A Randomized Clinical Trial Evaluating the Effects of Oligosaccharides on Transfer of Passive Immunity in Neonatal Dairy Calves

Effects of Different Galacto-Oligosaccharide Supplementation on Growth Performance, Immune Function, Serum Nutrients, and Appetite-Related Hormones in Holstein Calves

Our previous study showed that early supplementation with 10 g/(d·head) of galacto-oligosaccharides (GOS) in newborn Holstein dairy calves reduced the incidence of diarrhea and improved growth performance and mineral absorption. Since the dose of 10 g/(d·head) was the lowest by dose screening in our previous study, the present study was designed to investigate whether a lower amount of GOS has similar effects on growth performance, immune function, serum nutrients in newborn Holstein heifer calves, and to further investigate its effect on appetite-related hormones. Twenty-eight healthy newborn (1 day of age) Holstein heifers with similar average body weight (41.18 ± 1.90 kg) were randomly divided into four groups (n = 7): the control group (CON group), which received heated raw milk, and three experimental groups, which received heated raw milk supplemented with 2.5 (GOS2.5 group), 5 (GOS5 group), and 10 g/(d·head) (GOS10 group) GOS. All heifer calves were fed the same starter for 28 d. Supplementation with GOS linearly increased the final body weight, average daily gain, and feed efficiency in heifer calves (p < 0.01). Compared with the control group, the average daily gain and feed efficiency of heifer calves were significantly higher in the GOS5 and GOS10 groups than in the control group (p < 0.05). Furthermore, supplementation with GOS quadratically enhanced the starter and total average daily feed intake of the heifers (p < 0.01), especially in the GOS2.5 and GOS5 groups, (p < 0.05 vs. CON). The serum concentration of immunoglobulin A was linearly increased by GOS supplementation (p < 0.05), and the levels in the GOS5 and GOS10 groups were significantly higher than those in the CON group. Meanwhile, GOS linearly decreased serum interleukin-1β and interleukin-6 concentrations (p < 0.05). The serum concentration of triglycerides was also linearly decreased (p < 0.05), whereas total protein and blood urea nitrogen were linearly increased (p < 0.05). Supplementation with GOS linearly decreased the serum concentration of leptin (p < 0.05) but increased cholecystokinin and glucagon-like peptide-1 (p < 0.05). Increasing doses of GOS linearly improved serum calcium and copper concentrations (p < 0.01) and quadratically enhanced the concentration of magnesium, which peaked in the GOS5 group (p < 0.05). In conclusion, GOS supplementation reduced the incidence of diarrhea and improved the growth performance and immune function of Holstein heifer calves.

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.

Oligosaccharide concentrations in colostrum, transition milk, and mature milk of primi- and multiparous Holstein cows during the first week of lactation

The objective of this study was to characterize the oligosaccharide (OS) profile of colostrum and transition milk from primiparous (Pp, n = 10) and multiparous (Mp, n = 10) Holstein cows. The experiment was conducted on a commercial dairy farm, where cows were assigned to the study at calving. Colostrum (milking 1) was collected at 5.3 ± 0.7 h after parturition, followed by collection of milkings 2 through 6, milkings 8, 10, 12, and 14 at 0500 and 1600 h each day. Samples were analyzed for OS concentrations using liquid chromatography-mass spectrometry and for IgG and milk components. Concentration of IgG was highest in colostrum and milking 2. Colostral IgG concentration was less in Pp cows than in Mp cows (82.1 ± 3.1 vs. 106.1 ± 16.2 mg/mL). Colostrum and milkings 2 and 3 had 3'-sialyllactose and 6'-sialyllactose concentrations greater than those of mature milk (milkings 8+). For colostrum and milking 2, 6'-sialyllactosamine concentrations were higher than all other milkings, while disialyllactose was only higher in colostrum. In addition, 3'-sialyllactose was the most abundant OS in colostrum and milkings 2 and 3 compared with all other OS. A parity difference was observed for 6'-sialyllactosamine, with Mp having a higher concentration over the first 7 d in milk than Pp (46.4 ± 8.7 vs. 16.9 ± 3.2 μg/mL). Similar results were observed between milkings for OS yields. Parity differences were detected for 3'-sialyllactose, 6'-sialyllactose, and 6'-sialyllactosamine yield, with Mp yield being greater than Pp over the first 7 d in milk. These findings demonstrate that colostrum and transition milk contain elevated concentrations of certain OS compared with mature milk and suggest further research should be conducted regarding the potential benefits of OS in colostrum and transition milk when fed to newborn calves.

Short communication: Effect of feeding pooled and nonpooled high-quality colostrum on passive transfer of immunity, morbidity, and mortality in dairy calves

Pooling colostrum is commonly practiced on Irish dairy farms. Pooling can result in dilution when colostrums with high and low IgG concentrations are mixed, thereby predisposing calves to failure of passive immunity. The objectives of this study were to compare IgG concentrations in colostrum from individual cows with colostrum pooled from several cows, and assess serum IgG concentrations, morbidity, and mortality among calves fed colostrum from their own dam, from a different cow, or pooled from several cows. We hypothesized that pooling colostrum reduces IgG concentration due to dilution compared with colostrum from individual cows, and that calves fed pooled colostrum achieve lower serum IgG concentrations than calves fed colostrum from individual cows. Calves were randomly assigned to 1 of 3 groups: (1) fed colostrum from their own dam (n = 20); (2) fed colostrum from a different dam (n = 20); or (3) fed pooled colostrum (n = 18). A sample of colostrum fed to each calf was collected. Serum samples were collected from calves at birth (0 h) and at 24 h after colostrum feeding. Colostrum and serum IgG concentrations were measured by radial immunodiffusion. Calves were weighed at birth and at weaning, and the health status of each calf was assessed twice daily. Health assessment was based on general demeanor, rectal temperature, fecal consistency, respiratory rate, and the presence of cough, nasal, or ocular discharge. Colostrum and serum IgG concentrations, and weaning weights were compared using ANOVA. Associations between group and morbidity or mortality rates were compared using χ² or Fisher's exact tests. Median and 95% confidence intervals (95% CI) of IgG concentrations of colostrum were 99.4 (81.8-111.5), 95.2 (84.1-107.2), and 100.7 (90.5-104.4) g/L for own dam, different dam, and pooled groups, respectively. We did not find any differences in colostrum IgG concentrations among the colostrum sources. Median (95% CI) serum IgG concentrations at 24 h were 52.0 (45.6-65.9), 55.7 (51.2-65.9), and 53.1 (46.2-63.7) g/L for calves that received colostrum from own dam, different dam, and pooled, respectively. All calves achieved adequate passive immunity. Serum IgG concentrations at 24 h, weaning weights, and proportions of morbidity and mortality were not different among the 3 groups. Our results suggest that on dairy farms where median colostrum IgG concentrations are high and colostrum management is optimal, pooling has a minimal effect on passive immunity and subsequent calf health.

Glucan and Mannan-Two Peas in a Pod

In recent decades, various polysaccharides isolated from algae, mushrooms, yeast, and higher plants have attracted serious attention in the area of nutrition and medicine. The reasons include their low toxicity, rare negative side effects, relatively low price, and broad spectrum of therapeutic actions. The two most and best-studied polysaccharides are mannan and glucan. This review focused on their biological properties.

Immunostimulant effects and potential application of β-glucans derived from marine yeast Debaryomyces hansenii in goat peripheral blood leucocytes

Debaryomyces hansenii has been described to be effective probiotic and immunostimulatory marine yeast in fish. Nonetheless, to the best of our knowledge, it has been not assayed in ruminants. This study attempts to describe the immunostimulatory effects of its β-glucan content through in vitro assays using goat peripheral blood leukocytes at 24 h of stimulation. The structural characterization of yeast glucans by proton nuclear magnetic resonance indicated structures containing (1-6)-branched (1-3)-β-D-glucan. In vitro assays using peripheral blood leukocytes stimulated with β-glucans derived from three D. hansenii strains and zymosan revealed that β-glucans significantly increased cell immune parameters, such as phagocytic ability, reactive oxygen species production (respiratory burst), peroxidase activity and nitric oxide production. Antioxidant enzymes revealed an increase in superoxide dismutase and catalase activities in leukocytes stimulated with yeast β-glucans. This study revealed that yeast β-glucans were able to activate dectin-1 mRNA gene expression in leukocytes. The TLR4 gene expression was up-regulated in leukocytes after stimulation with yeast β-glucans. In conclusion, β-glucans were able to modulate the immune system by promoting cell viability, phagocytic activity, antioxidant immune response and immune-related gene expression in leukocytes. Therefore, β-glucans derived from Debaryomyces hansenii should be considered a potential immunostimulant for goat production systems.

In vitro bioassessment of the immunomodulatory activity of Saccharomyces cerevisiae components using bovine macrophages and Mycobacterium avium ssp. paratuberculosis

The yeast Saccharomyces cerevisiae and its components are used for the prevention and treatment of enteric disease in different species; therefore, they may also be useful for preventing Johne's disease, a chronic inflammatory bowel disease of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP). The objective of this study was to identify potential immunomodulatory S. cerevisiae components using a bovine macrophage cell line (BOMAC). The BOMAC phagocytic activity, reactive oxygen species production, and immune-related gene (IL6, IL10, IL12p40, IL13, IL23), transforming growth factor β, ARG1, CASP1, and inducible nitric oxide synthase expression were investigated when BOMAC were cocultured with cell wall components from 4 different strains (A, B, C, and D) and 2 forms of dead yeast from strain A. The BOMAC phagocytosis of mCherry-labeled MAP was concentration-dependently attenuated when BOMAC were cocultured with yeast components for 6 h. Each yeast derivative also induced a concentration-dependent increase in BOMAC reactive oxygen species production after a 6-h exposure. In addition, BOMAC mRNA expression of the immune-related genes was investigated after 6 and 24 h of exposure to yeast components. All yeast components were found to regulate the immunomodulatory genes of BOMAC; however, the response varied among components and over time. The in vitro bioassessment studies reported here suggest that dead yeast and its cell wall components may be useful for modulating macrophage function before or during MAP infection.

Short communication: The effect of heat treatment of bovine colostrum on the concentration of oligosaccharides in colostrum and in the intestine of neonatal male Holstein calves

The objective of this study was to determine the effect of the heat treatment (HT, 60°C for 60 min) on the concentration of bovine colostrum oligosaccharides (bCO) in pooled bovine colostrum and the intestine of neonatal male Holstein calves after feeding. First-milking colostrum was pooled from both primiparous and multiparous cows, and half of the pooled colostrum was heat-treated at 60°C for 60 min (HC), whereas the other half was not heat-treated and remained fresh (FC). At birth, 32 male Holstein calves were randomly assigned to 1 of 3 treatment groups: (1) control calves that did not receive colostrum for the duration of the experiment and were euthanized at 6 h (NC, n = 4) or 12 h (NC, n = 4), (2) calves fed fresh colostrum (FC) and were euthanized at 6 h (FC, n = 6) or 12 h (FC, n = 6), or (3) calves fed heat-treated colostrum (HC) and euthanized at 6 h (HC, n = 6) or 12 h (HC, n = 6). All calves were fed 2 L of colostrum within 1 h after birth. At dissection, digesta of the distal jejunum, ileum, and colon was collected and analyzed by liquid chromatography-mass spectrometry to determine the concentration of bCO within each intestinal region. The heat-treated colostrum displayed numerically higher concentrations of total bCO (3,511.6 μg/g) when compared with fresh colostrum (1,329.9 μg/g), with 3'-sialyllactose being the most abundant bCO in both fresh and HT colostrum. In contrast, calves fed HT colostrum displayed a lower amount of total bCO in the distal jejunum (221.91 ± 105.3 vs. 611.26 ± 265.1 μg/g), ileum (64.97 ± 48.39 vs. 344.04 ± 216.87 μg/g), and colon (25.60 ± 13.1 vs. 267.04 ± 125.81 μg/g) at 6 h of life when compared with calves fed fresh colostrum. No differences were observed in regard to the concentrations of total bCO in the intestine of FC and HC calves at 12 h of life. It is speculated that lower concentrations of bCO in the gastrointestinal tract of HC calves at 6 h of life could be due to the early establishment of beneficial bacteria, such as Bifidobacterium, in HC calves and their subsequent metabolism of bCO as a carbon source. These findings suggest that the heat treatment of colostrum increases the amount of free bCO, which may serve as prebiotics available to microbiota within the intestine of the neonatal calf.

Clinical Trials in Veterinary Medicine: A New Era Brings New Challenges

Randomized clinical trials (RCTs) are among the most rigorous ways to determine the causal relationship between an intervention and important clinical outcome. Their use in veterinary medicine has become increasingly common, and as is often the case, with progress comes new challenges. Randomized clinical trials yield important answers, but results from these studies can be unhelpful or even misleading unless the study design and reporting are carried out with care. Herein, we offer some perspective on several emerging challenges associated with RCTs, including use of composite endpoints, the reporting of different forms of risk, analysis in the presence of missing data, and issues of reporting and safety assessment. These topics are explored in the context of previously reported veterinary internal medicine studies as well as through illustrative examples with hypothetical data sets. Moreover, many insights germane to RCTs in veterinary internal medicine can be drawn from the wealth of experience with RCTs in the human medical field. A better understanding of the issues presented here can help improve the design, interpretation, and reporting of veterinary RCTs.

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.