Invited review: Bovine colostrum, a promising ingredient for humans and animals-Properties, processing technologies, and uses

Aloe arborescens supplementation in drying-off dairy cows: influence on rumen, rectum and milk microbiomes

BACKGROUND

In the context of the RABOLA project, which aimed to identify operational practices that lead to the reduction of antibiotic use in dairy cattle farming, lyophilised Aloe arborescens was administered orally to cows during the dry-off and peripartum periods. In this specific paper we wanted to examine whether oral administration of Aloe arborescens, in combination with the topical application of a teat sealant could exert an effect on the microbial populations of three cow microbiomes (rumen, milk, rectum), between dry-off and peripartum. Dry-off and peripartum are critical physiological phases of the cow's life, where both the mammary gland and the gastrointestinal tract undergo dramatic modifications, hence the relevance of evaluating the effects of dietary treatments.

METHODS

Thirty multiparous dairy cows were randomly allocated to three groups: Control (antibiotic treatment and internal teat sealant), Sealant (only internal teat sealant) and Aloe (internal teat sealant and Aloe arborescens homogenate administered orally). For 16S rRNA gene sequencing, rumen, rectum and milk samples were collected, not synchronously, at the most critical timepoints around dry-off and calving, considering the physiological activity of each biological site.

RESULTS

The rumen microbiome was predominantly characterized by Bacteroidetes and Firmicutes followed by Proteobacteria, while the rectum exhibited a prevalence of Firmicutes and Bacteroidetes. The milk microbiome mainly comprised Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. Alistipes spp., Ruminococcaceae UCG-10 group, Prevotellaceae UCG-001 group, and Bacteroides spp., involved in cellulose and hemicellulose degradation, enhancement of energy metabolism, and peptide breakdown, showed increment in the rectum microbiome with Aloe supplementation. The rectum microbiome in the Aloe group exhibited a significant increase in the Firmicutes to Bacteroidetes ratio and alpha-diversity at seven days after dry-off period. Beta-diversity showed a significant separation between treatments for the rectum and milk microbiomes. Aloe supplementation seemed to enrich milk microbial composition, whereas the Sealant group showed greater diversity compared to the Control group, albeit this included an increase in microorganisms frequently associated with mastitis.

CONCLUSIONS

Aloe arborescens administration during the dry-off period did not demonstrate any observable impact on the microbial composition of the rumen, a finding further supported by volatilome analysis. Instead, the oral Aloe supplementation at dry-off appears to significantly influence the composition of the dairy cow rectum and milk microbiomes in the following lactation.

Effect of Postbiotic Supplementation on Nutrient Digestibility and Milk Yield during the Transition Period in Dairy Cows

The metabolites secreted by probiotics or released after their lysis are called postbiotics. They provide physiological benefits to the host, preventing the colonisation of pathogens by improving the intestinal environment for beneficial commensal bacteria, which reduces the incidence of digestive disorders and improves the immune system. The aim of this work was to evaluate the addition of postbiotics to dairy cow rations during the transition period on nutrient digestibility, composition, and milk yield. The effects of two postbiotics were evaluated in twelve Friesian cows from 30 days before calving to two months of lactation. The animals were randomly allocated to two treatment groups: control (CT) and supplemented with postbiotics (PC and PR). Feeding was ad libitum with 60/40 of forage/concentrate ratio on dry matter basis. Daily feed intake and milk production were recorded individually throughout the study. Two digestibility balances were performed, one before parturition and one after parturition. Colostrum was sampled at first milking and milk was sampled weekly. Data were analysed using a mixed mode in R software 4.4.1. The results suggest that postbiotic supplementation in late gestation and early lactation increase the voluntary intake of dry matter, especially in the PR treatment, with higher apparent total tract digestibility of dry matter, organic matter and neutral detergent fibre. Both treatments including postbiotics induced an increase in colostral immunoglobulin concentration. Milk production of cows receiving the PC treatment was the highest, with high fat and protein yields and a higher persistence of the production curve throughout the lactation.

The ability of a handheld near-infrared spectrometer to do a rapid quality assessment of bovine colostrum, including the immunoglobulin G concentration

Portable infrared-based instruments have made important contributions in different research fields. Within the dairy supply chain, for example, most of portable devices are based on near-infrared spectroscopy (NIRS) and are nowadays an important support for farmers and operators of the dairy sector, allowing fast and real-time decision-making, particularly for feed and milk quality evaluation and animal health and welfare monitoring. The affordability, portability, and ease of use of these instruments have been pivotal factors for their implementation on farm. In fact, pocket-sized devices enable nonexpert users to perform quick, low-cost, and nondestructive analysis on various matrixes without complex preparation. Because bovine colostrum (BC) quality is mostly given by the IgG level, evaluating the ability of portable NIRS tools to measure antibody concentration is advisable. In this study we used the wireless device SCiO manufactured by Consumer Physics Inc. (Tel Aviv, Israel) to collect BC spectra and then attempt to predict IgG concentration and gross and fine composition in individual samples collected immediately after calving (<6 h) in primiparous and pluriparous Holstein cows on 9 Italian farms. Chemometric analyses revealed that SCiO has promising predictive performance for colostral IgG concentration, total Ig concentration, fat, and AA. The coefficient of determination of cross-validation (R2CV) was in fact ≥0.75). Excellent accuracy was observed for dry matter, protein, and S prediction in cross-validation and good prediction ability in external validation (R2CV ≥ 0.93; the coefficient of determination of external validation, R2V, was ≥0.82). Nonetheless, SCiO's ability to discriminate between good- and low-quality samples (IgG ≥ vs. < 50 g/L) was satisfactory. The affordable cost, the accurate predictions, and the user-friendly design, coupled with the increased interest in BC within the dairy sector, may boost the collection of extensive BC data for management and genetic purposes in the near future.

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.

A Review: The Effect of Bovine Colostrum on Immunity in People of All Ages

Bovine colostrum provides newborn calves with strong passive immunity, which will further affect the immunity of their offspring. Compared with other commercial dairy products, bovine colostrum emphasizes the limit of aflatoxin M1, pathogenic bacteria, microorganisms, antibiotics, stimulants, and other items, so it is safe to use. There are many reports that the use of bovine colostrum as a breast milk fortifier for preterm infants provides necessary immune support for premature infants, but the selection of bovine colostrum products chosen must be free of Bacillus cereus because they are very dangerous for premature infants. This also emphasizes that for the bovine colostrum that is used in preterm infants, more clinical research support is needed. At the same time, it should also be emphasized that the composition of BC is different from that of human colostrum, in particular, the main protein of BC is casein, while the main protein in breast milk is whey protein, especially α-lactalbumin, which together with ovalbumin is still the reference protein with the best biological value, especially for muscles. Therefore, bovine colostrum is currently not a complete substitute for breast milk. In recent years, in addition to reports of bovine colostrum use in preterm infants, studies have also found that bovine colostrum has immunomodulatory and promoting effects in adolescents, adults, and the elderly. This suggests that bovine colostrum has the potential to provide appropriate immune support for people of all ages. Therefore, this study aimed to evaluate the quality of nutritional characteristics of bovine colostrum on three dimensions. The effects of bovine colostrum on people of all ages is a narrative review of the effects of bovine colostrum on immunity in people of all ages. This review identified several classes of immunoactive substances in bovine colostrum, including immunoglobulins, cytokines, and enzymes, and compared the nutritional composition of bovine colostrum with mature milk, colostrum and mature milk in full-term breast milk, and colostrum and mature milk in preterm breast milk, to demonstrate that bovine colostrum provides a rich range of immunoactive components. In addition, the influencing factors affecting the quality of bovine colostrum (immunoglobulin) were reviewed, and it was found that individual differences, environmental factors, and processing methods had a great impact on the quality of BC. More importantly, the immunomodulatory effects of bovine colostrum in people of all ages were reviewed in detail (with an emphasis on preterm infants and immunocompromised children in neonates) as evidence to support the immunity effects of colostrum in people of all ages. This review hopes to use the above evidence to make people understand the health role of bovine colostrum as having a human immunomodulatory effect, and at the same time, when seeing the potential value of bovine colostrum in the future, the limitations of its application should also be deeply re-explored, such as lactose intolerance, allergies, etc., to provide effective solutions for the wide application of bovine colostrum.

Biodiversity and antibiotic resistance profile provide new evidence for a different origin of enterococci in bovine raw milk and feces

Enterococci are widely distributed in dairy sector. They are commensals of the gastrointestinal tract of animals, thus, via fecal contamination, could reach raw milk and dairy products. The aims of this study were: 1) to investigate the enterococcal diversity in cow feces and milk samples and 2) to evaluate the antibiotic resistance (AR) of dairy-related enterococci and their ability to transfer resistance genes. E. faecalis (59.9%), E. faecium (18.6%) and E. lactis (12.4%) were prevalent in milk, while E. faecium (84.2%) and E. hirae (15.0%) were dominant in bovine feces. RAPD-PCR highlighted a high number of Enterococcus biotypes (45 from milk and 37 from feces) and none of the milk strains exhibited genetic profiles similar to those of feces biotypes. A high percentage of enterococci isolated from milk (71%) were identified as multidrug resistant and resistance against streptomycin and tetracycline were widespread among milk strains while enterococci from feces were commonly resistant to linezolid and quinupristin/dalfopristin. Only E. faecalis strains were able to transfer horizontally the tetM gene to Lb. delbrueckii subsp. lactis. Our results indicated that Enterococcus biotypes from milk and bovine feces belong to different community and the ability of these microorganisms to transfer AR genes is strain-dependent.

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.

Impact of the mare colostral immunoglobulins on the expression of TLR3, TLR4, and TLR7 in foals

Colostrum contains substances such as hormones, enzymes, polyamides, nucleic acid derivatives, and amino acid derivatives and also includes immunomodulating substances, proline-rich polypeptides, immunoglobulins (Ig) as well as bacteriostatic compounds. The aim of the study was to evaluate the impact of colostral Ig on the level of expression of selected Toll-like receptor genes (TLR3, TLR4, and TLR7). The experiments were conducted on 25 Polish Pony foals. Blood samples were collected according to the following scheme: before first suckling, at the 1st, 3rd, 5th, 10th, 20th, and 30th, day of age. Colostrum was obtained before the first suckling, 24 hr, and 3 days after the delivery. Gene expression analyses were performed on Illumina Eco using a commercial kit TaqMan®MGB probes. The quality of colostrum was assessed via refractometer and BRIX value. The total Ig level was calculated from the spectrophotometric method. IgG levels were measured using ELISA assay. The quality of colostrum significantly correlated with TLR4 and TLR7 expression. Foals that ingested colostrum with low Ig content displayed a higher level of TLR4 gene expression, while in the case of TLR7 the opposite trend was shown. This result indicates that colostrum may play an important role in shaping the mechanisms of building the immune system's response to bacterial pathogens.

Characterization of Physicochemical and Sensory Properties of Cheeses Added with Bovine Colostrum

The objective of this study was to develop fresh and matured cheeses with different bovine colostrum levels, aiming to promote the consumption of dairy products with the addition of colostrum. Four different cheese formulations were produced with a mixture of 0:100, 15:85, 20:80, and 25:75, bovine colostrum:milk (v:v), and aged for 0, 10, 20, and 40 days. Milk, colostrum, and fresh and matured cheeses were submitted to physicochemical characterization. Moreover, microbiological quality, yield, texture profile, color, and sensory acceptance of cheese samples were evaluated. Colostrum supplementation favored low acidity, high moisture, a pH range of 5.0-6.2, and water activity of 0.94-99. Sensory attributes and overall evaluation of all cheese formulations achieved an Acceptability Index above 70, indicating good acceptability. Since cheese with colostrum presented the potential to be used as human food, assessing the presence of colostrum bioactive components in those dairy products is a promising goal for further research.

Minerals and essential amino acids of bovine colostrum: Phenotypic variability and predictive ability of mid- and near-infrared spectroscopy

Colostrum quality and volume are fundamental for calves because it is the primary supplier of antibodies and the first source of energy, carbohydrates, lipids, proteins, minerals, and vitamins for the newborn. Assessing the detailed composition (i.e., AA and mineral content) of bovine colostrum (BC) on-line and at a reasonable cost would help dairy stakeholders such as farmers or veterinarians for precision feeding purposes and industries producing preparations containing BC such as foodstuff, supplements, and medicaments. In the present study we evaluated mid- (MIRS) and near-infrared spectroscopy (NIRS) prediction ability for AA and mineral composition of individual BC. Second, we the investigated the major factors affecting the phenotypic variability of such traits also evaluating the correlations with the Ig concentration. Results demonstrated that MIRS and NIRS were able to provide sufficiently accurate predictions for all the AA. The coefficient of determination in external validation (R2V) fell, in fact, within the range of 0.70 to 0.86, with the exception of Ile, His, and Met. Only some minerals reached a sufficient accuracy (i.e., Ca, P, S, and Mg; R2V ≥ 0.66) using MIRS, and also S (R2V = 0.87) using NIRS. Phenotypically, both parity and calving season affected the variability of these BC composition traits. Heifers' colostrum was the one with the greatest concentration of Ca and P, the 2 most abundant minerals. These minerals were however very low in cows calving in summer compared with the rest of the year. The pattern of AA across parities and calving season was not linear, likely because their variability was scarcely (or not) affected by these effects. Finally, samples characterized by high IgG concentration were those presenting on average greater concentration of AA. Findings suggest that infrared spectroscopy has the potential to be used to predict certain AA and minerals, outlining the possibility of implementing on-site analyses for the evaluation of the broad-sense BC quality.