Effect of lordosis on the swimming performance of juvenile sea bass (Dicentrarchus labrax L.)

The critical swimming speed (U_crit, cm s⁻¹) value of normal juvenile sea bass (Dicentrarchus labrax) (64.7±6.33) was significantly higher than that of fish with lordosis (60.3±6.66) (P<0.05). Both normal fish and those with lordosis showed increased endurance with increasing length during exercise at a fixed water velocity of 50 cm s⁻¹. This speed was used to investigate the separation possibility of deformed specimen from the normal developed fish based on their swimming performance, and 28% separation was achieved without losing any normal fish by the end of the 10th minute. To achieve a better separation of the deformities from the normal, first grading of the juveniles and then a swimming endurance test is advised.     

Effect of the daily meal time on the growth of rainbow trout fed different ration levels

This study examined the effect of ration level and time of delivery of a single daily meal on the growth performance of rainbow trout held under constant water temperature and a natural photoperiod. Two similar trials were conducted, the first from March to July, 1992, using ration levels of 0.5, 1.5 and 2.5% BW d^–1 and the second from August 1992 to January 1993, using ration levels of 1.5, 2.0 and 2.5% BW d^–1.In five of the six treatment groups (three ration levels × two seasons), when the daily meal was presented in the post-dawn period the growth rate was lower than in trout fed at either mid-light or pre-dusk. No time-of-feeding effect was found when trout were fed excess rations. Specific growth rate (SGR) was not affected by feeding time, but was correlated with ration level; furthermore, there was a significant increase in SGR during the first section of the first trial and a significant decrease in the SGR throughout the duration of the second trial.Ration level was significantly correlated with condition factor, carcass visceral adipose tissue content and skeletal muscle lipid content, but there was no effect of the timing of the daily meal on these variables.     

Influence of all-trans retinoic acid on pigmentation and skeletal formation in larval Japanese flounder

ABSTRACT: The effect of all- trans retinoic acid (atRA) on pigmentation and skeletal formation of Japanese flounder Paralichthys olivaceus was investigated. Five groups of flounder larvae were fed live food enriched with 0.5 mL docosahexaenoic acid (DHA) 38G oil containing 10 mg of atRA/10 L of culture medium during different developmental stages; that is, A–B, C–D, E–F, G–H, and I. The control group was fed live food enriched with only DHA 38G oil. Flounder that were fed live food enriched with atRA during the A–B stages showed albinism, and mandible and severe caudal defects (albinism 75.7%, lower jaw defects 75%, caudal defects 100%). Occurrence of these abnormalities in other groups was 0%, 1–4%, and 4.5–10.7%, respectively. Administration of atRA during the A–B stages also caused a high number of vertebrae mainly in the caudal area. Moreover, additional abdominal vertebrae had formed in 25% of fish that were fed live food enriched with atRA in the A–B stages. These results indicate that the effect of atRA is dependent on the developmental stage of flounder larvae and they also suggest that morphological and color abnormalities in flounder were induced by atRA accumulated in live food (rotifers 13 mg/g; Artemia 1.6 mg/g), especially during the A–B stages.     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Maternal l-arginine supplementation during early gestation affects foetal skeletal myogenesis in pigs

To study the impact of maternal l-arginine supplementation during early gestation on skeletal muscle formation in the offspring, gilts were fed 3 kg of a standard diet (control group, n=10) or standard diet and additionally 26 g/d l-arginine from d 14 to 28 of gestation (arginine group, n=10). The gilts were sacrificed at d 75 of gestation. From each litter the lightest, the heaviest, and one medium-weight foetus per sex were selected and three different muscle samples were collected. In the longissimus dorsi muscle of all foetuses (n=99) biochemical properties were assessed. In the same muscle of a subset of the lightest and heaviest female foetuses (n=28), mRNA expression of selected genes involved in myogenesis were measured. In all three muscles, myosin heavy chain (MyHC) expression analyses (n=99) were performed. The protein/DNA ratio tended to be lower (P=0.08) in the offspring of the arginine group. Treatment×sex interactions revealed lower creatine kinase activity (P<0.05) and protein concentration (P=0.07) in female's of the arginine group. The MYF5 mRNA expression was lower (P<0.01) in the lightest, whereas IGF2 and IGFBP5 expressions (P<0.001) were lower in the heaviest females of the arginine group. The proportion of MyHC mRNA expression revealed an increase in the embryonic isoform (P=0.05) and a decrease by tendency in the Slow/I and IIx isoforms (P<0.10) in response to arginine supplementation. The results suggest that arginine supplementation during early gestation stimulates myogenic proliferation and delays muscular differentiation at d 75 of gestation.     

Effects of growth hormone treatment on the expression of somatotropic axis genes in the skeletal muscle of lactating Holstein cows

This study focused on the expression of somatotropic axis genes in the skeletal muscle of dairy cattle. A slow-release recombinant bovine growth hormone (GH) (rbGH) formulation was administered to 5 cows, and saline solution (control) was administered to another 5 cows every 2 wk for a total of 10 wk, starting from the peak of lactation. Tissue and blood samples were collected on days 2 and 14 after each rbGH injection. As target genes insulin-like growth factor (IGF)-1, IGF-2, IGFBPs (1, 2, 3, 4, 5, 6), acute labile subunit (ALS), IGF-1 receptor (IGF-1R), GH receptor (GHR), and the known GHR 5′-UTR variants were selected as target genes, and their relative expression was measured using real-time polymerase chain reaction. In GH-treated cows, an increase in expression was observed for GHR 5′-UTR variant 1I on day 14 (P < 0.05), whereas a significant down-regulation of GHR (P < 0.05) was found after comparing values of treated cows between day 2 and day 14. However, only IGF binding proteins (BP)-5 was found to be appreciably up-regulated in GH-treated cows (P < 0.001), which may indicate the importance of this gene in the overall molecular response to GH administration. Our study indicated that GH treatment did not affect the expression of most somatotropic axis genes, despite the marked increase in GH and IGF-1 in blood (P < 0.001). Nor did it have a large impact on the proportion of GHR 5′-UTR variants in the skeletal muscle of lactating cows. Finally, although we observed a significant variation in the expression of some genes, it would appear that the differences between GH-treated cows and controls were not great enough to be considered as reliable indirect indicators of GH treatment in dairy cattle.     

Morphological Deformities in the Wild Population of C. gariepinus in Ado-Ekiti,Nigeria

Clarias ganepinus from wild population, which was purchased from fish mongers in Ado-Ekiti, Nigeria, were examined for possible deformities in their body. Eighty individuals were collected. Various types of deformities observed were recorded and later photographed. The present study reported for the first time the occurrence of morphological deformities in C. gariepinus natural ecosystem in Ado-Ekiti, Nigeria. The rivers, where the fish were collected, were found to have been exposed to persistent human activities. The possible causes of the deformities may be pollution from human activities or other factors such as poor nutrition, heredity, diseases. The etiology of the deformities in Clarias under this condition is recommended to be studied in detail.     

Salt＇s Effect on Anatomy and Deformity of Pistacia vera Nut

This study attempts to examine the effects of salinity on leaf, stem, and nut of Pistacia vera （Ohady and Kaleh Ghochi cultivars） in order to characterize their anatomical structures with electron and light microscopy. A comparative study of the anatomy indicates a difference between the density of simple and glandular trichomes in leaf surface, deposit of wax, the thickness of leaf, the length of epidermal cells, palisade parenchyma cells, crystals in mesophyll, and the manner of compatibility to salinity. The results obtained in this research demonstrate that compatibility of Ohady cultivar is higher than Kaleh Ghochi and the degree of mechanical wounding depends on their development stages. In addition to results of previous studies which considered crop load as the main cause of fruit deformity. The present study indicates that, in spite of some reduction in total production of a tree, salinity decreases fruit deformity and to a high extent prevents the production of deformed fruit. Indeed, a remarkable reduction in production of deformed fruit will be yielded by selecting pistachio varieties which are resistant to salinity. Moreover, salinity increases the resistance of nuts to mechanical wounding. The results of this study suggest that in EC = 7.6, 12.6 deformity of nut is not related to crop load.     

不同稀释液对猪精液常温保存效果的研究

选取杜洛克公猪精液作为试验材料,比较5种稀释液对猪精液的保存效果,结果表明:用葡萄糖—柠檬酸稀释液,所保存精液的pH值、精子活率、精子畸形率等品质指标表现良好,且稀释液的成本低廉,自配简单易行,适于农村养猪户推行;基层常用的葡萄糖稀释液保存3 d时的精子活率性状表现不佳,仅适合于现配现用。BL─液(美国)稀释液的保存效果也比较好,但该稀释液组分复杂,配制较难,成本也较高,可在规模养猪场中推广。     

烟蚜茧蜂触角的超微结构与冷藏对触角的影响

【目的】明确烟蚜茧蜂（Aphidius gifuensis）触角和触角感觉器的外部形态及低温冷藏对其触角的影响,为烟蚜茧蜂的有效利用提供依据。【方法】采用扫描电镜观察正常羽化的烟蚜茧蜂雌、雄蜂触角的超微结构,比较雌、雄蜂触角感觉器的差异。将处于老熟幼虫期的烟蚜茧蜂在4℃低温下分别冷藏7、14、21和28 d,冷藏后用乙醇对样品进行脱水处理,并在扫描电镜下观察低温冷藏对烟蚜茧蜂触角外部形态及触角感觉器的影响。【结果】烟蚜茧蜂雌、雄成蜂触角外部形态相似,均属于丝状触角。雄蜂触角平均长度略长于雌蜂,雌蜂触角多为17节,雄蜂触角多为19节。成蜂触角上共有6种类型的感觉器：毛形感觉器、刺形感觉器、板形感觉器、Böhm氏鬃毛、腔锥形乳突状感觉器和锥形感觉器。毛形感觉器I主要分布在触角鞭节上,是触角上分布最广、数量最多的感觉器。板形感器主要分部在鞭节上,雄蜂从第1鞭节开始出现,雌蜂从第2鞭节开始出现。腔锥形乳突状感觉器II只存在于雄蜂触角上。雌、雄蜂感觉器的数量存在差异,雌蜂的刺形感觉器I数量多于雄蜂,雄蜂的刺形感觉器II和板形感觉器的数量则多于雌蜂。低温处理14、21、28 d后,板形感觉器、腔锥形乳突状感觉器均表现畸形,且触角最后两节分节不明显,有愈合成一节的趋势。冷藏28 d后,54%雄性触角不能正常分节,由正常情况下的19节而愈合为18节;69%的雌性触角不能正常分节,由正常情况下的17节而愈合为16节。【结论】烟蚜茧蜂触角属于丝状触角,共有6种类型感觉器。雄蜂触角长于雌蜂,感觉器的分布特点相似。低温冷藏对烟蚜茧蜂某些触角感觉器形态及触角末两节分节有显著影响。为减少冷藏对烟蚜茧蜂的伤害,应尽量避免在蛹期以前的虫态低温保存蜂种,且应缩短冷藏时间。