Association of different classifications of hypocalcemia with quantity and quality of colostrum, milk production, and health of Holstein dams and their calves

The aim of the present study was to assess the effect of serum calcium (Ca) status in the early postpartum period on the quantity and quality of colostrum, milk production, and the health of Holstein dams and their calves. One hundred multiparous Holstein cows were enrolled in this study. To determine serum Ca status, blood samples were taken at 1 and 4 days in milk (DIM). Cows were categorized into 1 of 4 groups based on their serum Ca concentrations: normocalcemic (CON; Ca >1.87 at 1 DIM and >2.10mmol/L at 4 DIM, n = 36), transient SCH (TSCH; Ca ≤1.87 at 1 DIM and >2.10mmol/L at 4 DIM, n = 14), persistent SCH (PSCH; Ca ≤1.87 at 1 DIM and ≤2.10mmol/L at 4 DIM, n = 15), or delayed SCH (DSCH; Ca >1.87 at 1 DIM and ≤2.10mmol/L at 4 DIM, n = 35). The ROC curve was utilized to determine the optimal cut-off value for serum total Ca, maximizing both sensitivity and specificity in predicting metritis. Metabolic disorders such as dystocia, retained placenta, and culling within 60 DIM were not affected by serum Ca status in the early postpartum period (P > 0.10). However, the incidences of metritis and endometritis were different based on the serum Ca status of the cows. The PSCH cows had a higher incidence of metritis than the CON cows (P = 0.05). Also, the DSCH cows tended to have an increased risk of metritis than the CON cows (P = 0.09). However, metritis incidence in the TSCH and CON cows was similar (P = 0.83). Cows with PSCH (P = 0.07) and DSCH (P = 0.10) tended to be at a higher risk for endometritis than the CON cows. But, the incidence of endometritis in the TSCH and CON cows was not different (P = 0.50). The TSCH cows had higher milk yield than the PSCH and DSCH cows (P = 0.05). However, milk yield was not different between the TSCH and CON cows and the PSCH and DSCH and CON cows. The serum Ca status of cows had no effect on colostrum volume and its quality, age and weight of weaning, and average daily gain of calves (P > 0.10). The proportion of calves experiencing failure of passive transfer (FPT) was greater in the PSCH group than in the CON group (P = 0.03). Also, the FPT tended to be higher in the DSCH calves compared to the CON calves (P = 0.10). However, the FPT in the TSCH and CON calves was not different (P = 0.83). The incidence of diarrhea tended to be higher in the PSCH and DSCH calves compared to the CON calves (P = 0.10). However, diarrhea incidence between the TSCH and CON calves was similar (P = 0.97). Overall, the findings of this study suggest that cows with TSCH showed better adaptation to lactation, experienced a lower occurrence of diseases and produced higher milk compared to PSCH and DSCH cows. Furthermore, despite the similar quantity and quality of colostrum across all groups, the PSCH and DSCH groups displayed a greater proportion of calves experiencing FPT and diarrhea in comparison to the TSCH group.

Energy and protein levels in dairy cow diets to recover milk ethanol stability

The objective of this study was to evaluate the effect of energy and protein in the diet on the recovery of milk ethanol stability (MES) induced by feed restriction. Twelve Holstein and Holstein x Jersey crossbred cows with an average of 146 ± 50 d in milk, 575.4 ± 70 kg of body weight, and 18.93 ± 5.46 kg/d of milk yield were distributed in a 3x3 Latin square design with 3 treatments and 3 experimental periods. Each experimental period lasted 24 d, comprising 3 phases: a 13-d adaptation phase (100E+100P), a 4-d induction phase for milk ethanol instability (50E+50P), and a 7-d recovery phase for MES (3 treatments). The 3 treatments during the recovery phase consisted of 3 diets aiming to meet the requirements of energy and protein (100E+100P), only energy (100E+50P), or only protein (50E+100P). The diet during the adaptation and induction phases was common for all cows. The energy and protein levels to meet each cow's requirements were based on the group average. Restriction of energy and protein reduced dry matter, crude protein, and total digestive nutrient intake for cows fed 100E+50P and 50E+100P. The lowest body weight was observed for cows fed 50E+100P, with no difference for body condition score. During the induction phase, MES "was" reduced by 9 percentage units. Cows fed 100E+100P recovered MES in the first days of the recovery phase, while 100E+50P slightly improved MES, and 50E+100P had a constant decrease in MES. Cows fed 100E+50P and 50E+100P produced, respectively, 3.6 and 5.9 kg less milk than those fed 100E+100P. The 50E+100P treatment exhibited the highest milk fat content and somatic cell score, along with the lowest milk lactose content. Protein content was higher in the 100E+100P treatment. Cows fed 50E+100P showed higher serum albumin levels compared with those on the 100E+100P treatment, not differing from the 100E+50P treatment. We concluded that the complete recovery of MES in cows with feed restrictions is possible only by supplying both the energy and protein requirements in the cows' diet. However, restricting energy intake poses a greater limitation on MES recovery compared with restricting protein.

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.

Effects of parity, seasonal heat stress, and colostrum collection time postpartum on colostrum quality of Holstein cattle in an arid region

The aim of this study was to determine effects of parity (primiparous vs. multiparous), seasonal heat stress at calving (summer vs. winter), and time postpartum on some parameters associated with colostrum quality in Holstein cows reared in the Sonoran Desert ecosystem. Forty-seven cows (11 primiparous and 36 multiparous) expected to calve during summer, and 46 cows during winter (14 primiparous and 32 multiparous) were randomly selected. Management and feeding before and after parturition were similar for cows in both seasons. After parturition, colostrum from all cows was evaluated for volume, weight, temperature, density, and content of fat, protein, solids non-fat (SNF), and immunoglobulins (IGG). Data were analyzed with a model that included effects of parity status, calving season, and time postpartum, as well as all interactions. Colostrum produced in summer was warmer (P < 0.01) by almost 6 °C than winter colostrum, while colostrum from multiparous was warmer (P = 0.02) by 1.2 °C than that produced by primiparous cows. Colostrum volume and weight were not impacted by parity, calving season or time postpartum. Density, protein, and SNF content in colostrum were higher (P < 0.01) in multiparous vs. primiparous cows, as well as at parturition (0 h postpartum) than at 12 h postpartum (P < 0.01). At calving (0 h), spring colostrum had higher fat content (P < 0.01) and lower (P < 0.01) IGG concentration than that collected in summer, and no difference (P > 0.05) between seasons was observed for these components at 12 h postpartum. Multiparous cows produced colostrum with higher (P < 0.01) IGG concentrations than primiparous cows. In conclusion, only 0-h colostrum and that from multiparous cows was categorized as "Excellent," meanwhile the colostrum produced under summer heat stress was characterized as "Good" with reduced fat content. While the lacteal secretion collected at 12 post-partum still classified as colostrum, substantially lower contents of IGG, protein, fat, and SNF decreased its classification to "Poor" from the classification of "Excellent" at 0 h postpartum.

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.

Bovine colostrum and its potential contributions for treatment and prevention of COVID-19

Bovine colostrum (BC) is the initial milk an animal produces after giving birth, particularly in the first few days. Numerous bioactive substances found in BC, including proteins, enzymes, growth factors, immunoglobulins, etc., are beneficial to human health. BC has a significant role to play as part of a healthy diet, with well-documented health and nutritional advantages for people. Therefore, the use of BC and its crucial derivatives in the development of functional food and pharmaceuticals for the prevention of several diseases such as gastrointestinal and respiratory system disorders is becoming increasingly popular around the world. A novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified as the cause of a cluster of pneumonia cases that is called Coronavirus Disease 2019 (COVID-19) in China. After the first SARS-CoV-2 virus-related fatality was announced, the illness quickly spread throughout China and to other continents, causing a pandemic. Since then, numerous studies have been initiated to develop safe and efficient treatments. To prevent viral infection and potential lingering effects, it is important to investigate alternative treatments for COVID-19. Due to its effective bioactive profile and its immunomodulatory roles in biological processes, BC might be considered a promising approach to assist in combating people affected by the SARS-CoV-2 or prevention from the virus. BC has immunomodulatory effects because to its high concentration of bioactive components such as immunoglobulins, lactoferrin, cytokines, and growth factors, etc., which might help control immunological responses, potentially fostering a balanced immune response. Furthermore, its bioactive components have a potential cross-reactivity against SARS-CoV-2, aiding in virus neutralization and its comprehensive food profile also supplies important vitamins, minerals, and amino acids, fostering a healthy immune system. Hence, the possible contributions of BC to the management of COVID-19 were reviewed in this article based on the most recent research on the subject. Additionally, the key BC components that influence immune system modulation were evaluated. These components may serve as potential mediators or therapeutic advantages in COVID-19.

Ascertaining the Influence of Lacto-Fermentation on Changes in Bovine Colostrum Amino and Fatty Acid Profiles

The aim of this study was to collect samples of bovine colostrum (BCOL) from different sources (agricultural companies A, B, C, D and E) in Lithuania and to ascertain the influence of lacto-fermentation with Lactiplantibacillus plantarum strain 135 and Lacticaseibacillus paracasei strain 244 on the changes in bovine colostrum amino (AA), biogenic amine (BA), and fatty acid (FA) profiles. It was established that the source of the bovine colostrum, the used LAB, and their interaction had significant effects (p < 0.05) on AA contents; lactic acid bacteria (LAB) used for fermentation was a significant factor for aspartic acid, threonine, glycine, alanine, methionine, phenylalanine, lysine, histidine, and tyrosine; and these factor's interaction is significant on most of the detected AA concentrations. Total BA content showed significant correlations with glutamic acid, serine, aspartic acid, valine, methionine, phenylalanine, histidine, and gamma amino-butyric acid content in bovine colostrum. Despite the differences in individual FA contents in bovine colostrum, significant differences were not found in total saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Finally, the utilization of bovine colostrum proved to be challenging because of the variability on its composition. These results suggest that processing bovine colostrum into value-added formulations for human consumption requires the adjustment of its composition since the primary production stage. Consequently, animal rearing should be considered in the employed bovine colostrum processing technologies.

Maternal Age, Parity and Nursing Status at Fertilization Affects Postpartum Lactation Up to Weaning in Horses

Nulliparity is associated with intra-uterine growth retardation and foal delayed catch-up growth. Older mares produce larger/taller foals than the precedents. Nursing at conception on foal growth had not been investigated yet. In any case, milk production conditions the foal's growth. This study aimed to determine effects of mare parity, age and nursing on subsequent lactation quantity and quality. Saddlebred mares and their foals (N = 43) run as a single herd over the same year were: young (6-7-year-old) primiparous, young multiparous, old (10-16-year-old) multiparous nursing at insemination time or old multiparous barren the previous year. No young nursing nor old multiparous mares were available. Colostrum was collected. Milk production and foal weight were monitored at 3-, 30-, 60-, 90- and 180-days postfoaling. The foal average daily weight gain (ADG) was calculated for each period between two measurements. Milk fatty acid (FA), sodium, potassium, total protein and lactose contents were determined. The primiparous versus multiparous colostrum was richer in immunoglobulin G, with lower production but greater FA contents in milk. The primiparous foals had a lower ADG for 3 to 30 days postpartum period. Old mares' colostrum contained more SFA and less polyunsaturated FA (PUFA) whereas their milk was richer in proteins and sodium and poorer in short-chain-SFA with a reduced PUFA/SFA ratio at 90 days. Nursing mares' colostrum was richer in MUFA and PUFA and late-lactation milk production was reduced. In conclusion, parity, age and nursing at conception affect mare's colostrum and milk production and foal growth and should be considered for broodmares' management.

Bovine Colostrum: Human and Animal Health Benefits or Route Transmission of Antibiotic Resistance-One Health Perspective

After calving, bovine colostrum is obtained from the mammary gland of the dam in the first days and fed to newborn ruminant to prevent microbial infections. Each bovine colostrum has a unique biochemical composition with high nutraceutical value compared to milk. However, bovine colostrum is influenced by various factors, such as environmental, individual, and genetic factors, as well as processing methods. Proper colostrum management is crucial for obtaining high-quality colostrum and mitigating bacterial contamination. This is important not only for the health and survival of calves but also for the health of humans who consume colostrum and its co-products. It is essential to ensure that the consumed colostrum is free of pathogens to reap its benefits. Health-promoting products based on colostrum have gained significant interest. However, colostrum can contain pathogens that, if not eliminated, can contribute to their transmission and spread, as well as antibiotic resistance. The aim of this review was to promote the animal and human health benefits of bovine colostrum by improving its microbial quality and highlighting potential routes of dissemination of antibiotic-resistant pathogens. Implementing hygienic measures is one of the key factors in mitigating colostrum bacterial contamination and obtaining safe and high-quality colostrum. This helps reduce the exposure of pathogens to newborn calves, other animals, and humans, in a One Health analysis.

Colostrum Composition, Characteristics and Management for Buffalo Calves: A Review

In this review, the composition, characteristics, and management of dairy buffalo calves were examined and compared with bovines. The neonatal period is critical for buffalo calves and is characterized by a high mortality rate (more than 40%). The early intake of high-quality colostrum (IgG > 50 mg/mL) is the one way to improve the immune system of calves (serum IgG > 10 mg/mL after 12 h), thus increasing their chances of survival. Mainly in intensive farms, the availability of high-quality colostrum is necessary; thus, good quality colostrum is often stored to provide newborn calves which cannot be fed by their mothers. Also, the manipulation of the immunological status of animals through vaccination has been depicted since the quality of colostrum tended to be influenced by vaccination against pathogens. Buffalo breeding is constantly expanding in Italy, mainly thanks to the Mozzarella cheese production that represents the excellence of the "Made in Italy" and is exported worldwide. Indeed, high calf mortality rates directly affect the profitability of the business. For these reasons, the aim of this review was to examine specific research on buffalo colostrum that, compared with other species, are scarce. Improving the knowledge of buffalo colostrum, in terms of characteristics and management, is critical to guarantee buffalo newborns' health in order to reduce their mortality rate. Importantly, considering the knowledge on cattle valid also for buffalo is a widespread, and often erroneous, habit in several fields, including colostrum feeding. Therefore, the two species were compared in this review.

Bovine Colostrum for Veterinary and Human Health Applications: A Critical Review

Bovine colostrum harbors a diverse array of bioactive components suitable for the development of functional foods, nutraceuticals, and pharmaceuticals with veterinary and human health applications. Bovine colostrum has a strong safety profile with applications across all age groups for health promotion and the amelioration of a variety of disease states. Increased worldwide milk production and novel processing technologies have resulted in substantial growth of the market for colostrum-based products. This review provides a synopsis of the bioactive components in bovine colostrum, the processing techniques used to produce high-value colostrum-based products, and recent studies utilizing bovine colostrum for veterinary and human health.

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.

Nanoemulsion: A novel delivery approach for thermosensitive IgG on inhibiting milk fat oxidation

IgG, a biologically active substance in bovine colostrum, is easily inactivated during heat treatment and edible process to lose its biological activity. Nanoemulsion can effectively protect IgG to maintain its biological activity from injurious treatment. In this study, a food-grade nanoemulsion system was developed to protect IgG from heat and acid damage. It can be found that the residual rate of nanoemulsion-protected IgG reaches 87.1 % after 10 min at 72 °C. After 5 min at 82 °C, the residual rate of IgG in nanoemulsion was 18.7 % higher than that in PBS. In the simulated gastric fluid at pH 2.0, the residual rate of IgG in the nanoemulsion reacted for 4 h was 21.5 % higher than that in PBS. It indicated that nanoemulsion system can improve the heat and acid resistance of IgG compared with others, which is attributed to the lowest water activity of nanoemulsion. The contents of hydroperoxide and malondialdehyde in the milk after storage for 72 h with nanoemulsion-protected IgG were 0.12 meq/kg and 0.04 mg/kg, respectively, less than that of PBS-protected IgG. IgG is protected by nanoemulsion can effectively protect its activity during processing, which provides a theoretical basis for its direct application in liquid milk.

Validation of a handheld refractometer to assess Merino ewe colostrum and transition milk quality

Colostrum quality is generally defined by the IgG concentration in colostrum, and many methods have been used to assess it. Methods to measure colostrum quality both in the laboratory and in the field have been validated in cattle; however, this is only a recent topic of interest for sheep colostrum. Laboratory-based methods are often time consuming and require trained personnel compared with new handheld evaluation tools such as the digital Brix refractometer, which gives real-time results. The aims of this study were to (1) evaluate the relationship between the digital Brix refractometer and constituents indicative of quality (IgG, protein, fat, and lactose) in colostrum and transition milk, and (2) determine an appropriate Brix % cut-off value for the Brix refractometer in sheep colostrum and transition milk. The study used 50 colostrum samples (collected at 0 h postpartum, before lambs' sucking) and 169 transitional milk samples (collected at 4 and 24 h postpartum, after lambs had sucked) collected over 6 lambing trials in 2 years (2019 and 2020). We concluded that the Brix refractometer results correlated weakly with IgG concentration determined by radial immunodiffusion assay in colostrum collected at 0 h postpartum (r = 0.11) and in transition milk collected at 4 h postpartum (r = 0.12); however, a moderate to strong correlation was shown in transition milk samples collected at 24 h (r = 0.66). Brix % was significantly correlated with fat %, lactose %, and protein % at all timepoints. To determine an appropriate Brix % cut-off value indicating an IgG concentration of 20 mg/mL, we analyzed sensitivity and specificity of the Brix refractometer at 0, 4, and 24 h. In samples collected at 0 and 4 h, the highest combination of sensitivity, specificity, and accuracy was achieved at a Brix % cut-off value of 29%; in samples collected at 24 h postpartum, a Brix % cut-off value of 27% gave the highest sensitivity, specificity, and accuracy. Overall, the Brix refractometer has potential as a useful in-field tool for researchers and producers in both extensively and intensively managed flocks to measure and determine the quality of sheep colostrum and transition milk.

Relation between Color and Chemical Composition of Dromedary Camel Colostrum

Camel milk industrialization faces technological problems related to the presence of colostrum in milk. The determination of color parameters may serve to differentiate between colostrum and milk. This work aimed to study the relationship between the chemical composition of camel colostrum and milk and their colors. Samples of colostrum were collected at 2, 12, 24, 48, 72, 96, 120, 144, 168, and 360 h postpartum (n = 16), and their physicochemical properties (pH, acidity, viscosity, color, dry matter, ash, protein, and fat) were analyzed. The results show that all the components decreased during the first 3 days except fat. The content of this later increased from zero in the three sampling on the first day (2, 12, and 24 h) to 1.92 ± 0.61% at 48 h postpartum. The amount of total dry matter and protein decreased from 20.95 ± 3.63% and 17.43 ± 4.28% to 13.05 ± 0.81% and 3.71 ± 0.46%, respectively, during the first 7 days postpartum. There was a weak correlation between the brightness (L*) of the camel milk and its contents of dry matter, protein, and fat; however, these parameters were strongly correlated with redness (a*) and yellowness (b*). Ash content was poorly correlated with the color parameters. Hence, the measurement of the color parameters of camel colostrum and milk can be a new tool to evaluate their quality.

Technical note: colorimetric methods for accurate determination of nutrient composition in beef cow colostrum and milk

Our objectives were to develop colorimetric methods to accurately measure nutrient concentrations of beef cow colostrum and milk, to determine if the yield of colostrum from a single rear quarter is representative of complete collection of colostrum in beef cows, and to compare data from our developed colorimetric methods with Fourier transform infrared spectroscopy (FTIR) analysis to determine the accuracy of FTIR for beef cow colostrum and milk. In Exp. 1, colostral weight and volume of the most full rear quarter were compared with complete collection of colostrum from post-calving, unsuckled beef heifers. Both volume and weight had r2 = 0.85 (P < 0.001) between single-quarter and 4 quarter yields. In Exp. 2, colostrum (n = 35) and milk at d 35 (n = 42) and d 60 (n = 38) of lactation were collected from multiparous, fall-calving, crossbred beef cows. Subsamples were submitted for FTIR analysis and frozen for colorimetric analysis. Colorimetric analyses were developed for lactose, triglycerides (measure of fat), protein, and urea N. To validate method accuracy, spike recoveries were determined for lactose (96.8% average) and milk protein (100.1% average), triglyceride concentration was compared with fat concentration determined by the Mojonnier method (r2 ≥ 0.91, P < 0.001), and colostral or milk urea N was compared with serum urea N from the same sampling day (r2 ≥ 0.72, P < 0.001). Coefficients of determination between colorimetric methods and FTIR were determined for colostrum, d 35 milk, and d 60 milk. Colostral lactose concentration from FTIR was positively associated (r2 = 0.24, P = 0.01) with colorimetric analysis, but there was no relationship (r2 ≤ 0.09, P ≥ 0.14) between methods for colostral fat, protein, or urea N. Milk nutrient composition was positively associated for all nutrients measured at d 35 (r2 = 0.28 to 0.58, P < 0.001), and coefficients of determination strengthened for all nutrients measured at d 60 (r2 = 0.38 to 0.82, P < 0.001). In conclusion, colostrum yield of a single rear quarter can be used to indicate complete collection of colostrum for beef cows, and colorimetric methods developed have adequate accuracy for beef cow colostral and milk nutrient analysis. Based on our analyses, nutrient composition of beef cow colostrum was not accurately analyzed by FTIR. Accuracy of FTIR for beef cow milk varies with component and may be affected by the day of lactation.

Nutritional Parameters in Colostrum of Different Mammalian Species

Colostrum (or first milk) is the food produced by all the mothers in all specific mammalian species, ruminants, monogastric and marine mammalians for their newborns during the first 24–48 h post-partum. Colostrum provides to the neonate all essential nutrients necessary for the first week of life, but the effect of colostrum shows a long-term effect not limited to these first days. Colostrum is considered to be a safe and essential food for human consumption. Some young children can show at the beginning of their colostrum-based diet some side effects, such as nausea and flatulence, but they disappear quickly. In human colostrum, the immunoglobulins and lactoferrin determined show the ability to create natural immunity in newborns, reducing greatly the mortality rate in children. Recent studies suggest that bovine colostrum (BC) may be an interesting nutraceutical food, due to its ability in preventing and/or mitigating several diseases in newborns and adults. This review aims to show the nutraceutical and functional properties of colostrum produced by several mammalian species, describing the different colostrum bio-active molecules and reporting the clinical trials aimed to determine colostrum nutraceutical and therapeutic characteristics in human nutrition.

Nutritional and physicochemical quality of formulations based on colostrum and bovine whey

The objective of this study was to investigate the nutritional quality of bovine colostrum and whey mixtures. Five whey with bovine colostrum formulations were prepared (90:10; 80:20; 70:30; 60:40 and 50:50 whey:colostrum v:v) to be subjected to low-temperature pasteurization (63°C to 65°C for 30 minutes) and freeze-drying. The samples underwent chemical composition characterization, fatty acid profile analysis, determination of contamination by Enterobacteriaceae, pH, and Dornic acidity measurements before and after vat pasteurization. The amount of protein, fat, total solids, defatted dry extract, Brix and density increased as the bovine colostrum concentration increased. The level of saturated fatty acids and the thrombogenicity and atherogenicity indices reduced, while unsaturated fatty acids increased as the level of added bovine colostrum increased. The low-temperature pasteurization of the formulations was possible and effective, eliminating contamination by Enterobacteriaceae in the samples. Mixing bovine colostrum and whey reduced the colostrum viscosity, allowing a successful pasteurization procedure. Due to colostrum composition, the formulations yielded a higher nutritional value when compared to whey alone. The parameters applied in the formulation of mixtures of bovine colostrum and whey resulted in valuable ingredients for preparing novel dairy products.

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.

First-milking colostrum mineral concentrations and yields: Comparison to second milking and associations with serum mineral concentrations, parity, and yield in multiparous Jersey cows

This observational study described first-milking colostrum mineral concentrations and total yields, and evaluated its associations with cow serum mineral concentrations, parity, and first postpartum milking yield in 100 multiparous Jersey cows from a single herd fed a negative dietary cation-anion difference diet prepartum. Additionally, first- and second-milking colostrum mineral concentrations and total yields were compared in a subset of 65 cows. Serum minerals (Ca, P, Mg, Na, K, Zn, Fe, Cu) were assessed before first milking. Cows were milked at 9 h and 4 min ± 3 h and 32 min and at 21 h and 11 min ± 3 h and 43 min postpartum (± standard deviation); yields were recorded and samples collected for mineral concentrations assessment (Ca, P, Mg, Na, K, Zn, Fe, Cu). Linear regression was used to evaluate the associations between first-milking colostrum mineral concentrations and total yields and cows' serum mineral concentrations, parity, first-milking colostrum yield, and calving-to-milking interval. The most abundant minerals in first-milking colostrum were (least squares mean ± standard error of the mean) Ca (55.71 ± 13.52 mmol/L; 8.75 ± 5.74 g) and P (41.91 ± 13.01 mmol/L; 5.26 ± 3.72 g), followed by Na (39.65 ± 13.23 mmol/L; 3.08 ± 1.77 g), K (36.47 ± 7.57 mmol/L; 5.79 ± 4.20 g), Mg (13.43 ± 3.09 mmol/L; 1.25 ± 0.78 g), Zn (272.12 ± 113.34 μmol/L; 71.98 ± 55.34 mg), Fe (12.51 ± 3.79 μmol/L; 2.56 ± 1.55 mg), and Cu (3.34 ± 1.22 μmol/L; 0.77 ± 0.56 mg). Higher concentrations of Ca, Mg, Na, Zn, Fe, and Cu, and total yields of Mg, Zn, Fe, and Cu were observed at first- compared with second-milking colostrum. Serum and first-milking colostrum Cu concentrations were positively associated, but no significant associations were observed between other minerals' serum and first-milking colostrum concentrations or total yields. Parity was associated with first-milking colostrum Ca, P, K, and Fe concentrations and yields; younger multiparous cows had higher concentrations and total yields of these minerals. Linear (Fe), quadratic (P, Na, and K), and cubic (Mg, Zn, and Cu) associations were observed between first-milking colostrum mineral concentrations and yield. In all cases, mineral total yields were linearly associated with first-milking colostrum yield. In conclusion, variation in first-milking colostrum mineral concentrations and total yields across cows could be partially explained by cow parity and colostrum yield. Further research including primiparous and cows under different management settings is needed to expand the knowledge and understanding of colostrum mineral concentrations and total yields in dairy cows.

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 postpartum milking strategy on plasma mineral concentrations and colostrum, transition milk, and milk yield and composition in multiparous dairy cows

The effects of postpartum milking strategy on plasma mineral concentrations, blood β-hydroxybutyrate (BHB) concentration, and colostrum, transition milk, and first monthly test milk yield and composition were evaluated in 90 multiparous Jersey and Jersey × Holstein crossbreed cows from a commercial farm. Before first postpartum milking, cows were randomly assigned to the following milking strategies, implemented during the first 2 d postpartum: twice-a-day milking (M2, standard industry practice, milking every 12 h; n = 22), once-a-day milking (M1, milking every 24 h; n = 24), restricted milking (MR, 3-L milking every 12 h; n = 21), and delayed milking (MD, no milking for the first 24 h, and milking every 12 h afterward; n = 23). Blood samples for total plasma Ca, P, and Mg determination were collected from enrollment every 4 h up to 48 h, and at 3 d in milk. Blood BHB concentration was determined at 3 and 11 d in milk. Colostrum and transition milk yields were recorded, and samples were collected at each study milking for IgG and somatic cell count (SCC) determinations. Information for first monthly test milk yield and composition was obtained from the Dairy Herd Improvement Association. Statistical analyses were conducted using generalized multiple linear and Poisson regressions with Dunnett adjustment and M2 as reference group for mean comparisons. Overall, plasma Ca concentration within 48 h after enrollment was higher for MD (2.17 mmol/L), tended to be higher for MR (2.15 mmol/L), and was similar for M1 (2.09 mmol/L) compared with M2 cows (2.06 mmol/L). No statistically significant differences compared with M2 cows were observed for plasma P and Mg concentrations. Colostrum and transition milk and total Ca harvested within 48 h after enrollment were lower for M1, MR, and MD compared with M2 cows. The MD strategy prevented harvesting colostrum with >50 g of IgG/L. No statistically significant effects were detected on plasma mineral concentrations at 3 DIM, blood BHB concentration, colostrum and transition milk SCC within 48 h after enrollment, or milk yield, energy-corrected milk yield, and SCC at first monthly test. Our results suggest that postpartum plasma Ca concentration may be influenced by postpartum milking strategy, without interfering with future milk yield and udder health. Further studies should evaluate whether the proposed milking strategies in early postpartum affect production, reproduction, or health.

Exploring Dry-Film FTIR Spectroscopy to Characterize Milk Composition and Subclinical Ketosis throughout a Cow's Lactation

The use of technologies for measurements of health parameters of individual cows may ensure early detection of diseases and maximization of individual cow and herd potential. In the present study, dry-film Fourier transform infrared spectroscopy (FTIR) was evaluated for the purpose of detecting and quantifying milk components during cows’ lactation. This was done in order to investigate if these systematic changes can be used to identify cows experiencing subclinical ketosis. The data included 2329 milk samples from 61 Norwegian Red dairy cows collected during the first 100 days in milk (DIM). The resulting FTIR spectra were used for explorative analyses of the milk composition. Principal component analysis (PCA) was used to search for systematic changes in the milk during the lactation. Partial least squares regression (PLSR) was used to predict the fatty acid (FA) composition of all milk samples and the models obtained were used to evaluate systematic changes in the predicted FA composition during the lactation. The results reveal that systematic changes related to both gross milk composition and fatty acid features can be seen throughout lactation. Differences in the predicted FA composition between cows with subclinical ketosis and normal cows, in particular C14:0 and C18:1cis9, showed that dietary energy deficits may be detected by deviations in distinct fatty acid features.

Bovine Colostrum Applications in Sick and Healthy People: A Systematic Review

Colostrum is the first secretion of mammalian glands during the early period after birth giving. Its components are biologically active and have beneficial effects on new-born growth and well-being. Bovine colostrum has the highest concentration of these substances and its supplementation or application may provide health benefits. This systematic review was conducted to update current knowledge on bovine colostrum effects including all administration routes on healthy and sick subjects. Full texts or abstracts of twenty-eight papers as reports of systematic reviews, randomized controlled trials, observational studies and case series were included after searches in Medline, Embase, Cochrane Library and Cinahl databases. The full texts of selected studies were assessed for quality using validated tools and their results were summarized in different categories. Studies were highly heterogeneous as regards to population, intervention, outcome and risk of bias. Bovine colostrum topical application was shown effective on vaginal dryness related symptoms limitation. Its use as food supplement showed interesting effects preventing upper respiratory illness in sportsmen, modulating immune system response and reducing intestinal permeability in healthy and sick subjects. Conflicting results were provided in pediatric population and little evidence is available on its use with older adults. Further studies are mandatory to better understand all factors influencing its activity.

Effect of protein concentrate mixtures and dietary addition of exogenous phytase on major milk minerals and proteins, including casein phosphorylation

Variations in major milk minerals, proteins, and their posttranslational modifications are largely under genetic influence, whereas the effect of nongenetic factors is less studied. Through a controlled feeding experiment (incomplete balanced Latin square design), the effect of concentrate mixtures, based on fava beans, rapeseed meal, or soybean meal as main P and protein sources, on milk composition was examined under typical Danish management conditions. Concentrations of P, Ca, and Mg, together with proteomics for relative quantification of major milk proteins and their isoforms, were analyzed in milk samples from 24 cows sampled in 4 periods. Each cow was fed 1 of the 3 diets in each period with or without addition of exogenous phytase. Cows were blocked by lactation stage into early and mid-lactation (23.3 ± 6.7 and 176 ± 15 d in milk, respectively, at the beginning of the experiment, mean ± standard deviation). Significant effects of feed concentrate mixture were observed for milk protein concentration, milk urea nitrogen, citrate, and the percentage of mixed and preformed fatty acids as well as mineral composition, and their distributions within micellar or serum phases. Furthermore, relative contents of α_S1-casein (CN) 9P form and unglycosylated κ-CN and thereby phosphorylation degree of α_S1-CN (PD) and the glycosylation degree of κ-CN were found to be significantly affected by these diets. To our knowledge, we are the first to document that feed concentrate mixture can affect the relative concentrations of α_S1-CN phosphorylation isoforms in milk, and the results suggested an effect on α_S1-CN 9P and PD, but not on α_S1-CN 8P. Furthermore, although only significant for α_S1-CN 8P, we found a lower relative concentration of α_S1-CN 8P and higher α_S1-CN 9P (and thus higher PD) in milk from cows in mid compared with early lactation. Also, protein concentration and concentration of Mg in skim milk and serum as well as relative concentration of α-lactalbumin were found to be significantly affected by lactation stage. Addition of dietary exogenous phytase only had a minor effect on milk composition or functionality with significant effect detected for α-lactalbumin and micellar Mg concentration.

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.

Isolation of extracellular vesicles with combined enrichment methods

Extracellular vesicles (EVs) are currently of tremendous interest in many research disciplines and EVs have potential for development of EV diagnostics or therapeutics. Most well-known single EV isolation methods have their particular advantages and disadvantages in terms of EV purity and EV yield. Combining EV isolation methods provides additional potential to improve the efficacy of both purity and yield. This review assesses the contribution and efficacy of using combined EV isolation methods by performing a two-step systematic literature analysis from all papers applying EV isolation in the year 2019. This resulted in an overview of the various methods being applied for EV isolations. A second database was generated for all studies within the first database that fairly compared multiple EV isolation methods by determining both EV purity and EV yield after isolation. From these databases it is shown that the most used EV isolation methods are not per definition the best methods based on EV purity or EV yield, indicating that more factors play a role in the choice which EV isolation method to choose than only the efficacy of the method. From the included studies it is shown that ~60% of all the included EV isolations were performed with combined EV isolation methods. The majority of EV isolations were performed with differential ultracentrifugation alone or in combination with differential ultrafiltration. When efficacy of EV isolation methods was determined in terms of EV purity and EV yield, combined EV isolation methods clearly outperformed single EV isolation methods, regardless of the type of starting material used. A recommended starting point would be the use of size-exclusion chromatography since this method, especially when combined with low-speed centrifugation, resulted in the highest EV purity, while still providing a reasonable EV yield.

Mammary gland cell's tight junction permeability from dairy cows producing stable or unstable milk in the ethanol test

Tight junctions are almost impermeable structures located near the apical border of epithelial cells; increase in the permeability of mammary gland cells' tight junctions may alter milk composition and its suitability for industrialization. Sixteen Holstein dairy cows were studied to evaluate mammary gland cells' tight junction permeability (indicated by plasma lactose levels) from cows producing stable or unstable milk to ethanol at 72 °GL concentration. Rectal temperature, respiratory rate and milk parameters were also compared and weather conditions (temperature-humidity index) monitored. Temperature-humidity index did not vary for cows producing stable or unstable milk, so there were no differences in physiological traits. Cows producing unstable milk presented elevated tight junctions' permeability, probably due to higher days in milk. The odds of cows producing unstable milk (clots formation when mixed with ethanol below or equal 72 °GL) increases according to elevations in days in milk and tight junction permeability.

Characterization and comparison of lipids in bovine colostrum and mature milk based on UHPLC-QTOF-MS lipidomics

Lipids in bovine milk have several biological activities, with implications for human health and the physical functionality of foods. However, alterations in the lipid profile of bovine milk during lactation are not well-studied. This study aimed to identify differences in lipids between bovine colostrum and mature milk, using a lipidomics approach. Using an advanced mass spectrometry-based quantitative lipidomics approach, 335 lipids assigned to 13 subclasses were characterized in bovine colostrum (BC) and mature milk (BM). In total, 63 significantly differential lipids (SDLs) were identified. Among the 63 SDLs, the levels of 21 lipids were significantly lower in BM than in BC, including 5 glycerophosphatidylethanolamines (PEs), 1 glycerophosphatidylglycerol (PG), and 15 triacylglycerols (TGs). The levels of the remaining 42 lipids increased in BM, including 1 cardiolipin (CL), 9 diacylglycerols (DGs), 9 dihexosylceramides (Hex2Cers), 3 hexosylceramides (HexCers), 3 glycerophosphatidic acids (PAs), 2 glycerophosphatidylcholines (PCs), 12 PEs, and 3 TGs. Furthermore, the correlations and related metabolic pathways of these 63 SDLs were analyzed to explore the mechanisms that alter bovine milk lipids during lactation. The seven most relevant pathways identified herein, ranked in accordance with their degree of influence on lactation, were glycerophospholipid metabolism, sphingolipid metabolism, glycerolipid metabolism, glycosylphosphatidylinositol-anchor biosynthesis, linoleic acid metabolism, alpha-linolenic acid metabolism, and arachidonic acid metabolism. Our results provide essential insights into mechanisms underlying alterations in bovine milk lipids during different lactation periods, along with practical information of specific nutrition and quality assessments for the dairy industry.

Quantitative assessment of German Holstein dairy cattle colostrum and impact of thermal treatment on quality of colostrum viscosity and immunoglobulins

OBJECTIVE

This study aimed to determine the color, fat, viscosity, IgG concentration, %Brix and refractive index of fresh postpartum colostrum of German Holstein dairy cattle and assess the impact of different thermal treatments on the visual and dynamic viscosity, in association to IgG concentration, of colostrum that can be used for pasteurization process.

RESULTS

Of the total 40 fresh postpartum colostrum, the color of colostrum (ranging from white-pale yellow to yellow and dark-yellowish), fat (1.4-8.2 100 g^-1), IgG (4-116 mg mL^-1), %Brix (8.5-35.4%), refractive index (1.3454-1.3905 nD), visual (ranging from watery to liquid and thick) and dynamic (4.9-219 cp) viscosity, were recorded. Statistical analysis between visual and dynamic viscosity of fresh colostrum showed significant correlation coefficients (r_s = 634). Moreover, a significant correlation between viscosity and three IgG concentrations was also observed. Heat-treated colostrum showed dynamic viscosity ranged from 25 to 3066 cP, where dynamic viscosity of colostrum before- and after heat-treatment showed no significant correlation. Treated colostrum at 60 °C/60 min and 63.5 °C/30 min containing IgG concentration ≤ 80 mg mL^-1 and ≤ 68 mg mL^-1 showed no significant change in the viscosity and can successfully be applied for pasteurization of first postpartum colostrum.

Composition and Factors Affecting Quality of Bovine Colostrum: A Review

Simple Summary

In an attempt to improve the most important production traits of dairy cows, breeders omit the problem of calf rearing, whose regularity has a major impact on subsequent dairy and reproductive use. Therefore, it should be made clear to farmers that one of the ways to improve profitability is to improve the quality of colostrum. The most critical time for calves is the first 2 weeks, when the most falls occur, which may result from disorders of the digestive system and contribute to poor quality of colostrum or poor husbandry. Colostrum possesses a number of properties, such as nourishing, energetic, protective, but also purgative. It activates peristalsis, thus the excretion of meconium, therefore preventing its excessive densification and problems with excretion. Colostrum contains bioactive components with immune enhancing properties: Immunoglobulins, lactoferrin, lysozyme, lactoperoxidase, α-lactalbumin, β-lactoglobulin, or fat that carries important vitamins and polyunsaturated fatty acids. The concentration of the above-mentioned compounds is variable and depends on many factors, including breed, productivity, parity, feeding intensity, season of the year, and/or production system.

Abstract

Colostrum as a secretion of the mammary gland is produced and accumulated in the final stage of pregnancy and in the first days after calving. It is designed to provide the calf with the necessary nutrients and biologically active ingredients. One of the most difficult periods in the life of animals is their rearing, and the most sensitive are the first days after birth. This is the time when most falls occur, and they are caused by mortality and morbidity, even at the level of 30%. Such losses affect the performance and profitability of animal production (the percentage of animals intended for reproduction or fattening is reduced and the intensity of selection in the herd is also reduced). Both diseases and mortality are the cause of serious economic, production, and breeding losses, which are the result of weak immune mechanisms. The adaptability of calves to the environment is determined by their immune status. Colostrum has a regulating function and stimulates the young organism to grow, and it has properties that support the functioning of systems: Endocrine and immunological. For colostrum to fulfil its role, it must be administered immediately after birth, because the immunoglobulins it contains are absorbed during the first 16–27 h after the birth of the calf, preferably within 2–4 h of age. Blood from calves that have been properly calved should have an antibody concentration of 15g/L (24–48 h of age). Therefore, immunoglobulins are the most important factor affecting infectious immunity; an adequate concentration of immunoglobulins in calves’ blood is related to their survival and health. It is the intent of this review to synthesize and summarize the information currently available on colostrum, as well as to discuss the interpretation of the results.

Genetic parameters of colostrum traits in Holstein dairy cows

The main objective of this study was to assess the genetic background of colostrum yield and quality traits after calving in Holstein dairy cows. The secondary objective was to investigate genetic and phenotypic correlations among laboratory-based and on-farm-measured colostrum traits. The study was conducted in 10 commercial dairy herds located in northern Greece. A total of 1,074 healthy Holstein cows with detailed pedigree information were examined from February 2015 to September 2016. All cows were clinically examined on the day of calving and scored for body condition. All 4 quarters were machine-milked, and a representative and composite colostrum sample was collected and examined. Colostrum total solids (TS) content was determined on-farm using a digital Brix refractometer. Colostrum fat, protein, and lactose contents were determined using an infrared milk analyzer, and energy content was calculated using National Research Council (2001) equations. Dry period length (for cows of parity ≥2), milk yield of previous 305-d lactation (for cows of parity ≥2), age at calving, parity number, season of calving, time interval between calving and first colostrum milking, and milk yield were recorded. Each trait (colostrum yield and quality traits) was analyzed with a univariate mixed model, including fixed effects of previously mentioned factors and the random animal additive genetic effect. All available pedigrees were included in the analysis, bringing the total animal number to 5,662. Estimates of (co)variance components were used to calculate heritability for each trait. Correlations among colostrum traits were estimated with bivariate analysis using the same model. Mean percentage (±SD) colostrum TS, fat, protein, and lactose contents were 25.8 ± 4.7, 6.4 ± 3.3, 17.8 ± 4.0, and 2.2 ± 0.7%, respectively; mean energy content was 1.35 ± 0.3 Mcal/kg and mean colostrum yield was 6.18 ± 3.77 kg. Heritability estimates for the above colostrum traits were 0.27, 0.21, 0.19, 0.15, 0.22, and 0.04, respectively. Several significant genetic and phenotypic correlations were derived. The genetic correlation of TS content measured on-farm with colostrum protein was practically unity, whereas the correlation with energy content was moderate (0.61). Fat content had no genetic correlation with TS content; their phenotypic correlation was positive and low. Colostrum yield was not correlated genetically with any of the other traits. In conclusion, colostrum quality traits are heritable and can be amended with genetic selection.

Dairy cow feeding system alters the characteristics of low-heat skim milk powder and processability of reconstituted skim milk

Low-heat skim milk powder (LHSMP) was manufactured on 3 separate occasions in mid lactation (ML, July 4-20) and late lactation (LL, September 27 to October 7) from bulk milk of 3 spring-calving dairy herds on different feeding systems: grazing on perennial ryegrass (Lolium perenne L.) pasture (GRO), grazing on perennial ryegrass and white clover (Trifolium repens L.) pasture (GRC), and housed indoors and offered total mixed ration (TMR). The resultant powders (GRO-SMP, GRC-SMP, and TMR-SMP) were evaluated for composition and color and for the compositional, physicochemical, and processing characteristics of the reconstituted skim milk (RSM) prepared by dispersing the powders to 10% (wt/wt) in water. Feeding system significantly affected the contents of protein and lactose, the elemental composition, and the color of the LHSMP, as well as the rennet gelation properties of the RSM. The GRO and GRC powders had a higher protein content; lower levels of lactose, iodine, and selenium; and a more yellow-green color (lower a* and higher b* color coordinates) than TMR powder. On reconstitution, the GRO-RSM had higher concentrations of protein, casein, and ionic calcium, and lower concentrations of lactose and nonprotein nitrogen (% of total N). It also produced rennet gels with a higher storage modulus (G') than the corresponding TMR-RSM. These effects were observed over the combined ML and LL period but varied somewhat during the separate ML and LL periods. Otherwise, feeding system had little or no effect on proportions of individual caseins, concentration of serum casein, casein micelle size, casein hydration, heat coagulation time, or ethanol stability of the RSM at pH 6.2 to 7.2, or on the water-holding capacity, viscosity, and flow behavior of stirred yogurt prepared by starter-induced acidification of RSM. The differences in the functionality of the LHSMP may be of greater or lesser importance depending on the application and the conditions applied during the processing of the RSM.

Ability of milk pH to predict subclinical mastitis and intramammary infection in quarters from lactating dairy cattle

Milk pH is increased in lactating dairy cattle with subclinical mastitis (SCM) and intramammary infection (IMI). We hypothesized that milk pH testing provides an accurate, low-cost, and practical on-farm method for diagnosing SCM and IMI. The main objective was to evaluate the clinical utility of measuring milk pH using 3 tests of increasing pH resolution: Multistix 10 SG Reagent Strips for Urinalysis (Multistix strips, Bayer HealthCare Inc., Elkhart, IN), pH Hydrion paper (Microessential Laboratory, Brooklyn, NY), and Piccolo plus pH meter (Hanna Instruments, Woonsocket, RI), for diagnosing SCM and IMI in dairy cattle. Quarter foremilk samples were collected from 115 dairy cows at dry off and 92 fresh cows within 4 to 7 d postcalving. Quarter somatic cell count (SCC) was measured using a DeLaval cell counter (DeLaval, Tumba, Sweden), with SCM defined as SCC >200,000 cells/mL and IMI defined as SCC >100,000 cells/mL and the presence of microorganisms at ≥10 cfu/mL of milk. Milk pH was measured at 37°C using the 3 test methods. The Hydrion pH paper performed poorly in diagnosing SCM and IMI. Receiver operating curve analysis provided optimal pH cutpoints for diagnosing SCM for the pH meter (dry off, ≥6.67; freshening, ≥6.52) and Multistix strips (dry off and freshening, ≥7.0). Test performance of the pH meter and Multistix strips was poor to fair based on area under the receiver operating curve, sensitivity, specificity, positive likelihood ratio, and kappa coefficient. The pH meter and Multistix strips performed poorly in diagnosing IMI at dry off and freshening. We concluded that milk pH does not provide a clinically useful method for diagnosing SCM or IMI in dairy cattle.

Analysis of Environmental Factors’ Impact on Donkeys’ Colostrum Quality

Colostrum is a natural product, issued by both mammals and humans in the first week of lactation. Among different species, donkey colostrum is considered to have, in addition to a valuable composition in nutrients and immune factors, an outstanding similitude with human colostrum. In this context, and taking into account the scarcity of available data concerning the interaction between climate factors and colostrum quality, a trial was conducted aiming to identify the possible influence of environmental factors on donkey colostrum nutritional traits. A stock of 175 jennies from 7 farms located in Cluj and Sălaj Counties was analyzed over a 7-day postpartum period. During the experimental period, the daily temperature, humidity, and wind velocity data were collected. Strong positive correlations are reported between the studied colostrum nutritional traits (fat, protein and lactose). Testing the impact of some environmental parameters upon nutritional content of donkey colostrum indicated three factors that have an influence on the nutritional quality of donkey milk colostrum, labelled as: colostrum nutritional traits, environmental air traits and some colostrum nutritional traits, and climatic traits and some colostrum nutritional traits.