Comparative composition, diversity, and abundance of oligosaccharides in early lactation milk from commercial dairy and beef cows.

Prebiotics are nondigestible dietary ingredients, usually oligosaccharides (OS), that provide a health benefit to the host by directly modulating the gut microbiota. Although there is some information describing OS content in dairy-source milk, no information is available to describe the OS content of beef-source milk. Given the different trait emphasis between dairy and beef for milk production and calf survivability, it is plausible that OS composition, diversity, and abundance differ between production types. The goal of this study was to compare OS in milk from commercial dairy and beef cows in early lactation. Early-lactation multiparous cows (5-12 d in milk) from 5 commercial Holstein dairy herds and 5 Angus or Angus hybrid beef herds were sampled once. Milk was obtained from each enrolled cow and frozen on the farm. Subsequently, each milk sample was assessed for total solids, pH, and OS content and relative abundance. Oligosaccharide diversity and abundance within and between samples was transformed through principal component analysis to reduce data complexity. Factors from principal component analysis were used to create similarity clusters, which were subsequently used in a multivariate logistic regression. In total, 30 OS were identified in early-lactation cow milk, including 21 distinct OS and 9 isomers with unique retention times. The majority of OS detected in the milk samples were present in all individual samples regardless of production type. Two clusters described distribution patterns of OS for the study sample; when median OS abundance was compared between the 2 clusters, we found that overall OS relative abundance was consistently greater in the cluster dominated by beef cows. For several of the structures, including those with known prebiotic effect, the difference in abundance was 2- to 4-fold greater in the beef-dominated cluster. Assuming that beef OS content in milk is the gold standard for cattle, it is likely that preweaning dairy calves are deprived of dietary-source OS. Although supplementing rations with OS is an approach to rectify this deficiency, understanding the health and productivity effects of improving OS abundance being fed to preweaning calves is a necessary next step before recommending supplementation. These studies should account for the observation that OS products are variable for both OS diversity and structural complexity, and some products may not be suitable as prebiotics

Characterization of recombinant human lactoferrin N-glycans expressed in the milk of transgenic cows.

Lactoferrin (LF) is one of the most abundant bioactive glycoproteins in human milk. Glycans attached through N-glycosidic bonds may contribute to Lactoferrin functional activities. In contrast, LF is present in trace amounts in bovine milk. Efforts to increase LF concentration in bovine milk led to alternative approaches using transgenic cows to express human lactoferrin (hLF). This study investigated and compared N-glycans in recombinant human lactoferrin (rhLF), bovine lactoferrin (bLF) and human lactoferrin by Nano-LC-Chip-Q-TOF Mass Spectrometry. The results revealed a high diversity of N-glycan structures, including fucosylated and sialylated complex glycans that may contribute additional bioactivities. rhLF, bLF and hLF had 23, 27 and 18 N-glycans respectively with 8 N-glycan in common overall. rhLF shared 16 N-glycan with bLF and 9 N-glycan with hLF while bLF shared 10 N-glycan with hLF. Based on the relative abundances of N-glycan types, rhLF and hLF appeared to contain mostly neutral complex/hybrid N-glycans (81% and 52% of the total respectively) whereas bLF was characterized by high mannose glycans (65%). Interestingly, the majority of hLF N-glycans were fucosylated (88%), whereas bLF and rhLF had only 9% and 20% fucosylation, respectively. Overall, this study suggests that rhLF N-glycans share more similarities to bLF than hLF

Under-utilized wild fruit <i>Lepisanthes rubiginosa</i> (Roxb.) Leenh: A discovery of novel lycopene and anthocyanin source and bioactive compound profile changes associated with drying conditions

Lepisanthes rubiginosa (Roxb.) Leenh (LRL), a wild fruit of Thailand, was characterized for phytochemicals including phenolic acids, flavonoids, carotenoids, anthocyanins, organic acids, and sugars. To process it, three drying methods were investigated, namely, freeze drying (FD), hot-air drying (HD), and sun drying (SD), which affected chemical components and antioxidant activities. The predominant phenolic acids and flavonoids were p-hydroxybenzoic acid, chlorogenic acid, vanillic acid, quercetin, rutin, and myricetin. Remarkably high amounts of lycopene (158 mg/100g db) and cyanidin-3-O-glucoside (2005 mg/100g db) were observed. Flavonoids, carotenoids, and anthocyanin were decreased by all drying methods. Overall, FD was considered to be the most suitable for drying LRL fruit. Fructose conversion to mannitol during drying was explored by FTIR spectroscopy analysis in FD and HD samples. This study has revealed new information about LRL fruits, which could be a potential source of bioactive compounds; an appropriate drying method is suggested for further applications.</p

Characterization of recombinant human lactoferrin N-glycans expressed in the milk of transgenic cows

Lactoferrin (LF) is one of the most abundant bioactive glycoproteins in human milk. Glycans attached through N-glycosidic bonds may contribute to Lactoferrin functional activities. In contrast, LF is present in trace amounts in bovine milk. Efforts to increase LF concentration in bovine milk led to alternative approaches using transgenic cows to express human lactoferrin (hLF). This study investigated and compared N-glycans in recombinant human lactoferrin (rhLF), bovine lactoferrin (bLF) and human lactoferrin by Nano-LC-Chip-Q-TOF Mass Spectrometry. The results revealed a high diversity of N-glycan structures, including fucosylated and sialylated complex glycans that may contribute additional bioactivities. rhLF, bLF and hLF had 23, 27 and 18 N-glycans respectively with 8 N-glycan in common overall. rhLF shared 16 N-glycan with bLF and 9 N-glycan with hLF while bLF shared 10 N-glycan with hLF. Based on the relative abundances of N-glycan types, rhLF and hLF appeared to contain mostly neutral complex/hybrid N-glycans (81% and 52% of the total respectively) whereas bLF was characterized by high mannose glycans (65%). Interestingly, the majority of hLF N-glycans were fucosylated (88%), whereas bLF and rhLF had only 9% and 20% fucosylation, respectively. Overall, this study suggests that rhLF N-glycans share more similarities to bLF than hLF

PCA plot of composition of released <i>N-</i>glycans of human lactoferrin (hLF), recombinant human lactoferrin (rhLfa) and bovine lactoferrin (bLf).

<p>Of the variance, 62.45% was explained by the first principal component and 36.97% was explained by the second principal component.</p

Comparison of bLF, rhLF and hLF <i>N-</i>glycan compositions.

<p>Comparison of bLF, rhLF and hLF <i>N-</i>glycan compositions.</p

Deconvoluted tandem spectrum of the neutral N-glycan 5Hex2HexNAc from recombinant human lactoferrin.

<p>This glycan corresponds to 1235.44 m/z. Green circles and blue squares represent mannose and HexNAc residues, respectively.</p

Heatmap of compound abundances associated with lactoferrin from different sources.

<p>Compound relative abundances were standardized (Z score, shown in legend) prior to unsupervised hierarchical clustering of samples (rows). Compound identity is noted below each column.</p

High mannose, sialylated and neutral complex/hybrid <i>N</i>-glycans released from hLF, rhLF and bLF by PNGase F.

<p>Tukey’s test was used to indicate significant differences (p<0.05) between groups. Same letters indicate no significant difference.</p

Recombinant human lactoferrin purification.

<p>(A) Skim milk protein profile analyzed by 12% SDS-PAGE. (B) Elution of rhLF purification by heparin Sepharose. (C) Elution of rhLF purification by ion-exchange chromatography.</p