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.

Prevalence of Cryptosporidium infection in goats maintained under semi-extensive feeding conditions in the southeast of Spain.

The aim of the present study was to estimate the prevalence of Cryptosporidium parvum infection in goats maintained under semi-extensive feeding conditions in the southeast of Spain. Four farms took part in the study. Samples were obtained during the autumn and spring kidding seasons. The goats were divided into three groups: group I (0-15 days), group II (> 15 days-2 months) and group III (> 2 months-9 years). Faecal specimens were concentrated and smears of the sediment (25 microl) were stained by the modified Ziehl-Neelsen acid fast technique. Parasite oocysts were identified in all the farms; of the 582 goats, 111 were found to have the parasite in their faeces, i.e. the prevalence was 19.1%. The frequency distributions of the Cryptosporidium oocyst counts according to the age categories were 10.4%, 13.4% and 25.2% for groups I, II and III respectively. With respect to the kidding season, nodifferences were found. The present study revealed the high prevalence of Cryptosporidium infection in goats in the studied zone.

Nutritional utilization in Malagueña dairy goats differing in genotypes for the content of alphaS1-casein in milk.

A study was carried out with 20 goats of the Malagueña breed, half with a high (HG) and half with a low (LG) genetic capability for alpha(S1)-casein (AS1-CN) synthesis, to determine whether the 2 different genotypes (that cause differences in goat milk composition) are related to differences in nutritional feed utilization. Among the 10 HG goats, 7 had BB and 3 had AB genotypes for AS1-CN, whereas there were 7 EF and 3 FF genotypes in the 10 LG goats. The goats were fed diets differing in crude protein content (13.6 vs. 17.7% dry matter for diets 1 and 2, respectively). For each genotype group, a balance trial was conducted with each of the 2 diets in a 2-period balanced changeover designed with half the animals consuming diet 1 and the other half diet 2, determining individual feed intake and the utilization of N and energy in the diets. Greater voluntary feed intake on a metabolic body weight basis among the HG goats was identified as the first possible cause of their milk production. The HG goats also had a greater level of feed utilization, on a metabolic body weight basis, for N and energy intake. Greater ratios of N balance/ digestible N, milk protein N/digestible N, milk energy/ digestible energy, and milk energy/ME were found for HG goats compared with LG. These effects appear to be dependent on the level of protein in the diet, indicating interactive effects. The greater N and energy utilization of HG versus LG goats may explain the differences in milk composition between the 2 genotype groups.

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.

Dietary supplements for lactating goats by polyunsaturated fatty acid-rich protected fat. Effects after supplement withdrawal.

The objective of this study was to investigate the persistence of the effects of supplements after they were withdrawn. Two groups of 12 goats were maintained under semiextensive breeding conditions; they were fed indoors with a concentrate with alfalfa hay and olivetree leaves. Goats were in their sixth month of lactation at initiation of the study. During the first month of the trials, the concentrate supplied to the goats was either nonsupplemented (group 1) or supplemented with 9% polyunsaturated fatty acids (PUFA)-rich protected fat (group 2). After this period, the 2 groups were given the nonsupplemented until the average daily production of milk per animal within each group had decreased to 300 g or less. The fat supplementation supplied increased milk production and also improved fat and protein yield. These effects persisted after the supplement was withdrawn. The supplement, moreover, produced noticeable changes in the fatty acids profile of the milk fat, namely a reduction in the concentration of saturated fatty acids and an increase in that of PUFA. In contrast to the effects on milk production and on the yield of its main constituents, the effects on fat composition disappeared when the supplement was withdrawn.

Polyunsaturated fatty acids and parasitism: effect of a diet supplemented with fish oil on the course of rat trichinellosis.

Dietary fish oil has a beneficial effect on heart and some bacterial diseases and apart from other effects, some studies have revealed their ability to modulate the course of inflammatory and autoimmune diseases. The study here reported was designed to evaluate the possible influence of a fish oil supplement on the course of a Trichinella infection. Nutritional, parasitological and immunological parameters were analyzed. Two groups of 20 Wistar rats, one fed a standard diet and the other one a standard diet supplemented with fish oil, were infected with 1000 L1 larvae. Other two uninfected groups served as control. Results were as follows: fish oil diet intake and infection have, respectively, a positive and a negative effect on growth and food utilization. The negative effect is detected later in animals fed the fish oil diet. A reduction of 30.9 and 36.6% in the number of adult worms and L1 larvae, respectively, was observed in the fish oil group as compared to the standard diet group. Production of IFNgamma (Th1 response) and IL4 (Th2) response was measured in stimulated splenic cells. The fish oil diet increased both IFNgamma and IL4 levels. At 6 days after infection both IFNgamma and IL4 responses were detected, but at 36 days after infection only IL4 was detected in the standard group. The level of somatic and cuticular antibodies was not affected by the diet.

Physiological responses of pre-ruminant kid goats and lambs to different environmental temperatures.

The purpose of this study was to establish the metabolic behaviour of both preruminant kid goats and lambs, when they are kept at different environmental temperatures (12, 24 and 30 degrees C). The animals were fed ad libitum with a milk replacer for the first two months of life. Blood samples were taken from all the animals on days 30, 40, 50 and 60 post partum, to determine serum levels of glucose, insulin, free fatty acids, triiodothyronine (T3) and thyroxine (T4), both when fasting and 4 hours after starting feeding. The high sensitivity of both kinds of animal to the lowest of the environmental temperatures used, particularly for the first periods of life here considered, was established from the glucose/insulin and T3/T4 molar ratios and from the concentrations of free fatty acids. The results obtained by species were also evidence of metabolic behaviour typical of leanner animals in kids.

Use of different dietary protein sources for lactating goats: milk production and composition as functions of protein degradability and amino acid composition.

To establish the effect of the nature of four different protein sources [fababeans, 27.8% crude protein (CP); sunflower meal, 41.7% CP; corn gluten feed, 18.8% CP; and cottonseed, 18.3% CP] on milk protein production by goats, the ruminal degradation of these feeds was studied as was the amino acid (AA) composition of the original material and that of the undegradable fractions of the protein sources. Four diets were designed; 20% of their protein was supplied by each of the different sources. Four groups of 5 Granadina goats were used to study the utilization of these diets for milk production. No significant differences were observed in dry matter intake or milk production. The milk produced by goats fed the diet containing sunflower meal had the lowest protein concentration; the highest milk protein concentration was observed for goats fed the diet containing corn gluten feed. From a multivariate analysis, it was deduced that the quickly degradable protein fraction in the rumen and the ruminally undegradable protein fraction were the components of the protein sources most directly related to the milk protein produced. Given the similar AA profiles of the undegradable fractions of the different protein sources, the possible supplementation achieved from these ruminally undegradable fractions must be established by the amount of protein supplied regardless of AA composition.

Dietary factors affecting the maximum feed intake and the body composition of pre-ruminant kid goats of the Granadina breed.

An experiment was carried out with kid goats of the Granadina breed to identify the dietary factors affecting voluntary feed intake of the kid goat and those that additively could determine its body composition. The animals used were from birth to 61 d of age, fed ad lib. on different milk replacers containing 200, 240 and 280 g crude protein/kg DM and 200, 240 and 280 g fat/kg DM, thus giving nine dietary treatments. The utilization of the milk replacers and the animals' body composition were determined by balance and slaughter trials. There were significant positive effects of protein concentration of the milk replacers on component digestibilities, energy metabolizability, feed intake, empty-body weights, empty-body composition and protein and fat retention. The concentration of fat in the milk replacers also had a significant positive effect on the digestible and metabolizable energy concentration of the diets and on fat retention. The relationships existing between feed intake and diet composition (concentration of digestible protein, metabolizable energy and digestible protein:metabolizable energy ratio) as well as between empty-body composition or protein and fat retention and diet composition, were examined. From these it was deduced that feed intake was significantly influenced by the digestible protein concentration of the diets. The higher the digestible protein concentration the higher the feed intake up to a maximum digestible protein concentration value. As the digestible protein concentration of the diets was the dietary factor which significantly influenced feed intake, this also significantly influences the body composition and the protein and fat retention. The protein concentration of the feed at which metabolizable energy intake in these animals would be greatest was estimated to be 347 g/kg DM.

[Vaccination against hepatitis B at the Palma-Palmilla Health Center of Málaga]. / Vacunación contra la hepatitis B en el Centro de Salud Palma-Palmilla de Málaga.

AIM: To describe the results of a programme of anti-hepatitis B vaccination of high-risk groups. DESIGN: Observational descriptive study, of a retrospective character. SITE. At a community level within the confines of Primary Care in the Palma-Palmilla (Málaga) Health Centre, between June 1989 and March 1990. PATIENTS AND OTHER PARTICIPANTS: Individuals with a high risk of Hepatitis B infection, according to a modified CDC (Centre for Diseases Control) scale. The subjects were found during their attendance as patients and from among the Health Centre staff. INTERVENTIONS: The second generation vaccine developed by genetic engineering (Engerix B) was used. It was administered by intramuscular injection in a dosage of 20 mcg to those weighing more than 25 kilos; and of 10 mcg to those weighing less than 25 kilos. The vaccination pattern was of three doses in months 0, 1 and 6, followed by a monthly sero-conversion check. MEASUREMENTS AND MAIN FINDINGS: 169 individuals began the vaccination programme: 17.7% were health workers and 81.6% lived with carriers of the virus. 87.6% completed the vaccination programme. Sero-conversion in the individuals controlled was 95.5%. Only five patients were sero-negative after the third vaccination. Of these four cases achieved sero-conversion after a fourth or fifth dosage. CONCLUSIONS: We found there was a high rate of sero-conversion; and also high acceptance of the programme by those living with a carrier.

Factors affecting the food intake, growth and protein utilization in the Helix aspersa snail. Protein content of the diet and animal age.

Food intake, growth and protein utilization were studied in the Helix aspersa snail by means of a nutritional balance experiment. This was designed in a 5 x 11 factorial arrangement involving 5 diets of different protein content (10.0, 12.5, 15.0, 17.5 and 20.0%) and 11 animal ages (ranging over 15 to 180 days of age). Dietary protein content and animal age determined food intake and protein utilization. The variations of dry matter and protein intake rates, growth rates, growth efficiency factors and protein retention rates, depending on dietary protein content or animal age were in agreement with what happens in other animals. These results suggest that there is no need to use diets with more than 17.5% of crude protein in these animals.

Land snails as experimental animals: a study of the variability and distribution of individual weights in Helix aspersa snails born from the same clutch.

A study was carried out to examine the distribution of individual weights in Helix aspersa snails, the aims being to establish the best estimate of the ponderal growth and also to obtain a model growth curve. Four groups of 20 snails from the same clutch were analysed and kept under experimental conditions from birth up to 6 months. The variability of their individual weights within groups was studied by calculating the coefficients of variation every 15 days. At the same time, the assumed normal distribution of those weights was being tested. The coefficients of variation increased with age and the assumed normal distribution of individual weights had to be rejected. By means of a log transformation of the original data, a model growth curve was constructed, and was used to assess the possibility of estimating age from weight. We finally reached the conclusion that median weight, rather than the mean, would be a better measure of central tendency to use until it is possible to obtain selected populations. The difficulty of estimating age from weight is emphasized.