Contribution of insulin to the ascorbate recycling system in the chicken liver

The effect of insulin on the ascorbate recycling system in the chicken liver was examined. First, insulin was injected subcutaneously into the chicken, and liver glutathione‐dependent dehydroascorbate reductase (GSH‐DHAR) activity was determined. Insulin increased liver GSH‐DHAR activity, but did not affect plasma and liver ascorbate concentration. Dehydroascorbate increased plasma and liver ascorbate levels, and liver GSH‐DHAR activity. However, distinct changes in plasma insulin level were not observed by dehydroascorbate injection. In addition, reduction of external dehydroascorbate in cultured chicken hepatocytes could not be observed in an insulin‐deprived culture, although the cells reduced external dehydroascorbate in a serum‐free culture with insulin. We concluded that insulin affects the ascorbate recycling system as an essential factor in the chicken liver.     

Development of X-ray computed tomography for live standing cattle

An X‐ray computed tomography (CT) system for live standing cattle was developed for studying the meat yield, carcass composition and so on. The gantry contained three X‐ray tubes and detectors that corresponded to each X‐ray tube. The system was able to operate while the animal remained standing. The scan area had a diameter of 900 mm. The Musculus longissimus and Musculus trapezius areas, and the back fat thickness in the CT image were evaluated and compared to the actual cross‐section of the carcass using eight cattle. The differences among the muscles, and the subcutaneous and intermuscular fat were easily recognized. The correlation coefficient between the CT image and the actual carcass photograph of the M. longissimus area and the back fat thickness was high (r = 0.84, r = 0.93, P < 0.01). The present study demonstrated that muscle, fat and bone can be clearly imaged from a live standing animal using X‐ray equipment.     

Sericin Accelerates the Production of Hyaluronan and Decreases the Incidence of Polyspermy Fertilization in Bovine Oocytes During In Vitro Maturation

Fetal bovine serum (FBS) has been widely used as a supplement in the maturation medium of bovine oocytes in vitro. However, serum contains many undefined factors and is potentially infectious to humans and animals. As a serum replacement, we evaluated the feasibility of using the silk protein, sericin, derived from the cocoons of silkworm. To examine the rates of oocyte maturation and fertilization, cumulus-oocyte complexes were cultured in TCM-199 supplemented with 0.01%, 0.05%, 0.1% or 0.15% sericin or 5% FBS. The sizes of the perivitelline space that might relate to polyspermy, the expressions of Has2 and CD44 mRNA, the amount of hyaluronan (hyaluronic acid: HA) contained in the oocytes and the rates of blastocyst formation following insemination were then compared between the oocytes cultured with 0.05% sericin and 5% FBS, because the polyspermy rates in oocytes cultured with 0.05% sericin were significantly lower than in those cultured with 5% FBS. After in vitro maturation (IVM), the mean size of the perivitelline space was significantly greater in oocytes cultured with sericin than in those cultured with FBS, although the rates of nuclear maturation, fertilization and blastocyst formation of oocytes under both IVM conditions were not significantly different. The expression of HAS2 and CD44 mRNA and the amount of HA in the denuded oocytes cultured with 0.05% sericin were significantly greater than in those cultured with FBS. These results indicate the feasibility of sericin as an alternative protein supplement for IVM in bovine oocytes.     

Comparison of the antioxidant activities of 22 commonly used culinary herbs and spices on the lipid oxidation of pork meat

The antioxidant activities of 22 selected culinary herbs and spices (i.e. ginger, cinnamon, clove, bay, sage, rosemary, thyme, savory, oregano, sweet basil, parsley, coriander, tarragon, sansho, allspice, cumin, black and white peppercorns, nutmeg, caraway, dill and fennel) when they were added to pork homogenate were measured and expressed as a thiobarbituric acid (TBA) value. The addition of liquid extracts of all the herbs and spices significantly suppressed lipid oxidation of the pork, especially the extracts of sansho, sage and ginger, which showed the strongest inhibition of lipid oxidation.