Two experiments were conducted to evaluate the effect of a lactic acid bacteria-based probiotic (FloraMax-B11^®) against Salmonella enterica serovar Enteritidis intestinal colonization and intestinal permeability in broiler chickens. Experiment 1 consisted of two independent trials. In each trial, day-old broiler chicks were assigned to one of two groups: control + S. Enteritidis or probiotic + S. Enteritidis. At 72 h post-S. Enteritidis challenge, haematology and caecal content were evaluated for S. Enteritidis colonization. In Experiment 2, day-old broiler chicks were assigned to one of four groups: negative control; probiotic; control + S. Enteritidis; or probiotic + S. Enteritidis. At 72 h post-S. Enteritidis challenge, chickens in all groups were given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). In both trials of Experiment 1, a significant reduction (P < 0.05) in colony-forming units/gram of S. Enteritidis in caecal content and a reduction in the incidence of S. Enteritidis enriched caecal samples were observed in probiotic + S. Enteritidis chickens. In addition, significant heterophilia and lymphopaenia were observed in control + S. Enteritidis chickens. In Experiment 2, a decrease in numbers of S. Enteritidis in caeca were observed in probiotic + S. Enteritidis chickens when compared to control + S. Enteritidis. Also, an increase in serum FITC-d concentration was detected in control + S. Enteritidis. These results suggest that early infection with S. Enteritidis can increase intestinal permeability, but the adverse effects can be prevented by the administration of the probiotic tested.

The effect of the fungus Metarhizium anisopliae Ma14 strain, D-limonene, and cypermethrin, alone and combined, on the mortality of Rhipicephalus sanguineus Latreille larvae was evaluated. Eight separate groups with 25 tick larvae were inoculated with the fungus, cypermethrin, and D-limonene, and four groups were used as untreated controls. The groups were inoculated with serial dilutions of each treatment material: for example, conidial concentrations were 1 × 10¹, 1 × 10², 1 × 10³, 1 × 10⁴, 1 × 10⁵, 1 × 10⁶, 1 × 10⁷, and 1 × 10⁸. A complete randomized experimental design was used. Significant differences were obtained between fungal concentrations, with larval mortalities ranging from 29 to 100%; the D-limonene concentrations showed significant differences, with mortalities that ranged from 47.9 to 82.6%, and cypermethrin mortalities ranged from 69.9 to 89.9% when each was applied alone. In the combined application, the serial dilution of the Ma14 fungus plus cypermethrin at 0.1% concentration caused mortalities ranging from 92.9 to 100%; the mix of serially diluted Ma14 plus D-limonene at 0.1% caused mortalities from 10.3 to 100%; and the mix consisting of serially diluted D-limonene plus cypermethrin at 0.1% caused mortalities from 7.4 to 35.9%. Further laboratory and field research could show that these materials, alone and in combinations, are useful in future tick management and control programs.

The aim of this study was to assess the relationship between biochemical analytes and milk fat/protein in high-yield (DIM: 42 ± 10 d postpartum) and low-yield (DIM: 91 ± 11 d postpartum) Holstein cows. Stepwise regression analysis was used to evaluate the relationships of biochemical analytes with the fat and protein content of the milk from 126 Holstein cows belonging to nine intensive housed dairy farms. The comparison between the two groups showed differences (P<0.05) in the milk yield, milk fat and milk fat/protein ratio, with the higher values in high-yield cows. The correlations between milk fat, milk protein, milk fat/protein ratio and biochemical analytes concentrations, were assessed within each group. Milk fat level was positively correlated to cholesterol, triglycerides, p-hydroxybutyrate and albumin in high-yield cows. Milk protein level was positively correlated to urea, and negatively correlated to sodium ion, potassium ion and chlorine ion in high-yield cows. A virtually linear dependence has also been found between milk fat and triglycerides, between milk protein and urea, and between milk fat/protein ratio and cholesterol, and triglycerides in low-yield cows. The metabolic profiles provide a practical tool, to present an insight into the underlying physiological mechanisms of lactation, and the identification of relationships between key analytes and components of milk, such as protein and fat content.

Crossbred Dairy Cattle is the Answer to Improve Environment Dependent Productive and Physiological Responses – A Review

Harina de atún negra en dietas de gallina para incrementar los ácidos eicosapentanoico y docosahexaenoico

English Thoroughbred horses, are widespread in Mexico and due to the lack of data on their exercise physiology, it is important to conduct exercise tests in order to obtain information the effects of exercise on more essential cations/anions in blood serum, as these horses are submitted to constant efforts. The study was carried out with 150 blood samples of English Thoroughbred horses clinically healthy. The blood sample collection was performed during three periods: 1) rest, 2) 30min after exercise (speed race of 12km/h for 30min with no rest) and 3) 60min after exercise. Mean values were calculated for cations (sodium and potassium) and anions (chloride and bicarbonate). The resulting data set was analyzed using Gaussian distribution and descriptive statistics. Confidence intervals of 95% were established. The linear relationships between ions were quantified, and an analysis of variance was performed to compare the mean values between groups. The concentrations of the described analytes are consistent with values reported by international literature. The comparison between groups, revealed that during exercise, sodium ion did not show changes 30min after exercise and increase 60min after. Potassium ion showed increase 30min after exercise and decrease 60min after. Chloride ion showed a decrease 30min after exercise, to recover gradually 60min after. Meanwhile, bicarbonate ion showed increase 30min after exercise, decreasing slightly in the final stage. Negative correlation between bicarbonate ion and chloride ion were determined. It was concluded that exercise tests are useful for the determination of acid-base balance and osmotic balance, and their main role is to evaluate the athletic ability of horses.Considering that chloride ion excretion and metabolic adjustments of potassium ion and bicarbonate ion are superior to water loss, compared to the normal osmolarity of blood serum. The results found can be used to structure an adequate replacement program of electrolytes lost in sweat.