Nutrient and immunity transfer from cow to calf pre- and postcalving

Colostrum composition of Santa Inês sheep and passive transfer of immunity to lambs

This study aimed to analyze the chemical composition and the IgG concentration of the colostrum, transitional milk, and mature milk of Santa Inês ewes as well as the transfer of passive immunity to lambs. Thirty-two pregnant ewes and 38 lambs were used. Ewes were milked immediately after lambing and at 12, 24, 36 h and 10 d postpartum. Colostrum was provided to the lambs at 40±15 min (mean±SE) after birth and then at 30-min intervals for obtaining the intake closest to 10% of body weight, and transitional milk was provided ad libitum. Blood from the lambs was collected 36 h after birth for measuring the serum concentrations of IgG, total protein, albumin, and gamma-globulin. The production was lower in primiparous than in multiparous ewes with body condition score (BCS)<2.75, but did not differ between primiparous and multiparous with BCS≥2.75 (interaction parity and BCS). The IgG concentration and fat, protein, lactose, and defatted dry extract percentages were not affected by the BCS of the ewe at lambing or by the parity. The total solids percentage in the colostrum was higher in ewes with BCS<2.75 (interaction BCS and time). The production and the protein, total solid, and defatted dry extract percentages showed quadratic behavior, the fat percentage decreased linearly, and the lactose percentage increased linearly with time postpartum. The IgG concentration in the colostrum was not correlated with the ewe's weight or BCS at the time of lambing. Moreover, the parity, the BCS, the ewe's type of gestation, and the lamb's sex did not influence the serum concentrations of IgG, total protein, albumin, and gamma-globulin in lambs. Adequate passive immune transfer (PIT) was observed in lambs for which the IgG intake was higher than 30 g. Failure in PIT was observed in 39.5% of lambs when considering a serum IgG concentration lower than 15 mg/mL and in 21% when considering a serum total protein concentration lower than 45 mg/mL. The mean apparent efficiency of absorption was 38.10%, with values between 0.02% and 98.80%. The serum IgG concentration was correlated with the total protein concentration (according to the enzymatic colorimetric method), the gamma-globulin concentration, and the absorption efficiency. The extreme variation on apparent efficiency of absorption may have an effect on the success of PIT. Lambs should consume at least 30 g of IgG in the first 24 h of life to ensure adequate PIT.

Bioavailability of the flavonol quercetin in neonatal calves after oral administration of quercetin aglycone or rutin

Polyphenols, such as flavonoids, are secondary plant metabolites with potentially health-promoting properties. In newborn calves flavonoids may improve health status, but little is known about the systemically availability of flavonoids in calves to exert biological effects. The aim of this study was to investigate the oral bioavailability of the flavonol quercetin, applied either as quercetin aglycone (QA) or as its glucorhamnoside rutin (RU), in newborn dairy calves. Twenty-one male newborn German Holstein calves were fed equal amounts of colostrum and milk replacer according to body weight. On d 2 and 29 of life, 9 mg of quercetin equivalents/kg of body weight, either fed as QA or as RU, or no quercetin (control group) were fed together with the morning meal. Blood samples were taken before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 12, 24, and 48 h after feed intake. Quercetin and quercetin metabolites with an intact flavonol structure (isorhamnetin, tamarixetin, and kaempferol) were analyzed in blood plasma after treatment with glucuronidase or sulfatase by HPLC with fluorescence detection. Maximum individual plasma concentration was depicted from the concentration-time-curve on d 2 and 29, respectively. Additional blood samples were taken to measure basal plasma concentrations of total protein, albumin, urea, and lactate as well as pre- and postprandial plasma concentrations of glucose, nonesterified fatty acids, insulin, and cortisol. Plasma concentrations of quercetin and its metabolites were significantly higher on d 2 than on d 29 of life, and administration of QA resulted in higher plasma concentrations of quercetin and its metabolites than RU. The relative bioavailability of total flavonols (sum of quercetin and its metabolites isorhamnetin, tamarixetin, and kaempferol) from RU was 72.5% on d 2 and 49.6% on d 29 when compared with QA (100%). Calves fed QA reached maximum plasma concentrations of total flavonols much earlier than did RU-fed calves. Plasma metabolites and hormones were barely affected by QA and RU feeding in this experiment. Taken together, orally administrated QA resulted in a greater bioavailability of quercetin than RU on d 2 and 29, respectively, and quercetin bioavailability of quercetin and its metabolites differed markedly between calves aged 2 and 29 d.

Effect of feeding whole compared with cell-free colostrum on calf immune status: The neonatal period

Mortality and decreased weight gain resulting from infection and disease in dairy calves are problems within the dairy industry. The bovine neonate relies solely on colostrum to acquire antibodies through passive transfer. To date, colostrum quality is determined by the concentration of antibodies. However, proteins and cells in the colostrum might also enhance immune development in the neonate. To determine the effect of maternal colostral immune cells on calf health and immune status, maternal colostrum was fed either fresh or after lysis of cells by flash-freezing in liquid nitrogen. Thirty-seven female Holstein and Jersey dairy calves were fed 4 quarts total of whole colostrum (WC) or cell-free colostrum (CFC) at birth. Respiratory and fecal scores were measured from birth to d 45 of life. Calf peripheral blood samples were obtained before and after feeding colostrum as well as on d 1, 3, 7, 14, 21, and 28 of life. Peripheral blood mononuclear cells were collected and analyzed for cellular parameters by flow cytometry. Total respiratory scores were greater in CFC-fed calves compared with WC-fed calves on d 38 of life. There were fewer CD4+ T cells and CD4+CD62L+CD45RO- T cells on d 1 and fewer CD4+CD62L+CD45RO+ T cells on d 1 and 3 in CFC-fed calves compared with WC-fed calves. Compared with WC-fed calves, CFC-fed calves had a greater percentage of CD4+CD62L-CD45RO+ T cells on d 0.25, 1, 3, and 7, and a greater percentage of monocytes on d 7. Our data suggest that colostral cells adoptively transfer and enhance neonatal immunity during the first month of life.

Relationships between immunoglobulin and fat-soluble vitamins in colostrum of Japanese Black multiparous cows

Data from 19 Japanese Black multiparous cows were collected to clarify the relationships among immunoglobulin (Ig) G, IgA, β-carotene, vitamin A and α-tocopherol contents in colostrum of cows in order to evaluate the role of fat-soluble vitamins on colostral IgG and IgA production. Mean colostral IgG was 141 mg/mL, ranging from 65 to 208 mg/mL, whereas mean colostral IgA was 8.7 mg/mL, ranging from 1.0 to 34.6 mg/mL. Colostral IgG increased with aging in multiparous cows. There were positive correlations between colostral IgG and colostral vitamin A or colostral α-tocopherol in cows, and the higher adjusted R(2) was obtained in the prediction model of colostral IgG from age and colostral vitamin A. Colostral vitamin A was positively correlated with colostral β-carotene or colostral α-tocopherol in cows, but there were no relationships between colostral IgA and colostral IgG or colostral fat-soluble vitamins. These results indicate that fat-soluble vitamin contents in colostrum of cows may change in similar patterns and high colostral vitamin A is related with high colostral IgG.

Effect of heat stress during late gestation on immune function and growth performance of calves: isolation of altered colostral and calf factors

Calves born to cows exposed to heat stress during the dry period and fed their dams' colostrum have compromised passive and cell-mediated immunity compared with calves born to cows cooled during heat stress. However, it is unknown if this compromised immune response is caused by calf or colostrum intrinsic factors. Two studies were designed to elucidate the effects of colostrum from those innate to the calf. The objective of the first study was to evaluate the effect of maternal heat stress during the dry period on calf-specific factors related to immune response and growth performance. Cows were dried off 46 d before expected calving and randomly assigned to 1 of 2 treatments: heat stress (HT; n=18) or cooling (CL; n=18). Cows of the CL group were housed with sprinklers, fans and shade, whereas cows of HT group had only shade. After calving, the cows were milked and their colostrum was frozen for the subsequent study. Colostrum from cows exposed to a thermoneutral environment during the dry period was pooled and stored frozen (-20 °C). Within 4h of birth, 3.8L of the pooled colostrum from thermoneutral cows was fed to calves born to both HT and CL cows. Day of birth was considered study d 0. All calves were exposed to the same management and weaned at d 49. Blood samples were collected before colostrum feeding, 24h after birth and twice weekly up to d 28. Total serum IgG concentrations were determined. Body weight was recorded at birth and at d 15, 30, 45, and 60. Relative to CL calves, HT calves were lighter at birth (38.3 vs. 43.1 kg), but no difference in weight gain was observed at d 60. Additionally, HT calves had lower apparent efficiency of IgG absorption (26.0 vs. 30.2%), but no differences were observed for total IgG concentration. The objective of the second study was to evaluate the isolated effect of the colostrum from HT cows on calf immune response and growth performance. The experimental design was identical to the first study, but all calves were born to cows under thermoneutral conditions during the dry period. At birth, calves were blocked by sex and birth weight and then randomly assigned to 1 of 2 treatments, which meant they received pooled colostrum from HT cows or CL cows. No treatment effect was observed on passive immune transfer or on postnatal growth. Thus, heat stress during the last 6 wk of gestation negatively affects the ability of the calf to acquire passive immunity, regardless of colostrum source.

Effect of the mass of immunoglobulin (Ig)G intake and age at first colostrum feeding on serum IgG concentration in Holstein calves

Forty-four Holstein calves (19 male and 25 female) were used in this study of the relationships among age at first colostrum feeding, IgG intake, and apparent efficiency of IgG absorption. Time of birth was recorded for each calf and the calves were fed colostrum ad libitum after birth at either 0930 or 1630 h. Blood samples were collected immediately before and 24h after colostrum feeding. Data from calves were then categorized into 4 groups representing time from birth to colostrum feeding: A=fed within 1h (n=5); B=fed from 1 to 6h (n=10); C=fed from 6 to 12 h (n=21); and D=fed from 12 to 18 h (n=8) after birth. Average total intake of colostrum was 3.6 ± 0.1L. Over 80% of the calves consumed ≥3 L of colostrum. Apparent efficiency of IgG absorption declined remarkably 12 h after birth. Mean apparent efficiency of absorption of IgG in group D (15.8 ± 3.0%) was lower than that in groups A (30.5 ± 3.9%) and B (27.4 ± 2.8%). Serum IgG concentration in calves was positively correlated with IgG intake in all groups. The relationship between mass of IgG consumed and calf serum IgG at 24 h was different for each time of colostrum feeding, with only limited differences observed between groups A and B. We concluded that failure of transfer of passive immunity in newborn calves may be avoided if calves consume ≥3 L of colostrum with IgG concentration >40 mg/mL within 6 h after birth. These findings help define the opportunity to minimize failure of transfer of passive immunity to newborn calves under management programs similar to those used on commercial dairy farms.

Continuous milking of dairy cows disrupts timing of peak IgG concentration appearance in mammary secretions

The length of the dry period in commercial dairy production is under close scrutiny. While the main concern is the composition and volume of milk produced, the evaluation of colostrum quality under these new paradigms has suggested a decline in IgG concentrations, while some reports indicate no change. Colostrum quality has been defined as an adequate concentration (>50 mg/ml) of immunoglobulin in the secretions to provide the newborn with maximal disease resistance. We investigated the appearance of IgG in mammary pre- and post partum secretions in cows without a dry period (continuously milked, Dry0) and compared the secretions with cows that experienced a dry period of 60 d (Dry60). Blood was collected during the experimental period and plasma analysed for progesterone (P4) and prolactin (Prl). Approximately −6 d relative to parturition, the Dry0 animals exhibited increased concentration of IgG in their secretions to an average of ∼35 mg/ml that remained rather constant through subsequent pregnancy and following parturition. Dry0 cows were producing an average IgG concentration in parturition colostrum of 44·2±17·6 mg/ml that was not different than that of controls (66·86±16·8 mg/ml). However, Dry0 cows exhibited high variation, different peak times (day) of IgG concentration including times that occurred both pre and post parturition. IgG mass of the Dry0 cows remained rather constant pre- and post partum and did not show the same declining mass following parturition that was shown for the Dry60 cows. The change in plasma P4 and Prl were shown to have no timing effect on colostrum IgG concentration.

Bovine colostrum: changes in lipid constituents in the first 5 days after parturition

Despite the great interest paid to protein components in colostrum, fat also plays an important role in the supply of essential nutrients to provide energy, increase metabolism, and protect the newborn calf against microbial infections. This work aimed to elucidate levels of different fat components in colostrum, in particular fatty acid (FA), triglyceride (TG), cholesterol, and phospholipid contents. Colostrum samples from primiparous and multiparous (3-5 lactations) Holstein dams, fed the same ration indoors, were collected on the first 5d after parturition, analyzed, and compared with milk samples from the same cows collected at 5mo of lactation. Fat content during the first 5d of milking did not vary. However, the proportion of short-chain saturated FA increased and that of long-chain FA decreased. The concentration of n-3 FA was higher on the first day of calving than on the other days, with clear differences in the number and type of n-3 FA. Conjugated linoleic isomers and trans FA slowly increased from d 1 to 5, reaching a maximum at 5mo of lactation. Changes in the distribution profile of TG were observed as lactation progressed, with a shift from a prevalence of high-carbon-number TG (C48-50) on d 1 to a bimodal distribution (maxima at C38 and C50) on d 5, characteristic of mid-lactation milk. Cholesterol content was high in the first hours after calving and rapidly decreased within 48h. Colostrum sampled on d 1 also had a high content of phospholipids. Phosphatidylethanolamine and sphingomyelin were, respectively, lower and higher in the first 5d than in mid-lactation milk. The influence of lactation number on colostrum fat composition was also considered and significant results were obtained for all FA groups (except for polyunsaturated and n-6 FA) and TG content.

Effect of supranutritional maternal and colostral selenium supplementation on passive absorption of immunoglobulin G in selenium-replete dairy calves

Selenium (Se) is an essential micronutrient for ruminant animals affecting both performance and immune functions. Adding 3 mg of Se/L (in the form of Na selenite) to colostrum has been shown to improve IgG absorption in Se-deficient newborn dairy calves. The objective of our study was to determine the effect of supranutritional maternal and colostral Se supplementation on IgG status of Se-replete dairy calves. The study design was a 2 × 2 × 2 factorial design. During the last 8 wk before calving, dairy cows at a commercial dairy were fed either 0 (control cows) or 105 mg of Se-yeast once weekly (supranutritional Se-yeast-supplemented cows), in addition to Na selenite at 0.3 mg of Se/kg of DM in their ration. After birth, calves were fed pooled colostrum from control or supranutritional Se-yeast-supplemented cows to which 0 or 3 mg of Se/L (in the form of Na selenite) was added. Concentrations of whole-blood (WB) Se and serum Se measured at birth and at 48 h and 14 d of age, and serum IgG concentrations measured at 48 h and 14 and 60 d of age were determined. Calves born to Se-yeast-supplemented cows had higher WB-Se and serum-Se concentrations for the first 2 wk, and higher IgG absorption efficiency (62% at 48 h), resulting in higher serum-IgG concentrations (43% at 48 h and 65% at 14 d) and higher total serum-IgG content (50% at 48 h and 75% at 14 d), compared with calves born to control cows. Calves that received colostrum with added Na selenite had higher WB-Se concentrations for the first 2 wk, but only at 14 d of age were serum-Se concentrations, serum-IgG concentrations (53% higher), and total serum-IgG content (56% higher) higher, compared with calves that were fed colostrum without added Na selenite. Calves born to Se-yeast-supplemented cows that received colostrum from Se-yeast cows without added Na selenite had a higher IgG absorption efficiency compared with all other treatment groups. Our results support that feeding cows supranutritional Se-yeast supplement during the dry period or spiking colostrum with Na selenite both improve IgG status of Se-replete calves.

Colostrogenesis: IgG1 transcytosis mechanisms

Biological transport of intact proteins across epithelial cells has been documented for many absorptive and secretory tissues. Immunoglobulins were some of the earliest studied proteins in this category. The transcellular transport (transcytosis) of immunoglobulins in neonatal health and development has been recognized; the process is especially significant with ungulates because they do not transcytose immunoglobulins across the placenta to the neonate. Rather, they depend upon mammary secretion of colostrum and intestinal absorption of immunoglobulins in order to provide intestinal and systemic defense until the young ungulate develops its own humoral defense mechanisms. The neonatal dairy calf's ability to absorb immunoglobulins from colostrum is assisted by a ~24 h "open gut" phenomenon where large proteins pass the intestinal epithelial cells and enter the systemic system. However, a critical problem recognized for newborn dairy calves is that an optimum mass of colostrum Immunoglobulin G (IgG) needs to be absorbed within that 24 h window in order to provide maximal resistance to disease. Many calves do not achieve the optimum because of poor quality colostrum. While many studies have focused on calf absorption, the principal cause of the problem resides with the extreme variation (g to kg) in the mammary gland's capacity to transfer blood IgG1 into colostrum. Colostrum is a unique mammary secretory product that is formed during late pregnancy when mammary cells are proliferating and differentiating in preparation for lactation. In addition to the transcytosis of immunoglobulins, the mammary gland also concentrates a number of circulating hormones into colostrum. Remarkably, the mechanisms in the formation of colostrum in ungulates have been rather modestly studied. The mechanisms and causes of this variation in mammary gland transcytosis of IgG1 are examined, evaluated, and in some cases, explained.

Heat treatment of colostrum increases immunoglobulin G absorption efficiency in high-, medium-, and low-quality colostrum

Previous studies with heat-treated colostrum fed to neonatal calves have consistently used average-quality colostrum. Studies have not compared colostrum across a range of immunoglobulin levels. This study was conducted to investigate IgG absorption in neonatal dairy calves using colostrum of various qualities. Colostrum from the Pennsylvania State University dairy was collected over 2 yr and sorted into high, medium, and low quality based on colostrometer measurement. Colostrum within each category was pooled to create 3 unique, uniform batches. Half of each batch was frozen to be fed without heat treatment. The second half of each batch was heat treated at 60°C for 30min. This process was conducted in September 2011, and repeated in June 2012. Colostrum treatments were analyzed for standard plate count, coliforms, noncoliform gram-negative bacteria, and total IgG concentration. Plasma samples were collected from 145 calves 48h after birth and analyzed for IgG1, IgG2, total protein, and hematocrit. Colostrum quality (high, medium, or low), treatment (unheated or heat treated), and their interactions were analyzed as fixed effects, with year included as a random effect. Heat treatment significantly reduced all types of bacteria and IgG concentration. Plasma IgG concentration at 48h increased linearly with the concentration of IgG in the colostrum that was consumed. Heat treatment of colostrum increased plasma IgG concentration by 18.4% and apparent efficiency of absorption by 21.0%. Results of this study suggest that heat treatment of colostrum containing approximately 50 to 100mg IgG/mL increases absorption of IgG from colostrum.

Effect of feeding maternal colostrum or plasma-derived or colostrum-derived colostrum replacer on passive transfer of immunity, health, and performance of preweaning heifer calves

The objective of this study was to evaluate the effect of feeding maternal colostrum (MC), a plasma-derived (PDCR) or colostrum-derived colostrum replacer (CDCR) on passive transfer of immunity, health, and performance of preweaning heifer calves. Preplanned contrasts were performed for MC versus CR (PDCR combined with CDCR) and PDCR versus CDCR. At birth, calves were randomly assigned to 1 of 3 treatment groups: MC (n=49), 3.8L of maternal colostrum; PDCR (n=49), 550 g (1 dose; 150 g of IgG) of a PDCR; or CDCR (n=49), 470 g (1 dose; 100g IgG) of a CDCR. The best total protein cutoff for determining passive transfer was >5.2, 5.6, and 5.1g/dL for MC, PDCR, and CDCR, respectively. Serum total protein was greater for calves fed MC (mean ± SE; 6.14 ± 0.11 g/dL) than for calves fed PDCR (5.29 ± 0.11 g/dL) and CDCR (5.27 ± 0.11 g/dL). Serum IgG concentrations were greater for calves fed MC (2,098 ± 108 g/dL) than for calves fed PDCR (927 ± 107 g/dL) or CDCR (1,139 ± 108 g/dL). Apparent efficiency of absorption was greater for CDCR than PDCR (38.8 ± 3.0 vs. 21.6 ± 3.0%). Adequate passive transfer was greatest for MC (91.8%), followed by CDCR (49%) and PDCR (28.6%). Calves fed MC had greater weaning weights and body weight gain than calves fed CR. Morbidity was lower for calves fed MC (46.9%) than for calves fed PDCR (71.4%) or CDCR (67.3%). Calves fed MC tended to have lower mortality than calves fed CR. Given the conditions of this trial, feeding 3.8L of MC was superior to feeding one dose of CR. Further research is needed to evaluate calf performance when a higher dose of CR is fed.

Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells

Bovine colostrogenesis is distinguished by the specific transfer of IgG1 from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E2 ) and progesterone (P4 ) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta-2-Microglobulin (β2M). We hypothesized that steroid hormone treatments (E2 and P4 ) of bovine mammary epithelial cells in vitro would induce up-regulation of IgG1 transcytosis candidate gene mRNA expression suggesting involvement in IgG1 transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up-regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG1 transcytosis in bovine mammary cells.

Evaluation of the Brix refractometer to estimate immunoglobulin G concentration in bovine colostrum

Refractometry using a Brix refractometer has been proposed as a means to estimate IgG concentration in bovine maternal colostrum (MC). The refractometer has advantages over other methods of estimating IgG concentration in that the Brix refractometer is inexpensive, readily available, less fragile, and less sensitive to variation in colostral temperature, season of the year and other factors. Samples of first-milking MC were collected from 7 dairy farms in Maine, New Hampshire, Vermont, and Connecticut (n=84) and 1 dairy farm in California (n=99). The MC was milked from the cow at 6.1 ± 5.6h postparturition and a sample was evaluated for Brix percentage by using an optical refractometer. Two additional samples (30 mL) were collected from the milk bucket, placed in vials, and frozen before analysis of total IgG by radial immunodiffusion (RID) using commercially available plates and by turbidimetric immunoassay (TIA). The second sample was analyzed for total bacterial counts and coliform counts at laboratories in New York (Northeast samples) and California (California samples). The Brix percentage (mean ± SD) was 23.8 ± 3.5, IgG concentration measured by RID was 73.4 ± 26.2g/L, and IgG concentration measured by TIA was 67.5 ± 25.0 g/L. The Brix percentage was highly correlated (r=0.75) with IgG analyzed by RID. The Brix percentage cut point to define high- or low-quality colostrum (50 g of IgG/L measured by RID) that classified more samples correctly given the proportion of high- (86%) and low-quality (14%) samples in this study was 21%, which is slightly lower than other recent estimates of Brix measurements. At this cut point, the test sensitivity, specificity, positive and negative predictive values, and accuracy were 92.9, 65.5, 93.5, 63.3, and 88.5%, respectively. Measurement of IgG by TIA correlated with Brix (r=0.63) and RID (r=0.87); however, TIA and RID methods of IgG measurement were not consistent throughout the range of samples tested. We conclude that Brix measurement of total solids in fresh MC is an inexpensive, rapid, and satisfactorily accurate method of estimating IgG concentration. A cut point of 21% Brix to estimate samples of MC >50 g/L was most appropriate for our data. Measurement of IgG in MC by TIA differed from measurement by RID.

Short communication: addition of sodium bicarbonate to maternal colostrum: effects on immunoglobulin G absorption and hematocrit in neonatal calves

Twenty-six Holstein bull calves born from primiparous and multiparous cows without dystocia were assigned in a randomized complete block design to 1 of 2 treatments: pooled maternal colostrum (PMC) or PMC supplemented with 30 g of sodium bicarbonate (NaHCO(3)). Calves were fed PMC from 9 different batches containing (mean ± SD) 82.05±8.45 g/L of IgG. Calves were fed 2.68 L of PMC at birth (referred to as 0 h) and 1.32 L of PMC 6h later. The total amount of IgG fed was 329.89±34.56 g. Calves were fed 2L of milk replacer at 24, 36, and 48 h postpartum. The addition of NaHCO(3) had no effect on IgG absorption. Serum IgG concentrations at 0, 6, 12, 24, and 48 h postpartum were not different between calves supplemented with or without 30 g of NaHCO(3) to colostrum. Area under the curve, apparent efficiency of absorption, and hematocrit were not affected by the NaHCO(3) treatment.

Short communication: Addition of varying amounts of sodium bicarbonate to colostrum replacer: effects on immunoglobulin G absorption and serum bicarbonate in neonatal calves

Fifty-two dairy calves were blocked by birth date and, within each block, randomly assigned to 1 of 4 treatments to investigate the effects of incremental levels of sodium bicarbonate (NaHCO(3)) on IgG metabolism. Treatments were (1) colostrum replacer (CR)+0 g of NaHCO(3) (control); (2) CR+15 g of NaHCO(3); (3) CR+30 g of NaHCO(3); or (4) CR+45 g of NaHCO(3). Calves were fed colostrum replacer (>200 g of IgG) in one feeding within 45 min of birth (0 h) and 2 L of milk replacer at 12, 24, 36, and 48 h. Only calves born in calving pens from multiparous cows with no dystocia were used in this study. Blood samples were taken at 0, 6, 12, 24, and 48 h postpartum, and serum was analyzed for IgG using radial immunoassay and bicarbonate using spectrophotometry. Feeding increasing levels of sodium bicarbonate had negative linear effects on IgG concentration, IgG apparent efficiency of absorption, and IgG area under the curve, primarily due to the effect of the highest dose of NaHCO(3) (45 g). Sodium bicarbonate treatments had no effect on serum bicarbonate concentration. However, area under the curve of serum bicarbonate increased linearly with the amount of NaHCO(3) fed.

Increased colostral somatic cell counts reduce pre-weaning calf immunity, health and growth

Our objective was to study the relationships between colostral somatic cell counts (SCC, a criterion for mastitis severity at parturition) and early calf growth, blood indicators of immunity, and pre-weaning faecal and health states. Sixty-nine Holstein cows were assigned to three groups of greater (n = 21, 5051 × 10(3)), medium (n = 38, 2138 × 10(3)) and lower (n = 10, 960 × 10(3)) colostral SCC (per ml) in a completely randomized design. Calves received 2 l of colostrum on day 1, and jugular blood was sampled at birth, at 3 h after the first colostrum feeding and at 42 days of age for immunoglobulin G (IgG) measurements. Calves were fed transition milk from their dams until 3 days of age and whole milk from 4 to 60 days of age twice daily at 10% of body weight. Health status and faecal physical scores were recorded daily for 42 days. Increased colostral SCC was associated with increased serum IgG at parturition. Colostral pH increased and fat percentage decreased linearly with the rising SCC. Feeding colostrum with greater SCC was associated with reduced serum IgG concentrations at 3 h after first colostrum feeding, greater incidences of diarrhoea and compromised health status during the first 42 days of age, and reduced weaning weight gain, but had no effects on calf body length and withers height. Colostral volume and percentages of protein, lactose, solids-non-fat, total solids and IgG were comparable among groups. Results suggest a role for SCC, as an indicator of mastitis and colostral health quality, in affecting calf health. As a result of the novelty of calf health dependence on colostral SCC found, future studies to further characterize such relationships and to uncover or rule out possible mediators are required before colostral SCC could be recommended for routine on-farm use in managing dry cow and calf production.

Supplemental β-carotene increases IgA-secreting cells in mammary gland and IgA transfer from milk to neonatal mice

Mortality of neonates continues to be a major problem in humans and animals. IgA provides protection against microbial antigens at mucosal surfaces. Although β-carotene supplementation has been expected to enhance retinoic acid-mediated immune response in neonates, the exact mechanism by which β-carotene enhances IgA production is still unclear. We investigated the effect of supplemental β-carotene for maternal mice during pregnancy and lactation on IgA antibody-secreting cells (ASC) in mammary gland and guts and on IgA transfer from milk to neonatal mice. Pregnant mice were fed untreated or 50 mg/kg β-carotene-supplemented diets from 6·5 d postcoitus (dpc) to 14 d postpartum (dpp). Supplemental β-carotene increased the numbers of IgA ASC in mammary gland (P < 0·05) and ileum (P < 0·001), and also mRNA expression of IgA C-region in ileum (P < 0·05) of maternal mice at 14 dpp, but few IgA ASC were detected in mammary gland at 17·5 dpc. IgA concentration in stomach contents, which represents milk IgA level, was significantly higher (P < 0·01) in neonatal mice born to β-carotene-supplemented mothers at 7 and 14 dpp, and IgA concentration in serum, stomach contents and faeces increased (P < 0·001) drastically with age. These results suggest that β-carotene supplementation for maternal mice during pregnancy and lactation is useful for enhancing IgA transfer from maternal milk to neonates owing to the increase in IgA ASC in mammary gland and ileum during lactation.

Expression and immunohistochemical localization of the neonatal Fc receptor (FcRn) in the mammary glands of the Egyptian water buffalo

Although a marginal placental transfer of maternal immunoglobulin (Ig) has been demonstrated in buffalo, the colostrum still provides the main source of immune components and nutrients to neonate buffalo calves. The neonatal Fc receptor (FcRn) transports maternal Ig across the gut wall and is involved in the transport of IgG in the mammary gland. In this study we used RT-PCR to examine the gene expression of FcRn in the mammary gland during several physiological states of the Egyptian water buffalo. The buffalo FcRn showed a high sequence homology to that of other mammalian species and especially the cow. Immunohistochemistry demonstrated positive immunolabelling of FcRn in the epithelial cells of the acini and ducts of the examined mammary gland tissue. Remarkable differences in both the cellular localization and in the intensity of FcRn immunopositivity were observed depending on the functional state of the mammary gland tissues. In late pregnancy, the FcRn immunolabelling was homogeneously distributed in the cytoplasm of the epithelial cells. In recently parturient animals, positive FcRn immunolabelling was mainly located at the luminal surface and apical cytoplasm of the mammary gland epithelium, while in dry and lactating animals, the FcRn immunolabelling was in the apical cytoplasm of the cells. The strongest FcRn immunolabelling was observed in late pregnancy and in recently parturient animals. In conclusion, the present data support the notion that FcRn might be involved in the transfer of maternal immunoglobulins and in the local defense mechanism of the mammary gland.

Neuroprotective effects of consuming bovine colostrum after focal brain ischemia/reperfusion injury in rat model

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-1β, IL-6, and TNF-α levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model.

Effects of natural (RRR alpha-tocopherol acetate) or synthetic (all-rac alpha-tocopherol acetate) vitamin E supplementation on reproductive efficiency in beef cows

The objective was to determine the effects of natural- or synthetic-source vitamin E on reproductive efficiency in Angus-cross beef cows. In Exp. 1, one hundred fifty-two cows were fed hay and corn silage based diet and assigned to 1 of 3 dietary supplements (3 pens/treatment): 1) containing no additional vitamin E (CON), 2) formulated to provide 1,000 IU x d(-1) of synthetic-source vitamin E (SYN; all-rac or dl-alpha-tocopherol acetate), or 3) formulated to provide 1,000 IU x d(-1) of natural-source vitamin E (NAT; RRR or D-alpha-tocopherol acetate). In Exp. 2, seventy-five cows (2 reps/treatment) were assigned to similar treatments as Exp. 1; however, a vitamin-mineral supplement was offered for ad libitum intake and vitamin intake was calculated from predicted mineral intakes. Cows grazed pastures rather than being fed hay and corn silage as in Exp. 1. In Exp. 1 and 2, supplementation began 6 wk prepartum and continued until initiation of the breeding season. Blood samples were collected at calving (Exp. 1) or breeding (Exp. 2) to determine alpha-tocopherol concentration and weekly beginning 4 wk postpartum (Exp. 1) or 7 and 14 d before estrus synchronization (Exp. 2) to determine return to estrus via progesterone concentration. Cows were synchronized and bred by AI based on heat detection; nonresponding cows were time bred (AI) 66 h after PGF(2 alpha) injection, and cows returning to estrus after AI were bred by natural service. In Exp. 1, cows supplemented with NAT and SYN had greater (P < 0.001) serum concentrations of alpha-tocopherol at calving compared with CON cows. Dietary supplement did not affect (P >or= 0.55) the percentage of cows cycling before synchronization or the number of days to return to estrus by cows that resumed estrus before synchronization. Cows supplemented with SYN tended to have greater first service conception rates compared with CON and NAT (P = 0.09); however, first plus second services combined and overall conception rates were not affected (P >or= 0.23). In Exp. 2, NAT cows had greater (P = 0.002) concentrations of alpha-tocopherol at breeding, whereas there was no difference (P > 0.05) between SYN and CON. Supplementation of SYN or NAT did not affect (P >or= 0.17) days to resumption of estrus before breeding, first service, first plus second services combined, or overall conception rates. These data suggest that supplementation of SYN or NAT source vitamin E increased alpha-tocopherol concentration in cows; however, effects on reproductive efficiency are minimal.

Feeding heat-treated colostrum or unheated colostrum with two different bacterial concentrations to neonatal dairy calves

The objective of this study was to determine the effects of feeding heat-treated colostrum or unheated colostrum of different bacterial counts on passive transfer of immunity in neonatal dairy calves. First milking colostrum was collected from Holstein cows, frozen at -20 degrees C, and then thawed and pooled into a single batch. One-third of the pooled colostrum was transferred into plastic containers and frozen at -20 degrees C until needed for feeding (unheated-low bacteria). Another third was heat-treated at 60 degrees C for 30 min and then frozen at -20 degrees C until needed for feeding (heat-treated). The final third of colostrum was transferred into plastic containers, stored at 20 degrees C for bacteria to grow for 24 h (unheated-high bacteria), and then frozen at -20 degrees C until needed for feeding. A total of 30 Holstein bull calves weighing >or=30 kg at birth were systematically enrolled into 1 of the 3 treatment groups. Calves were separated from their dams at birth before suckling occurred. Before colostrum was fed, a jugular blood sample was collected from each calf. The first feeding consisted of 3.8 L of colostrum containing, on average, 68 g of IgG/L using an esophageal feeder between 1.5 and 2 h after birth. For the second and third feeding pasteurized whole milk at 5% of birth weight was fed. Blood samples were collected before colostrum feeding and at 24 and 48 h of age to determine serum total protein (STP) and IgG concentrations. Heat treatment of colostrum at 60 degrees C for 30 min reduced colostrum bacteria concentration yet maintained colostral IgG concentration and viscosity at similar levels to the control treatment. Calves fed heat-treated colostrum had significantly greater STP and IgG concentrations at 24 h and greater apparent efficiency of absorption (AEA) of IgG (STP = 62.5 g/L; IgG = 26.7 g/L; AEA = 43.9%) compared with calves fed unheated-low bacteria colostrum (STP = 57.0 g/L; IgG = 20.2 g/L; AEA = 35.4%) or unheated-high bacteria colostrum (STP = 56.2 g/L; IgG = 20.1 g/L; AEA = 32.4%). High bacteria load in colostrum did not interfere with total protein or IgG absorption or AEA.

Feeding heat-treated colostrum to neonatal dairy heifers: effects on growth characteristics and blood parameters

Newborn Holstein heifer calves were studied to compare absorption of immunoglobulin G (IgG(1) and IgG(2)), total serum protein concentration, lymphocyte counts, health scores, growth, and starter intake after receiving unheated or heat-treated colostrum. First-milking colostrum was collected from Holstein cows and frozen at -20 degrees C to accumulate a large batch. After thawing and mixing, half of the colostrum was transferred into 1.89-L plastic containers and frozen at -20 degrees C until needed for feeding. The remaining half was heated at 60 degrees C for 30 min, transferred into 1.89-L plastic containers, and then frozen at -20 degrees C until needed for feeding. Forty heifer calves weighing > or =32 kg at birth were enrolled into 1 of 2 treatment groups before suckling occurred. For the first feeding, 3.8 L of colostrum was bottle fed by 1.5 to 2 h of age. For the second and third feedings, pasteurized whole milk at 5% of birth body weight (BW) was fed. Subsequently, calves received milk replacer containing 20% crude protein and 20% fat at 10% of birth BW/d until wk 5. Milk replacer was reduced to 1 feeding of 5% birth BW until weaning at 6 wk of age. Blood samples and growth data were collected through wk 8. Batch heat-treatment of colostrum at 60 degrees C for 30 min lowered colostrum bacteria concentration while maintaining colostral IgG concentration and viscosity. Calves fed heat-treated colostrum had significantly greater IgG concentrations at 24 h and greater apparent efficiency of IgG absorption (IgG = 23.4 g/L; apparent efficiency of absorption = 33.2%) compared with calves fed unheated colostrum (IgG = 19.6 g/L; apparent efficiency of absorption = 27.7%). There was no difference between treatment groups in growth measurements, calf starter intake, lymphocyte counts, or health scores.

Effects of colostrum replacer supplemented with lactoferrin on the blood plasma immunoglobulin G concentration and intestinal absorption of xylose in the neonatal calf

The objective of this experiment was to determine the effect of lactoferrin (Lf) supplementation of colostrum replacer (CR) fed as 1 or 2 doses on apparent efficiency of IgG absorption, serum IgG concentrations, and xylose absorption/intestinal development in neonatal Holstein bull calves. Eighty bull calves were assigned to a 2 x 4 factorial arrangement of treatments in a randomized complete block design. Calves used were from the University of New Hampshire (n = 48) or a commercial dairy (n = 32). All calves were fed CR according to manufacturer's recommendations +/- Lf treatment within 90 min of birth. Lactoferrin treatments were 0 (control), 0.5, 1, and 2 g/d of supplemental Lf. At 12 h of age, calves were fed a second feeding of CR +/- supplemental Lf or 2 L of milk replacer +/- supplemental Lf. Calves continued to be fed milk replacer +/- supplemental Lf every 12 h for the duration of study. Blood samples were collected for determination of IgG and total serum protein at 0, 6, 12, 18, 24, and 48 h. Calves, except those fed 1 dose of CR plus 1 or 2 g of Lf, had serum IgG concentrations > or = 10 g/L at 24 h. Lactoferrin supplementation had no effect on serum IgG or total serum protein concentrations. Calves fed 2 doses of CR had greater serum IgG concentrations compared with calves fed 1 dose of CR. Apparent efficiency of absorption of IgG was less in calves fed 2 doses of CR compared with calves fed 1 dose of CR. Lactoferrin supplementation (up to 1 g/d) resulted in decreased apparent efficiency of absorption of IgG. At the sixth feeding (60 +/- 2 h of age), D-xylose (0.5 g/kg BW) was mixed with milk replacer +/- supplemental Lf (n = 48) to determine xylose absorption by the small intestine. Blood was collected at 0, 2, 4, 6, 8, and 12 h after feeding xylose for determination of plasma glucose and xylose concentrations. Xylose means and area under the curve resulted in quadratic effects. Feeding calves 0.5 or 1 g/d supplemental Lf resulted in decreased plasma xylose concentrations compared with calves fed 0 or 2 g/d of supplemental Lf. Colostrum replacer or supplemental Lf did not affect plasma glucose concentrations. This study indicates that supplementing Lf at 0.5 or 1 g/d to calves fed CR has a negative effect on apparent efficiency of IgG absorption and xylose absorption.

Concentrations of ganglioside type M1 and immunoglobulin G in colostrum are inversely related to bacterial infection at early lactation in cows

The levels of IgG and ganglioside type M1 in the colostrum of cows and heifers were analyzed to examine their utility in predicting acquisition of intramammary infection (IMI) during the first weeks postpartum. In general, high levels of IgG and ganglioside type M1 in cows were associated with lower new incidence of IMI, and linear discriminate analysis based on these 2 variables yielded 69.4% successful classification into cows that did or did not acquire new IMI. This analysis was less successful in heifers because a high proportion of them joined the herd when already infected with bacteria in their udders. It is suggested that application of a wider range of measures that reflect the immune status would enable the identification of most cows prone to new IMI.

Insulin-like growth factors (IGFs), IGF binding proteins, and other endocrine factors in milk: role in the newborn

The role of colostrum and milk in the neonate has been chiefly recognized as a comprehensive nutrient foodstuff. In addition, the provision of colostrum-the first milk-for early immune capacity has been well documented for several species. Colostrum is additionally a rich and concentrated source of various factors that demonstrate biological activity in vitro. Three hypotheses have been proposed for the phenotypic function of these secreted bioactive components: (1) only mammary disposal, (2) mammary cell regulation, and (3) neonatal function [gastrointestinal tract (GIT) or systemic]. Traditionally, it was assumed that the development of the GIT is preprogrammed and not influenced by events occurring in the intestinal lumen. However, a large volume of research has demonstrated that colostrum (or milk-borne) bioactive components can basically contribute to the regulation of GIT growth and differentiation, while their role in postnatal development at physiological concentrations has remained elusive. Much of our current understanding is derived from cell culture and laboratory animals, but experimentation with agriculturally important species is taking place. This chapter provides an overview of work conducted primarily in neonatal calves and secondarily in other species on the effects on neonates of selected peptide endocrine factors (hormones, growth factors, in part cytokines) in colostrum. The primary focus will be on insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) and other bioactive peptides, but new interest and concern about steroids (especially estrogens) in milk are considered as well.

A survey of bovine colostrum composition and colostrum management practices on Pennsylvania dairy farms

Colostrum composition and management were surveyed via sample and data collection from 55 dairy farms in Pennsylvania. Colostrum samples were analyzed for fat, protein, lactose, total solids, ash, Ig, lactoferrin, water- and fat-soluble vitamins, and minerals. Mean percentages of fat, protein, and lactose in colostrum were 6.7, 14.9, and 2.5, respectively. Concentrations of IgG1, IgG2, IgA, IgM, and lactoferrin were 35.0, 6.0, 1.7, 4.3, and 0.8 mg/mL, respectively. Mean concentrations of fat-soluble vitamins, including retinol, tocopherol, and beta-carotene, were 4.9, 2.9, and 0.7 microg/g, respectively. Mean concentrations of water-soluble vitamins were 0.34, 0.90, 4.55, 0.60, 0.15, 0.21, and 0.04 microg/mL for niacin, thiamine, riboflavin, vitamin B12, pyridoxal, pyridoxamine, and pyridoxine, respectively. Mean concentrations (mg/kg) of selected minerals in colostrum were also determined (Ca 4,716; P 4,452; Mg 733; Na 1,058; K 2,845; Zn 38; Fe 5.3; Cu 0.3; S 2,595; and Mn 0.1). The findings of this study revealed that the mean concentrations of most nutrients in colostrum have increased when compared with values previously reported. Results also showed that management practices have improved over time, particularly with regard to colostrum storage and feeding. Additionally, we observed that herd size influenced colostrum management and quality. It can be inferred, based on these findings, that although improvements have been made with regard to colostrum management and quality, there is still a need to educate producers on issues related to storage and timely feeding of colostrum to increase passive transfer and decrease the rate of calf morbidity and mortality.