Colostrum Of Dairy Cows Research Articles

Fluctuations in Immunoglobulin a Level in Colostrum of Dairy Cows: Implication for Daily Postpartum Measurement

Fluctuations in Immunoglobulin a Level in Colostrum of Dairy Cows: Implication for Daily Postpartum Measurement

295 Effects of a Supraphysiological Oxytocin Injection After Parturition on Blood-Milk-Barrier Closure and Igg Transfer into Milk in Dairy Cows

Abstract Oxytocin (OT) can affect the blood-milk-barrier integrity by modulating the closure of tight junctions. Earlier research demonstrated a transfer of circulating immunoglobulins (Ig) into milk upon OT application during an LPS-induced mastitis. The role of OT in colostrogenesis, i.e., IgG transfer into colostrum, is not fully understood. Our study aimed at retarding the postpartum closure of the blood-milk-barrier and concomitantly prolonging the transfer of IgG into colostrum of dairy cows by a supraphysiological OT injection. Multiparous Holstein cows (n = 28) were enrolled. Blood and milk samples were collected at the first 2 milkings after parturition and milk yields were recorded. Ten cows received 50 IU OT i.v. at 30 min after the first milking (OT+30), 9 cows were injected 50 IU OT i.v. at 120 min before the second milking (OT-120), and 9 cows remained untreated (CTRL). Cows were milked at 6.7 ± 0.7 h after parturition (first milking) and 11.5 ± 0.3 h later (second milking). Milk was analyzed for fat, protein, lactose and IgG, serum albumin (SA), and electrolytes (Na, K, Cl) concentrations and for lactate dehydrogenase (LDH) activity. Concentration of α-lactalbumin (α-LA) was measured in blood plasma. Data were evaluated using a mixed model (SAS) with group, milking number, and group x milking number as fixed effects, and cow as random subject. In all groups, concentrations of protein, IgG, SA, LDH in milk decreased from first to second milking, while lactose content in milk increased (P < 0.05). Milk yield and milk fat content did not differ between first and second milking (P > 0.05). Concentration of α-LA in plasma tended to decrease from first to second milking. Treatments did not affect changes in blood and milk from first to second milking. In conclusion, a single injection of supraphysiological OT either at 30 min after the first milking postpartum or 2 h before the second milking postpartum did not retard the closure of the blood-milk-barrier in dairy cows. Furthermore, OT application did not prolong the active transport of IgG into milk after the first milking.

Holştayn İneklerde Bir Laktasyonda Üretilen Toplam Kolostral IgG’nin Araştırılması

Since dairy cows have greater milk production than beef cows, because of the dilution of IgG colostrum of dairy cows assumed to be of poorer quality compared with beef cows. The objective of the present study was to investigate quality of colostrum and total IgG produced in a lactation by Holstein cows. The average colostrum volume at the first seven milking were measured as 5.42 L, 6.73 L, 8.55 L, 9.26 L, 8.44 L, 9 L, 10.01 L respectively. The average total colostrum produced by cows in the first 3 days period was calculated as 57.41L. The average colostrum IgG concentration were calculated as 90.81 mg/ml, 68.67 mg/ml, 58.40 mg/ml, 37.33 mg/ml, 15.22 mg/ml, 10.7 0mg/ml, 5.9 mg/ml respectively for each milking. In conclusion, enough colostrum and IgG are produced in the first 3 days in Holstein cows for calf feeding. In addition to this, there is huge opportunity that excessive amount of IgG and colostrum could be processed for other by-products.

Performance of carotenoid contents in colostrum of dairy cows during the initial to five days of lactation

Colostrum is the main food for newborn calves, due to contain immunoglobulin, vitamin, zinc, magnesium, riboflavin, folic acid and carotene. This research was conducted to performance of carotene contents in the colostrum of lactating dairy cows. This research was held on testing laboratory of food quality and food safety Faculty of Agriculture Technology Universitas Brawijaya. The material of this research had using total of 10 pregnant dairy cows. After giving birth to the calf/parturition, colostrum samples were taken from all cows on different milking days (milking fifth days). The method in this research was used case study an data obtained with exploratory descriptive. Based on the research results, the highest carotene level was 4.12 µg/g on the first day of milking

Oral supplementation with organically modified clinoptilolite during prepartum period influences the redox status of peripheral blood and colostrum of primiparous dairy cows

Redox imbalance in peripartum period influences health of dairy cows and their foetus and, through the colostrum, health of new-born calves. Oxidative stress in cattle can be suppressed by dietary supplementation with natural minerals, and we investigated the effect of supplementation with organically modified clinoptilolite on redox status parameters in healthy pregnant primiparous dairy cows. Holstein cows were randomly assigned to receive daily oral drenching, with 1 L of water containing either 0 g/L (n = 14; control group) or 150 g/L of clinoptilolite (n = 17; supplemented group). Treatment lasted from 24 ± 4 days prior to parturition until 2 days postpartum (pp). Blood samples were collected on days 24 ± 4 (–24 D) and 4 ± 2 (–4 D) prior to parturition and on days 1 (+1 D), 2 (+2 D), and 7 (+7 D) pp, and colostrum were collected at 2, 12, 24 and 36 h pp. Total antioxidant capacity, lipid peroxides, and advanced oxidation protein products (AOPP) levels were determined in peripheral blood plasma, erythrocytes, and colostrum whey. The concentration of antioxidants in the peripheral blood of supplemented cows was increased by 41% and 19% on (+2 D) and (+7 D), respectively, while the concentration of lipid peroxides on (+7 D) was lowered by 57% compared with the control group. In addition, this supplementation increased erythrocyte AOPP level on (–4 D) 61%) and colostral lipid peroxides level (90%) at 24 h pp. The results of this study showed that applied short-term supplementation with clinoptilolite influences redox homeostasis and may contribute to effective adaptation of primiparous cows to redox imbalance in the peripartum period. Highlights Short-term dietary supplementation with clinoptilolite in the prepartum period modulates redox homeostasis of the dairy cows’ blood plasma. Short-term dietary supplementation with clinoptilolite contributes to adaptation of dairy cows to redox imbalance in the peripartum period. Short-term dietary supplementation with clinoptilolite increase the level of lipid peroxides in colostrum of dairy cows.

Isolation and selection of proteolytic lactic acid bacteria from colostrum of dairy cattle

Lactic Acid Bacteria (LAB) are bacteria that produce lactic acid and are very useful bacteria, one of which can act as a probiotic because it can produce bacteriocins and produce peptide compounds with high biological activity. Colostrum is the first fluid that comes out of the udder of the mother cattle after giving birth which is very good for newborns because it contains antibodies. This research aimed to isolate, selection and identify the types of LAB found in dairy cow colostrum, especially LAB which have superior proteolytic activity. LAB obtained is expected to have a positive effect on livestock productivity. This research was conducted In-vitro in a laboratory. The research procedure included the isolation of LAB from the colostrum of dairy cows, then the selection procedure by looking at the best protease enzyme activity qualitatively and quantitatively, and testing for resistance to low pH. Lactic acid isolation, selection, and identification were analyzed using descriptive analysis and quantitative analysis using one-way ANOVA for a completely randomized design. The results obtained 6 superior proteolytic LAB isolates based on the protease enzyme activity coded LAB pro 4, LAB pro 3, LAB pro 8, LAB pro 9, LAB pro 21, and LAB pro 20.

Measurement of transfer of colostral passive immunity in dairy calves

Measurement of transfer of colostral passive immunity in dairy calves

Effect of immunoglobulin G concentration in dairy cow colostrum and calf blood serum on Cryptosporidium spp. invasion in calves.

Aim:The research aimed to test the association between the level of immunoglobulin G (IgG) in bovine colostrum and calf blood serum and to evaluate its relation to Cryptosporidium spp. invasion in calves.Materials and Methods:Fresh colostrum and fecal specimens from cows (n=114) as well as blood and fecal specimens from newborn calves (n=114) were collected in the dairy cattle farm. Investigated calves were separated from their mothers directly after birth and received 2 L of colostrum in two separate feedings within the first 24 h. Blood samples were taken from calves at the age of 2 days. Coprological samples were taken from calves at the age of 1, 10, and 15 days. Both colostrum and fecal samples from cows were taken on the 1st day after calf birth. Rectal fecal samples were collected separately from each calf and cow into plastic bags. The collected calf serum samples and bovine colostrum samples were tested for bovine IgG by competitive enzyme-linked immunosorbent assay kit bovine Ig. To record oocysts of Cryptosporidium spp. in feces, the flotation method was used. Binomial logistic regression was performed to ascertain the effects of IgG in bovine colostrum and calf blood serum on the likelihood of Cryptosporidium spp. infection in calves.Results:The concentration of IgG in bovine colostrum was higher (70.7±26.6 g/L, mean±standard deviation) than that in calf blood serum (13.2±6.1 g/L); the statistically significant difference was 57.4 g/L (95% confidence interval, 52.4-62.4), t (124.872)=22.536, p<0.001. Mann–Whitney’s U-test showed a significant difference between samples collected on days 10 and 15 of the experiment (U=1944, z=2.330, p=0.020). The higher number of oocysts in calf feces was recorded on day 15 (median=6.5) compared to day 10 (median=4). The prevalence of calf infection from days 10 to 15 increased from 26.3 to 45.6% and was at least 3 times higher than in cows. A statistically significant positive correlation was recorded between IgG concentration of cow colostrum and calf blood serum (r (114)=0.414, p=0.001), whereas a correlation between the concentration of IgG and the intensity of Cryptosporidium spp. infection was not recorded (p>0.05). The logistic regression model was not statistically significant (χ2(2)=0.013, p=0.99 (10 days) and χ2(2)=0.100, p=0.95 (15 days)).Conclusion:Mother passive transfer of immunity to the offspring through colostrum does not influence the susceptibility of calves to Cryptosporidium infestation.

Associations between body condition score at parturition and microRNA profile in colostrum of dairy cows as evaluated by paired mapping programs

MicroRNA (miRNA) are abundant in milk, and likely have regulatory activity involving lactation and immunity. The objective of this study was to determine the miRNA profile in colostrum of overconditioned cows compared with cows of more moderate body condition score (BCS) at calving. Multiparous cows with either high (≥4.0 on a scale of 1 to 5; n = 7) or moderate BCS (2.75 to 3.50; n = 9) in the week before parturition were selected from a commercial dairy herd. Blood and colostrum were sampled within 24 h after calving. Blood serum was analyzed for free fatty acid (FFA) concentration. MicroRNA was isolated from colostrum samples after removing milk fat and cells. MicroRNA were sequenced, and reads were mapped to the bovine genome and to the existing database of miRNA at miRBase.org. Two programs, Oasis 2.0 and miRDeep2, were employed in parallel for read alignment, and analysis of miRNA count data was performed using DESeq2. Identification of differentially expressed miRNA from DESeq2 was not affected by the differences in miRNA detected by the 2 mapping programs. Most abundant miRNA included miR-30a, miR-148a, miR-181a, let-7f, miR-26a, miR-21, miR-22, and miR-92a. Large-scale shifts in miRNA profile were not observed; however, colostrum of cows with high BCS contained less miR-486, which has been linked with altered glucose metabolism. Colostrum from cows with elevated serum FFA contained less miR-885, which may be connected to hepatic function during the transition period. Potential functions of abundant miRNA suggest involvement in development and maintenance of cellular function in the mammary gland, with the additional possibility of influencing neonatal tissue and immune system development.

332 Young Scholar Presentation: regulation of immune signaling by extracellular vesicles

Abstract Exosomes and other extracellular vesicles traffic a variety of protein and nucleic acid cargo throughout the body. Immune cells especially utilize these vesicles for communication, and they are being studied in clinical settings for their potential to act as disease markers, but also to serve as drug delivery systems. In animal science, a large part of the research around exosomes has centered around their presence in milk, as well as their bioavailability and potential impact for the neonate and for humans; milk-derived exosomes are enriched with immune-related proteins and microRNA that may relate to maternal health, mammary function, or neonate development. We sequenced miRNA isolated from colostrum of dairy cows predicted to feature either moderate or high degree of immune suppression, but found minimal differences (2 differentially expressed miRNA of 343 miRNA analyzed) between the two groups. Immune suppression exhibited during early lactation may also be related to altered exosome-mediated communication between immune cells. We studied the ability of bovine exosomes to alter immune responses of primary bovine monocyte-derived macrophages and found that exosomes alone or in combination with LPS were able to stimulate cytokine production to a greater extent than LPS alone. The ability of exosomes to transport cytokine, bioactive lipid, and regulatory RNA cargo suggests potential involvement in transition cow health. Altered exosome content and function have been associated with uterine infection, mastitis, and metabolic dysfunction; future studies with exosome signaling may help clarify the complexities of transition cow immune function and point to strategies to support immunity.

Application of transmission infrared spectroscopy and partial least squares regression to predict immunoglobulin G concentration in dairy and beef cow colostrum.

The objective of this study was to explore the potential of transmission infrared (TIR) spectroscopy in combination with partial least squares regression (PLSR) for quantification of dairy and beef cow colostral immunoglobulin G (IgG) concentration and assessment of colostrum quality. A total of 430 colostrum samples were collected from dairy (n = 235) and beef (n = 195) cows and tested by a radial immunodiffusion (RID) assay and TIR spectroscopy. Colostral IgG concentrations obtained by the RID assay were linked to the preprocessed spectra and divided into combined and prediction data sets. Three PLSR calibration models were built: one for the dairy cow colostrum only, the second for beef cow colostrum only, and the third for the merged dairy and beef cow colostrum. The predictive performance of each model was evaluated separately using the independent prediction data set. The Pearson correlation coefficients between IgG concentrations as determined by the TIR-based assay and the RID assay were 0.84 for dairy cow colostrum, 0.88 for beef cow colostrum, and 0.92 for the merged set of dairy and beef cow colostrum. The average of the differences between colostral IgG concentrations obtained by the RID- and TIR-based assays were -3.5, 2.7, and 1.4 g/L for dairy, beef, and merged colostrum samples, respectively. Further, the average relative error of the colostral IgG predicted by the TIR spectroscopy from the RID assay was 5% for dairy cow, 1.2% for beef cow, and 0.8% for the merged data set. The average intra-assay CV% of the IgG concentration predicted by the TIR-based method were 3.2%, 2.5%, and 6.9% for dairy cow, beef cow, and merged data set, respectively.The utility of TIR method for assessment of colostrum quality was evaluated using the entire data set and showed that TIR spectroscopy accurately identified the quality status of 91% of dairy cow colostrum, 95% of beef cow colostrum, and 89% and 93% of the merged dairy and beef cow colostrum samples, respectively. The results showed that TIR spectroscopy demonstrates potential as a simple, rapid, and cost-efficient method for use as an estimate of IgG concentration in dairy and beef cow colostrum samples and assessment of colostrum quality. The results also showed that merging the dairy and beef cow colostrum sample data sets improved the predictive ability of the TIR spectroscopy.

Mannan oligosaccharide prepartum supplementation: effects on dairy cow colostrum quality and quantity

Providing the neonatal calf with a sufficient quantity and quality of colostrum may optimise future health, performance and reduce the risk of morbidity. A 6-month double blind trial with 80 prepartum dairy cows was conducted to determine if supplementation with mannan oligosaccharide (MOS) influences colostrum quality, quantity and subsequent calf performance. The Holstein cross Friesian 80 cows (no heifers) were allocated into a control and treatment group at the point of drying off by previous lactation number and yield. The control and treatment group were fed the same commercial standard dry cow diet throughout the trial supplemented with a mineral concentrate without or with 1.33% MOS, respectively. Cows were milked out of colostrum within 40 min of calving prior to calf suckling, weight was recorded. Mannan oligosaccharide fed cows produced significantly more colostrum on first milking (7.5 kg, SEM±0.69) compared with cows fed without MOS (5.6 kg, SEM±0.43). The immunoglobulin G (IgG) concentrations (control 53.7 IgG g/l, SEM±5.8 and MOS of 42.7 IgG g/l, SEM±4.9) and total mass of IgG did not differ between treatments. No significant observable MOS-derived effect on calf health or weight gain occurred during the study.

Quarter variation and correlations of colostrum albumin, immunoglobulin G1 and G2 in dairy cows.

A high variation in immunoglobulin G1 (IgG1) concentration in first milked quarter colostrum has been reported, but BSA quarter colostrum variation is not known. The occurrence of serum albumin in milk has been attributed to increased blood-milk barrier penetration. Reports of serum albumin binding to the Fc Receptor of the neonate, the receptor thought to be responsible for IgG1 transcytosis, suggested that a correlation with the appearance of IgG1 in colostrum of dairy cows was likely. The objective of the study was to establish the quarter colostrum concentration and mass of immunoglobulins and serum albumin. First colostrum was quarter collected within 4 h of parturition from healthy udders of 31 multiparous dairy cows. Individual quarter colostrum weight was determined and a sample of each was frozen for subsequent analysis. Concentrations of immunoglobulin G1, G2, and BSA were measured by ELISA and total mass of components was calculated. In addition, colostrum was also analysed for L-lactate dehydrogenase activity. Analysis of concentration and mass of BSA, immunoglobulin G1, G2 established that the quarter variations were different by cow, quarter and quarter within cow. Partial correlations corrected for colostrum weight indicated that BSA and IgG2 concentration and mass are closely correlated while that of BSA and IgG1 concentration and mass exhibited no correlation suggesting that BSA and IgG1 may have different transport mechanisms. Interestingly, immunoglobulin G1 and G2 concentration and mass exhibited strong correlations suggesting that also some unknown mechanism of immunoglobulin G2 appearance in colostrum is occurring. Finally, no measured protein exhibited any correlation with the activity of lactate dehydrogenase in colostrum.

IgG1 variations in the colostrum of Holstein dairy cows

High-immune quality colostrum (IgG1 concentration ⩾50 g/l) is crucial for the health and development of the young calf. Studies on colostrum quality tend to focus on external factors such as breed, parity or dry period length, but few have focused on within-cow variations. Here we ran experiments to gain a deeper insight into within-cow variation in IgG1 concentrations in dairy cow colostrum. Trials were performed in an experimental farm, located in the Western part of France. Colostrum from each quarter and a composite sample (mix of four quarters) were concomitantly collected on 77 Holstein dairy cows just after calving to assess the influence of sample type on IgG1 concentrations. Variation in IgG1 concentrations during the first milking was studied on samples from nine cows collected every minute from the start of milking. Repeatability of colostral IgG1 concentration was estimated from 2009 and 2010 data on 16 healthy cows. IgG1 concentrations were tested using a radial immunodiffusion method. Sensitivity and specificity were similar regardless of sample type tested (individual quarter or composite milk). Mean average IgG1 concentration was 54.1 g/l in composite colostrum, and was significantly higher in hind quarter teats (56.2 g/l) than front quarter teats (53.1 g/l). Average IgG1 concentration did not change significantly during colostrum milking, and the variations observed (15% or less) were likely due to the laboratory method (CV 15%). IgG1 concentrations in dam colostrum increased slightly from 2009 to 2010 due to BW and parity effects. In 56% of cases, colostrum quality could have been assessed on either individual or composite colostrum samples collected at any time during the first milking without affecting the reliability of the measurement. However, in other cases, differences were significant enough to mean that estimates of average IgG1 concentration in colostrum from any one quarter would not be reliable. It is concluded that colostrum quality, from an IgG1 concentration point of view, could be assessed with a composite sample taken at any time during the first milking.

Colour measurement of colostrum for estimation of colostral IgG and colostrum composition in dairy cows.

Instruments for on-farm determination of colostrum quality such as refractometers and densimeters are increasingly used in dairy farms. The colour of colostrum is also supposed to reflect its quality. A paler or mature milk-like colour is associated with a lower colostrum value in terms of its general composition compared with a more yellowish and darker colour. The objective of this study was to investigate the relationships between colour measurement of colostrum using the CIELAB colour space (CIE L*=from white to black, a*=from red to green, b*=from yellow to blue, chroma value G=visual perceived colourfulness) and its composition. Dairy cow colostrum samples (n=117) obtained at 4·7±1·5h after parturition were analysed for immunoglobulin G (IgG) by ELISA and for fat, protein and lactose by infrared spectroscopy. For colour measurements, a calibrated spectrophotometer was used. At a cut-off value of 50mg IgG/ml, colour measurement had a sensitivity of 50·0%, a specificity of 49·5%, and a negative predictive value of 87·9%. Colostral IgG concentration was not correlated with the chroma value G, but with relative lightness L*. While milk fat content showed a relationship to the parameters L*, a*, b* and G from the colour measurement, milk protein content was not correlated with a*, but with L*, b*, and G. Lactose concentration in colostrum showed only a relationship with b* and G. In conclusion, parameters of the colour measurement showed clear relationships to colostral IgG, fat, protein and lactose concentration in dairy cows. Implementation of colour measuring devices in automatic milking systems and milking parlours might be a potential instrument to access colostrum quality as well as detecting abnormal milk.

Peripartal progesterone and prolactin have little effect on the rapid transport of immunoglobulin G into colostrum of dairy cows

Colostrum formation and lactogenesis in the mammary gland and the timing of parturition are regulated by endocrine signals. Changes in progesterone (P4) and prolactin (PRL) are considered key events that inhibit colostrum formation, trigger parturition, and signal the onset of lactation. The goal of our study was to determine if colostrum yield and composition and immunoglobulin transfer are affected by prepartum milking relative to the decrease in P4, peak of PRL, or occurrence of parturition. Twenty-three multiparous cows were randomly assigned to 1 of 2 groups: (1) control with first milking at 4h postcalving (CON, n=11), and (2) treatment group with first milking approximately 1d before calving and second milking at 4h after parturition (APM, n=12). Colostrum yields were recorded and proportional samples were analyzed for immunoglobulin G (IgG) concentration. Blood plasma samples for the analyses of P4 and PRL were collected 3 times daily at 8-h intervals for 4d prepartum and again taken at 4h after parturition. Total colostrum mass of APM cows was higher than that of CON cows. Immunoglobulin G concentration and protein content did not differ between antepartum milking in APM cows and postpartum milking in CON cows. Colostrum IgG concentration and protein content in APM cows at the postpartum milking were lower compared with the IgG concentration established at the prepartum (APM) and postpartum milkings of CON cows. Immunoglobulin G mass did not differ in first and second colostrum collection in APM cows but was lower compared with that of CON cows. The sum of IgG mass in APM cows (prepartum + postpartum collections) did not differ from that of CON cows. Lactose and fat in milk (concentration and mass) increased from first to second milking in APM cows. Total mass of lactose and fat in APM cows (prepartum + postpartum collections) was greater compared with that of CON cows. The finding that the time of milking relative to parturition, P4 decrease, and PRL peak slightly affected yield and quality of colostrum emphasizes the complex interactions of numerous endocrine and morphological changes occurring during colostrogenesis and lactogenesis in dairy cows. The considerably rapid transfer of immunoglobulins into colostrum of prepartum-milked cows within a few hours leads to the hypothesis that the transfer of IgG can be very fast and—contrary to earlier findings—persist at least until parturition.

AVX-470

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, which is currently treated with injected monoclonal antibodies specific for tumor necrosis factor (TNF). We developed and characterized AVX-470, a novel polyclonal antibody specific for human TNF. We evaluated the oral activity of AVX-470m, a surrogate antibody specific for murine TNF, in several well-accepted mouse models of IBD. AVX-470 and AVX-470m were isolated from the colostrum of dairy cows that had been immunized with TNF. The potency, specificity, and affinity of both AVX-470 and AVX-470m were evaluated in vitro and compared with infliximab. AVX-470m was orally administered to mice either before or after induction of colitis, and activity was measured by endoscopy, histopathology, immunohistochemistry, and quantitative measurement of messenger RNA levels. Colitis was induced using either 2,4,6-trinitrobenzene sulfonate or dextran sodium sulfate. AVX-470 and AVX-470m were shown to be functionally comparable in vitro. Moreover, the specificity, neutralizing potency, and affinity of AVX-470 were comparable with infliximab. Orally administered AVX-470m effectively reduced disease severity in several mouse models of IBD. Activity was comparable with that of oral prednisolone or parenteral etanercept. The antibody penetrated the colonic mucosa and inhibited TNF-driven mucosal inflammation with minimal systemic exposure. AVX-470 is a novel polyclonal anti-TNF antibody with an in vitro activity profile comparable to that of infliximab. Oral administration of a surrogate antibody specific for mouse TNF is effective in treating mouse models of IBD, delivering the anti-TNF to the site of inflammation with minimal systemic exposure.

Factors associated with the concentration of immunoglobulin G in the colostrum of dairy cows

Transfer of sufficient immunoglobulin G (IgG) to the neonatal calf via colostrum is vital to provide the calf with immunological protection and resistance against disease. The objective of the present study was to determine the factors associated with both colostral IgG concentration and colostral weight in Irish dairy cows. Fresh colostrum samples were collected from 704 dairy cows of varying breed and parity from four Irish research farms between January and December 2011; colostral weight was recorded and the IgG concentration was determined using an ELISA method. The mean IgG concentration in the colostrum was 112 g/l (s.d. = 51 g/l) and ranged from 13 to 256 g/l. In total, 96% of the samples in this study contained >50 g/l IgG, which is considered to be indicative of high-quality colostrum. Mean colostral weight was 6.7 kg (s.d. = 3.6 kg) with a range of 0.1 to 24 kg. Factors associated with both colostral IgG concentration and colostral weight were determined using a fixed effects multiple regression model. Parity, time interval from calving to next milking, month of calving, colostral weight and herd were all independently associated with IgG concentration. IgG concentration decreased (P < 0.01) by 1.7 (s.e. = 0.6) g/l per kg increase in the colostral weight. Older parity cows, cows that had a shorter time interval from calving to milking, and cows that calved earlier in spring or in the autumn produced colostrum with higher IgG concentration. Parity (P < 0.001), time interval from calving to milking (P < 0.01), weight of the calf at birth (P < 0.05), colostral IgG concentration (P < 0.01) and herd were all independently associated with colostral weight at the first milking. Younger parity cows, cows milked earlier post-calving, and cows with lighter calves produced less colostrum. In general, colostrum quality of cows in this study was higher than in many previous studies; possible reasons include use of a relatively low-yielding cow type that produces low weight of colostrum, short calving to colostrum collection interval and grass-based nutritional management. The results of this study indicate that colostral IgG concentration can be maximised by reducing the time interval between calving and collection of colostrum.

Effects of prepartum supplementary fat and muscle hypertrophy genotype on cold tolerance in newborn calves.

Effects of feeding pregnant dams supplemental dietary fat during the last 55 d of gestation on cold tolerance of newborn crossbred calves with (Piedmontese cross, P, n = 15) or without (Hereford cross, H, n = 16) the muscle hypertrophy allele was determined. Primiparous F1 dams gestating F2 calves of the respective breeds were assigned randomly within breed to receive gestation diets containing either 2.2 (Low Fat; LF) or 5.1% fat (High Fat; HF). Safflower (Carthamus tinctorius L.) seeds containing 37% oil with 79% linoleic acid were the supplemental fat source in diets formulated to be isocaloric-isonitrogenous. At parturition, calves were separated from their dams, fed 38 degrees C pooled dairy cow colostrum (30 mL/kg BW), muzzled to prevent suckling, and returned to their dams in a heated (22 degrees C) room for 3.5 h. At 4 h of age (birth = 0 h), a catheter was inserted into the jugular vein. At 5 h of age, calves were placed in a 0 degrees C room for 140 min, and rectal temperatures and blood samples were obtained at 10- and 20-min intervals. Blood was assayed for cortisol and glucose. Rectal temperature was affected by diet (P<.05), time, diet x time, and breed x time (P<.01 for time and the interactions). Cortisol and glucose concentrations were not affected by diet, breed, or the diet x breed interaction, but they were affected by time, breed x time (both P<.01), and diet x time (P = .06). Calves from HF dams had higher rectal temperatures than calves from LF dams, and the HF calves maintained higher rectal temperatures throughout cold exposure. Cortisol concentrations were lower (P = .06) in calves from HF dams, and these calves had more (P = .06) glucose available for metabolic heat production than calves from LF dams. Piedmontese-cross calves maintained higher (P<.01) rectal temperatures and had higher cortisol and glucose (both P<.01) concentrations than did H-cross calves. We conclude that feeding dams supplemental fat during late gestation increased heat production in newborn calves and potentially could increase calf survival; calves with muscle hypertrophy may have a different ratio of shivering vs nonshivering thermogenesis due to differences in body composition or relationships among uncoupling proteins.

乳牛の初乳中ミネラル含量の分娩後5日間における変動

乳牛の初乳中ミネラル含量の分娩後5日間における変動