Estimates of (co)variance components for direct and maternal effects on birth weight of Karayaka lambs

The purpose of this study was to estimate the genetic parameters for birth weight of Karayaka lambs by separating direct genetic, maternal genetic, and maternal permanent environmental effects. Records of 1013 Karayaka lambs born between 2005 and 2010 were analyzed. Six different animal models were examined, all including direct additive genetic variance and various combinations of genetic and environmental maternal effects. The most appropriate model was chosen based on log-likelihood ratio tests. Since model 1 had the smallest likelihood value, it was chosen as the best model in this study. Depending on the model, direct heritability varied from 0.37 to 0.55 and maternal heritability ranged from 0.08 to 0.20 for birth weight.     

日粮中添加锌对家禽热应激的作用

<正>在家禽生产的所有环节中,环境温度最为人们所关注。严重的热应激对采食量、体重、孵化率、死亡率、胴体品质以及其他影响养禽业效益的重要特性产生不利的影响。由于羽化和缺乏汗腺,家禽的     

Changes in gas exchange capacity and selected physiological properties of squash seedlings (Cucurbita pepo L.) under well-watered and drought stress conditions

Water use efficiency (WUE) is considered as an important component of adaptation to drought stress. This study was conducted to determine the effect of drought stress on gas exchange parameters and selected physiological properties, and also its relations with WUE in summer squash seedlings (Cucurbita pepo L.). Plants were grown in pots under different irrigation levels (D0: 100%, D1: 67% and D2: 33% of the water required to reach the field capacity) in controlled greenhouse. The results show that drought treatments significantly decreased the leaf chlorophyll reading values (LCRV), leaf relative water content (LRWC), stomatal conductance (g_s), photosynthetic rate (P_N), transpiration rate (T_r), fresh weight (FW) and dry weight (DW) of squash seedlings by 7, 42, 69, 62, 62 63 and 82%, respectively, in D2 treatment compared to D0. However, electrolyte leakage (EL) values increased 72% with severe drought treatments (D2). The highest WUE was obtained by D0 treatment as 0.26 g mm^?1. The relationship between P_N and WUE is the strongest one among all leaf gas exchange parameters. Together with T_r, the linear relation with WUE was considerably higher compared to other measured parameters.     

The zonal distributions of alkaline phosphatase, adenosine triphosphatase, laminin, fibronectin and chondroitin 4-sulphate in growing rat humerus proximal epiphyseal cartilage: a histochemical and an immunohistochemical study

Although there are many studies about epiphyseal cartilage extracellular matrix (ECM) macromolecules in bone formation, studies of their distribution and role in the mineralization of these components in growing rat humerus proximal epiphyseal cartilage have not been sufficiently detailed. The aim of this study was to determine the distributions of alkaline phosphatase (ALP), adenosine triphosphatase (ATPase), laminin, fibronectin and chondroitin 4-sulphate in growing rat humerus proximal epiphyseal cartilage. The rats were killed by cervical dislocation, and the humeri were removed, sectioned (6 and 10 microm) on a cryotome or paraffin microtome, and stained using histochemical and immunohistochemical methods. ALP and ATPase were markedly observed in the hypertrophy and calcifying cartilage. In addition, ATPase was found to be very strongly positive in the tangential zone of articular cartilage. Results of immunohistochemical staining for laminin, fibronectin and chondroitin 4-sulphate showed that the immunostaining was the heaviest in the tangential zone of articular cartilage. In growing epiphyseal plates, there were differences in the density of these macromolecules of chondrocytes as a function of the maturation process. In conclusion, these ECM macromolecules of epiphyseal cartilage may regulate the cell-cell and cell-matrix interactions as well as the matrix calcification during the ossification of epiphyseal cartilage.     

Hydrated sodium calcium aluminosilicate for reduction of aflatoxin in quails (Coturnix coturnix japonica)

The purpose of the present study was to evaluate the toxic effects of aflatoxin (AF) on growth performance and various processing parameters of quails and to determine the preventive efficacy of hydrated sodium calcium aluminosilicate (HSCAS). One hundred and eighty 1-d-old quails of both sexes were randomly divided into 4 experimental groups with 5 replicates and 45 birds following weighing.The experimental design consisted of four dietary treatments: 1) control with 0 mg AF/kg of diet and 0% HSCAS; 2) 0.5% HSCAS; 3) 2.5 mg AF/kg of diet; 4) 2.5 mg AF/kg of diet plus 0.5% HSCAS.The chicks were housed in electrically heated battery cages and exposed to light for 24 h from hatching to 3 weeks of age. Quails consumed the diets and water ad libitum. Body weight (BW) was significantly (p < 0.001) increased by addition of HSCAS to AF diet.The lowest BW gains in groups received AF alone was observed at all periods.The reduction in BW gain caused by 2.5 mg AF/kg of diet was significantly (p < 0.001) diminished by the addition of 0.5% HSCAS to the diet.The addition of HSCAS to the AF diet significantly (p < 0.001) protected against decrease of feed intake at all periods with exception of the first period. None of the treatments altered significantly the feed conversion ratio (FCR).The relative weights of the liver, kidney and spleen were increased in the chickens consuming the AF alone diet. However, light microscopic examination demonstrated the addition of HSCAS to quail feed to partially decrease fat deposition caused by the toxin, and besides, electron microscopic examination of indicated a reorganization in the endoplasmic reticulum and increase in the number of ribosomes and polisomes. Furthermore, the decrease in the antibody titre induced by Newcastle vaccine, due to aflatoxins, was relatively prevented. No significant differences were observed for serum total protein, total cholesterol and glucose levels.The results of indicate that HSCAS is effective in preventing the deleterious effects of AF.     

Molecular characterization of Cereal Cyst Nematode diagnostic markers Cre1 and Cre3 in some winter wheat germplasm and their potential use against Heterodera filipjevi

Two PCR based markers tightly linked to Cre1 and Cre3 resistant genes against the Cereal Cyst Nematode (CCN, causal agent Heterodera avenae) were used to characterize a number of diploid, tetraploid and hexaploid wheat germplasm consisting of obsolete, advanced lines and new cultivars from the Turkish National Breeding Program and the joint TURKEY CIMMYT ICARDA International Winter Wheat Improvement Program. In addition a number of landraces and wild relatives of wheat collected from the Turkish side of the Fertile Crescent, the centre of origin of cereals, were included. None of the genetic material tested positive for either marker except the land race Sardari which originated from neighboring Iran was found positive for Cre1 gene. Combining both of these molecular markers in one assay for fast and cost-effective screening of the germplasm was not effective, so marker genotyping with germplasm was realized using each primer alone. Most work that has been reported is on the CCN species H. avenae, however the predominant species in Turkey is the closely related H. filipjevi. In vitro resistance assaying for this species indicates that Cre1 is a moderate source of resistance against the H. filipjevi population, however Cre3 gene appears ineffective. It is suggested that a larger pool of a range of germplasm should be screened for Cre1 in Turkey. Furthermore, the landrace Sardari could be used as a parent to deploy CCN resistance in to genetic background of Turkish bread wheat cultivars with a targeted Marker Assisted Selection Backcrossing approach.     

Systemic dexamethasone concentration in horses after continued topical treatment with an ophthalmic preparation of dexamethasone.

OBJECTIVE: To determine concentrations of dexamethasone in serum and urine of horses treated repeatedly with a topically administered ophthalmic dexamethasone preparation. ANIMALS: 4 clinically normal horses (2 mares, 2 geldings). PROCEDURE: 0.1% dexamethasone ophthalmic ointment was administered to the left eye of each horse every 5 to 9 hours for 8 consecutive days, yielding an estimated cumulative dexamethasone dose of 6.4 microg/kg of body weight. Serum and urine samples were obtained before the first dexamethasone treatment, on days 4 and 8 of treatment, and 24, 48, and 96 hours after cessation of treatment. To detect small concentrations of dexamethasone, serum and urine samples were analyzed by use of a competitive enzyme immunoassay. RESULTS: During the period of continued topical treatment, serum dexamethasone concentrations increased to between 0.10 and 0.49 ng/ml, then decreased below the limit of detection (0.06 ng/ml) within 24 hours after cessation of treatment. Dexamethasone also was detected in urine samples at concentrations of up to 0.98 ng/ml. CONCLUSIONS: Repeated topical administration of dexamethasone ophthalmic ointment generated low, but detectable glucocorticoid concentrations in serum and urine. CLINICAL RELEVANCE: Because treatment of performance horses with dexamethasone is prohibited for most types of competitions and because enhanced glucocorticoid detection methods may result in positive test results, owners and trainers may wish to reconsider entering horses in competitions during periods of treatment with ophthalmic dexamethasone preparations.