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

Spectroscopic techniques combined with chemometrics for rapid detection of food adulteration: Applications, perspectives, and challenges

Food adulteration is an important threat to food safety and can be difficult to detect. Some analytical methods are complex and difficult to meet the needs of large numbers of samples. In this study, we introduced the application of six spectroscopic techniques (NIR, FTIR, HSI, Raman, UV-Vis, and FS) and chemometric methods in common food adulteration (powdered food, meat, honey, drink, edible oil, and dairy product) over the last three years. We introduced the consequences of food adulteration, the principles, advantages, and limitations of spectroscopic techniques, spectral data preprocessing and key wavelength selection methods, chemometrics methods, dataset division methods, and evaluation methods for models. Moreover, it provided a perspective for the future application of spectroscopic techniques in food adulteration. The results showed that linear chemometric methods were still the main method used by many researchers, which may limit the application potential of spectroscopic techniques. Therefore, deep learning-based chemometrics methods and their interpretability should be further explored in food adulteration. Secondly, data fusion and ensemble models based on multiple spectroscopic techniques and chemometrics can further improve the accuracy of the models. Future research should select appropriate spectroscopic techniques based on food type and spectroscopic principles, and consider portable technical solutions wherever possible to improve the application scenarios of spectroscopic techniques.

Randomized prospective study exploring health and growth outcomes for 5 days of extended transition milk feeding in pre-weaned Scottish replacement dairy heifers

Typically, calves are fed a single feed of first milking colostrum followed by milk replacer, but there is an increasing body of evidence to suggest that feeding transition milk or 'extended colostrum feeding' may have health, growth and production benefits in dairy calves. Transition milk (milkings 2-6) may be preserved for extended feeding with potassium sorbate to prevent bacterial proliferation (even at ambient temperatures). The objective of this study was to observe the effects of feeding potassium sorbate preserved transition milk on calf health and growth outcomes on two commercial Scottish dairy farms. Calves were fed one feed of 4-5 L of first milking colostrum followed by either milk replacer (FC group) or 5 days (10 feeds) or preserved second and third milking transition milk (PTM group). Calves were blood sampled within the first week of life, health scored every second day and weighed at birth and weaning. First milking colostrum and transition milk samples were tested for Brix (%) and bacterial contamination. Small differences in health outcomes and average daily gains were observed, but first milking colostrum was highly contaminated (median total bacteria count = 107,250 colony forming units per ml (CFU/ml), range = 0- 3,120,000 CFU/ml), which may have interfered with the results. Several risk factors including age and season were significantly associated with health outcomes. Transition milk feeding could be a viable alternative for neonatal calves where first milking colostrum for feeding in an extended fashion is in short supply, but special attention must be given to scrupulous hygiene practices on farm.

Effects of high-volume voluntary feed consumption on growth and health of Brown Swiss calves: Continued dam's milk feeding versus early introduction of milk replacer during the first week of life

Understanding nutritional needs and management during the neonatal period is crucial for reducing mortality rates and improving the overall health of calves, thereby impacting the economic viability of farming operations. Therefore, this study aimed to evaluate performance differences between calves fed dam's milk or milk replacer (MR) at high milk allowances during their first week of life. Twenty Brown Swiss calves (both male and female) were fed their dam's colostrum and transition milk for the first 6 feedings twice daily in unlimited amounts. They were then randomly assigned to 1 of 2 treatments: receiving either their dam's milk or MR for 8 consecutive feedings, twice daily in unlimited amounts. The calves were weighed 3 times during the experiment, and growth differences were visible at the end of the trial, with milk-fed calves exhibiting superior growth compared with MR-fed calves. Differences were also observed in fecal consistency, with MR calves showing higher occurrence of loose feces. Calves fed with dam's milk exhibited greater weight gain and a greater relative increase in BW, achieving a 22% increase compared with a 15% increase in MR-fed calves, both relative to their birth weight. The differences were explained by a higher nutrient density of dam's milk during the first week of life compared with MR, which, upon feed transition, decreased the daily consumed energy by 30% for MR-fed calves, without changing feed consumption. The higher feces scores were interpreted as a multifactorial issue likely caused by an abrupt change in feedstuff, higher concentrations of osmolality-influencing agents such as lactose and minerals, or a lack of abomasal clotting for high-volume MR-fed calves. Our findings demonstrate that Brown Swiss calves fed with dam's milk during their initial week of life exhibited superior growth performance, fewer health impairments, and improved fecal consistency compared with calves transitioned early and abruptly to MR. In order for MR to better imitate dam's milk during this early stage of life, lower lactose and lower ash but higher fat inclusion should be considered by manufacturers.

Review: Mammary gland physiology and modulation during colostrogenesis in dairy goats

Newborn ruminants are highly dependent on the intake of high-quality colostrum immediately after birth to obtain energy and achieve an appropriate immunisation. Previous research indicates that poor management practices in the last months of gestation can lead to increased neonatal mortality rates by reducing colostrum quality among other factors. In ruminants, colostrum synthesis is a well-preserved mechanism which has been speculated to be regulated by the neuroendocrine system. However, this review aims to explore different approaches such as alternative dry-off management practices, the inclusion of different nutrients on prepartum diets, and the stimulation of the mammary gland immune response to modulate colostrogenesis and consequently, to enhance colostrum quality. Ensuring correct dry-off practices combined with controlled dietary supplementation can support mammary gland reorganisation and potentially modulate colostrogenesis. Despite positive effects on colostrum yield, the bioactive composition of colostrum seems to be irresponsive to prepartum energy, protein, and fat supplementation in dairy goats. On the other hand, mastitis has obvious negative effects on animal health; however, an experimentally induced local inflammation seems to trigger helpful modifications on the blood-milk barrier, enhancing the concentration of some immune components (i.e., immunoglobulin G and M) in goat colostrum. Yet, most research has focused on dairy cattle, leaving a significant knowledge gap on colostrogenesis in small ruminants. Therefore, future studies should focus on developing novel dry-off and dietary strategies to not only promote a healthy lactation but also to guarantee a successful colostrum synthesis.

Insulin, IGF-I, and lactoferrin concentrations and yields and their associations with other components within colostrum, transition, and whole milk of primiparous and multiparous Holstein cattle

The primary objective of the study was to characterize concentrations and yields of lactoferrin (LF), insulin, and IGF-I in colostrum, transition milk (TM), and whole milk (WM) of multiparous (MP) and primiparous (PP) cows. A secondary objective was to determine associations between colostrum and TM components (fat, protein, lactose), IgG, and bioactive compounds (oligosaccharides, LF, insulin, IGF-I; defined as compounds present in micro quantities that stimulate physiological responses systemically or locally within the neonate). Holstein cows (10 MP and 10 PP) were assigned to the study at calving and colostrum was collected 5.3 ± 0.7 h (mean ± SE) after calving, followed by twice daily sampling of milkings 2-5 (TM) and milking 12 (WM). Colostrum, TM, and WM samples were analyzed by commercial ELISA to determine concentrations of LF, insulin, and IGF-I. Concentrations of insulin, IGF-I, and LF were greatest in colostrum compared with all other milkings. Similarly, IGF-I and LF yields were greatest in colostrum, whereas insulin yield was greatest in colostrum and milking 2 compared with milking 4, 5, and 12. Primiparous cows had greater insulin and lower LF concentrations in colostrum compared with MP cows. Additionally, lower LF concentrations in PP cows persisted through milkings 2 and 3. The majority of associations between components and bioactive compounds in colostrum were positive; however, correlations were different between PP and MP cows. Specifically, there were a greater number of strong (ρ > 0.80) correlations between components and IgG in PP cows. In contrast, MP cows demonstrated a greater number of strong correlations among bioactive compounds. To the authors' knowledge, this study is the first to characterize the yields of IGF-I, LF, and insulin during the colostral (collection within 6 h) and TM period in both MP and PP cows. The study findings indicate that parity influences the levels of LF and insulin, but not IGF-I. Our study also uniquely demonstrates associations between early lactation components and bioactive compounds, which are not consistent among parities.

Long-term effects of transition milk feeding on feed intake, growth performance, feeding behavior, and oxidative status of Holstein calves

This study investigated the long-term effects of feeding 5-d transition milk (TRANS) compared with milk replacer (MR) on parameters including intake, growth, feeding behavior, and oxidative stress. Fifty Holstein calves (30 females and 20 males) were fed 12 L/d of either TRANS or MR for the first 5 d after an initial colostrum feeding of 3.5 L. Thereafter, all calves were fed with 12 L of MR/d (140 g/L) and were gradually weaned starting in wk 8 until wk 14. Throughout the 14 wk, the calves had unrestricted access to concentrate (up to 9.8 kg/calf per day), hay, and water. After weaning all heifers were fed a TMR for young cows. Oxidative status was assessed in blood samples from birth to first insemination. Parameters assessed included the ferric-reducing ability of plasma (FRAP) for antioxidant capacity and the concentration of reactive oxygen metabolites via detection of reactive oxygen metabolites (dROM) assay. In addition, the activity of glutathione peroxidase (GSHPx) and oxidative damage in the form of lipid peroxidation as thiobarbituric acid-reactive substances (TBARS) and as advanced oxidation protein products (AOPP) were measured. An oxidative stress index was calculated: dROM/FRAP × 100. Total protein concentration was also quantified via Bradford assay. The only significant difference in feeding behavior between the 2 treatment groups was a higher concentrate intake by the TRANS calves during the weaning phase. Body weight and ADG did not differ significantly between the TRANS and MR groups. The TRANS calves showed a trend for fewer cases of health disorders. Markers of oxidative status, including TBARS, AOPP, GSHPx, FRAP, and reactive oxygen metabolites, showed no treatment effects but varied significantly over time. Of note, the oxidative stress index, as ratio between pro- and antioxidants in both groups, peaked during weaning and then returned to baseline, suggesting an effective response to this transition phase. Overall, the results indicate that feeding TRANS during the first 5 d of life had no long-term effect on the parameters studied as compared with MR feeding under the present rearing conditions. These results provide insight into the changes of oxidative status with age and confirm that the relatively high milk feeding level, with slow and late weaning, enables calves to adapt well to solely solid feed.

A Comparative Analysis of Milk Oligosaccharides via LC-MS: Globally Distributed Cattle Breeds and Native Northern Finncattle

Milk oligosaccharides are complex carbohydrates composed of various monosaccharide units linked together by glycosidic bonds. They play an essential role in promoting gut health by fostering beneficial bacteria, supporting the development of the immune system, and protecting against infections and diseases. This work compared the oligosaccharide profiles in widely utilized breeds such as Holstein and Ayrshire (Nordic Red), with the native Northern Finncattle, which is considered an endangered breed. Oligosaccharides were extracted from milk and analyzed by liquid chromatography-mass spectrometry. The composition and relative abundance of the identified oligosaccharides were characterized and compared. The statistical analyses showed that neutral, sialylated, and fucosylated oligosaccharides vary among the breeds. Ayrshire and Northern Finncattle oligosaccharides formed a cluster, while Holstein's profile shared features with both Ayrshire and Northern Finncattle. Holstein had the lowest abundance of fucosylated OS among the three breeds, with Ayrshire having the highest content followed by Northern Finncattle. The relatively higher sialylated over neutral content of Northern Finncattle is an important feature that should be preserved. Ayrshire is a good candidate to recover more diverse oligosaccharides with potential gut health implications for consumers.

Structural Characterization and Abundance of Sialylated Milk Oligosaccharides in Holstein Cows during Early Lactation

Among other bioactive molecules, milk contains high amounts of sialylated milk oligosaccharides (MOs) that influence numerous processes in the offspring. For instance, sialylated MOs inhibit the invasion of pathogens and positively influence the gut microbiome to support the optimal development of the offspring. For these reasons, sialylated MOs are also used in infant formula as well as food supplements and are potential therapeutic substances for humans and animals. Because of the high interest in sialylated bovine MOs (bMOs), we used several analytical approaches, such as gas and liquid chromatography in combination with mass spectrometry, to investigate in detail the profile of sialylated bMOs in the milk of Holstein Friesian cows during early lactation. Most of the 40 MOs identified in this study were sialylated, and a rapid decrease in all detected sialylated bMOs took place during the first day of lactation. Remarkably, we observed a high variance within the sialylation level during the first two days after calving. Therefore, our results suggest that the content of sialylated MOs might be an additional quality marker for the bioactivity of colostrum and transitional milk to ensure its optimized application for the production of milk replacer and food supplements.

Invited review: Nutritional and management factors that influence colostrum production and composition in dairy cows

Colostrum is a rich source of nutritional and non-nutritional components and is recognized as essential to transfer passive immunity to newborn calves. Because of the individual and seasonal variability in colostrum yield and composition, maintaining an adequate supply of high-quality colostrum year-round remains a challenge for commercial dairy producers. In this narrative review, we described the individual, seasonal, and herd-level variability of colostrum production and summarized the association between individual animal factors such as parity, sex of the calf, calf birth weight, as well as indicators of the cow's metabolic status and the yield and composition of colostrum. Further, we reviewed the current knowledge on the influence of prepartum nutrition and management strategies on colostrum production. Research on the metabolizable energy and protein supplied in the prepartum diet as well as on the inclusion and source of vitamins, minerals, and feed additives suggests prepartum nutrition influences the yield, quality, and composition of colostrum. Furthermore, the prepartum environment and dry period length remain influential factors in the production of colostrum. However, additional research is needed to understand the mechanisms by which prepartum nutrition and management affect colostrum production. Finally, time from calving to colostrum harvest and oxytocin administration as well as the current knowledge on the effect of heat treatment and colostrum storage strategies on colostral components were discussed. To conclude, we identify critical gaps in knowledge for future focus of investigation in colostrum research.

Unlocking the mysteries of milk oligosaccharides: Structure, metabolism, and function

Milk oligosaccharides (MOs), complex carbohydrates prevalent in human breast milk, play a vital role in infant nutrition. Serving as prebiotics, they inhibit pathogen adherence, modulate the immune system, and support newborn brain development. Notably, MOs demonstrate significant variations in concentration and composition, both across different species and within the same species. These characteristics of MOs lead to several compelling questions: (i) What distinct beneficial functions do MOs offer and how do the functions vary along with their structural differences? (ii) In what ways do MOs in human milk differ from those in other mammals, and what factors drive these unique profiles? (iii) What are the emerging applications of MOs, particularly in the context of their incorporation into infant formula? This review delves into the structural characteristics, quantification methods, and species-specific concentration differences of MOs. It highlights the critical role of human MOs in infant growth and their potential applications, providing substantial evidence to enhance infant health and development.

Effects of supplementing colostrum beyond the first day of life on growth and health parameters of preweaning Holstein heifers

The preweaning period for a dairy calf is characterized by high morbidity and mortality rates, leading to financial losses for producers. Identifying strategies to improve the health and welfare of calves while reducing antimicrobial use continues to be crucial to the success of the dairy industry. The objective of this study was to determine the effects of feeding colostrum replacer (CR) to dairy heifer calves beyond d 1 of life on growth, serum IgG, the incidence of diarrhea and bovine respiratory disease (BRD), and the risk of mortality in the preweaning period. At birth, Holstein heifer calves (n = 200; 50/treatment) weighing 40.7 ± 0.35 kg (mean ± SE) were fed 3.2 L of CR (205 g IgG/feeding) at 0 h and 12 h of life. Calves were then randomly assigned to 1 of 4 treatments: 450 g of milk replacer (MR) from d 2 to 14 (control, CON), 380 g of CR + 225 g of MR from d 2 to 3, then 450 g of MR from d 4 to 14 (transition, TRAN), 45 g of CR + 450 g of MR from d 2 to 14 (extended, EXT); or 380 g of CR + 225 g of MR from d 2 to 3, then 45 g of CR + 450 g of MR from d 4 to 14 (transition + extended, TRAN+EXT). Each treatment was reconstituted to 3 L and fed twice daily. All CR treatments were fed using bovine-derived CR containing 27% IgG. From d 15 to 41, all calves were fed 600 g of MR reconstituted to 4 L twice daily. Body weight was recorded at birth and every 7 d until study completion on d 49. Blood samples were taken daily until d 7 to evaluate serum IgG and then every 7 d until d 49. A health assessment was performed daily to evaluate calves for BRD and diarrhea. Data were analyzed using mixed linear regression, mixed logistic regression, and survival analysis models in SAS 9.4. Serum IgG concentrations were not affected by treatment for the study period. The EXT and TRAN+EXT groups had greater average daily gain (ADG) from d 7 to 14 (0.14 kg/d) and the TRAN group had greater ADG from d 14 to 21 (0.11 kg/d), compared with CON. There was no association of treatment with the odds or the duration of a diarrhea bout. However, provision of CR to the TRAN and EXT calves was associated with a reduced hazard of diarrhea compared with CON calves. Furthermore, TRAN and EXT calves have a lower hazard of mortality compared with CON calves, with TRAN and EXT calves had a 2.8- and 3.8-times lower hazard of mortality, respectively. Our findings suggest that the supplementation of CR to dairy calves positively affects ADG, and reduces the hazard of diarrhea and mortality during the preweaning period. Future research should look to further refine the supplementation strategy of CR to calves and explore the mechanism of action.

Bovine milk microbiota: Key players, origins, and potential contributions to early-life gut development

BACKGROUND

Bovine milk is a significant substitute for human breast milk and holds great importance in infant nutrition and health. Apart from essential nutrients, bovine milk also contains bioactive compounds, including a microbiota derived from milk itself rather than external sources of contamination.

AIM OF REVIEW

Recognizing the profound impact of bovine milk microorganisms on future generations, our review focuses on exploring their composition, origins, functions, and applications.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Some of the primary microorganisms found in bovine milk are also present in human milk. These microorganisms are likely transferred to the mammary gland through two pathways: the entero-mammary pathway and the rumen-mammary pathway. We also elucidated potential mechanisms by which milk microbiota contribute to infant intestinal development. The mechanisms include the enhancing of the intestinal microecological niche, promoting the maturation of immune system, strengthening the intestinal epithelial barrier function, and interacting with milk components (e.g., oligosaccharides) via cross-feeding effect. However, given the limited understanding of bovine milk microbiota, further studies are necessary to validate hypotheses regarding their origins and to explore their functions and potential applications in early intestinal development.

A Comprehensive Review of Bovine Colostrum Components and Selected Aspects Regarding Their Impact on Neonatal Calf Physiology

Colostrum contains macro- and micronutrients necessary to meet the nutritional and energy requirements of the neonatal calf, bioactive components that intervene in several physiological aspects, and cells and microorganisms that modulate the calf's immune system and gut microbiome. Colostrum is sometimes mistaken as transition milk, which, although more nutritive than whole milk, has a distinct biochemical composition. Furthermore, most research about colostrum quality and colostrum management focuses on the transfer of maternal IgG to the newborn calf. The remaining components of colostrum and transition milk have not received the same attention, despite their importance to the newborn animal. In this narrative review, a large body of literature on the components of bovine colostrum was reviewed. The variability of these components was summarized, emphasizing specific components that warrant deeper exploration. In addition, the effects of each component present in colostrum and transition milk on several key physiological aspects of the newborn calf are discussed.

Feeding colostrum and transition milk facilitates digestive tract functionality recovery from feed restriction and fasting of dairy calves

The objective of this study was to evaluate the digestive tract recovery and metabolism of feeding either bovine colostrum (BC), transition milk (TM), or milk replacer (MR) after an episode of feed restriction and fasting (FRF) in dairy calves. Thirty-five Holstein male calves (22 ± 4.8 d old) were involved in a 50-d study. After 3 d of feeding 2 L of rehydration solution twice daily and 19 h of fasting (d 1 of study), calves were randomly assigned to one of the 5 feeding treatments (n = 7): calves were offered either pooled BC during 4 (C4) or 10 (C10) days, pooled TM during 4 (TM4) or 10 (TM10) days, or MR for 10 d (CTRL) at the rate of 720 g/d DM content. Then, all calves were fed the same feeding program, gradually decreasing MR from 3 L twice daily to 2 L once daily at 12.5% DM until weaning (d 42), and concentrate feed, water, and straw were offered ad libitum until d 50. Citrulline, Cr-EDTA, β-hydroxybutyrate (BHB), and nonesterified fatty acids (NEFA) in serum and complete blood count (CBC) were determined on d -3, 1, 2, 5, and 11 relative to FRF, except BHB and NEFA at d -3. Volatile fatty acids (VFA), lactoferrin (LTF), IgA, and microbiota (Firmicutes to Bacteroidetes ratio and Fecalis prausnitzii) were analyzed in feces on d 5 and 11 before the morning feeding. Health scores were recorded daily from d -3 to d 14 as well as d 23 and 30. Feed concentrate, MR, and straw intake were recorded daily, and body weight on d -3, 1, 2, 5, and 11 and weekly afterward. Calf performance, intake, serum Cr-EDTA, CBC, fecal LTF concentrations and microbiota parameters were similar among treatments throughout the study. Serum NEFA concentrations were greater in TM4, TM10 and C10 calves compared with the CTRL ones from d 2 to 11, and after the FRF, serum concentrations of BHB were lower in CTRL calves than in the other treatments, and on d 11, serum BHB concentrations in the long treatments (C10 and TM10) remained greater than those in the shorter ones (C4 and TM4) and CTRL. Serum citrulline concentrations were similar on d -3 and 1 in all treatments, but they were greater in C4, C10, TM4, and TM10 on d 2 and 5, and on d 11 they were only greater in C10 and TM10 than in CTRL calves. Fecal IgA concentrations tended to be greater in C10 than in CTRL, TM4, and TM10 calves, and in C4 and TM10 than in CTRL animals. Fecal propionate proportion was lesser in C10 than in CTRL, TM4, and TM10 calves, while butyrate was greater in C4 and C10 than in TM4 and CTRL calves. The proportion of non-normal fecal scores of C10 fed calves was greater than TM4 and TM10 calves. Results showed that TM and BC may help to recover intestinal functionality, provide gut immune protection, and increase liver fatty acid oxidation in calves after a FRF episode.

Characterization and profiling of the microRNA in small extracellular vesicles isolated from goat milk samples collected during the first week postpartum

Colostrum contains nutrients, immunoglobulins, and various bioactive compounds such as microRNA (miRNA). Less is known about the temporal changes in miRNA profiles in ruminant milk samples during the first week postpartum. In this study, we characterized and compared the profiles of miRNA in the small extracellular vesicles (sEV) isolated from colostrum (CM, collected immediately after parturition, n = 8) and transition milk (TM, collected 7 d postpartum, n = 8) from eight 1-yr-old Guanzhong dairy goats with a milk yield of approximately 500 kg/year. A total of 192 unique sEV-associated miRNA (transcripts per million >1 at least 4 samples in either CM or TM) were identified in all samples. There were 29 miRNA uniquely identified in the TM samples while no miRNA was uniquely identified in the CM samples. The abundance of the top 10 miRNA accounted for 82.4% ± 4.0% (± SD) of the total abundance, with let-7 families (e.g., let-7a/b/c-5p) being predominant in all samples. The top 10 miRNA were predicted to target 1,008 unique genes that may regulate pathways such as focal adhesion, TGF-β signaling, and axon guidance. The expression patterns of EV miRNA were similar between the 2 sample groups, although the abundance of let-7c-5p and miR-30a-3p was higher, whereas that of let-7i-5p and miR-103-3p was lower in CM than in TM. In conclusion, the core miRNAome identified in the samples from CM and TM may play an important role in cell proliferation, bone homeostasis, and neuronal network formation in newborn goat kids. The lack of differential miRNA expression between the CM and TM samples may be due to a relatively short sampling interval in which diet composition, intake and health status of ewes, and environment were relatively stable.

Associations among Milk Microbiota, Milk Fatty Acids, Milk Glycans, and Inflammation from Lactating Holstein Cows

Milk oligosaccharides (MOs) can be prebiotic and antiadhesive, while fatty acids (MFAs) can be antimicrobial. Both have been associated with milk microbes or mammary gland inflammation in humans. Relationships between these milk components and milk microbes or inflammation have not been determined for cows and could help elucidate a novel approach for the dairy industry to promote desired milk microbial composition for improvement of milk quality and reduction of milk waste. We aimed to determine relationships among milk microbiota, MFAs, MOs, lactose, and somatic cell counts (SCC) from Holstein cows, using our previously published data. Raw milk samples were collected at three time points, ranging from early to late lactation. Data were analyzed using linear mixed-effects modeling and repeated-measures correlation. Unsaturated MFA and short-chain MFA had mostly negative relationships with potentially pathogenic genera, including Corynebacterium, Pseudomonas, and an unknown Enterobacteriaceae genus but numerous positive relationships with symbionts Bifidobacterium and Bacteroides. Conversely, many MOs were positively correlated with potentially pathogenic genera (e.g., Corynebacterium, Enterococcus, and Pseudomonas), and numerous MOs were negatively correlated with the symbiont Bifidobacterium. The neutral, nonfucosylated MO composed of eight hexoses had a positive relationship with SCC, while lactose had a negative relationship with SCC. One interpretation of these trends might be that in milk, MFAs disrupt primarily pathogenic bacterial cells, causing a relative increase in abundance of beneficial microbial taxa, while MOs respond to and act on pathogenic taxa primarily through antiadhesive methods. Further research is needed to confirm the potential mechanisms driving these correlations. IMPORTANCE Bovine milk can harbor microbes that cause mastitis, milk spoilage, and foodborne illness. Fatty acids found in milk can be antimicrobial and milk oligosaccharides can have antiadhesive, prebiotic, and immune-modulatory effects. Relationships among milk microbes, fatty acids, oligosaccharides, and inflammation have been reported for humans. To our knowledge, associations among the milk microbial composition, fatty acids, oligosaccharides, and lactose have not been reported for healthy lactating cows. Identifying these potential relationships in bovine milk will inform future efforts to characterize direct and indirect interactions of the milk components with the milk microbiota. Since many milk components are associated with herd management practices, determining if these milk components impact milk microbes may provide valuable information for dairy cow management and breeding practices aimed at minimizing harmful and spoilage-causing microbes in raw milk.

Evaluation of Parity Effect on Characteristics and Minerals in Buffalo (Bubalus Bubalis) Colostrum and Mature Milk

Colostrum is a vital performance for buffaloes and potentially functional foods in the future. Therefore, this study aimed to evaluate the difference between the parity of buffalo colostrum and mature milk. Twenty pregnant buffaloes (primiparous = 10; multiparous = 10) were assigned to the same diet prepartum and milking routine postpartum. Calves were separated from the dams immediately after birth and colostrum was harvested within 2 h, whilst mature milk was harvested at 7 days postpartum. The colostrum was analyzed for immunoglobulin G and milk composition as the mature milk. The results showed that there was a higher level of protein, solid not fat, and milk urea nitrogen (p < 0.05), with a tendency for higher total solids (p = 0.08) in primiparous buffaloes' colostrum compared with multiparous. No parity effect was observed in colostrum immunoglobulin G, fat, lactose, and yields of colostrum and composition (p > 0.05). There was no difference in mature milk composition and yield by parity affected (p > 0.05). Compared with mature milk composition, colostrum had a higher content protein, total solids, solid not fat, and milk urea nitrogen (p < 0.05); however, fat and lactose were lower than that of mature milk (p < 0.05). For minerals, multiparous buffaloes' colostrum had a higher concentration of Fe (p = 0.05), while the mature milk had higher concentrations of K and P compared with primiparous. Buffalo colostrum had higher concentrations of Na, Mg, Co, Fe, and K with a lower concentration of Ca relative to mature milk (p < 0.05). It was observed that parity affected colostrum characteristics rather than mature milk and caused subtle variations in minerals in colostrum and mature milk of buffaloes. As lactation proceeded, both milk composition and minerals in the milk changed drastically.

An Evaluation of Nutritional and Therapeutic Factors Affecting Pre-Weaned Calf Health and Welfare, and Direct-Fed Microbials as a Potential Alternative for Promoting Performance—A Review

The priority for calf rearing has been to maintain good health and welfare in order to promote and sustain future production. However, there have been numerous reports of undesirable levels of morbidity and mortality amongst pre-weaned calves. This may be mitigated or exacerbated by nutritional management practices. Some areas of concern include colostrum feeding, utilization of waste milk, and restrictive milk feeding regimes. Antibiotics may be prescribed at lethal or sub-inhibitory doses to treat or prevent disease. However, extensive antibiotic use may disrupt the gastrointestinal microbiota and aid in expanding the antibiotic resistant gene pool. In an attempt to reduce the use of antibiotics, there is a demand to find alternative performance enhancers. Direct-fed microbials, also known as probiotics, may comply with this role. A DFM consists of live microorganisms that are biologically active and able to confer health benefits onto the host. Lactic acid bacteria have been the most frequently investigated; however, this field of research has expanded to include spore-forming bacteria and live yeast preparations. This review aims to provide a comprehensive evaluation of the nutritional management strategies that may increase a calf’s susceptibility to morbidity and mortality, the efficacy and sustainability of antibiotics as a tool for managing calf health and welfare, and the potential for DFMs as a supportive strategy for promoting calf wellbeing.

Bovine colostrum promoted ileal health in newborn lambs at 24 h after birth: insight from intestinal morphology and innate immunity

The contribution of colostrum to passive immunity transfer and intestinal protection in newborn ruminants is well known; however, it is currently unclear how colostrum intake affects intestinal innate immunity. We investigated the effects of bovine colostrum intake on ileal morphology, expression of genes involved in intestinal innate immunity, and serum concentrations of inflammatory cytokines in newborn lambs. Twenty-seven newborn male Hu lambs were used, of which 18 were bottle-fed either bovine colostrum (C24h; n = 9) or bovine mature milk (M24h; n = 9) within the first 2 h after birth at an intake of approximately 8% of BW; the remaining nine lambs did not receive any feeding (N24h). Blood and ileal tissue samples were collected after the lambs were slaughtered at 24 h after birth. Ileal villus height and villus height-to-crypt depth ratio were significantly higher in C24h than those in N24h and M24h lambs (P < 0.01). Messenger RNA (mRNA) abundance of toll-like receptor (TLR)-2, TLR3, TLR4, TLR6, TLR7, TLR8 and tumour necrosis factor alpha in the ileum was lower in C24h than that in N24h lambs (P < 0.05). Moreover, C24h lambs had a lower TLR3 mRNA abundance (P < 0.01) and a trend of lower TLR6 (P = 0.06) and interleukin 1 beta (P = 0.08) expression compared with those in M24h lambs. We also observed strong positive correlations of tumour necrosis factor alpha expression with that of TLR2 (r = 0.71; P < 0.001), TLR4 (r = 0.88; P < 0.001) and TLR8 (r = 0.83; P < 0.001). Interestingly, the expression of barrier-related molecules, including mucin-13, lysozyme, claudin (CLDN)-1, CLDN2, CLDN4, CLDN7, CLDN12, occludin, zonula occluden-1 and junctional adhesion molecule-1, was consistently lower in C24h lambs than that in N24h and M24h lambs (P < 0.05). These results indicated that the beneficial roles of colostrum intake on intestinal protection in newborn lambs were associated with low TLR expression, which was reflected by improved intestinal development and reduced inflammatory response. Further studies using fluorescence in situ hybridisation and immunohistochemical methods are needed to further explore the mechanisms underlying the lower expression of intestinal barrier-related molecules due to colostrum feeding.

Dietary Fiber to Starch Ratio Affects Bovine Milk Oligosaccharide Profiles

Background

Bovine milk oligosaccharides (BMOs) have several demonstrated and hypothesized benefits including roles in cognitive development and antipathogenic activities, making them promising ingredients for infant formulas and nutraceutical applications. BMO extraction from bovine milk is challenged by low concentrations relative to nonbioactive simple sugars like lactose. BMO abundances are known to vary with a cow's lactation stage, breed, and parity, but these characteristics are difficult to modify in existing dairy herds. In contrast, diet modification is an accessible target, and is already known to influence milk yield, lipid content, protein levels, and monosaccharide compositions.

Objectives

To determine the impact of a low starch high fiber versus a high starch low fiber diet on overall BMO profiles and individual BMO abundances in Holstein dairy cattle.

Methods

Milk samples were collected from 59 midlactation Holsteins in a crossover study featuring dietary modification with either a low starch high fiber or high starch low fiber feed. BMO profiles were evaluated by nano-LC quadrupole time-of-flight tandem MS, and differences in BMO abundances between diets were evaluated using linear mixed effects modeling.

Results

A total of 19 BMOs were identified across the sample set, including 4 large fucosylated compounds. Seven BMOs were found to have significantly more positive percent changes in yield-adjusted abundance from the pre-experiment baseline period for milk samples collected during feeding with the low starch high fiber diet compared with the high starch low fiber diet.

Conclusions

Consuming the low starch high fiber diet promoted greater overall BMO production than the high starch low fiber diet in a population of midlactation Holsteins. Additionally, this study afforded the opportunity to investigate the impact of other factors potentially influencing BMO abundances, furthering understanding of how dairy herd management practices can positively impact milk composition and support the potential use of BMOs as functional ingredients.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 38% and 19% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 72% higher in PP cows throughout the milking period, as well as 13% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 25% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 29% higher in colostrum than mature milk and 33% higher in MP cows. Linoleic acid was also 15% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 2.7-fold higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 40% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

Sialyloligosaccharides Content in Mature Milk of Different Cow Breeds

Sialyloligosaccharides (SOS) are bioactive molecules that play an important role in brain development and the increase in immunity in infants. In adults, they act as prebiotics, enhancing protection against microbial pathogens. In the present work, we aimed to analyze the levels of SOS in mature milk, at days 60 and 120 after calving in four cow breeds: Holstein (HO), Simmental × Holstein (SM × HO), Simmental (SM), all fed with total mixed ration (TMR) in intensive production, and Podolica (POD) raised on pasture in an extensive system. The concentrations of SOS (3′-sialyllactose = 3′-SL, 6′-sialyllactose = 6′-SL, 6′-Sialyl-N-acetyllactosamine = 6′-SLN, disialyllactose = DSL, expressed in mg/L) were determined using HPAEC-PAD, a high-performance anion-exchange chromatography with pulsed amperometric detection. Results showed both breed and lactation effects. The contents of 3′-SL, 6′-SL, 6′-SLN, and DSL were higher at 60 than 120 days (p < 0.001), as well as in POD, as compared to the other breeds (p < 0.001). Furthermore, SM showed a significantly greater level of 3′-SL than HO (p < 0.001), as well as a significantly higher level of 6′-SLN in SM than HO (p < 0.001) and SM × HO (p < 0.001). Our findings may have implications for several areas of sustainability that might be used in the cattle management system.

A live yeast supplementation to gestating ewes improves bioactive molecule composition in colostrum with no impact on its bacterial composition and beneficially affects immune status of the offspring

Colostrum quality is of paramount importance in the management of optimal ruminant growth and infectious disease prevention in early life. Live yeast supplementation effect during the last month of gestation was evaluated on ewes’ colostrum composition. Two groups of ewes (n = 14) carrying twin lambs were constituted and twins were separated into groups (mothered or artificially fed) 12 h after birth. Nutrient, oligosaccharides (OS), IgG and lactoferrin concentrations were measured over 72 h after lambing, and bacterial community was described in colostrum collected at parturition (T0). Immune passive transfer was evaluated through IgG measurement in lamb serum. In both groups, colostral nutrient, OS concentrations and IgG concentrations in colostrum and lamb serum decreased over time (P < 0⋅01), except for lactose, which slightly increased (P < 0⋅001), and lactoferrin, which remained stable. Bacterial population was stable over time with high relative abundances of Aerococcaceae, Corynebacteriaceae, Moraxellaceae and Staphylococcaceae in T0 colostrum. No effect of supplementation was observed in nutrient and lactoferrin concentrations. In supplemented ewes, the level of colostral IgG was higher at T0 and a higher level of serum IgG was observed in lambs born from supplemented mothers and artificially fed, while no effect of supplementation was observed in the mothered lamb groups. Using a metabolomic approach, we showed that supplementation affected OS composition with significantly higher levels of colostral Neu-5Gc compounds up to 5 h after birth. No effect of supplementation was observed on bacterial composition. Our data suggest that live yeast supplementation offsets the negative impact of early separation and incomplete colostrum feeding in neonate lambs.

Invited review: The importance of colostrum in the newborn dairy calf

It is critical that bovine maternal colostrum is fed to newborn calves during their first hours of life. Colostrum is the secretion a cow produces after mammary involution that is rich in various nutrients. In addition to the nutritive value for newborn calves, immunoglobulins are of interest due to their role in developing the naïve immune system of calves at birth. The process by which a calf acquires immunity via absorption of immunoglobulins is defined as passive immunity. When calves consume an adequate amount of immunoglobulins, they are classified as having successful passive immunity (SPI). In contrast, if they are deprived of adequate colostrum, they are considered to have had a failure of transfer of passive immunity (FPI). Transfer of passive immunity is assessed by measuring serum IgG concentrations at 24 to 48 h of age. The major factors that influence whether a calf has SPI or FPI are colostrum IgG concentration, quantity fed, and age of calf at colostrum feeding. Monitoring apparent efficiency of immunoglobulin absorption in calves is often recommended to evaluate overall colostrum management practices. Serum IgG analyses can be determined with direct (radial immunodiffusion) or indirect (refractometry) methods and used to assess SPI or FPI prevalence.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 16% and 27% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 42% higher in PP cows throughout the milking period, as well as 15% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 13% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 23% higher in colostrum than mature milk and 25% higher in MP cows. Linoleic acid was also 13% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 63% higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 25% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

Colostrogenesis: Role and Mechanism of the Bovine Fc Receptor of the Neonate (FcRn)

Colostrogenesis is a separate and unique phase of mammary epithelial cell activity occurring in the weeks before parturition and rather abruptly ending after birth in the bovine. It has been the focus of research to define what controls this process and how it produces high concentrations of specific biologically active components important for the neonate. In this review we consider colostrum composition and focus upon components that appear in first milked colostrum in concentrations exceeding that in blood serum. The Fc Receptor of the Neonate (FcRn) is recognized as the major immunoglobulin G (IgG) and albumin binding protein that accounts for the proteins' long half-lives. We integrate the action of the pinocytotic (fluid phase) uptake of extracellular components and merge them with FcRn in sorting endosomes. We define and explore the means of binding, sorting, and the transcytotic delivery of IgG1 while recycling IgG2 and albumin. We consider the means of releasing the ligands from the receptor within the endosome and describe a new secretion mechanism of cargo release into colostrum without the appearance of FcRn itself in colostrum. We integrate the insulin-like growth factor family, some of which are highly concentrated bioactive components of colostrum, with the mechanisms related to FcRn endosome action. In addition to secretion, we highlight the recent findings of a role of the FcRn in phagocytosis and antigen presentation and relate its significant and abrupt change in cellular location after parturition to a role in the prevention and resistance to mastitis infections.

Effects of colostrum management on transfer of passive immunity and the potential role of colostral bioactive components on neonatal calf development and metabolism

Neonatal dairy and beef calves are required to ingest adequate volumes of high-quality colostrum during their first hours of life to acquire transfer of passive immunity (TPI). As such, immunoglobulin G (IgG) has largely been the focus of colostrum research over recent decades. Yet, little is known about the additional bioactive compounds in colostrum that potentially influence newborn calf development and metabolism. The purpose of this narrative review is to synthesize research regarding the effects of colostrum management practices on TPI, as well as to address the potential role of additional colostral bioactive molecules, including oligosaccharides, fatty acids, insulin, and insulin-like growth factor-I, in promoting calf development and metabolism. Due to the importance of IgG in ensuring calf immunity and health, we review past research describing the process of colostrogenesis and dam factors influencing the concentrations of IgG in an effort to maximize TPI. We also address the transfer of additional bioactive compounds in colostrum and prepartum management and dam factors that influence their concentrations. Finally, we highlight key areas of future research for the scientific community to pursue to ultimately improve the health and welfare of neonatal dairy calves.

A Narrative Review on the Unexplored Potential of Colostrum as a Preventative Treatment and Therapy for Diarrhea in Neonatal Dairy Calves

Diarrhea is the leading cause of morbidity and mortality in pre-weaned dairy calves and, as such, represents a significant animal health and welfare concern. Furthermore, digestive disease early in life is associated with several long-term consequences such as reduced growth rate and decreased milk yield during the first lactation, thus generating severe economic losses. The majority of diarrheic cases in young calves are treated with antimicrobials; however, it is necessary to develop alternative treatments, as excessive antimicrobial usage can lead to antimicrobial resistance and can negatively impact the gut microflora of a calf. Bovine colostrum is abundant in immune and bioactive factors that improve immune function and development. This rich and natural combination of immunoglobulins, natural antimicrobial factors, growth factors, anti-inflammatories and nutrients may be an attractive alternative to antimicrobials in the treatment of diarrhea in young dairy calves. There is evidence that supports the use of colostrum as an early treatment for diarrhea in young calves. Future research should investigate its therapeutic and economic effectiveness.

Effects of colostrum feeding on the mRNA abundance of genes related to toll-like receptors, key antimicrobial defense molecules, and tight junctions in the small intestine of neonatal dairy calves

The objective of the present study was to elucidate the effect of feeding either colostrum or milk-based formula on the mRNA abundance of genes related to pathogen recognition [toll-like receptors (TLR1-10)], antimicrobial defense [β-defensin 1 (DEFB1) and peptidoglycan recognition protein 1 (PGLYRP1)], and tight junctions (claudin 1 = CLDN1, claudin 4 = CLDN4, and occludin = OCLN) in different sections of the small intestine of neonatal calves at d 4 of life. Holstein dairy calves were fed either colostrum (COL; n = 7) or milk-based formula (FOR; n = 7) with comparable nutrient composition but lower contents of several bioactives in the formula than in the respective colostrum group until d 4 of life. Following euthanasia on d 4 (2 h after feeding), tissue samples from the duodenum, jejunum (proximal, middle, and distal), and ileum were collected. The mRNA abundance of the target genes was quantified by quantitative PCR. The mRNA abundance of TLR1, TLR6, TLR9, and TLR10 were greater in COL than in FOR calves. However, the mRNA abundance of TLR2, TLR3, TLR4, TLR5, and TLR7 did not differ between groups. A group × gut region interaction was observed for the mRNA abundance of TLR8 with greater values in duodenum and proximal jejunum of COL than in FOR calves but in the more distal regions, in mid and distal jejunum, and ileum, this diet effect disappeared or was reversed. We observed greater mRNA abundance of TLR1 in the jejunum (middle and distal) and ileum, TLR2, TLR4, TLR6, and TLR9-10 in the distal jejunum and ileum, and of TLR3 in the distal jejunum, and TLR5, TLR7, and TLR8 in the ileum compared with the other gut regions. The mRNA abundance of PGLYRP1, DEFB1, and OCLN did not differ between groups. The mRNA abundance of CLDN1 was greater, but the CLDN4 mRNA tended to be lower in COL than in FOR calves. The mRNA abundance of PGLYRP1 was lower in the distal jejunum and DEFB1 mRNA in the middle jejunum compared with the other gut regions. The mRNA abundances of OCLN and CLDN4 were greater in the duodenum, and of CLDN1 in the middle and proximal jejunum compared with the other gut regions. Overall, the greater mRNA abundance of 5 different TLR, and CLDN1 in most intestinal sections of the COL calves may suggest that feeding colostrum improves immune responsiveness and epithelial barrier function in neonatal calves.

ADSA Foundation Scholar Award: New frontiers in calf and heifer nutrition-From conception to puberty

Dairy calf nutrition is traditionally one of the most overlooked aspects of dairy management, despite its large effect on the efficiency and profitability of dairy operations. Unfortunately, among all animals on the dairy farm, calves suffer from the highest rates of morbidity and mortality. These challenges have catalyzed calf nutrition research over the past decade to mitigate high incidences of disease and death, and improve animal health, growth, welfare, and industry sustainability. However, major knowledge gaps remain in several crucial stages of development. The purpose of this review is to summarize the key concepts of nutritional physiology and programming from conception to puberty and their subsequent effects on development of the calf, and ultimately, future performance. During fetal development, developmental plasticity is highest. At this time, maternal energy and protein consumption can influence fetal development, likely playing a critical role in calf and heifer development and, importantly, future production. After birth, the calf's first meal of colostrum is crucial for the transfer of immunoglobulin to support calf health and survival. However, colostrum also contains numerous bioactive proteins, lipids, and carbohydrates that may play key roles in calf growth and health. Extending the delivery of these bioactive compounds to the calf through a gradual transition from colostrum to milk (i.e., extended colostrum or transition milk feeding) may confer benefits in the first days and weeks of life to prepare the calf for the preweaning period. Similarly, optimal nutrition during the preweaning period is vital. Preweaning calves are highly susceptible to health challenges, and improved calf growth and health can positively influence future milk production. Throughout the world, the majority of dairy calves rely on milk replacer to supply adequate nutrition. Recent research has started to re-evaluate traditional formulations of milk replacers, which can differ significantly in composition compared with whole milk. Transitioning from a milk-based diet to solid feed is critical in the development of mature ruminants. Delaying weaning age and providing long and gradual step-down protocols have become common to avoid production and health challenges. Yet, determining how to appropriately balance the amount of energy and protein supplied in both liquid and solid feeds based on preweaning milk allowances, and further acknowledging their interactions, shows great promise in improving growth and health during weaning. After weaning and during the onset of puberty, heifers are traditionally offered high-forage diets. However, recent work suggests that an early switch to a high-forage diet will depress intake and development during the time when solid feed efficiency is greatest. It has become increasingly clear that there are great opportunities to advance our knowledge of calf nutrition; yet, a more concentrated and rigorous approach to research that encompasses the long-term consequences of nutritional regimens at each stage of life is required to ensure the sustainability and efficiency of the global dairy industry.

Analysis of the biosynthetic flux in bovine milk oligosaccharides reveals competition between sulfated and sialylated species and the existence of glucuronic acid-containing analogues

We previously observed that sialylated bovine milk oligosaccharides (BMOs) decline in both absolute and relative abundances over the initial stages of bovine lactation, with initial evidence suggesting that this decline occurred due to increased concentrations of unique sulfated BMOs. Since both sulfated and sialylated BMOs have distinct bioactivites, a follow up study was launched in order to more clearly define relative changes in these classes of BMOs over the first week of lactation in dairy cattle. Capillary electrophoresis (CE) and several liquid chromatography mass spectrometry (LC-MS) methods, including a novel multiplexed tandem MS method, were used to profile the BMOs extracted from milk collected from the same 20 Holstein cows at milkings 1, 2, 3, 4, 8, and 14 post-partum. In addition to clearly validating that sulfated and sialylated BMOs exist in direct biosynthetic completion, our study has identified over 170 unique BMOs including 14 unique glucuronic acid-containing trisaccharides.

Calf health from birth to weaning - an update

Research on calf health and welfare has intensified in the past decades. This is an update on a review series on calf health from birth to weaning published ten years ago.

Good colostrum management is still recognised as the single most important factor to preventing calf morbidity and mortality, however, it is now known that immunoglobulins are only one of many components of colostrum that are vital for the calf’s development. Other non-nutrient factors like leucocytes, hormones and growth factors, oligosaccharides as well as microRNAs have significant effects on the development and maturation of the intestinal and systemic immune functions. They also promote the maturation and function of the intestine, thus enabling the calf to digest and absorb the nutrients provided with colostrum and milk. The improved energetic status of colostrum-fed neonates is reflected by an accelerated maturation of the somatotropic axis, which stimulates body growth and organ development. Colostrum oligosaccharides are presumed to play a major role in the development of a healthy intestinal flora.

A biologically normal (intensive) milk-feeding programme is subsequently necessary for optimal body growth, organ development and resistance to infectious diseases. Ad-libitum or close to ad-libitum feeding in the first three to four weeks of life also leaves calves less hungry thus improving calf welfare. Only calves fed intensively with colostrum and milk are able to reach their full potential for performance throughout their life.

Public interest in farm animal welfare is growing in past decades, which makes it necessary to have a closer look at contentious management practices in the dairy industry like early separation of the dairy calf from the dam with subsequent individual housing. Public objection to these practices cannot be mitigated through educational efforts. Contrary to common opinion there is no evidence that early cow-calf separation is beneficial for the health of calf or cow. There is evidence of behavioural and developmental harm associated with individual housing in dairy calves, social housing improves feed intake and weight gains, and health risks associated with grouping can be mitigated with appropriate management.

In conclusion, there are still many management practices commonly applied, especially in the dairy industry, which are detrimental to health and welfare of calves.

Extended transition milk feeding for 3 weeks improves growth performance and reduces the susceptibility to diarrhea in newborn female Holstein calves

Dairy calves may benefit from extending the duration of feeding transition milk (TM; the subsequent two to six milkings after parturition) to enhance performance and health during early life. The objective of this study was to assess the effect of replacing pasteurized waste milk (non-saleable milk containing antibiotic and/or drug residues) with pasteurized TM for 3 weeks on the growth performance and health of dairy calves. A total of 84 healthy newborn female Holstein calves were blocked by birth order and assigned randomly to 4 treatment groups with partial replacement of pasteurized waste milk by TM (second milkings after parturition) at 0 (0 l/day TM + 6 l/day milk), 0.5 (0.5 l/day TM + 5.5 l/day milk), 1 (1 l/day TM + 5 l/day milk), or 2 l (2 l/day TM + 4 l/day milk) for a 21-day period. From day 22 onward, all calves were fed individually with 6 l/day pasteurized waste milk. Calves were weaned on day 60 and monitored until day 90 of the study. Liquid feed DM intake (DMI) was increased with increasing levels of TM (P = 0.001). Starter feed DMI and total DMI (liquid feed DMI + starter feed DMI) were not affected by the treatment effect. Calves were fed 2 l/day TM gained more BW compared with those in the control group during the postweaning and overall periods. The average daily gain tended (P = 0.06) to be higher in calves fed 2 l/day TM compared with calves fed 0 (+ 65 g/day), 0.5 (+ 53 g/day), or 1 (+ 76 g/day) l/day TM during the preweaning period. Daily weight gain was also higher in calves fed 2 l/day TM compared with calves in the control group during the postweaning (+ 137 g/day; P = 0.04) and overall (+89 g/day; P < 0.01) periods, respectively. Calves fed 2 l/day TM had a higher feed efficiency compared with calves in the control group during all studied periods. The calves fed TM2 had a lower chance of having diarrhea compared with other treatment groups. Duration but not the frequency of diarrhea was lower in calves fed TM2 vs TM0 (2.5 vs 4.2days; P = 0.03). In general, partial replacement of waste milk with TM (2 l/day) may be recommended to feed dairy calves at an early stage of life to support a higher growth rate and health benefits.

Comparison of bovine milk oligosaccharides in native North European cattle breeds

Milk oligosaccharides are of high interest due to their bioactive properties. This study is the first to characterise milk oligosaccharides from native North European cattle breeds, as represented by 80 milk samples collected from eight native breeds originated from Norway (Norwegian Doela cattle and Norwegian Telemark cattle), Sweden (Swedish Mountain cattle), Denmark (Danish Red anno 1970), Iceland (Icelandic cattle), Lithuania (native Lithuanian Black and White) and Finland (Western Finncattle and Eastern Finncattle). Using high-performance liquid-chromatography chip/quadrupole time-of-flight mass-spectrometry, 18 unique monosaccharide compositions and a multitude of isomers were identified. No N-glycolylneuraminic acid was identified among these breeds. Western Finncattle milk was most abundant in neutral, acidic and fucosylated oligosaccharides. Further, Eastern Finncattle milk was significantly higher in acidic oligosaccharides and Icelandic cattle milk significantly higher in fucosylated oligosaccharides, compared to the mean. This study highlights specific native breeds of particular interest for future exploitation of milk oligosaccharides and breeding strategies.

Evaluation of colostrum bioactive protein transfer and blood metabolic traits in neonatal lambs in the first 24 hours of life

Colostrum is a unique resource that contributes to the passive transfer of immunity and plays a central role in the health status of neonatal ruminants. However, digestion and absorption of colostral proteins in the gut remain incompletely understood. Therefore, this study aimed to investigate the effect of bovine colostrum feeding on blood metabolic traits and to quantify colostral bioactive proteins in the gastrointestinal digesta and blood to evaluate intestinal transfer in neonatal lambs in the first 24 h of life. Fifty-four newborn lambs were used in this study, including 27 lambs fed pooled bovine colostrum and slaughtered at 6 (C6h), 12 (C12h), or 24 h (C24h) after birth; 18 lambs not fed any colostrum or milk and slaughtered at birth (N0h) or 24 h (N24h) after birth; and 9 milk-fed lambs slaughtered at 24 h (M24h) after birth. Lambs receiving colostrum or milk were bottle-fed within the first 2 h to obtain intakes of 8% of body weight at birth. Samples of blood and digesta from the abomasum, jejunum, and ileum were collected after slaughter. Serum concentrations of glucose, insulin, total protein, and aspartate aminotransferase were higher in colostrum-fed lambs than in N0h lambs. Serum concentrations of insulin, total protein, insulin-like growth factor 1, and γ-glutamyl transpeptidase were higher in C24h lambs than in N24h or M24h lambs. Apparent efficiencies of IgG absorption in C6h, C12h, and C24h lambs were 14.4, 26.8, and 17.2%, respectively, whereas apparent efficiencies of lactoferrin (LF), α-lactalbumin (α-LA), and β-lactoglobulin (β-LG) absorption were very low in colostrum-fed lambs, with mean values of 0.06, 0.002, and 0.003%, respectively. Concentrations of IgG, LF, α-LA, and β-LG in the digesta of the abomasum, jejunum, and ileum rapidly decreased from C6h to C24h lambs, and the disappearance rates of IgG, LF, α-LA, and β-LG were higher in lambs from C6h to C12h (62.1, 75.7, 91.3, and 95.0% for IgG, LF, α-LA, and β-LG, respectively) than from C12h to C24h (34.6, 22.5, 7.5, and 2.2% for IgG, LF, α-LA, and β-LG, respectively). These results indicated that bovine colostrum feeding improved the metabolic and immunological status of lambs, and that ingested colostral IgG was prone to intact uptake into the blood, whereas almost all ingested LF, α-LA, and β-LG disappeared in the lumen of the gastrointestinal tract in a time-dependent manner. The findings provide novel information for exploring selective absorption of colostral compounds in the small intestine of lambs.

Short communication: Odd-chain and branched-chain fatty acid concentrations in bovine colostrum and transition milk and their stability under heating and freezing treatments

Although odd-chain fatty acids (OCFA) and branched-chain fatty acids (BCFA) are found in bovine milk and have some positive influences on human and animal health, their concentrations in bovine colostrum and transition milk have not been reported. In this study, we reported the OCFA and BCFA concentrations in colostrum and transition milk and their stability after heating or freezing treatments (or both), which are processes commonly applied in dairy calf management. Milk samples were collected from 12 Holstein dairy cows (6 primiparous and 6 multiparous) at the first milking (colostrum), fifth milking (transition milk), and ninth milking (mature milk) after calving, respectively, and were used for fatty acid analysis using gas chromatography. The sum concentration of OCFA and BCFA (termed OBCFA) was 134 mg/100 g of milk in the colostrum, which was 24% and 35% lower than that in the transition milk and mature milk, respectively. Among these fatty acids detected, C15:0 and C17:0 were the top 2 abundant fatty acids in all milk types, accounting for 20 to 25% and 21 to 24% of the total concentration of OBCFA, respectively. Additionally, anteiso-C17:0 was the most abundant BCFA, followed by iso-C17:0, anteiso-C15:0, iso-C16:0, iso-C15:0, iso-C18:0, and iso-C14:0 in 3 types of milk. Significant interactions between milk type and cow parity were observed for all OCFA and BCFA concentrations. The milk samples were also treated with heating (at 65°C for 60 min), freezing (at -20°C for 30 d), and heating and freezing (at 65°C for 60 min and then at -20°C for 30 d), and milk OCFA and BCFA concentrations were similar between these treatments. In conclusion, the OBCFA concentration was lower in colostrum, compared with transition and mature milks, and it remained stable after heating and freezing treatments.

Shifts in the Holstein dairy cow milk fat globule membrane proteome that occur during the first week of lactation are affected by parity

Background

The milk fat globule membrane (MFGM) proteomes of colostrum and transition milk are rich sources of proteins that are likely important for neonatal calf health. In addition, characterization of these proteomes could also yield valuable information regarding mammary gland physiology of the early postpartum lactating cow. The objectives of this research were to characterize the MFGM proteomes of colostrum and transition milk through sample collections at four timepoints postpartum, including the first milking (M1, colostrum), second milking (M2, transition milk), fourth milking (M4, transition milk), and fourteenth milking (M14, mature milk), and compare these proteomes between multiparous (MP; n = 10) and primiparous (PP; n = 10) Holstein dairy cows. Isolated MFGM proteins were labeled using Tandem Mass tagging and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein identification was completed using MASCOT and Sequest in Proteome Discoverer 2.2. The scaled abundance values were analyzed using PROC MIXED in SAS to determine the effects of milking (MIL), parity (PAR), and MIL × PAR. The adaptive false-discovery rate (FDR)-adjusted P values were determined using PROC MULTTEST. Protein characterization and bioinformatic analysis were completed using a combination of PANTHER, Blast, and Uniprot.

Results

A total of 104 common proteins were identified in each of the MFGM samples. Statistical analysis revealed that 70.2% of identified proteins were affected by MIL. Of these, 78.1% were lower in M14 compared with M1, including immune-related proteins lactotransferrin, lactadherin and hemopexin. Parity affected 44.2% of proteins. Of the proteins affected by PAR, 84.8% were higher in MP cows compared with PP cows, including apolipoprotein E and histones 2A, 2B, 3, and 4 b. Butyrophilin subfamily 1 member 1A and annexin 5 were higher in samples from PP cows. Milking × parity affected 32.7% of identified proteins, including lactotransferrin, gelsolin, vitamin D binding protein, and S100 proteins.

Conclusions

This research supports previous findings that the Holstein MFGM proteome changes rapidly during the first week of lactation. In addition, this research identifies the impact of parity on the colostrum and transition milk MFGM proteomes, which may be important for milk-fed calf health or for the identification of protein biomarkers for mammary functionality.