及比较试验

对浙江省夏秋蚕品种薪杭，白云，丰1和54A等进行了充血复壮改良，基本稳定后的复壮系与现行生产系进行了生产性能的比较试验。结果表明复壮系在各项性状都有一定的提高，其中龄期经过，各品种的复壮系与生产系之间差别不大，只有薪杭丙和白云丙稍有延长。全茧量和茧层量基本上复壮系都比生产系有所提高。生命率差异比较大，奠中薪杭的复壮系低下生产系，差异达到显著水平，白云复壮系略微低于白云甲，但高于白云乙，丰1的复壮系与生产系无明显差异，54A则是复壮系高于生产系。良卵数除薪杭丙比薪杭甲略低外，其他品种的复壮系都比生产系显著提高，有的甚至达到极显著水平。说明复壮系在生产性能上有较大的改良，有一定的推广应用价值。     

蚕品种选育多用途化发展趋势

为了满足蚕桑生产发展多元化和提升改造传统蚕桑业发展需要开展的特殊用途蚕品种选育进展迅速,本文就以蚕丝生产为目的如雄蚕品种、细纤度蚕品种、粗纤度蚕品种、人工饲料育品种及广食性蚕品种、天然彩色茧蚕品种等的选育,以及非蚕丝生产为目的如吐平面丝蚕品种、吐丝胶茧蚕品种、生物反应器专用蚕品种、药食专用蚕品种等育种研究进展进行概述.     

二甲基甲酰胺对家蚕毒性试验

二甲基甲酰胺对家蚕的毒性较低，只有在很高的浓度食下时才表现出急性中毒死亡，并且随着龄期的增加，家蚕的耐毒性增加，3龄蚕比2龄蚕有更强的耐毒性。低浓度的二甲基甲酰胺（DMF）对家蚕生命率和经济性状都没有显著影响。DMF对家蚕的毒性有积累作用，3龄期连续添毒稀释10倍的DMF原液24h没有观察到急性中毒死亡，但连续添毒90h后，可最终导致家蚕中毒死亡。     

Liver biopsy techniques for adult horses and neonatal foals to assess copper status

Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares.     

Blooming phenology and self-incompatibility of some commercial cherry (Prunus avium L.) cultivars in Iran

Self-sterility in cherry (Prunus avium L.) is one of the most important problems in commercial cherry orchards in Iran and many other countries. The main objective of this research was to determine self-fertility rate and blooming phenology of 25 commercial cherry (P. avium L.) cultivars in Iran. This study was conducted during 2006–2007.Results revealed that the stage of bud swell in all cultivars began late second decade of March, which lasts 8–11 days. In all cultivars the duration end bloom to petal fall stage took 5 days. Cherry cultivars were classified into three groups considering their overlapping pollination. The cultivars each group had a great overlapped pollination toward each other. The results also showed that there was a significant difference among cultivars in respect of the fruit set (P < 1%). The fruit set of open pollination treatment among the cultivars varied in range of 7.36–41.58%. However fruit set was not observed in isolated pollination (artificial and natural self-pollination). In open pollination, the cultivars were also classified into four groups, i.e. weak fertility (Moreau and Ferracida), mean fertility (Siah Mashhad, Napelon, Proteva, Haj usefy, Lambert, Roshun, Sefid Ghermeze Baghno, Arak, Belamarka, Siah Shabestar, Ghermeze Rezaeyeh, Abardeh, Soraty Lavisan and Victoria), good fertility (Peshrase Mashhad, Dovoumras Mashhad, Bing, Shesheiy Mashhad, Siah Ghazvin and Sefid Rezaeyeh), very good fertility (Zarde Daneshkadeh, Dirrase Italia and No. 1 karaj). All cultivars were found to need cross-pollination and included in self-sterile group.     

Effect of high-dose phytase and citric acid,alone or in combination,on growth performance of broilers given diets severely limited in available phosphorus

1. Two trials were conducted to evaluate the effect of high-dose phytase alone or in combination with citric acid (CA) in the diet severely limited in available phosphorus (P) on performance, plasma P and plasma Ca of broilers from 22 to 42 d of age.

2. In Trial 1, 297 21-d-old female chicks were placed into 27 pens and allocated to 9 maize-soybean meal-based dietary treatments, which were a positive control [PC, 4.23 g/kg non-phytate P (NPP)] and 8 negative control (NC, 1.35 g/kg NPP) groups consisting of two concentrations of CA (0 and 20 g/kg) and 4 concentrations of phytase (0, 1000, 2000 and 4000 U/kg) in a 2 × 4 factorial arrangement. In Trial 2, 192 21-d-old male chicks were placed into 24 pens and allocated to 6 wheat-canola meal-based dietary treatments, which were a PC (4.2 g/kg NPP), a NC (1.68 g/kg NPP) and 4 NC groups consisting of two concentrations of CA (0 and 20 g/kg) and two concentrations of phytase (2000 and 4000 U/kg) in a 2 × 2 factorial arrangement.

3. In both trials, birds fed on the PC had significantly higher average daily gain (ADG), average daily feed intake (ADFI), plasma P and lower feed conversion ratio (FCR) and plasma Ca than those of birds fed on the NC. CA supplementation significantly increased ADG and ADFI. There was a significant interaction between CA and phytase on plasma P where CA improved the effect of phytase on plasma P. In Trial 1, phytase addition improved ADG, ADFI, FCR and plasma Ca linearly.

4. Briefly, this research showed the interaction effect between CA and phytase on plasma P when broilers were fed on diets based on maize-soybean meal or wheat-canola meal. The results showed that CA supplementation lowered the concentration of phytase that is needed in low NPP diets to increase plasma P.     

Herbaceous species diversity in relation to fire severity in Zagros oak forests,Iran

Zagros forests are mainly covered byQuercus brantii L. coppices and oak sprout clumps occupy the forest area like patches. We investigated post-fire herbaceous diversity in the first growing season after fire. For this purpose neighboring burned and unburned areas were selected with the same plant species and ecological conditions. The data were collected from areas subjected to different fire severities. Overall 6 treatments were considered with respect to fire severity and the mi-crosites of inside and outside of oak sprout clumps including： unburned inside and outside of sprout clumps （Ni and No）, inside of sprout clumps that burned with high fire severity （H）, inside of sprout clumps that burned with moderate fire severity （M）, outside of sprout clumps that burned with low fire severity （OH and OM）. Different herbaceous com-position was observed in the unburned inside and outside of oak sprout clumps. The species diversity and richness were increased in treatments burned with low and moderate fire severity. However, in treatment burned with high fire severity （H）, herbaceous cover was reduced, even-ness was increased, and richness and diversity were not significantly changed. We concluded that besides the microsites conditions in forest, fire severity is an inseparable part of the ecological effect of fire on her-baceous composition.