The use of an optimised concentration of quercetin limits peroxidation of lipids in the meat of broiler chickens fed a diet containing flaxseed oil rich in omega-3.

Ross 308 chickens were used to investigate fatty acid (FA) composition and oxidative stability of broiler chicken meat following the controlled inhibition of peroxidation in feed containing a concentrated source of omega-3 fatty acids (flaxseed oil, FLO), approximately 50% omega-3. Ninety-six one-day-old chicks were randomly allocated to four dietary treatments (n = 24/group) that included rapeseed oil (RO), flaxseed oil (FLO), RO with optimised quercetin (Q) - RO_Q, or FLO with optimised Q (FLO_Q). On day 35, breast and thigh muscles were collected in order to analyse their FA profile and malondialdehyde (MDA) levels. Dietary treatments had no effect on weight gain or feed conversion ratio in chickens. However, dietary FLO increased the deposition of α-linolenic acid in both pectoral and thigh meat (P < 0.05), and tended to decrease the ratio of omega-6/omega-3 FA in pectoral muscles (P < 0.07). Addition of an optimised concentration of Q proved to be an efficient way of limiting lipoperoxidation in breast and thigh muscles subjected to refrigeration at 2-3 °C for either 1 or 7 days. Results were consistent with the observed inhibition of peroxidation in feed mixtures and significantly correlated with MDA levels found in feed mixtures. These results provide evidence that it is possible to produce poultry meat with an improved proportion of omega-3 FA without significantly altering the performance of broiler chickens or the oxidative stability of their meat.

Tissue-specific responses of antioxidant pathways to poor hygiene conditions in growing pigs divergently selected for feed efficiency.

BACKGROUND: Poor hygiene of housing induces a systemic inflammatory response. Because inflammation and oxidative stress are processes that can sustain each other, the ways pigs are able to activate their antioxidant defenses are critical for production performance and health during periods when the immune system is solicited. Selection for production performance can also influence reactive oxygen species (ROS) production and expression levels of genes involved in cellular response to oxidative stress in different tissues. To establish the extent by which poor hygiene and selection for feed efficiency affected redox status, pigs divergently selected for residual feed intake (RFI) were housed in poor or good hygiene during 6 weeks. At the end, blood was collected in all pigs, and half of them were killed for tissue sampling. The remaining pigs were reared in good hygiene conditions during a recovery period of 7-8 weeks. RESULTS: At week 6, poor hygiene was associated with a lower total antioxidant capacity assessed by plasma ferric reducing ability in all pigs, and with greater plasma levels of hydrogen peroxides in the high RFI pigs (less efficient). Adipose tissue of high RFI pigs exhibited higher activities of catalase and glutathione reductase, and greater thiobarbituric acid reactive substances (TBARS) concentrations when compared with the low RFI pigs (more efficient). Poor hygiene conditions activated the antioxidant enzymes activities (glutathione reductase, superoxide dismutase and catalase) in adipose tissue of both lines, but led to higher ROS production by mature adipocytes isolated from the high RFI pigs only. In liver and muscle, there were only minor changes in antioxidant molecules due to genetics and hygiene conditions. After the resilience period, adipose tissue of pigs previously challenged by poor hygiene maintained higher antioxidant enzyme activities, and for the high RFI line, displayed higher TBARS concentrations. CONCLUSIONS: Pigs selected for improved feed efficiency showed a lower susceptibility to oxidative stress induced by poor hygiene conditions. This could led to a lower inflammatory response and less impaired growth when these pigs are facing sanitary challenges during the production period.

Cultural differences in preferences for shapes.

It was predicted that since there is less sexual restraint in Jamaica the sex difference in shape preference should be larger for native adult Jamaicans than Caymanian adults. Pairs of drawings of a "female" and a "male" object, depicted according to the theory of sexual symbolism, were shown to 200 subjects, who indicated which of each pair they preferred. The larger sex difference found among Jamaicans was interpreted in terms of primary sexual stimulus generalization.