M. Rodríguez Osorio

Evaluation of the allergenicity of goat milk, cow milk, and their lactosera in a guinea pig model.

The object of this study was to determine the allergenicity of goat milk (GM) and cow milk (CM) and that of their respective lactosera (GML and CML), by in vivo and in vitro assays. Two systemic tests for anaphylaxis were carried out in guinea pigs, the animals being sensitized orally with the 2 types of milk and lactosera. Sera were taken from the orbital sinus of the experimental animals at 0 and 22 d of the experiment to perform the serological study and the passive cutaneous anaphylaxis test. For the latter, the guinea pigs were sensitized passively with antibodies against the 4 antigen solutions. Enzyme-linked immunosorbent assay and Western blot were used to determine the specific antibodies of the isotypes immunoglobulin G1 and immunoglobulin G(Fc) developed against the same 4 antigen solutions. From these anaphylaxis and antibody-production tests, it was concluded that GM is hypoallergenic when compared with CM. The lactosera produced more closely grouped results, with values always below those of the corresponding milk. None of the proteins in the 4 immunizing solutions were identified as being their main allergen. These results show the hypoallergenicity of GM versus CM, and also that both casein and lactoserum proteins may be responsible for allergy in each case. To analyze the possibility of producing an innocuous food for those allergic to milk proteins, it would be of interest to identify the epitope(s) responsible for such allergenicity.

Thermogenesis associated to the intake of a diet non-supplemented or supplemented with n-3 polyunsaturated fatty acid-rich fat, determined in rats receiving the same quantity of metabolizable energy.

The beneficial effects of n–3 polyunsaturated fatty acids (PUFA) are well known, but their consumption in western countries is chronically insufficient, and so it is recommended that diets should be supplemented with a fat rich in these fatty acids. However, the effect of such diets on the energy expenditure remains a controversial question. Precise data concerning the effect of using under the same metabolizable energy intake, a diet non-supplemented or supplemented with a fat rich in n–3 PUFA are not available. This type of information was obtained using rats at weaning fed a diet supplemented or non-supplemented with 10% of fish oil. Between the 30th and 60th day after starting the experiment, the energy and protein balance was established by means of the comparative slaughter method. The blood levels of different metabolites were also determined. Although total thermogenesis did not vary between the two groups, consumption of the fish oil diet led to a lower level of thermogenesis associated with the oxidation of protein, and a higher one of that associated with the oxidation of fat. We conclude that the thermic effect of feeding is a combination of independent processes. Due to their specific metabolism, n–3 PUFA may be considered essential compounds to maintain the energy balance.

Effect of rumen-protected supplements of fish oil on intake, digestibility and nitrogen balance of growing goats

Two groups of six male goats were used to assess the effects of rumen-protected supplements offish oil on intake, digestibility and nitrogen (N) balance. The animals were offered a diet consisting of forage and concentrate, the latter fraction supplemented with 0 (control) or lOOg/kg of rumen-protected fish oil supplement (PFO), containing a high proportion of the n-3 series (whole diet contained 0 or 60 g PFO per kg dry matter). No significant differences (P > 0.05) were found between the two groups concerning live-weight gain, food intake, digestibility of DM, organic matter, N, neutral-detergent fibre and energy. In contrast, there were differences (P 0-05) were found regarding digestibility of total C18:1. In contrast, the coefficients for C18:2 (n-6) and C18:3 (n-3) were higher (P

Antigenic stimulation with goat and cow milk by oral and parenteral route in guinea pigs.

Abstract The aim of this study was to examine the sensitisation capacity of goat milk (GM) and cow milk (CM) by the oral or the parenteral route, and thus determine whether the serologic responses developed are different, identify the proteins targeted by the antibodies thus formed, and determine whether these antibodies depend on the immunisation route employed. Enzyme-linked immunosorbent assay was used to determine the specific antibodies of the isotypes IgG1 and IgG(Fc) developed against GM and CM. The sera from the animals immunised parenterally developed a stronger serologic response than did those immunised by the oral route. When CM was used as the immunising agent, the specific isotopic response was stronger than that obtained with GM. There were no differences in the antigen profile revealed by the sera of the animals immunised by the oral or parenteral routes. A marked degree of cross-reactivity between the two types of milk was found.Abstract The aim of this study was to examine the sensitisation capacity of goat milk (GM) and cow milk (CM) by the oral or the parenteral route, and thus determine whether the serologic responses developed are different, identify the proteins targeted by the antibodies thus formed, and determine whether these antibodies depend on the immunisation route employed. Enzyme-linked immunosorbent assay was used to determine the specific antibodies of the isotypes IgG1 and IgG(Fc) developed against GM and CM. The sera from the animals immunised parenterally developed a stronger serologic response than did those immunised by the oral route. When CM was used as the immunising agent, the specific isotopic response was stronger than that obtained with GM. There were no differences in the antigen profile revealed by the sera of the animals immunised by the oral or parenteral routes. A marked degree of cross-reactivity between the two types of milk was found.