Assessment of the ideal ratios of digestible essential amino acids for pacu,Piaractus mesopotamicus,juveniles by the amino acid deletion method

The present study aimed to determine the ideal ratios of digestible essential amino acids (EAAs) for pacu (Piaractus mesopotamicus) juveniles by the amino acid (AA) deletion method. A completely randomized design which consisted of 11 treatments and three replicates each was used. The treatments included a control diet (CD) containing 55% of nonpurified natural ingredients and 45% of purified synthetic amino acids and ingredients, and other ten isonitrogenous and isoenergetic EAA limiting diets (LDs), each being deficient in 44.4 ± 0.02% of the respective EAA. Pacu juveniles with initial average body weight of 6.22 ± 0.09 g were distributed among 33 fiber glass tanks. Fish were fed with semipurified and extruded diets for 113 days two times a day until apparent satiation. The ideal ratio of each dietary EAA was calculated on the basis of the relationship between body N retention and amount of EAA deleted from the respective EAA LD. Based on the AA deletion method, the ideal ratios of digestible EAAs for pacu juveniles, relative to lysine requirement of 100% were estimated as: methionine 14.6%, threonine 35.0%, tryptophan 6.6%, arginine 62.8%, histidine 13.6%, isoleucine 26.3%, leucine 43.7%, phenylalanine 27.2%, and valine 35.8%.     

Intercropping fenugreek (Trigonella foenum‐graecum L.) and barley (Hordeum vulgare L.) with and without biochar: Tests along a competition gradient

Integrating soil amendment biochar to legume‐based intercropping systems may amplify the intercropping benefits and lead to more sustainable production due to its positive effects on the soil physicochemical and biological environment. Fenugreek (Trigonella foenum‐graecum) is a legume used in an intercropping system in several countries in Southern Europe, the Middle East, and Asia. A barley cultivar and an Iranian fenugreek ecotype were studied in two replacement series experiments to find the best combination of the two species as well as the effect of adding biochar to the soil. Fenugreek and barley were grown in 4‐L pots in five density combinations (20:0, 15:5, 10:10, 5:15, 0:20) with and without application of biochar in sandy loam soil. The biomass, nitrogen (N) and carbon (C) amount of the two crops were measured fifty days after sowing, and the Relative Yield Total (RYT) was estimated. Our results showed that biochar application resulted in a higher total biomass, N and C amount in all combinations of fenugreek and barley. Total biomass was increased by biochar 19.2% when fenugreek was grown alone and 8.1 and 12.9% in series with 25 and 50% barley when biochar was added, respectively. Biochar increased dry matter, N and C accumulation in both crop species in the mixtures. An exception was the C amount of barley which was not influenced by biochar in intercropping. RYT values were largest for biomass, C and N amount in mixtures with 15 fenugreek plants per pot and 5 barley plants per pot corresponding to approximately 400 fenugreek plants per m mixed with 130 barley plants per m². Biochar application increased RYT of the total dry weight by 2.7 and 5.5% in mixtures of 25 and 50% barley plants, RYT of the total nitrogen by 0.8% in mixtures with 25% barley plants, and RYT of the total carbon by 2.7 and 6.6% in mixtures with 25 and 50% barley plants. The RYT values declined with increasing number of barley plants as a result of a less competitive ability of fenugreek when growing in high barley densities. The yield was highest with intercropping but monoculture of barley also resulted in high yields. The total highest yield was found when approximately 130 fenugreek plants per m² were mixed with 400 barley plants per m². Mixtures with 75% fenugreek and 25% barley obtained RYT values larger than 1 for biomass, carbon and nitrogen percentages.     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.     

Immunohistochemical studies on the splenic lobe of the pancreas in young Japanese quails (Coturnix c. japonica)

The splenic lobe (Lobus splenicus) of the pancreas of young meat-type quails (Coturnix c. japonica) was examined by immunohistochemical and light microscopic methods. The endocrine cells are mainly grouped as alpha, beta and mixed islets. A large region consisting of alpha cells is located in the central region of the splenic lobe whereas numerous beta islets are detected in the periphery of the splenic lobe. Alpha islets are in the majority composed of toluidine blue positive A cells and a few toluidine blue negative D and / or avian pancreatic polypeptide (APP) endocrine cells. Beta islets contain only a few toluidine blue negative B and a few D cells. Immunohistochemical staining of the splenic lobe reveal in the centre of beta islets numerous insulin immunoreactive cells and scarcely in alpha islets, exocrine tissue and / or among acinar cells. Somatostatin immune-reactive cells form a circular layer in the periphery of beta islets whereas these cells are uniformly distributed throughout the alpha islet parenchyma and exocrine tissue. In conclusion, the morphology but also the endo- and exocrine functions of the splenic lobe of quails are similar to observations in other avian species such as chicken, duck, goose and pigeon.     

Investigation of developmental toxicity and teratogenicity of macrolide antibiotics in cultured rat embryos

Macrolides are considered to be one of the safest anti-infective groups in clinical use, with severe adverse reactions being rare. However, there are limited data about their embryotoxicity and teratogenicity. We aimed to investigate and compare the effects of these agents on embryonic growth and development. Rat embryos were cultured in vitro for 48 h in rat serum. Whole rat serum was used as a culture medium for the control group while different concentrations of spiramycin and azithromycin (1.25-6.25 microg/ml), and clarithromycin (2.5-30 microg/ml) were added to rat serum for the experimental groups. Dose-dependent effects of macrolides on embryonic developmental parameters were compared using morphological methods. Embryos were evaluated for the presence of any malformations. After morphological examination of the embryos, total DNA was extracted from the cells using standard procedures to determine fragmentation of nuclear DNA of embryonic cells. When compared with the control embryos, the macrolides significantly decreased all growth and developmental parameters dose dependently. While clarithromycin was found to cause more developmental toxicity than spiramycin and azithromycin, azitromycin was determined to have more teratogenicity potential. Compared with controls, there was no difference regarding the fragmentation of nuclear DNA of all the agents used. According to these results, when the toxic and teratogenic potential of the used agents compared, because of the lower toxic and teratogenic effects observed with spiramycin, this agent may be preferred for parturients.     

Search for Borrelia burgdorferi in kidneys of dogs with suspected "Lyme nephritis"

BACKGROUND: "Lyme nephritis" is a poorly characterized condition associated with proteinuria and often fatal renal failure in dogs with serological evidence of infection with Borrelia burgdorferi. OBJECTIVE: The aim of this study was to determine if intact B. burgdorferi organisms were present in the kidneys of serologically Lyme-positive dogs with histopathologic features of Lyme nephritis. ANIMALS: Twenty-six affected and 10 control dogs were identified over an 8-year period (1996-2004) in databases at Cornell University's College of Veterinary Medicine. Case inclusion required serologic evidence of natural exposure to B. burgdorferi and availability of renal tissue (frozen or paraffin embedded) exhibiting pathology consistent with Lyme nephritis. METHODS: Renal tissue samples were assessed using modified Steiner (silver) (MS) staining, immunohistochemistry (IHC), polymerase chain reaction (PCR) using 4 primer sets (eubacterial, B. burgdorferi, Bartonella, and canine genomic DNA), and fluorescence in situ hybridization (FISH) using a 5'-cy3-eubacterial probe for 16S rRNA. RESULTS: MS stain was positive in 1 case; IHC was negative in all cases. None of the B. burgdorferi or Bartonella PCR reactions was positive. Two of the B. burgdorferi FISH analyses were positive. CONCLUSIONS AND CLINICAL IMPORTANCE: Minimal evidence of the presence of intact B. burgdorferi or any other bacterial organism was found in the renal tissue of dogs with suspected Lyme nephritis. Direct renal invasion by B. burgdorferi organisms does not appear to be responsible for this syndrome.     

Sequence analysis of both genome segments of three Croatian infectious bursal disease field viruses

In order to determine the mutations responsible for virulence, three Croatian field infectious bursal disease viruses (IBDV), designated Cro-Ig/02, Cro-Po/00, and Cro-Pa/98 were characterized. Coding regions of both genomic segments were sequenced, and the nucleotide and deduced amino acid sequences were compared with previously reported full-length sequenced IBDV strains. Phylogenetic analysis, based on the nucleotide and deduced amino acid sequences of polyprotein and VP1, was performed. Eight characteristic amino acid residues, that were common to very virulent (vv) IBDV, were detected on polyprotein: 222A, 256I, 294I, 451L, 685N, 715S, 751D, and 1005A. All eight were found in Cro-Ig/02 and Cro-Po/00. C-Pa/98 had all the characteristics of an attenuated strain, except for glutamine on residue 253, which is common for vv, classical virulent, and variant strains. Between less virulent and vvIBDV, three substitutions were found on VP5: 49 G --> R, 79 --> F, and 137 R --> W. In VP1, there were nine characteristic amino acid residues common to vvwIBDV: 146D, 147N, 242E, 390M, 393D, 511S, 562P, 687P, and 695R. All nine residues were found in A-Ig/02, and eight were found in B-Po/00, which had isoleucine on residue 390. Based on our analyses, isolates Cro-Ig/02 and Cro-Po/00 were classified with vv IBDV strains. C-Pa/98 shared all characteristic amino acid residues with attenuated and classical virulence strains, so it was classified with those.     

Polymerase chain reaction detection of Salmonella spp. in fecal samples of pet birds

The aims of this study were 1) to determine the prevalence of Salmonella in clinically ill birds in aviaries in Ankara, Turkey, and 2) to compare conventional culture and polymerase chain reaction (PCR) for detection of Salmonella in feces from clinically ill pet birds. In the study, 185 fecal samples (feces and/or swabs) collected from the pet birds kept in the seven different aviaries in the city of Ankara were investigated for the existence of Salmonella spp. by bacterial isolation and PCR. The conventional isolation and identification methods were performed for Salmonella isolation from fecal cultures. Suspected colonies were confirmed with the Salmonella polyvalent O antiserum and serogrouped with Salmonella group-specific antiserum. PCR was performed after the fecal swabs were incubated for 18 hr in 10 ml of tetrathionate broth. Three (1.63%) out of 185 fecal samples were found to harbor Salmonella spp. by conventional identification tests and were found to belong to serogroup B. Five (2.7%) swab samples were found to harbor Salmonella DNA by PCR tests. As a conclusion, PCR following incubation of clinical samples in pre-enrichment broth seemed to be a fast and practicable method for Salmonella spp. diagnosis when compared to protracted labor-intensive conventional culture techniques.     

Corticosterone administration and dietary glucose supplementation enhance fat accumulation in broiler chickens

1. The effects of exogenous corticosterone administration and glucose supplementation on energy intake, lipid metabolism and fat deposition of broiler chickens were investigated. 2. A total of 144 three-d-old male chickens were randomly assigned to one of the following 4 treatments for 7 d: a low energy diet (10.9 MJ ME/kg, 200 g/kg CP) with or without corticosterone (30 mg/kg diet) and drinking water supplemented with glucose (80 g/l) or saccharine (2 g/l, control). 3. Body weight (BW) gain and breast and thigh muscle yields (% body mass) were all significantly decreased by corticosterone treatment. The relative cumulative feed intake (RCFI) and relative ME intake (RMEI), rather than the feed (FI) or ME intake (MEI) were increased by corticosterone administration. Both feed efficiency (FE) and caloric efficiency (CE) were decreased by corticosterone administration. Corticosterone administration had no obvious effect on water consumption. 4. Glucose supplementation had no influence on BW gain and breast and thigh muscle yield (as % of body mass). FI or RCFI was decreased while MEI or RMEI was increased by glucose supplementation. FE was improved by glucose treatment, whereas CE was reduced. 5. Liver weight and abdominal, cervical and thigh fat deposits were all significantly increased by either corticosterone or glucose treatment. 6. Plasma concentrations of glucose, urate, triglyceride, non-esterified fatty acids (NEFA), very low density lipoprotein and insulin were all significantly increased by corticosterone treatment. Glucose supplementation had no obvious influence on any of the measured plasma parameters except for NEFA, which were significantly increased. 7. Lipoprotein lipase activities in either cervical or abdominal adipose tissues, rather than in thigh fat tissue, were significantly elevated by either glucose or corticosterone treatment.