Effects of Thyroxin and Domperidone on Oocyte Maturation and Spawning Performances in the Rabbit Fish,Siganus guttatus          下载免费PDF全文

Hung Q. Pham  Hoang M. Le 《Journal of the World Aquaculture Society》2016,47(5):691-700

Thyroxin (T₄) is proven to have various functions in fish reproduction. In this study, we investigated oocyte maturation and spawning performance in the rabbit fish, Siganus guttatus, orally exposed to different doses of T₄ (0.05, 0.25, and 0.5 mg/kg fish) during vitellogenesis. No statistically significant differences of reproductive characteristics were observed among the treatments. However, the group that was exposed to the dose of 0.5 mg/kg spawned after receiving a hormone injection. The findings suggest that feeding T₄ during vitellogenesis did not advance oocyte maturation, but probably could induce spawning in rabbit fish. In a separate experiment, we investigated the effects of orally administered domperidone (DOM) on reproductive performances of the female rabbit fish. The study showed that oral administration of DOM during the early stages of the reproductive cycle had no significant effects on oocyte maturation and spawning performance. Overall, these findings suggest that DOM may not be needed for the induction of maturation and spawning of this species under aquaculture conditions. These practical investigations were conducted with a view to attempt reducing drug use, production costs, and support sustainable aquaculture.  相似文献   

Study on the Stability of Blue-tongue Virus after Long Time Storage in Cold Room     

MIAO Hai-sheng  LI Le  ZHU Jian-bo  XIAO Lei  LI Hua-chun 《中国畜牧兽医》2013,40(6):41-44

In order to understand the stability of blue-tongue virus (BTV)storage in cold room for long time, 18 tissue samples which were kept in 4℃ for 10 to 15 years were test by Real-time PCR, and 10 blood samples which were kept in 4℃ for 15 years were subjected to virus isolation process, then was proved by monoclonal antibody staining,research results showed all old samples were positive in Real-time PCR, further more, 5 live virus were isolated from 10 old blood samples. The results suggested the stability of BTV was higher than we thought before.  相似文献   

Intermuscular variation in tenderness: association with the ubiquitous and muscle-specific calpains   总被引：19，自引：0，他引：19  

Ilian MA  Morton JD  Kent MP  Le Couteur CE  Hickford J  Cowley R  Bickerstaffe R 《Journal of animal science》2001,79(1):122-132

The biochemistry of intermuscular variation in tenderness is not fully understood. To investigate the role of the calpains in this process we performed two experiments using bovine and ovine species. In the bovine experiment, two distinct muscles, longissimus thoracis et lumborum (LT) and psoas major (PM), were used. In the ovine experiment, four muscles, LT, PM, semimembranosus (SM), and semitendinosus (ST), were used. Muscles were sampled at death for the determination of the steady-state mRNA level of calpains and calpastatin and the activities of calpain 1, 2, and calpastatin. Muscles were also sampled to determine the temporal changes in pH, tenderness, and the activity of the ubiquitous calpain system during postmortem aging. The results of the relative rate of tenderization in both species was found to be related to muscle type; LT had the highest value in both species. Within species, the mRNA steady-state levels of calpain 1 and calpastatin were similar in various bovine and ovine muscles. Bovine calpain 2 mRNA level was significantly lower in the LT than in the PM. Ovine calpain 2 mRNA level was lower, but not significantly different, in the LT compared to the other muscles. The mRNA level of bovine calpain 3 was significantly higher in the LT muscle than in the PM. In the ovine, the mRNA level of calpain 3 was highest in the LT, followed by SM, PM, and ST. Results on the activity of the ubiquitous calpain system in various muscles at death were dependent on muscle type and species. Temporal changes in the activity of calpains and calpastatin during the first 24 h of postmortem aging were similar in the muscles studied: calpain 1 and calpastatin declined significantly and calpain 2 remained relatively unchanged. The temporal changes in muscle pH in both experiments indicated that the extent and rate of pH decline during aging was related to muscle type. Correlation analysis between the relative rate of tenderization and mRNA expression of calpains revealed a strong relationship with calpain 3 in both species.  相似文献   

Distribution and repeatability of faecal egg counts and blood parameters in dairy goats naturally infected with gastrointestinal nematodes     

Hoste H  Le Frileux Y  Pommaret A 《Research in veterinary science》2001,70(1):57-60

The frequency, distribution and repeatability of measurements related to infection with gastrointestinal nematodes have been estimated in dairy goats. Monthly faecal and blood samples were taken over two grazing seasons from a flock of 120 naturally infected goats. The frequency distribution of egg excretion was positively skewed at each sampling date, suggesting an aggregative distribution of parasites. Overdispersed distributions were also apparent for pepsinogen and inorganic phosphate values. Repeatabilities for each parameter were estimated within each year. The values ranged between 0.23 to 0.43 and were relatively similar during the 2 years, with the highest coefficients recorded for pepsinogen. For each parameter, moderate to high repeatabilities were also estimated between the 2 years. Overall, the data suggest that, in dairy goats, the distribution of worms is overdispersed with a few individuals repeatedly harbouring large worm populations. These results have practical implications for genetic selection for resistance to worm infection and for selective administration of anthelmintics.  相似文献   

Tuberculosis in an Iberian lynx (Lynx pardina)     

Pérez J  Calzada J  León-Vizcaíno L  Cubero MJ  Velarde J  Mozos E 《The Veterinary record》2001,148(13):414-415

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Correlations of measurements of subclinical claw horn lesions in dairy cattle     

Le Fevre AM  Logue DN  Offer JE  McKendrick I  Gettinby G 《The Veterinary record》2001,148(5):135-138

Measurements were made of the extent of sole and white line lesions on the claws of 115 Holstein-Friesian cows on at least three and at most 16 occasions, and some cows were followed up to their third lactation. All the measurements were made between 12 weeks before calving and 45 weeks after calving. In total, 1016 repeated observations were made. Correlations were calculated between pairs of claws, between types of lesion (sole and white line), and between pairs of the different measurements (number of lesions, proportion of the claw affected, maximum severity score and proportion of the claw affected weighted for severity). The outer hind claws had the greatest extent of lesions of both types. Spearman correlation coefficients and confidence intervals measured the strength of the association. All the associations between claws were positive, suggesting that the lesions did not occur in isolation. Sole and white line lesions were not associated at individual observation points. Lesions on the left and right claws were markedly similar, except for sole lesions on the two inner hind claws, and for white line lesions on the two outer hind claws.  相似文献   

Spatial distribution of leaf dry weight per area and leaf nitrogen concentration in relation to local radiation regime within an isolated tree crown     

Le Roux X  Sinoquet H  Vandame M 《Tree physiology》1999,19(3):181-188

To assess the spatial distribution of photosynthetic capacity within an isolated 20-year-old walnut tree (Juglans regia L.) crown, the distribution of relevant leaf characteristics was measured. Variations in leaf dry weight per area (W(a)), and nitrogen content on a weight (N(w)) and area basis (N(a)) were studied along two horizontal and one vertical gradients of leaf irradiance, at two dates (July 30 and September 3). In addition, the content of total nonstructural carbon on a weight (TNC(w)) and area basis (TNC(a)) was measured on July 30. Concurrently, the spatial distribution of daily integrated leaf irradiance within the crown was simulated by a three-dimensional radiation transfer model over a one week period before sampling at each date. High spatial heterogeneity was observed for W(a) (from 50 to 140 g m(-2)), TNC(a) (from 4 to 17 g m(-2)) and N(a) (from 1.2 to 3.6 g m(-2)) among the foliage. Although TNC(w) and N(w) were not correlated and only weakly correlated to daily leaf irradiance, respectively, W(a), TNC(a) and N(a) were strongly correlated to daily leaf irradiance. The relationship between observed N(a) and simulated daily leaf irradiance was used to assess the spatial distribution of N(a) within the crown at each date. Total leaf nitrogen in the foliage was estimated to be 339 g in late July and 317g in early September. For the whole crown (i.e., 1729 current-year shoots), N(a) increased strongly with basal shoot diameter (an index of "shoot vigor"), highlighting the fact that large shoots were mainly located in sunlit locations and exhibited high photosynthetic capacity.  相似文献   

Effects of the halothane genotype and slaughter weight on texture of pork   总被引：4，自引：0，他引：4  

Monin G  Larzul C  Le Roy P  Culioli J  Mourot J  Rousset-Akrim S  Talmant A  Touraille C  Sellier P 《Journal of animal science》1999,77(2):408-415

The objective of this study was to investigate the effects of the halothane (HAL) genotype, slaughter weight (SW), and the HAL x SW interaction on compositional and textural traits of raw and cooked pork. Pigs were bred to exhibit one of the three HAL genotypes (NN, Nn, and nn) with otherwise equivalent genomes. The nn halothane reactors are known to typically produce PSE pork, whereas NN pigs do not typically produce PSE pork. Pietrain x Large White gilts and boars, all with verified Nn genotype (by DNA test), were mated to obtain F2 littermates of the three HAL genotypes. These pigs were slaughtered at either 101 +/- 3 ("light") or 127 +/- 3 ("heavy") kg BW and were evaluated for longissimus muscle traits. The pH at .5 h after death (pH1) was 6.35, 6.13, and 5.68 in NN, Nn, and nn pigs, respectively. Sarcomere length was greater in nn than in NN and Nn pigs (1.94 vs 1.83 and 1.85 microm, respectively). Mechanical resistance was higher in nn than in NN pigs for both raw and cooked meat. Meat from nn pigs was judged by a trained panel to be less rough, more cohesive, harder, more fibrous, less granular, more elastic, and less easy to swallow than meat from NN pigs. For most traits under study, the heterozygotes were intermediate between the homozygotes but closer to NN than to nn pigs. Muscle from heavy pigs had longer sarcomeres and less moisture than muscle from light pigs. The n allele of the HAL gene unfavorably affects pork texture, and this effect is maintained throughout the range of 101 to 127 kg BW.  相似文献   

Effects of acute asphyxia at birth on subsequent heat production capacity in newborn pigs     

Herpin P  Wosiak F  Le Dividich J  Bertin R 《Research in veterinary science》1999,66(1):45-49

The effect of acute asphyxia at birth on subsequent ability to produce heat was investigated in 30 newborn pigs. A model of experimentally induced asphyxia consisting of the prevention of breathing within the first four minutes of life was used. Blood was sampled from an umbilical artery catheter within the first 75 minutes of life for blood gas, pH, glucose, lactate and catecholamine analysis. After the treatment and 24 hours later, heat production capacity, shivering intensity and rectal temperature were measured 10 degrees C below thermoneutrality. Effects on blood gas parameters were severe but transient whereas alterations in carbohydrate metabolism were maintained during the first 75 minutes (P < 0.05). Acute asphyxia at birth induced only minor alterations of thermoregulatory abilities during the first day of life: rectal temperature was lower one hour after birth (P < 0.05) and the postnatal increase in heat production capacity was less pronounced than in controls. It is suggested that the lower viability usually reported for piglets suffering from asphyxia during delivery is most likely to result from reduced vigour and colostrum intake, as well as altered carbohydrate metabolism early after birth.  相似文献   

BA和激素对试管番茄愈伤组织形态发生的影响   总被引：12，自引：0，他引：12  

乐锦华  杨国臣 《园艺学报》1991,18(1):44-48

用番茄‘Bonny Best’品种的子叶和下胚轴作为外植体,在MS附加不同水平的BA和激素的培养基中,愈伤组织形态发生的情况是不同的。本试验结果表明:在相同的植物生长调节剂水平下,番茄子叶外植体较下胚轴外植体更容易形成愈伤组织和生根;番茄子叶和下胚轴愈伤组织的形成要求不同的激素水平,较高的水平适合于子叶愈伤组织的生长,而下胚轴愈伤组织的生长要求较低的激素水平;较高浓度的BA诱导子叶和下胚轴外植体形成白色紧密的愈伤组织,而且茎的分化出现较早,较低水平的BA产生疏松的愈伤组织,分化效迟;在MS BA22.2-44.4μM IAA1-5μM的培养基上,番茄子叶和下胚轴切段可直接分化成茎;在无激素MS培养基上,下胚轴切段可直接成苗;疏松的愈伤组织是进行悬浮培养的良好材料,可利用它们进行原生质体培养和抗性克隆的筛选。  相似文献