M. Bernardini

Effect of dietary vitamin E on the oxidative stability of raw and cooked rabbit meat

The effect of dietary α-tocopheryl acetate supplementation (200mg/kg diet) on plasma and muscle levels of α-tocopherol and the oxidative stability of raw and cooked rabbit meat was determined. Two groups of 20 male hybrid rabbits were fed the experimental diets from 35 to 80 days of age. Feed intake, live weight, feed efficiency and qualitative traits of the carcass and meat were recorded. The α-tocopherol levels in plasma and muscle were significantly higher (p≤0·01) in the supplemented group, which also showed an increase in oxidative stability in both raw and cooked meat. The higher α-tocopherol level improved the physical traits of the meat, significantly reducing shear value and increasing water-holding capacity; n-3 fatty acids in raw and cooked meat increased (p≤0·05) and the thrombogenic index decreased (p≤0·05). Dietary vitamin E did not influence weight gain, feed intake and dressing yield.

Performance and behaviour of chickens with different growing rate reared according to the organic system

Abstract The performance and the behaviour of three different chicken strains, reared according to the EEC-Regulation 1804/1999 on organic system, were compared. The strains had very slow (Robusta maculata), slow (Kabir) and fast (Ross) growing rates, respectively. The trial was carried out on 200 chickens (male and female) per strain. Rearing lasted 81 days as required by the EEC Regulation. At slaughter age, 20 birds per group were killed. Robusta maculata and Kabir chickens showed more intense walking activity and better foraging aptitude; their antioxidant capacity was also superior. Ross chickens had a good growth rate and feed conversion index, reaching an excellent body weight, but the mortality and the culling rate were high indicating that fast-growing strains do not adapt well to organic production. Robusta maculata showed the worst productive performance although the mortality was low and Kabir birds gave intermediate results. The carcass traits were the best in Ross and the poorest in Robusta maculata. Male chickens were heavier and leaner than females.

Effect of dietary n-3/n-6 ratio on fatty acid composition of liver, meat and perirenal fat in rabbits

The metabolic pathways of dietary fatty acids were studied in rabbits by analysing the fatty acid profile of different tissues (liver, perirenal fat, longissimus lumborum muscle). Four groups of 24 hybrid males each were assigned to four semi-purified diets, varying in the source oflipids which differed in n-3/n-6 ratios: 180 g/kg sunflower (S), 80 g/kg flaxseed + 90 g/kg sunflower (SF), 160 g/kg flaxseed (F) and 60 g/kg fish oil (FI). The liver showed a very important role in fatty acid syntheses and was the tissue richest in long-chain (≥20 C) polyunsaturated fatty acids (LCP) of n-3 and n-6 series. The S diet gave the highest mono-unsaturated fatty acids and n-6 LCP (respectively, 201·9 and 384·9 g/kg, P P P P

Improvement of lipid stability of rabbit meat by vitamin E and C administration

The effect of administering vitamins E (E50 or E200: 50 or 200 mg kg diet) and C (C500 or C1000: 500 or 1000 mg l−1 water) singly and in combination was verified on plasma and muscle levels of α-tocopherol and the oxidative stability of rabbit meat during display. Six groups of 10 hybrid males were fed experimental diets from 35 to 85 days of age. Productive performance and carcass drip loss were also recorded. Performance was unaffected by treatments, but drip loss was improved by simultaneous administration of the two antioxidants. The α-tocopherol levels in plasma and muscle were significantly higher in animals which simultaneously ingested the highest amounts of the two vitamins, and the oxidative processes (TBA-RS values) of their meat during storage were lower. The results confirm the synergistic action of ascorbate and the benefit of using high levels of the two vitamins to prevent oxidative stress during meat processing and storage. © 2000 Society of Chemical Industry

Effect of dietary α-tocopheryl acetate and ascorbic acid on rabbit semen stored at 5 °C

Abstract The objective of this research was to verify the effects of dietary α-tocopheryl acetate (50 vs. 200 mg/kg diet) and ascorbic acid (0 vs. 1 g/L water) on the relative amounts on semen and motion characteristics, oxidative stability and fertilizing ability of rabbit spermatozoa stored for 24 h at 5 °C. A high amount of dietary α-tocopheryl acetate significantly increased the level of Vitamin E in the semen (0.90 vs. 0.41 μmol/L) and its oxidative stability after storage (Thiobarbituric Acid Reactive Substances — TBARS 15.88 vs. 20.90 nmol Malondialdehyde — MDA/mL). Ascorbic acid showed a different effect in relation to the Vitamin E status of animals: when associated with the higher level of Vitamin E it increased the α-tocopherol and the oxidative stability of semen (2.67 μmol/L and 12.25 nmol MDA/mL, respectively), whereas both parameters were reduced with lower Vitamin E (0.13 μmol/L and 21.20 nmol MDA/mL). Semen traits were not modified by the separate supplementation of supranutrional levels of vitamins, whereas their combination significantly improved the viability and the kinetics of spermatozoa (e.g. track speed: 95.13 vs. 71.31 μm sec −1 ) with an increase in fertility rate (70.0 vs. 63.3; P=0.06) that could be considered almost significant.