Ultrasound modification on milk fat globule membrane and soy lecithin to improve the physicochemical properties, microstructure and stability of mimicking human milk fat emulsions.

Starting from the consideration of the structure of human milk fat globule (MFG), this study aimed to investigate the effects of ultrasonic treatment on milk fat globule membrane (MFGM) and soy lecithin (SL) complexes and their role in mimicking human MFG emulsions. Ultrasonic power significantly affected the structure of the MFGM-SL complex, further promoting the unfolding of the molecular structure of the protein, and then increased solubility and surface hydrophobicity. Furthermore, the microstructure of mimicking MFG emulsions without sonication was unevenly distributed, and the average droplet diameter was large. After ultrasonic treatment, the droplets of the emulsion were more uniformly dispersed, the particle size was smaller, and the emulsification properties and stability were improved to varying degrees. Especially when the ultrasonic power was 300 W, the mimicking MFG emulsion had the highest encapsulation rate and emulsion activity index and emulsion stability index were increased by 60.88 % and 117.74 %, respectively. From the microstructure, it was observed that the spherical droplets of the mimicking MFG emulsion after appropriate ultrasonic treatment remain well separated without obvious flocculation. This study can provide a reference for the screening of milk fat globules mimicking membrane materials and the further utilization and development of ultrasound in infant formula.

Characterization of sow milk N-linked glycoproteome over the course of lactation.

Milk proteins serve as nutrition and affect neonate development and immunity through their bioactivity. Post-translational modifications of proteins affect their bioactivity. Glycosylation is the attachment of sugar moieties to proteins, with attachment of glycans to asparagine indicated as N-linked glycosylation. Our objective was to characterize N-linked glycosylated proteins in homogenate swine milk samples collected from sows (n = 5/6) during farrowing to represent colostrum and on days 3 and 14 post-farrowing to represent transitional and mature milk, respectively. Glycopeptides were isolated with lectin-based extraction and treated with Peptide N-glycosidase F (PNGase F) to identify N-linked glycosylation sites. Purified glycopeptides were analyzed by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). MaxQuant software was used to align spectra to Sus scrofa Uniport database to identify proteins and measure their relative abundances. Analysis of variance and Welch's t-test analysis identified glycoproteins differentially abundant between colostrum, transitional, and mature milk (false discovery rate <0.05). Shotgun proteome analysis identified 545 N-linked and glutamine, Q, -linked, glycosylation (P > 0.75 for deamidation) sites on 220 glycoproteins in sow milk. Glycoproteins were found across all three phases of swine milk production and varied by number of glycosylation sites (1-14) and in abundance and distribution between colostrum, transitional, and mature milk. Polymeric immunoglobulin receptor was the most glycosylated protein with 14 sites identified. Also highly glycosylated were casein and mucin proteins. These data are described and the relevance of glycosylated milk proteins in neonate development, such as protection against pathogens, is discussed.

Milk is essential for healthy growth and development of neonates, with proteins in milk serving as key nutrients and regulators of these processes. Protein activity is affected by modifications made to their structure including the addition of sugar groups called glycans. Here we present the characterization of sow milk proteins modification with glycan groups on asparagine and glutamine amino acids in colostrum, transitional, and mature milk of pigs. We found 220 high confidences (found in at least two sows on one day) glycoproteins, and that the abundance of glycosylated proteins varied by stage of milk production and number of glycosylated sites.

Metal oxide-based macroporous ordered double affinity molecularly imprinted polymer for specific separation and enrichment of glycoprotein from food samples: a co-modification of DMSA and boronate affinity.

Metal oxide-based macroporous ordered double affinity molecularly imprinted polymers (D-MIPs) were developed as solid phase extraction (SPE) adsorbents for the specific identification of ovalbumin (OVA) under physiological pH conditions prior to ultraviolet visible (UV-vis) spectrophotometric detection. Herein, macroporous alumina (MA) was used as a matrix; dimercaptosuccinic acid (DMSA) and 3-aminophenylboric acid (APBA) were employed as dual-functional monomers; APBA is a self-polymerizing monomer. The effects of synthesis conditions, SPE conditions as well as selectivity, reproducibility, and reusability were studied. The co-modification of DMSA and boronate affinity renders the adsorbent exhibiting a high adsorption capacity (114.4 mg g-1) and short equilibrium time (30 min). The surface imprinting technology causes the adsorbent to have high selectivity towards OVA. The OVA recovery range is 91.1-99.6%. This study provides a promising method for the enrichment of OVA and other cis-diol-containing analytes in complex biological samples. A novel metal oxide-based macroporous ordered nanoparticle with a combination of DMSA and boronate affinity was successfully prepared for specific separation and enrichment of glycoprotein from complex biological samples.

Investigation of cell wall proteins of C. sinensis leaves by combining cell wall proteomics and N-glycoproteomics.

BACKGROUND: C. sinensis is an important economic crop with fluoride over-accumulation in its leaves, which poses a serious threat to human health due to its leaf consumption as tea. Recently, our study has indicated that cell wall proteins (CWPs) probably play a vital role in fluoride accumulation/detoxification in C. sinensis. However, there has been a lack in CWP identification and characterization up to now. This study is aimed to characterize cell wall proteome of C. sinensis leaves and to develop more CWPs related to stress response. A strategy of combined cell wall proteomics and N-glycoproteomics was employed to investigate CWPs. CWPs were extracted by sequential salt buffers, while N-glycoproteins were enriched by hydrophilic interaction chromatography method using C. sinensis leaves as a material. Afterwards all the proteins were subjected to UPLC-MS/MS analysis. RESULTS: A total of 501 CWPs and 195 CWPs were identified respectively by cell wall proteomics and N-glycoproteomics profiling with 118 CWPs in common. Notably, N-glycoproteomics is a feasible method for CWP identification, and it can enhance CWP coverage. Among identified CWPs, proteins acting on cell wall polysaccharides constitute the largest functional class, most of which might be involved in cell wall structure remodeling. The second largest functional class mainly encompass various proteases related to CWP turnover and maturation. Oxidoreductases represent the third largest functional class, most of which (especially Class III peroxidases) participate in defense response. As expected, identified CWPs are mainly related to plant cell wall formation and defense response. CONCLUSION: This was the first large-scale investigation of CWPs in C. sinensis through cell wall proteomics and N-glycoproteomics. Our results not only provide a database for further research on CWPs, but also an insight into cell wall formation and defense response in C. sinensis.

Potential Benefits of Bovine Colostrum in Pediatric Nutrition and Health.

Bovine colostrum (BC), the first milk produced from cows after parturition, is increasingly used as a nutritional supplement to promote gut function and health in other species, including humans. The high levels of whey and casein proteins, immunoglobulins (Igs), and other milk bioactives in BC are adapted to meet the needs of newborn calves. However, BC supplementation may improve health outcomes across other species, especially when immune and gut functions are immature in early life. We provide a review of BC composition and its effects in infants and children in health and selected diseases (diarrhea, infection, growth-failure, preterm birth, necrotizing enterocolitis (NEC), short-bowel syndrome, and mucositis). Human trials and animal studies (mainly in piglets) are reviewed to assess the scientific evidence of whether BC is a safe and effective antimicrobial and immunomodulatory nutritional supplement that reduces clinical complications related to preterm birth, infections, and gut disorders. Studies in infants and animals suggest that BC should be supplemented at an optimal age, time, and level to be both safe and effective. Exclusive BC feeding is not recommended for infants because of nutritional imbalances relative to human milk. On the other hand, adverse effects, including allergies and intolerance, appear unlikely when BC is provided as a supplement within normal nutrition guidelines for infants and children. Larger clinical trials in infant populations are needed to provide more evidence of health benefits when patients are supplemented with BC in addition to human milk or formula. Igs and other bioactive factors in BC may work in synergy, making it critical to preserve bioactivity with gentle processing and pasteurization methods. BC has the potential to become a safe and effective nutritional supplement for several pediatric subpopulations.

Short communication: A decrease in diameter of milk fat globules accompanies milk fat depression induced by conjugated linoleic acid supplementation in lactating dairy cows.

Milk fat is secreted from the mammary gland in the form of milk fat globules (MFG). Although milk fat depression has been studied since the beginning of the last century, the extent to which this phenomenon alters MFG synthesis is not fully understood. The aim of this study was to evaluate the effect of conjugated linoleic acid (CLA) on the size and distribution of MFG during milk fat depression in dairy cows. Twelve Holstein cows in mid lactation (145 ± 31 d in milk, 583 ± 34.6 kg of body weight, and 27.2 ± 2.4 kg of milk/d) were randomly assigned to a control diet or control plus Ca-protected CLA at 15 g/kg of dry matter for a 6-d period. The average diameter and particle size distribution of MFG were measured using a Mastersizer 3000 laser particle size analyzer (Malvern Instruments Ltd., Malvern, UK). Feeding CLA did not affect dry matter intake (16.2 ± 0.4 kg/d), milk production (28.4 ± 0.4 kg/d), milk protein, or lactose, but it decreased milk fat content (3.46 vs. 2.52%). In addition, surface area-related mean diameter of fat globules in cows fed CLA was lower compared with controls (3.02 vs. 3.45 µm). The percentage of large fat globules decreased and that of small fat globules increased in response to CLA. Overall, the data suggest that the milk fat depression induced by CLA is accompanied by a decrease in average diameter of MFG.

Energy balance in lactating goats: Response to mixture of conjugated linoleic acid.

The objective of this study was to determine the energy balance in early lactating local goats when supplemented with conjugated linoleic acid. Fifteen local goats from the north-east of Mexico were used. Three treatments were evaluated: (a) Control (Base diet); (b) CLA 50 g; and (c) CLA 90 g. The CLA was a mixture of micro-encapsulated FA, which supplied c9, t11 and t10, c12. Goats had an adaptation period of 2 weeks and 7 experimental weeks. The variables evaluated were body weight, DMI, milk yield, and fat, protein, and lactose yield, FA milk profile, and energy balance. The analysis of the data was analyzed as repeated measures using the PROC MIXED procedure and Tukey test (p < .05). In milk of goats from the treatment 90 g of the isomer t10, c12 CLA (p < .05) the milk fat content and milk fat yield with respect to the control treatment were reduced and the energy balance was improved. In goats treated with 11 g of t10, c12 CLA increased (p < .05) milk yield and milk lactose content. These results suggest that energy not used to synthesize dairy fat was used to increase milk yield and improve energy balance.

Effects of feeding a quebracho-chestnut tannin extract on lactating cow performance and nitrogen utilization efficiency.

The effects of feeding a quebracho-chestnut tannin extract mixture on performance and nitrogen (N) utilization were assessed with 36 multiparous lactating Holstein cows (mean ± standard deviation; 706 ± 59 kg of body weight; 126 ± 20 d in milk) randomly assigned to 3 dietary treatments in a randomized complete block design. Following a 2-wk covariate adjustment period, cows were fed their assigned treatment diets for 13 wk. Rice hulls were removed from a total mixed ration with a 54:46 forage:concentrate ratio (% of dry matter; DM), and a tannin extract mixture from quebracho and chestnut trees (2:1 ratio) was included at 0, 0.45, and 1.80% of dietary DM. There was no interaction between dietary treatments and experimental week for the reported measurements except milk lactose percentage. Overall, treatments did not affect milk yield (48.6 ± 7.8 kg/d), fat- and protein-corrected milk (46.1 ± 7.6 kg/d), milk fat content (3.88 ± 0.65%) and yield (1.85 ± 0.38 kg/d), and true protein yield (1.45 ± 0.21 kg/d). However, incremental levels of tannin extracts in the diet produced a linear increase in DM intake (29.2 to 30.9 kg/d) and a linear decrease in kilograms of milk per kilogram of DM intake (1.67 to 1.57 kg/kg) and MUN (12.2 to 10.8 mg/dL). Furthermore, there was a quadratic effect of tannin extracts on milk true protein content (2.96, 3.13, and 3.00% for 0, 0.45, and 1.80% tannin extract, respectively) and a tendency for linear and quadratic response for body weight gain (0.31, 0.16, and 0.44 kg/d for 0, 0.45, and 1.80% tannin, respectively). Intake of N increased linearly (782, 795, and 820 g/d) and N utilization efficiency (milk N/intake N) decreased linearly (0.300, 0.301, and 0.275 for 0, 0.45, and 1.80% tannin, respectively). Relative to the 0% diet, 1.80% tannin extract reduced estimated urinary N excretion by 11%. In this study, adding 0.45% tannin extract to the diet reduced feed efficiency but had a positive effect on milk protein content. Feeding a tannin extract mixture from quebracho and chestnut may reduce environmental labile urinary N excretion without affecting milk yield but at the expense of a lower feed utilization efficiency.

Effect of stearic or oleic acid on milk performance and energy partitioning when fed in diets with low and high rumen-active unsaturated fatty acids in early lactation.

This experiment was conducted to determine the effects of stearic acid (SA; C18:0) or rumen-protected oleic acid (OA; C18:1 cis-9) on milk performance and energy partitioning of early lactation cows when supplemented in diets with low and high level of rumen unsaturated fatty acids (RUFA). In low RUFA experiment (LRUFA), FA supplement rich in either SA or calcium salts OA was added to a basal diet with a low concentration of RUFA (0.75% vs. 1.4%, LRUFA-SA vs. LRUFA-OA). In high RUFA experiment (HRUFA), 2% soybean oil was added to the diet fed in the LRUFA experiment. In each experiment, 30 multiparous cows were blocked by parity and predicted transmitting ability for milk yield and were randomly fed 1 of 2 treatment diets from 2 to 13 wk postpartum. In the LRUFA experiment, LRUFA-SA had 2.4 kg/d more dry matter intake (DMI) (P < 0.01), 3.8 kg/d more energy-corrected milk (P < 0.01), and 0.3% units more milk fat percentage (P < 0.01) and 0.2 kg/d more milk fat yield (P < 0.01). Dietary treatments did not affect body weight, energy balance, and energy intake partitioning into milk, maintenance, and body tissues (P > 0.1). In the HRUFA experiment, HRUFA-SA had 1.4 kg/d more DMI (P = 0.03) but similar milk and milk components yields (P > 0.1). HRUFA-SA had a tendency to gain more body weight (P = 0.07) and had more positive energy balance (P = 0.01) and decreased gross feed efficiency (milk yield/DMI) (P = 0.01). Consistently, HRUFA-SA increased intake energy partitioning into body tissues (P = 0.02) and decreased energy partitioning into milk (P = 0.01). In summary, SA supplementation had more DMI relative to OA, but the effects on milk and milk fat production were different and affected by the level of RUFA in the basal diet. In application, SA supplementation was more effective to improve milk production when included in the basal diet with the low RUFA.

The effects of cereal type and α-tocopherol level on milk production, milk composition, rumen fermentation, and nitrogen excretion of spring-calving dairy cows in late lactation.

Grass-based production systems use concentrate supplementation primarily when pasture quality and availability have declined. Barley is a common concentrate ingredient; however, oat grain grows well in Ireland, is a source of lipids and fiber, and may provide an alternative to barley. The antioxidant α-tocopherol (α-TOC) plays a role in cell membrane structure, and it has the potential to improve tight junction structures of the mammary gland that deteriorate in late lactation. The objective of this research was to investigate the effect of cereal type and α-TOC level on milk yield, milk composition, rumen fermentation, and N excretion in late-lactation dairy cows at pasture and when housed indoors on grass silage. Forty-eight Holstein Friesian dairy cows were blocked on days in milk (+185 d in milk) and balanced for parity, pre-experimental milk yield, milk composition, and body condition score and assigned to 1 of 4 dietary treatments in a randomized complete block design (n = 12). The dietary treatments were control (C) base diet; base diet + barley-based concentrate + low α-TOC (350 IU/kg) (B); base diet + oat-based concentrate + low α-TOC (350 IU/kg) (O); and base diet + oat-based concentrate + high α-TOC (1,050 IU/kg) (O+T). Following a 14-d acclimation period, diets were offered for a 49-d experimental period at pasture (P1) and a 21-d experimental period indoors (P2). The base diet was grazed grass in P1 and grass silage in P2. In P2, cows on C also received 2.65 kg (dry matter) of a standard concentrate. In P1, supplementation increased milk and milk solids yield (B: 20.7 kg/d, 1.74 kg/d; O: 20.6 kg/d, 1.81 kg/d; O+T: 20.5 kg/d, 1.77 kg/d, respectively) compared with C (17.8 kg/d, 1.60 kg/d). Cows offered B had a lower milk fat (4.60%) concentration than C (5.00%) and O (4.90%). In P2, cereal type and α-TOC level did not alter milk production. In conclusion, concentrate supplementation increased milk and milk solids yield and cows offered O had a higher milk fat concentration than cows offered B. Increasing the level of α-TOC had no major effect on production parameters measured in P1 or in P2.

Effects of dietary supplementation with yeast glycoprotein on growth performance, intestinal mucosal morphology, immune response and colonic microbiota in weaned piglets.

Antibiotics are commonly provided to weaned piglets; however, this practice has become controversial due to the increased occurrences of microbial resistance, and alternatives are needed. This study aimed to investigate the effects of dietary supplementation with yeast glycoprotein (YG) on growth performance, intestinal mucosal morphology, immune response and colonic microbiota in weaned piglets. A total of 240 weaned piglets (d 23 ± 2) from 16 pens (15 piglets per pen) were randomly allocated to an antibiotics group (25% quinocetone 200 mg kg-1 and 4% enduracidin 800 mg kg-1 of the basal diet) or a YG group (800 mg kg-1 YG of the basal diet), respectively. The trial lasted 14 days, and at the end of the trial, one piglet per pen was chosen to collect plasma, intestinal tissue and colonic digesta samples. The results indicate that piglets fed diets containing YG tended to show increased final body weight (0.05 < P < 0.1), increased average daily gain (P < 0.05) and decreased F/G (P < 0.05) when compared with the antibiotics group. Moreover, intestinal permeability showed that YG led to an improvement in the intestinal development via decreasing serum content of DAO (P < 0.01). Histological evaluations showed that YG contributed to the improvement of the intestinal development via increasing villous height (P < 0.05) and the villous height to crypt depth ratio (P < 0.01), and decreasing crypt depth (P < 0.01) and villous width (P < 0.05) in the ileum. Intestinal integrity also showed that YG was conducive to improvement of the intestinal development via upregulating the m-RNA expression of occludin (P < 0.05) in the duodenal and jejunal mucosa. Interestingly, YG supplementation downregulated the m-RNA expression of IL-12 (P < 0.05), upregulated the m-RNA expression of Hsp-70 (P < 0.05) in the duodenal mucosa, downregulated the m-RNA expression of Hsp-70 (P < 0.05) and IFN-γ (P < 0.05), upregulated the m-RNA expression of Hsp-90 (P < 0.05) in the jejunal mucosa, and upregulated the m-RNA expression of Hsp-70 (P < 0.05) in the ileal mucosa. On the other hand, colonic microbiota results showed that YG supplementation increased the relative abundance of Lactobacillus (P < 0.05) in the genus level. Colonic metabolite results showed that YG supplementation decreased the content of acetate (P < 0.05). Taken together, it is speculated that YG would be a potent alternative to prophylactic antibiotics in improving the gut health in weaned piglets.

Interrogation of Milk-Driven Changes to the Proteome of Intestinal Epithelial Cells by Integrated Proteomics and Glycomics.

Bovine colostrum is a rich source of bioactive components which are important in the development of the intestine, in stimulating gut structure and function and in preparing the gut surface for subsequent colonization of microbes. What is not clear, however, is how colostrum may affect the repertoire of receptors and membrane proteins of the intestinal surface and the post-translational modifications associated with them. In the present work, we aimed to characterize the surface receptor and glycan profile of human HT-29 intestinal cells after exposure to a bovine colostrum fraction (BCF) by means of proteomic and glycomic analyses. Integration of label-free quantitative proteomic analysis and lectin array profiles confirmed that BCF exposure results in changes in the levels of glycoproteins present at the cell surface and also changes to their glycosylation pattern. This study contributes to our understanding of how milk components may regulate intestinal cells and prime them for bacterial interaction.

Nematicidal activity of 'major royal jelly protein'-containing glycoproteins from Acacia honey.

Parasitic nematodes infect more than two billion people worldwide particularly in developing countries. We previously reported nematicidal activity of natural honey using model nematode Caenorhabditis elegans. In this study, characterization of nematicidal effects of natural honey and its glycoproteins has been carried out. Chromatographically separated honey glycoproteins showed potent anti-C. elegans activity (LD50 = 100 ng proteins/µL). Honey glycoproteins with molecular masses of ∼260 kD and ∼160 kD comprised of 'major royal jelly protein-1'-containing complexes. In these complexes, MRJP1 was present in different glycosylation forms. Quantitative PCR based gene expression assays described molecular functions of C. elegans affected by honey and honey glycoproteins. Expression of 14 gene transcripts associated with key cellular and molecular functions including energy metabolism, cytoskeleton, cell division, transcription and translation was analyzed. Acacia honey exerted a concentration-dependent alteration of gene transcripts involved in the citric acid cycle (mdh-1 and idhg-1) and cytoskeleton (act-1, act-2, and arp6). Likewise, MRJP1-containing glycoproteins caused down-regulation of arp-6 and idhg-1; and up-regulation of act-1 and mdh-1 gene transcripts. Consistent down-regulation of isocitrate dehydrogenase encoding idhg-1 gene which is among the rate-controlling enzymes of the citric acid cycle was considered as main biochemical factor involved in the nematicidal activity of honey and MRJP-containing glycoproteins. Acacia honey suppressed the expression of gene transcripts encoding actin-2, while honey glycoproteins did not. Hence, honey partly exerted anti-C. elegans activity by decreasing the transcription of actin-2 gene transcripts, demonstrated by a defect in the movement and egg laying. Moreover, arp-6 gene transcripts encoding actin-related protein 6 was significantly and constantly down-regulated by honey and honey proteins.

Effects of Mn supplementation in late-gestating and lactating red deer (Cervus elaphus hispanicus) on milk production, milk composition, and calf growth.

This study describes the effects of Mn supplementation of 20 late-gestating and lactating Iberian red deer (Cervus elaphus hispanicus) females (hinds) fed a balanced diet on milk production and milk composition over the lactation period. Body weight of their calves at birth and at weaning was also evaluated. In addition, the effect of lactation stage was studied. For these purposes, 2 groups of hinds, one composed by 12 individuals (experimental) and the other by 8 individuals (control) were compared. Experimental hinds were s.c. injected weekly with Mn (2 mg Mn/kg BW) from day 140 of gestation until the end of lactation (week 18; forced weaning by physical separation). Control hinds were injected with a physiological saline solution with the same volume and at the same frequency as the experimental group. Serum Mn content of hinds was assessed just before the first Mn injection and at week 10 of lactation to assess whether the injected Mn increased Mn concentrations in blood. No differences were observed for BW of calves at birth but calves whose mothers were injected with Mn tended (P = 0.07) to have greater gain of BW from birth to weaning in proportion of BW at birth compared to calves from control hinds. In addition, supplementation with Mn increased (P ≤ 0.05) daily milk production by 10.2%, milk fat content by 11.2%, and total fat yield by 17.8%. Also, milk from hinds supplemented with Mn had more Ca (P < 0.001) and P (P < 0.05) than milk from control hinds. Manganese supplementation did not influence Mn serum content when blood was analyzed at week 10 of lactation, but increased the Mn content of milk by 18.3% (P < 0.001). Lactation stage affected (P < 0.001) fat, protein, lactose, and DM. Their contents increased as lactation proceeded, and protein was substituted by fat. Therefore, results suggest that Mn supplementation of hinds is recommended, even when they are fed a balanced diet, to increase milk production and the content of fat, Ca, P, and Mn of milk.

Comparisons of IgA response in saliva and colostrum against oral streptococci species.

The present study compared IgA specificity against oral streptococci in colostrum and saliva samples. Sixty-two mother-and-child pairs were included; samples of colostrum (C) and saliva (MS) were collected from the mothers and saliva samples were collected from babies (BS). The specificity of IgA against Streptococcus mutans and S. mitis were analyzed by western blot. Only 30% of babies' samples presented IgA reactivity to S. mutans, while 74 and 80% of MS and C, respectively, presented this response. IgA reactivity to S. mutans virulence antigens (Ag I/II, Gtf and GbpB) in positive samples showed differences between samples for Gtf and especially for GbpB (p < 0.05), but responses to Ag I/II were similar (p > 0.05). The positive response of Gtf-reactive IgA was different between C (90%) and MS (58%) samples (p < 0.05), but did not differ from BS (p > 0.05). GbpB was the least detected, with 48 and 26% of C and MS, and only 5% of BS samples presenting reactivity (p > 0.05). Eight percent of MS and C samples presented identical bands to SM in the same time-point. In conclusion, the differences of IgA response found between C and MS can be due to the different ways of stimulation, proliferation and transportation of IgA in those secretions. The colostrum has high levels of IgA against S. mutans virulence antigens, which could affect the installation and accumulation process of S. mutans, mainly by supplying anti-GbpB IgA to the neonate.

Short- and longer-term effects of feeding increased metabolizable protein with or without an altered amino acid profile to dairy cows immediately postpartum.

The first few weeks after parturition is marked by low, but increasing feed intake and sharply increasing milk production by dairy cows. Because of low intake, the nutrient density of the diet may need to be higher during this period to support increasing milk yields. We hypothesized that feeding higher levels of metabolizable protein (MP) or a protein supplement with rumen-protected lysine and methionine during the immediate postpartum period would increase yields of milk and milk components. Fifty-six Holstein cows (21 primiparous and 35 multiparous) starting at 3 d in milk were used in a randomized block design. In phase 1 (3 through 23 d in milk), cows were fed 1 of 3 diets that differed in supply of MP and AA profile. At 23 d in milk, all cows were moved to a common freestall pen and fed the control diet used in phase 1 for an additional 63 d (phase 2). Diets were formulated using the National Research Council model and were control [16.5% crude protein (CP), 10.9% rumen-degradable protein (RDP), and 5.6% rumen-undegradable protein (RUP)], high MP (HMP; 18.5% CP, 11.6% RDP, 6.9% RUP), and AA (MPAA; 17.5% CP, 10.5% RDP, 7.0% RUP 29.7). The MPAA diet included a proprietary spray-dried blood meal product (Perdue Agribusiness, Salisbury, MD) and contained a model-estimated 7.2 and 2.6% of digestible lysine and methionine (% of MP). The HMP and control diets contained 6.3 and 6.7% digestible lysine and both had 1.8% digestible methionine. In phase 1, diet did not affect milk yield (33.6, 34.7, and 33.2 kg for control, HMP, and MPAA, respectively), dry matter intake (17.8, 18.0, and 18.5 kg/d for control, HMP, and MPAA), or milk protein yield (1.07 kg/d). Feeding additional protein (HMP or MPAA) increased both the concentration and yield of milk fat, and milk protein concentration was greater (3.30 vs. 3.17%) for MPAA compared with the HMP diet. Energy-corrected milk was greater (38.4 and 38.6 vs. 35.3 kg/d, respectively) for MPAA and HP than for the control. Cows fed MPAA had the greatest plasma concentrations of Met and the lowest concentrations of isoleucine, but lysine was not affected by treatment. Feeding additional MP (HMP or MPAA) reduced the concentrations of 3-methylhistidine in plasma, indicating reduced muscle breakdown. Diet effects on milk composition continued after cows were changed to a common diet in that cows fed MPAA the first 3 wk of lactation had greater concentration of milk protein for the entire experiment than cows fed HMP, and cows fed additional MP (HMP and MPAA) during phase 1 had greater concentrations of milk fat for the entire experiment. Increasing dietary protein and AA supply in early lactation had short-term effects on yield of energy-corrected milk and long-term effects on milk composition.

Contribution of glomalin to dissolve organic carbon under different land uses and seasonality in dry tropics.

Glomalin related soil protein (GRSP) is a hydrophobic glycoprotein that is significant for soil organic carbon (SOC) persistence and sequestration, owing to its large contribution to SOC pool and long turnover time. However, the contribution of GRSP to dissolve OC (DOC) leach from soil is not yet comprehensively explored, though it could have implication in understanding SOC dynamics. We, therefore, aim to measure the contribution of GRSP to DOC, in a range of land uses and climatic seasons in the dry tropical ecosystem. Our results demonstrated that a significant proportion of GRSP (water soluble GRSP; WS-GRSP) leached with DOC (7.9-21.9 mg kg-1), which accounts for 0.2-0.23% of soils total GRSP (T-GRSP). Forest exhibited significantly higher WS-GRSP and DOC leaching than fallow and agriculture. WS-GRSP and DOC accumulations were higher in the dry season (summer and winter) than in rainy. The extent of seasonal variations was higher in forest than in other two land uses, indicating the role of vegetation and biological activity in soil dissolve organic matter (DOM) dynamics. The regression analysis among WS-GRSP, T-GRSP, DOC and SOC prove that the accumulations and leaching of GRSP and other soil OM (SOM) depend on similar factors. The ratio of WS-GRSP-C to DOC was higher in agriculture soil than in forest and fallow, likely a consequence of altered soil chemistry, and organic matter quantity and quality due to soil management practices. Multivariate analysis reflects a strong linkage among GRSP and SOC storage and leaching, soil nutrients (nitrogen and phosphorus) and other important soil properties (pH and bulk density), suggesting that improving GRSP and other SOM status is an urgent need for the both SOC sequestration and soil health in dry tropical agro-ecosystems.

Effects of feeding sodium stearoyl-2-lactylate diets to lactating sows on performance, digestibility of nutrients, composition, and fat globule size in milk.

The objective of this study was to determine the effects of feeding sodium stearoyl-2-lactylate (SSL) as a new feeding emulsifier diet with and without soybean oil (SO) on the milk fat globule (MFG) size, milk composition, digestibility of nutrients, and performance in lactating sows. Sixty sows (Large White × Landrace) were randomly assigned to 1 of 4 treatments according to a 2 × 2 factorial arrangement of treatments. Each treatment had 15 replicates composed of 1 sow. The factors included 1) the fat level (0% vs. 3% SO) and 2) the emulsifier content (0% vs. 0.1% SSL). Treatments included 1) Control (without SO and SSL), 2) SO (3% SO without SSL), 3) SSL (0.1% SSL without SO), and 4) SO + SSL (3% SO and 0.1% SSL). During the suckling period, sows in the SO + SSL group lost less back fat thickness ( < 0.05) compared to other groups; sows fed 3% SO diets consumed less feed ( < 0.05) compared to sows fed diets without SO, but there were no significant effects ( > 0.05) of dietary fat and its interaction with a dietary emulsifier on energy intake and the weaning-estrus interval. The digestibility of ether extract in the SO + SSL group was greater than in the SO group ( < 0.05). Moreover, greater digestibility of CP, Ca, and P in the SO+SSL group was observed compared to that of other groups ( < 0.05). Feeding the SO + SSL diet improved the concentrations of milk fat, protein, and total solids on d 11 of lactation compared to other diets ( < 0.05). Also, an interaction between supplemental SSL and SO was observed for the milk fat and total solids concentrations. The average diameter of MFG on d 11 of lactation was significantly decreased by the addition of 0.1% SSL compared to a diet with no SSL supplementation ( < 0.05). No significant differences among the dietary treatments were observed in cholesterol, triglyceride, high-density lipoprotein cholesterol, or low-density lipoprotein cholesterol in sows' plasma ( > 0.05). In conclusion, feeding a 0.1% SSL diet to lactating sows may decrease the average diameter of MFG and improve the digestibility of nutrients and composition of milk.

Comparisons of IgA response in saliva and colostrum against oral streptococci species

Abstract The present study compared IgA specificity against oral streptococci in colostrum and saliva samples. Sixty-two mother-and-child pairs were included; samples of colostrum (C) and saliva (MS) were collected from the mothers and saliva samples were collected from babies (BS). The specificity of IgA against Streptococcus mutans and S. mitis were analyzed by western blot. Only 30% of babies’ samples presented IgA reactivity to S. mutans, while 74 and 80% of MS and C, respectively, presented this response. IgA reactivity to S. mutans virulence antigens (Ag I/II, Gtf and GbpB) in positive samples showed differences between samples for Gtf and especially for GbpB (p < 0.05), but responses to Ag I/II were similar (p > 0.05). The positive response of Gtf-reactive IgA was different between C (90%) and MS (58%) samples (p < 0.05), but did not differ from BS (p > 0.05). GbpB was the least detected, with 48 and 26% of C and MS, and only 5% of BS samples presenting reactivity (p > 0.05). Eight percent of MS and C samples presented identical bands to SM in the same time-point. In conclusion, the differences of IgA response found between C and MS can be due to the different ways of stimulation, proliferation and transportation of IgA in those secretions. The colostrum has high levels of IgA against S. mutans virulence antigens, which could affect the installation and accumulation process of S. mutans, mainly by supplying anti-GbpB IgA to the neonate.

Impact of Lipid Components and Emulsifiers on Plant Sterols Bioaccessibility from Milk-Based Fruit Beverages.

Sterol bioaccessibility (BA) of three plant sterol (PS)-enriched milk-based fruit beverages (MFb) with different fat contents (1.1-2.4%), lipid sources (animal or vegetable), and without or with emulsifiers (whey proteins enriched with milk fat globule membrane (MFGM) or soy lecithin) was evaluated after simulated gastrointestinal digestion. The BA of total PS followed the order 31.4% (MFbM containing milk fat and whey proteins enriched with MFGM) = 28.2% (MFbO containing extra virgin olive oil and soy lecithin) > 8.7% (MFb without fat addition). Total and individual PS content in the bioaccessible fractions followed the order MFbM > MFbO > MFb. Consequently, formulation with MFGM is proposed in beverages of this kind to ensure optimum bioavailability of PS. Our results suggest that the BA of PS is influenced by the type and quantity of fat and the emulsifier type involved.