A novel test for evaluating horses' spontaneous visual attention is predictive of attention in operant learning tasks.

Attention is described as the ability to process selectively one aspect of the environment over others. In this study, we characterized horses' spontaneous attention by designing a novel visual attention test (VAT) that is easy to apply in the animal's home environment. The test was repeated over three consecutive days and repeated again 6 months later in order to assess inter-individual variations and intra-individual stability. Different patterns of attention have been revealed: 'overall' attention when the horse merely gazed at the stimulus and 'fixed' attention characterized by fixity and orientation of at least the visual and auditory organs towards the stimulus. The individual attention characteristics remained consistent over time (after 6 months, Spearman correlation test, P < 0.05). The validity of this novel test as a predictor of individual attentional skills was assessed by comparing the results, for the same horses, with those obtained in both a 'classical' experimental attention test the 'five-choice serial reaction time task' (5-CSRTT) and a work situation (lunge working context). Our results revealed that (i) individual variations remained consistent across tests and (ii) the VAT attention measures were not only predictive of attentional skills but also of learning abilities. Differences appeared however between the first day of testing and the following test days: attention structure on the second day was predictive of learning abilities, attention performances in the 5-CSRRT and at work. The VAT appears as a promising easy-to-use tool to assess animals' attention characteristics and the impact of different factors of variation on attention.

Oral administration of pectin-rich plant extract enhances C3 and C4 complement concentration in woman colostrum.

C3 and C4 components of the complement are normally present in human colostrum. These compounds are natural antibacterial agents. Pectin-rich plant extracts have been shown to induce prolactin release and milk synthesis when administered by the oral route in rat. In the present work, extract from a plant rich in pectin, Gossypium herbaceum was given orally to women 2 days after parturition. The extract enhanced concentration of C3 and C4 in colostrum but did not modify the total hemolytic complement activity (TCH50). No change in the concentration of the three compounds was observed in serum of the treated women. Control experiments showed that a treatment by placebo had no effect on colostrum composition. These data suggest that pectin-rich plant extracts favour transfer of C3 and C4 from blood to colostrum by an unknown mechanism. This observation suggests that some plant extracts might be used to reinforce the antibacterial activity of human colostrum.

Recombinant human extracellular superoxide dismutase produced in milk of transgenic rabbits.

Expression of human extracellular superoxide dismutase (EC-SOD), a glycosylated, tetrameric metalloprotein, was targeted to the lactating mammary gland of transgenic rabbits. Efficient expression of the recombinant whey acidic protein/ec-sod gene was achieved and up to 3 mg ml-1 of the enzyme was secreted into the milk. Rabbit milk-produced recombinant EC-SOD was primarily found in the whey and purified by a two-step chromatographic method. To evaluate the rabbit milk-produced human EC-SOD, comparisons with native and Chinese hamster ovary cell (CHO)-produced EC-SOD were performed. All proteins were tetrameric and N-glycosylated. The behaviour on SDS-PAGE and size-exclusion chromatography indicated that the masses, and thereby the extent of post-translational modification of the proteins was similar. The monosaccharide composition of both recombinant EC-SOD variants was analysed and indicated similarities in the attached N-glycans on the two proteins. Furthermore, the peptide maps of the three EC-SOD variants revealed that all proteins had similar polypeptide backbones.