Selective decline of bacteria colonizing the calf hindgut during colostrum to milk transition, with persistence of taxa correlating with host passive immunity.

In neonate calves, the association between gut microbial colonization and passive immunity acquisition remains largely unknown. We evaluated the effect of transition from colostrum to milk on the hindgut microbiota, and the correlations between acquired passive immunity and this microbiome. In 14 Holstein calves, colostrum quality and host passive immunity were measured, feces were sampled when feeding colostrum and after transition to milk. Then, in eight calves displaying a wide range of passive immunity, the hindgut microbiota was evaluated with DNA sequencing; differential abundance was analyzed with Maaslin2. With transition from colostrum to milk, many initial bacterial colonizers did not survive; genus Ralstonia decreased, but Lactobacillus and Bacteroides increased. When feeding colostrum, the amount of immunoglobulins consumed positively correlated with abundance of Lactobacillaceae and Lachnospiraceae, but Escherichia-Shigella and Clostridium sensu stricto 1 correlated negatively with host passive immunity. After transition to milk, acquired passive immunity negatively correlated with Clostridium sensu stricto 1, Ralstonia, and Veillonella. Overall, many initial hindgut colonizers did not thrive during transition from colostrum to milk, homogenizing the bacterial profile with prevalence of milk digesters. Several bacterial taxa showed strong correlation with host passive immunity, suggesting an interplay between calf passive immunity acquisition and the colonizing microbiota.

Goats' Feeding Supplementation with Acacia farnesiana Pods and Their Relationship with Milk Composition: Fatty Acids, Polyphenols, and Antioxidant Activity.

BACKGROUND: Research efforts have focused on the evaluation of the bioactive quality of animal products (milk, cheese, meat, and other by-products) contrasting various feeding strategies coming from different ecological zones. The study aimed to describe the fatty acids (FA), polyphenols (P), bioactive compounds (BC), and antioxidant activity (AA) of goat's milk. METHODS: Dairy goats were fed with five systems: (1) Grazing; (2) conventional diet (CD); (3) CD + 10% of Acacia farnesiana (AF) pods; (4) CD + 20% AF; and (5) CD + 30% AF. The fatty acid profile, health promoting and thrombogenic indexes were calculated. Milk extracts were evaluated by HPLC to determent phenolic compounds (gallic, caffeic, chlorogenic, and ferulic acids, catechin, epicatechin, and quercetin). Antioxidant activity of goat's milk extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) assays. RESULTS: Conventional diet showed the highest content of polyunsaturated fatty acids while grazing showed the best n-6:n-3 and the linoleic:alpha linolenic acid ratio. Similarly, grazing and AF boosted the polyphenol content. CONCLUSIONS: Acacia farnesiana inclusion in the goats' diets increased the presence of bioactive compounds and the antioxidant activity while diminishing the cholesterol content of goat's milk.

Antioxidant activity and protection against oxidative-induced damage of Acacia shaffneri and Acacia farnesiana pods extracts: in vitro and in vivo assays.

BACKGROUND: Obesity is a worldwide public health issue, reaching epidemic condition in developing countries associated to chronic diseases. Oxidative damage is another side effect of obesity. Antioxidant activity from plant components regulates at some extent this imbalance. Main goal of the present study was to determine the antioxidant activity and protection against oxidative-induced damage of Acacia shaffneri (AS) and Acacia farnesiana (AF) pods extracts. METHODS: To evaluated antioxidant activity and radical scavenging capacity of AS and AF extracts, two experiments were performed: 1) pods extracts were challenged against H2O2 using kidney cells in an in vitro assay; and 2) (Meriones unguiculatus) was employed in an in vivo assay to observe the effect of pods extracts on scavenging properties in plasma. RESULTS: Both pods extracts presented an important protective effect on radical scavenging capacity against ABTS• + and DPPH(+), and also in TBARS formation in vitro. Vegetal pods extracts did not induce any pro-oxidative effect when added to kidney cells in DMEM. Cells damage in DMEM with addition of H2O2 was significantly higher than those when vegetal pods extracts were added at 50 (P < 0.05) or 200 ppm (P < 0.001). Plasma scavenging properties presented an important dose-dependent positive effect in those groups where pods extracts were administered. CONCLUSIONS: The antioxidant protection of the acacia pods extracts reported in this study suggests the possible transference of antioxidant components and protective effects to animal products (milk, meat, and by-products) from Acacia pods when this vegetation is included in the diet. In order to evaluate, the possible transference of theirs antioxidant components to animal products, the incorporation of these non-conventional resources to ruminant feeding is a good opportunity of study. Profiling of Acacia farnesiana pods extract is necessary to identify the responsible bioactive compounds of protective properties.