Effects of sexual maturation and Salmonella infection on the expression of avian β-defensin genes in the chicken testis

Rooster infertility is a major concern in the poultry industry and protection of the male reproductive organs from pathogens is an essential aspect of reproductive physiology. During the last years, research on antimicrobial protection has elucidated the critical role of the antimicrobial peptides avian β-defensins (AvBDs) in the innate immunity in chickens. AvBDs have been reported to be expressed in the hen reproductive organs, providing protection against microbial pathogens including Salmonella Enteritidis (SE). However, mechanisms of antimicrobial protection of rooster reproductive organs and especially the testis, mediated by AvBDs are poorly understood. The aim of this study was to investigate the expression of the complete family of the 14 AvBD genes, in the rooster testis in vivo, to determine whether sexual maturation affects their testicular mRNA abundance and to investigate whether SE infection alters their expression. Expression analysis revealed that 9 members of the AvBD family, namely AvBD1, 2, 4, 5, 6, 9, 10, 12 and 14 were expressed in the testis. Quantitative real-time PCR analysis revealed that the mRNA abundance of three AvBDs was up regulated and of three AvBDs was down regulated with respect to sexual maturation. In addition, SE infection resulted in a significant induction of AvBD4, 10, 12 and 14 in the testis of sexually mature roosters. These findings provide strong evidence to suggest that an AvBD-mediated immune response mechanism exists in the rooster testis providing protection against bacterial pathogens including Salmonella species.     

Effects of acetylated wood powder on growth performance,hepatic and muscular free amino acid profiles,and inosine 5’-monophosphate concentration of breast meat in broiler chickens

1. The present study was conducted to determine the effects of acetylated wood powder (AW) as a new feed additive on performance, liver and muscle metabolism of amino acids and fatty acids and nucleotide-related substances of meat in broiler chickens. It was hypothesised that acetic acid desorbed from AW during intestinal digestion affects tissue metabolism.

2. Two-week-old broiler chicks were divided into four groups and fed on diets supplemented with wood powder (30 g/kg) less than 106 µm in diameter, except for controls. The AW was added to diets at 0, 10 and 30 g/kg to replace the non-acetylated wood powder (NAW) for 26 d. Plasma, liver tissue and breast muscle were taken from half of birds at 40 d of age under the fed condition. After the remaining chickens were fasted for 14 h, breast muscle was taken and refrigerated for 24 h.

3. Consumption of wood powder with or without acetyl groups had no effect on growth performance including tissue weights of abdominal fat and breast muscle and plasma metabolites.

4. Feeding AW decreased total free amino acid concentrations in the liver compared to the group only fed on the NAW. This response was dependent mainly on reduced non-essential and glucogenic amino acid concentrations. However, in breast muscle, alterations of free amino acid concentrations were observed only for histidine and tryptophan. In addition, the fatty acid composition of liver and breast muscle was not affected by feeding AW.

5. In breast meat obtained from fasted chickens, the higher level of AW increased the concentration of inosine 5′-monophosphate, a taste-active compound, and in contrast, decreased the subsequent catabolites (inosine and hypoxanthine). However, the concentration of glutamic acid, a taste-active compound, was lowered at this level of AW ingestion.

6. Therefore, this study suggested that feeding AW as a new feed additive regulates ante-mortem amino acid utilisation in the liver and contributes to retard post-mortem degradation of inosine 5′-monophosphate as a taste-active compound in chicken meat.

     

Comparisons of mammalian Giardia duodenalis assemblages based on the β-giardin, glutamate dehydrogenase and triose phosphate isomerase genes

The objective of this study was to determine and compare the assemblages of Giardia duodenalis isolated from mammalian fecal samples using the β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. A total of 202 samples, either submitted to the Veterinary Diagnostic Laboratory (Parasitology) at Colorado State University or part of ongoing research studies, were typed. A subset of 50 dog samples were also assessed by the tpi-D-specific primers. Of these, 183 were from dogs, 13 were from cats, two were from llamas, and one each was from a calf, an alpaca, a sheep, and a horse. The majority of the dogs (171 of 183 isolates) in this study were infected with only dog-adapted Assemblage C or D. The tpi-D-specific primers confirmed that 28 of the samples that typed as Assemblage D by the bg and gdh genes were also Assemblage D by the tpi-D-specific primers. Only 12 isolates were Assemblage A alone or Assemblage A and Assemblage C or D. Of the 13 cat isolates, seven were Assemblage F, two were Assemblage D, three were Assemblage A and 1 contained both Assemblages C and D. The calf isolate was Assemblage E (gdh, tpi) and the alpaca (bg, gdh), llamas (gdh), sheep (bg, gdh, tpi) and horse (tpi) isolates were all Assemblage A. When the assemblage could be determined for more than one gene, 91 of 117 dog isolates gave consistent results and 8 of 9 cat isolates gave consistent results.     

Identification of key genes affecting porcine fat deposition based on coexpression network analysis of weighted genesOA

Background: Fat deposition is an important economic consideration in pig production. The amount of fat deposition in pigs seriously affects production efficiency, quality, and reproductive performance, while also affecting consumers’ choice of pork. Weighted gene co-expression network analysis(WGCNA) is effective in pig genetic studies. Therefore, this study aimed to identify modules that co-express genes associated with fat deposition in pigs(Songliao black and Landrace breeds) with extreme lev...     

Serological detection of chicken flocks naturally infected with salmonella enteritidis,using an enzyme‐linked immunosorbent assay based on monoclonal antibodies against the flagellar antigen

Summary

The Dutch Salmonella enteritidis monitoring and eradication programme for poultry prescribes a periodic examination of all breeding flocks for the presence of S. enteritidis. For the first years of the programme this was done by bacteriological examination of 50 faecal samples per visit per flock.

In this study we compare the results of bacteriological examination of faecal samples taken at 1580 visits from 545 flocks with those of a S. enteritidis enzyme‐linked immunosorbent assay (ELISA) applied on 24 serum samples per visit per flock. Two flocks were found positive for S. enteritidis by bacteriological examination; both flocks were also detected by ELISA. Ten flocks, bacteriologically negative for S. enteritidis were found positive by ELISA. S. enteritidis was isolated from three of these flocks by repeated and extensive bacteriological examination for verification. Verification was not possible in the fourth EL1SA positive flock. S. enteritidis infections were likely in three other flocks because of the farm histories.

On the basis of the results of this study it was decided to use this ELISA, starting from April 1992, as screening technique in the Dutch S. enteritidis programme instead of bacteriological examination of faecal samples. The ELISA is regarded as a flock test; an extensive, confirmatory bacteriological investigation for S. enteritidis is carried out in ELISA positive flocks to decide whether the flocks are truly infected.     

Comparison the effects of 5-Aza-2′-deoxycytidine and zebularine on the in vitro development,blastocyst quality,methylation pattern and conception rate on handmade cloned buffalo embryos

In this study we treated the handmade cloned (HMC) buffalo embryos with the DNA methylation inhibitors; 5-aza-2′-deoxycytidine (AzadC) or Zebularine individually after post-fusion and during in vitro culture till eighth day. The blastocysts production rate significantly improved (p < .01) after treating embryos independently with 5 nM AzadC and 5 nM zebularine compared with 2 and 10 nM AzadC or zebularine groups, respectively. The highest cleavage rates were obtained for 5 nM treatment of AzadC and zebularine compared with other treatments and untreated control group. Quality of blastocysts were evaluated using total cell number (TCN) and the ratio of number of inner cell mass (ICM) cells/total cell number (ICM/TCN). Zebularine treatments (2/5/10 nM) significantly improved both TCN and ICM/TCN ratio compared with AzadC treatments (2/5/10 nM); however, control group TCN and ICM/TCN ratio was found lower. The methylation percentage of pDS4.1 and B. bubalis satellite DNA were comparatively more attenuated with 5 nM zebularine than 5 nM AzadC treatment. The increased in vitro development rates of the treated embryos were correlated with the decreased level of DNA methylation and the improved blastocyst quality. Following transfer of 5 nM zebularine treated embryos to 6 recipients, 4 were found to be pregnant, though the pregnancies were not carried to full term.