The Evaluation of the Effects of Dietary Vitamin E or Selenium on Lipid Oxidation in Rabbit Hamburgers: Comparing TBARS and Hexanal SPME-GC Analyses

The effects and specificity of dietary supplementation of EconomasETM (EcoE), mainly consisting of organic selenium (0.15 or 0.30 mg/kg feed; Se) or of vitamin E (100 or 200 mg/kg feed; VE), on lipid oxidation were evaluated in rabbit hamburgers during refrigerated storage. Oxidation data obtained by thiobarbituric acid-reactive substances (TBARS) spectrophotometric analysis and solid-phase microextraction (SPME) coupled with gas chromatography (GC) to determine hexanal content were compared. The relationships between oxidation levels, colour and pH and the discriminability of EcoE- or VE-treatment compared with control were also examined. TBARS content decreased in both VE and EcoE groups, while hexanal showed lower values only in the VE100 dietary group. The colour parameters were compatible with acceptable product quality and seemed to parallel the TBARS values up to the second day storage. Both VE and EcoE improved oxidative stability without affecting the sensory properties, but the VE effect appeared to more specifically hamper lipid oxidation, as evidenced by the determination and quantification of hexanal, a specific product of fatty acid peroxidation

RADICAL SURGICAL TECHNIQUE FOR TREATMENT OF WHITE LINE DISEASE IN DAIRY COWS

Introduction: this clinical research investigates whether rigorous and aggressive surgical debridement of white line disease (WLD) lesions in 236 lame cows, in association with a medicated bandage, would promote clinical healing (as evidenced by coverage of the lesion with new horn) with subsequent improvement in milk production. Materials and methods: after claw trimming, wall and sole horn were removed and the horn rim trimmed around and inside the lesion using a hoof knife, until abundant bleeding was present. The wound was then rinsed, covered with a topical antibiotic and bandaged. Results: out of the initial 236 lame cows, on day two 40 cows were not lame anymore and 196 cows showed a score of 2 out of 5. On day 18, two cows had a grade 4 lameness, with the lesions being smaller but not completely healed. On days 30 and 40, none of the remaining 234 cows developed recurrence of pathology or lameness. At day 60, lesions were completely healed. Discussion: this aggressive surgical treatment allows milk production not to decrease comparing to the control group and can be easily implemented in practice. Conclusions: Since bovine claw lesions represent one of the main problems in dairy cattles, this surgical technique could be suggested as a valid option for the treatment of WLD in cows

In vivo and in vitro effects of selected antioxidants on rabbit meat microbiota

The purpose of this study was to investigate the effect of dietary vitamin E or EconomasE™ supplementation on the growth of several background/pathogenic bacteria on rabbit carcasses and hamburgers during refrigerated storage. For 51days, 270 New Zealand rabbits received either a basal diet, or experimental diets enriched with 100 or 200mg/kg of vitamin E or EconomasE™. The bacteria studied were Salmonella, Listeria monocytogenes, Pseudomonas, Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, plus both mesophilic and psychrotrophic aerobes. The growth of Listeria monocytogenes on contaminated patties was evaluated through a challenge test. The potential protective or antimicrobial effect of vitamin E or EconomasE™ on Listeria monocytogenes or Pseudomonas aeruginosa was assessed in vitro. Diet did not influence the concentrations of bacteria found on rabbit carcasses and developing on hamburgers. Vitamin E (in vivo and in vitro) and EconomasE™ in vivo had a protective antioxidant role, while EconomasE™ in vitro had strong antibacterial activity against Listeria monocytogenes, but not against Pseudomonas aeruginosa

Effect of dietary inclusion of different lipid supplements on performance and carcass quality traits of growing beef heifers

The aim of this study was to evaluate the impact of dietary extruded flaxseed and/or rumen-protected lipids on growth performance and carcass quality of growing beef heifers. Sixty-three crossbreed heifers (Charolais X Limousine) were distributed into seven experimental groups, balanced in terms of age and live weight. Diets fed to the groups were isoproteic and differed in both, the dietary lipid source (extruded linseed and/or rumen-protected conjugated linoleic acid) and the supplementation length (90 or 180 days before slaughtering), having the same total amount of lipids and vitamin E, during their finishing period. The results obtained in the present study confirm that in low-protein diets, the inclusion of rumen-protected CLA, alone or in combination with flaxseed, did not bring any evident effect on feed intake, performance and carcass quality traits of growing beef heifers