Effect of aflatoxin B1 and sterigmatocystin on DNA repair genes in common carp.

The present study aimed to investigate the short-time (24 h) effect of aflatoxin B1 (AFB1) and sterigmatocystin (STC) on the expression of hsp70, p53, gadd45, and ogg1 genes in common carp hepatopancreas. Our results showed that aflatoxin B1 and sterigmatocystin can stimulate the expression of DNA repair genes, mainly by hour 24. This significant finding contributes to our understanding of the short-term effects of these mycotoxins on ogg1 genes in common carp hepatopancreas. One-year-old common carp juveniles were randomly distributed into five groups (Control, AFB1 0.4 mg kg-1 feed, STC1 1 mg kg-1 feed, STC2 2 mg kg-1 feed, and STC3 3 mg kg-1 feed). Hepatopancreas samples were collected three times (8, 16, and 24 h) in each group. No significant ogg1 and p53 expression changes were observed at 8 and 16 h after exposure. All measured genes were upregulated by the 24th hour in aflatoxin and STC3 groups. An increase in hsp70 gene expression was detected in all groups and all sampling. A significant decrease in gadd45aa gene expression was observed in the aflatoxin B1 group at hour 8. At hour 16, there was no significant change, while at hour 24, all treated groups were significantly different from the control. In summary, our results suggest that aflatoxin B1 and sterigmatocystin can stimulate the expression of DNA repair genes, mainly by hour 24. Further investigations are needed to get information about DNA damage parallel to the DNA repair mechanisms.

Effect of Lighting Methods on the Production, Behavior and Meat Quality Parameters of Broiler Chickens.

Many farms have been replacing traditional lighting sources with light-emitting diode (LED) bulbs because of technological modernization. We aimed to investigate the effects of incandescent lighting (IL) and LED lighting on Cobb 500 broiler chickens for six weeks. Production parameters (body weight, feed consumption, feed conversion ratio), calculated slaughter values (yield%, relative breast%, thigh%) and breast meat quality parameters (pH at 45 min and 24 h postmortem, color, drip loss, kitchen equipment losses, shear force, meat composition) were recorded. Non-stop recordings were used to analyze the behavior of the birds during several periods of rearing. The LED group was significantly better in the body weight parameter between week 1 and 5 and the feed conversion ratio between week 2 and 3. The most significant difference in behavior was observed in the middle of the rearing period. The chickens in the LED group spent more time eating, drinking and interacting, and rested less. There was no difference in the meat quality parameters; only shear force was significantly lower in the LED group (1781.9 g/s vs. 2098.8 g/s). According to our results, LED lighting can bring about positive changes in animal production efficiency, behavior and other important characteristics for meat consumers.

Effects of Short- and Medium-Chain Fatty Acids on Production, Meat Quality, and Microbial Attributes-A Review.

The non-therapeutic use of antimicrobials in poultry production contributes to the spread of drug-resistant pathogens in both birds and humans. Antibiotics are known to enhance feed efficiency and promote the growth and weight gain of poultry. New regulatory requirements and consumer preferences have led to a reduced use of antibiotics in poultry production and to the discovery of natural alternatives to antibiotic growth promoters. This interest is not only focused on the direct removal or inhibition of causative microorganisms but also on the prevention of diseases caused by enteric pathogens using a range of feed additives. A group of promising feed additives is composed of short- and medium-chain fatty acids (SCFAs and MCFAs) and their derivatives. MCFAs possess antibacterial, anticoccidial, and antiviral effects. In addition, it has been proven that these acids act in synergy if they are used together with organic acids, essential oils, or probiotics. These fatty acids also benefit intestinal health integrity and homeostasis in broilers. Other effects have been documented as well, such as an increase in intestinal angiogenesis and the gene expression of tight junctions. The aim of this review is to provide an overview of SCFAs and MCFAs as alternatives to antibiotic growth promoters and to summarize the current findings in the literature to show their possible benefits on production, meat quality, and gut health in poultry.

Changes of DNA Damage Effect of T-2 or Deoxynivalenol Toxins during Three Weeks Exposure in Common Carp (Cyprinus carpio L.) Revealed by LORD-Q PCR.

The present study aimed to adapt a Long-run Real-time DNA Damage Quantification (LORD-Q) qPCR-based method for the analysis of the mitochondrial genome of Common carp (Cyprinus carpio L.) and detect the DNA damaging effect of T-2 (4.11 mg kg-1) and deoxynivalenol (5.96 mg kg-1) mycotoxins in a 3-week feeding period. One-year-old Common carp were treated in groups (control, T-2 and DON). The mycotoxins were sprayed over the complete pelleted feed, and samples were taken weekly. Following the adaptation of LORD-Q PCR method for the Common carp species, the number of lesions were calculated to determine the amount of DNA damage. In the first and second weeks, the T-2 and the DON treated groups differed significantly from each other; however these differences disappeared in the third week. There was a significant difference in the DNA lesion values between weeks 1 and 3 in the deoxynivalenol-contaminated groups. While in the T-2 treated groups, the DNA lesion values were significantly reduced on weeks 2 and 3 compared to week 1. The results suggested that the trichothecene mycotoxins have a relevant DNA damaging effect.

Comet assay study of the genotoxic effect of T-2 and HT-2 toxins in chicken hepatocytes.

BACKGROUND AND AIMS: The aim of this study was to verify that the comet assay can be used to investigate the DNA damaging effects of T-2 and HT-2 toxins in the liver of broiler chickens. The comet assay is a favorable genotoxic analysis because it is cheap, simple, and can be used in many organisms and different tissues. MATERIALS AND METHODS: Male broiler chickens were fed with T-2/HT-2 toxins-contaminated diet for 14 days. The comet assay was successfully adapted to chicken liver cells, and the DNA damage was determined by a decrease in the comet parameter (DNA % in the tail) in the experimental groups. RESULTS: The method of evaluation was found to be critical because DNA damage could not be detected exactly using the CometScore software, due to inaccurate separation of head and comet. However, this problem can be solved by visual evaluation. CONCLUSION: In the case of the visual evaluation, each toxin-treated group differed significantly from the control group, indicating that the assay can be useful for the assessment of primary DNA damage caused by T-2/HT-2 toxins.

Effects of subclinical Mycobacterium avium ssp. paratuberculosis infection on some physiological parameters, health status and production in dairy cows.

Milk yield, milk ingredients, health and other, production-related parameters of subclinically infected, Mycobacterium avium ssp. paratuberculosis (MAP-) shedding (positive faecal PCR, n = 20) and non-shedding (negative faecal PCR, n = 10) dairy cows were compared in the period from 10 days prepartum to 120 days postpartum. Body condition, rumen fill and faeces scores were lower in the MAP-shedding cows. There was no significant difference in plasma or urine metabolic parameters between the groups. Milk yield and lactose content tended to be lower (P = 0.074 and 0.077, respectively), somatic cell count tended to be higher (P = 0.097), while milk fat content was significantly higher (P = 0.006) in MAP-shedding cows than in the controls. Milk protein content did not differ between the groups. All other health and production parameters [number of reproductive tract treatments, number of udder treatments, number of artificial inseminations (AIs), calving interval, and service period] were significantly better in the control group. It is concluded that MAP infection, even in a subclinical form, has a significant impact on some production and health parameters of dairy cows.