Health Of Neonatal Calves Research Articles

Identification of the glycopeptide epitope recognized by a protective Cryptosporidium monoclonal antibody.

Cryptosporidium species are a leading cause of pediatric diarrheal disease and death in low- and middle-income countries and pose a particular threat to immunocompromised individuals. As a zoonotic pathogen, Cryptosporidium can have devastating effects on the health of neonatal calves. Despite its impact on human and animal health, consistently effective drug treatments for cryptosporidiosis are lacking and no vaccine is available. We previously showed that C. parvum mucin-like glycoproteins, gp40, and gp900 express an epitope identified by a monoclonal antibody 4E9. 4E9 neutralized C. parvum infection in vitro as did glycan-binding proteins specific for the Tn antigen (GalNAc-α1-S/T). Here, we show that 4E9 ameliorates disease in vivo in a calf challenge model. The 4E9 epitope is present on C. hominis in addition to C. parvum gp40 and gp900 and localizes to the plasma membrane and dense granules of invasive and intracellular stages. To characterize the epitope recognized by 4E9, we probed a glycan array containing over 500 defined glycans together with a custom-made glycopeptide microarray containing glycopeptides from native mucins or C. parvum gp40 and gp15. 4E9 exhibited no binding to the glycan array but bound strongly to glycopeptides from native mucins or gp40 on the glycopeptide array, suggesting that the antibody epitope contains both peptide and glycan moieties. 4E9 only recognized glycopeptides with adjacent S or T residues in the motif S*/T*-X-S*/T* where X = 0 or 1. These data define the 4E9 epitope and have implications for the inclusion of the epitope in the development of vaccines or other immune-based therapies.

Evaluation of hemogram parameters in neonatal diarrhoeic calves with and without gastrointestinal protozoa infections

Objective: The aim of this study was to compare the hemogram analysis results of neonatal diarrheal calves with and without gastrointestinal protozoa infection.
 Materials and Methods: A total of 21 neonatal calves with diarrhoea were examined within the scope of the study. A total of 21 neonatal calves with diarrhoea were examined within the scope of the study. Eleven of the cases were calves with gastrointestinal protozoa infection and 10 were calves without gastrointestinal protozoa infection. Demographic, clinical, and laboratory data of calves were evaluated.
 Results: When demographic data and vital signs were evaluated between the two groups, no statistically significant difference was found between the two groups (p>0.05). However, when the hemogram values between the two groups were compared, it was determined that there was a significant difference in white blood cell (p=0.003) and neutrophil (p=0.01) numbers.
 Conclusions: Evaluating hemogram parameters should be taken into account as it is an inexpensive and easy-to-apply analysis and offers important outputs in the control and follow-up of neonatal calf health especially in neonatal calf diarrhoea cases which is one of the common diseases.

Bioactive supplements influencing bovine in vitro embryo development.

Ovum pickup and in vitro production (IVP) of bovine embryos are replacing traditional multiple ovulation embryo transfer (MOET) as the primary means for generating transferable embryos from genetically elite sires and dams. However, inefficiencies in the IVP process limit the opportunities to produce large numbers of transferable embryos. Also, the post-transfer competency of IVP embryos is inferior to embryos produced by artificial insemination or MOET. Numerous maternal, paternal, embryonic, and culture-related factors can have adverse effects on IVP success. This review will explore the various efforts made on describing how IVP embryo development and post-transfer competency may be improved by supplementing hormones, growth factors, cytokines, steroids and other bioactive factors found in the oviduct and uterus during early pregnancy. More than 40 of these factors, collectively termed as embryokines, are reviewed here. Several embryokines contain abilities to promote embryo development, including improving embryo survivability, improving blastomere cell numbers, and altering the distribution of blastomere cell types in blastocysts. A select few embryokines also can benefit pregnancy retention after IVP embryo transfer and improve neonatal calf health and performance, although very few embryokine-supplemented embryo transfer studies have been completed. Also, supplementing several embryokines at the same time holds promise for improving IVP embryo development and competency. However, more work is needed to explore the post-transfer consequences of adding these putative embryokines for any adverse outcomes, such as large offspring syndrome and poor postnatal health, and to specify the specific embryokine combinations that will best represent the ideal conditions found in the oviduct and uterus.

Temporal kinetics of bovine mammary IgG secretion into colostrum and transition milk.

Neonatal calf survival and health is predominantly dependent on sufficient consumption of immunoglobulin G (IgG) and the resulting transfer of passive immunity (TPI). In this study, we investigate the potential for continued IgG secretion and temporal kinetics of mammary IgG output in sequential milkings performed at 0, 4, 16, 28, 40, and 52 hr postcalving in Holstein dairy cows. For colostrum (0 hr), we also scrutinize the relationships between IgG concentration, volume, refractometer readings (˚Bx values, Brix) and concentration of sugars (lactose and glucose). Mammary transcripts postpartum (0 hr) indicated that active IgG secretion continues beyond the first milking (colostrum; n = 4 to 5). IgG measurements at the different timepoints indicated that colostrum represents only 25.1% of the total IgG produced across the 6 sequential milking timepoints, with a substantial 48.9% being secreted into transition milk over the next 3 timepoints (4-, 6-, and 28-hr) combined. The differences on the basis of IgG concentrations across 0-, 4-, and 16-hr milking timepoints were not statistically significant (P = 0.1522; n = 9). For colostrum, volume remained highly variable, even with induced let-down prior to milking (n = 27). Nonetheless, colostrum IgG secretion was significantly co-regulated with volume (R2 = 0.915; P < 0.001; n = 18), an association that was stronger than that measured for lactose (R2 = 0.803; P < 0.001; n = 18) and glucose (R2 = 0.467; P = 0.002; n = 17). Comparing colostrum ˚Bx values to absolute IgG concentrations showed no correlation (R2 = 0.127; P = 0.07; n = 27); biochemical separation of colostrum components indicated that both proteins and nonprotein solutes could affect ˚Bx values (P < 0.0001 for both; n = 5). This suggests that ˚Bx values do not reasonably indicate IgG concentration to serve as a measure of "colostrum quality." Additionally, our finding that early transition milk (4-, 6-, and 28-hr) can contribute substantially more IgG than colostrum forces a rethink of existing feeding paradigms and means to maximize TPI in calves. Collectively, our results reveal the remarkable value of early transition milk and caveats to colostrum assessments that could advance application in enhancing neonatal calf health.

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

BackgroundThe milk fat globule membrane (MFGM) proteomes of colostrum and transition milk are rich sources of proteins that are likely important for neonatal calf health. In addition, characterization of these proteomes could also yield valuable information regarding mammary gland physiology of the early postpartum lactating cow. The objectives of this research were to characterize the MFGM proteomes of colostrum and transition milk through sample collections at four timepoints postpartum, including the first milking (M1, colostrum), second milking (M2, transition milk), fourth milking (M4, transition milk), and fourteenth milking (M14, mature milk), and compare these proteomes between multiparous (MP; n = 10) and primiparous (PP; n = 10) Holstein dairy cows. Isolated MFGM proteins were labeled using Tandem Mass tagging and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein identification was completed using MASCOT and Sequest in Proteome Discoverer 2.2. The scaled abundance values were analyzed using PROC MIXED in SAS to determine the effects of milking (MIL), parity (PAR), and MIL × PAR. The adaptive false-discovery rate (FDR)-adjusted P values were determined using PROC MULTTEST. Protein characterization and bioinformatic analysis were completed using a combination of PANTHER, Blast, and Uniprot.ResultsA total of 104 common proteins were identified in each of the MFGM samples. Statistical analysis revealed that 70.2% of identified proteins were affected by MIL. Of these, 78.1% were lower in M14 compared with M1, including immune-related proteins lactotransferrin, lactadherin and hemopexin. Parity affected 44.2% of proteins. Of the proteins affected by PAR, 84.8% were higher in MP cows compared with PP cows, including apolipoprotein E and histones 2A, 2B, 3, and 4 b. Butyrophilin subfamily 1 member 1A and annexin 5 were higher in samples from PP cows. Milking × parity affected 32.7% of identified proteins, including lactotransferrin, gelsolin, vitamin D binding protein, and S100 proteins.ConclusionsThis research supports previous findings that the Holstein MFGM proteome changes rapidly during the first week of lactation. In addition, this research identifies the impact of parity on the colostrum and transition milk MFGM proteomes, which may be important for milk-fed calf health or for the identification of protein biomarkers for mammary functionality.

Relation between non-infectious factors and neonatal calf health status in dairy herd.

The aim of this research was to determine some non-infectious factors (sex of calf, calf birth weight, calving season and dam parity and dam body condition score at dry and calving) that can under control by breeders affecting calf health status (CHS) in neonatal period. A total of 517 calves (from delivery of calf until 28days) and their dams (at dry and calving) were assessed according to study criteria. Relationship between CHS and dam parity (DP), body condition score at calving (BCSC ), body condition score at dry (BCSD ), sex of calf (SC), calf birth weight (CBW), and calving season (CS) was examined and connection between CHS and BCSD , CS, and CBW was found important. Also, influences of DP, SC BCSC , and BCSD on CBW were examined and while effects of DP and SC on CBW were found important, effects of others were not. These results show that relation between CHS and CBW, CS, and BCSD is important and CHS is higher in female calves or calves born to multiparous dams. As a conclusion, it can be said that planning the herd management practices according to these results will be beneficial for the healthier completion of the neonatal period.

Effect of feeding heat-treated and unheated colostrum on immunoglobulin G absorption, health and performance of neonatal Holstein dairy calves

First colostrum is an important source of nutrients and immune factors which are necessary for calves in the first weeks of life. Despite these benefits, colostrum can also represent one of the earliest potential exposures of dairy calves to infectious agents which these patogens can act directly on growth and cause diseases such as scours or septicemia. With recent increased interest in pasteurized milk feeding systems, producers have been curious to learn if there may also be benefits from feeding pasteurized colostrum. This study was realized to determine the effects of feeding heat-treated colostrum or unheated colostrum on passive transfer of immunity, immunoglobulin G (IgG) concentration, total plate count, health and performance of neonatal dairy calves. First-milking colostrum was collected from Holstein cows and frozen at -20°C to accumulate a large batch. Pooled batches of colostrum were mixed and divided equally: One half was fed unheated colostrum; whereas the other half was fed after heat treatment at 60°C for 30 min. Forty newborn male Holstein dairy calves were fed either unheated (n = 20) and heat-treated colostrum (n = 20), 10% of their birth weight. Calves received 4 L within 1 to 2h after birth and residuals was fed 6h after birth. Serum samples collected from calves and were assayed for serum total protein (STP) and IgG. Feed intake recorded weekly and body weight and skeletal growth measures recorded at d 3 and d 63 (weaning). Every day, calves clinically diagnosed either as being healthy or suffering from respiratory disease and neonatal calf diarrhea. Heat-treated colostrum resulted in lower colostrum bacterial concentration (2.01 vs. 3.96 cfu mL-1). Calves fed heat treated colostrum had greater STP in 24, 72h and 23d, IgG concentrations at 24 and 72h plus unheated colostrum. Also weaning weight and average daily gain were greater in calves feed heated colostrum. There were no differences in starter intake and feed efficiency between two groups. Calves fed heat-treated colostrum had lower fecal scores, diarrhea and pneumonia incidence. There were not differences in skeletal growth measurements except body barrel. These results shows that feeding heated colostrum can provide better growth and health in neonatal calves.

Establishing blood gas ranges in healthy bovine neonates differentiated by age, sex, and breed type

Calf mortality and morbidity commonly occurs within the first month of life postpartum. Standard health ranges are invaluable aids in diagnostic veterinary medicine to confirm normal or the degree and nature of abnormal parameters in (sub)clinically ill animals. Extensive research has indicated significant differences between the physiologies of neonate and adult cattle, particularly for blood parameters such as pH, base excess, anion gap, and bicarbonate (HCO3-). The objective of this research was to determine the influence of age, sex, and breed type, in addition to environmental factors, on the normal blood gas profiles of neonatal calves, and thus develop a scientifically validated reference range accounting for any significant factors. The study was conducted on healthy neonatal calves (n = 288), and completed over a 2-yr period. Individual calf blood gas analysis was conducted for parameters of pH, base excess, Na+, K+, Ca2+, Cl-, glucose, total hemoglobin, HCO3-, pCO2, anion gap, strong ion difference, and hematocrit levels. Regression procedures examined the combined effect of year, farm, age, breed type, sex, and hours postfeeding on each variable. Significant effects were observed for age, sex, and breed type on several of the blood gas variables. Furthermore, year, farm, and hours postfeeding appeared to have less of an influence on neonatal bovine blood gas profiles. Consequently, specific ranges based on the neonate's age, sex, and breed type will allow for more detailed and accurate diagnosis of health and ill health in neonatal calves.

Colostrum and milk protein rankings and ratios of importance to neonatal calf health using a proteomics approach

Administration of colostrum to the newborn calf before gut closure is pivotal to its health, because of the transfer of passive immunity. Traditionally, passive immunity has been attributed to the transfer of immunoglobulins although it is increasingly clear that multiple other factors contribute, including innate immune proteins, developmental factors, immunomodulatory factors, and the presence of cellular immunity. The objective of this study was to produce a comprehensive comparison of the bovine colostrum proteome and the milk proteome by applying 2-dimensional liquid chromatography-tandem mass spectrometry. Further, the objectives were to rank proteins mutually and generate protein ratios from the spectral counts of the 2 proteomes and ELISA to gain insight into which proteins could be of most relevance to neonatal calf health. To obtain an in-depth picture of the bovine colostrum and milk proteome, we compared the contents of different fractions from bovine colostrum and milk from our 2 previous studies. A total of 140 colostrum fluid-phase proteins and 103 milk fluid-phase proteins were detected. In the cellular fraction, 324 and 310 proteins were detected in colostrum and milk, respectively. In total, 514 proteins were detected, of which 162 were in the fluid phase. Of these, 50 proteins were exclusively seen in colostrum, 13 were exclusively seen in milk, and 99 were common to colostrum and milk. Ranking of proteins mutually and calculating protein ratios based on spectral counts and ELISA resulted in new information on how proteins were associated with the fluid or cellular fraction of the samples. Interestingly, despite lower counts/concentrations than the classical proteins such as immunoglobulins, β-lactoglobulin, and lactotransferrin, several proteins appeared in higher or similar colostrum:milk spectral count ratios as these. Using this approach indicated, for example, that osteopontin, haptoglobin, milk amyloid A, and gelsolin may be interesting molecules to study in detail in their relation to calf health. Although the sensitivity, identification, and ranking of proteins varied between the 2 methods, and proteome analysis clearly suffers from low sensitivity, we believe that this idea and approach of generating ratios and ranking proteins can contribute new information and perspectives on how to prioritize the importance of multiple proteins, beyond immunoglobulins, in relation to neonatal calf health.

The effect of cow-level factors on colostrum quality, passive immunity and health of neonatal calves in a pasture-based dairy operation

A study of 95 cows (19 primiparous and 76 multiparous) and their offspring was performed on a pasture-based dairy in the coastal region of South Africa. Collected data included weight changes during the dry period, colostrum immunoglobulin G (IgG) and calf serum IgG at 24–48 h after birth. Colostrum and serum IgG concentrations were measured using radial immunodiffusion and colostrum was regarded as having adequate IgG concentration if the amount was ≥50 g/L. Calf serum IgG concentration of ≥10 g/L was considered an adequate transfer of passive immunity. The median (range in parentheses) colostrum quality for cows with weight loss during the dry period was 23.1 g/L (9.0, 108.1) compared with 61.9 g/L (10.9, 200.0) in cows without weight loss. The median serum IgG of calves from cows with weight loss was 9.9 g/L (0.5, 44.6) compared with 14.0 g/L (0.5, 76.3) in calves from cows that did not lose weight during the dry period. Cows experiencing weight loss were four times more likely to have colostrum with lower concentrations of IgG (OR = 0.25; 95% CI, 0.07–0.88; P = 0.030). Lactation number was also significantly associated with colostrum IgG concentration (P &lt; 0.001), with younger cows tending to have higher IgG concentrations. Failure of passive transfer did not have a significant effect on any calf-health or production variables measured in the study. The effect of dry-cow feeding on colostrum IgG concentration is poorly understood and inadequate pasture management could have an impact on colostrum quality in pasture-based dairy herds.

Effect of colostrum heat treatment and bacterial population on immunoglobulin G absorption and health of neonatal calves

Improved IgG absorption in calves fed heat-treated colostrum has been attributed to the reduced bacteria content in colostrum after heat treatment. However, at least one study reported that colostrum bacteria content did not affect IgG absorption. The main objective of the current study was a more conclusive test of the combined effects of colostrum bacteria content and heat treatment on IgG absorption. Comparison of conclusions from plasma IgG as measured by radial immunodiffusion and ELISA and comparison of health scores in the first week of life were secondary and tertiary objectives. Colostrum from individual cows was pooled, divided, either heat treated or unheated, and allowed to incubate for bacterial growth or not. The 4 treatments were unheated, low bacteria; unheated, high bacteria; heat-treated, low bacteria; and heat-treated, high bacteria. Plasma samples were collected from bull calves (n=25–27 per treatment) before and 48h after colostrum feeding for IgG and total protein analysis. Fecal, respiratory, and general health scores were assigned daily for the first 7 d. Plasma IgG, total protein, apparent efficiency of IgG absorption, and frequency of illness were analyzed using the MIXED and FREQ procedures in SAS (SAS Institute Inc., Cary, NC). Plasma IgG values from ELISA were lower than radial immunodiffusion; however, conclusions were similar. Greater colostrum bacteria content reduced total protein, plasma IgG, and efficiency of IgG absorption. Heat treatment tended to improve 48-h plasma IgG as measured by ELISA. Respiratory scores were not affected by colostrum treatment, but calves fed heat-treated, low-bacteria colostrum tended to experience fewer scour days. These results provide conclusive evidence for the benefits of minimizing bacterial contamination in colostrum for feeding calves.

Calf's sex, parity and the hour of harvest after calving affect colostrum quality of dairy cows grazing under high tropical conditions.

High-quality colostrum is an important factor influencing neonatal calf health, and quality assessment is essential to obtain good health results. This research evaluated the effects of the calf's sex, the parity of the cow and the hour of colostrum harvest after parity on the fat, nonfat solids, protein and Ig contents in Holstein colostrum for cows under high grazing conditions in the tropics. The effects of the calf's sex and parity on somatic cell count (SCC) at the first milking postpartum were determined. A comparison was made between a laboratory method and a farm method for the estimation of the fat and protein content of colostrum. Thirty-three cows were sampled in the study. The calf's sex was shown to have an effect on the amount of colostrum, on the concentration of fat, and on the amount of milk produced by lactating Holstein cows; all were higher in cows that gave birth to a female calf. Colostrum protein decreased after the first hour postpartum, and the Ig concentration had a tendency to decrease after 4h. The cows that had parity 1-2 had lower Ig concentrations and total production of Igs, and higher SCC at the first milking postpartum. Ekomilk was a reliable method to measure the colostrum fat on the farm.

Short communication: Effect of pomegranate-residue supplement on Cryptosporidium parvum oocyst shedding in neonatal calves

Cryptosporidium parvum is considered one of the most common enteropathogens, responsible for the high incidence of diarrhea and deleterious implications on immunity and health in neonatal calves. The pomegranate is well known for its health-promoting properties. Two experiments were designed to test the antiparasitical and antidiarrheal effects of concentrated pomegranate extract (CPE) supplement in milk in neonatal Holstein calves. Forty-one calves were randomly divided into control (n=20) and treatment (n=21) groups. For the first experiment, the treatment group was supplemented with 3.75% CPE in the daily milk ration, between 3 and 14 d of age, whereas the control group received only milk. Fecal samples were collected between d 5 and 13 to quantify Cryptosporidium oocysts, and the duration and intensity of diarrhea were evaluated. Reduced fecal oocyst count and diarrhea intensity and duration were revealed in the 3.75% CPE calves. No difference was noted in average daily gain between groups. In a second experiment, which was designed to test the effect of a lower CPE concentration (0.6% of daily milk allocation), no effects on fecal oocyst count and average daily gain were observed. However, compared with control, the lower CPE group was characterized by a shorter duration of diarrhea and higher weight gain among males at 14 d of age. These results suggest that the CPE supplement-to-calf milk ratio may potentially alleviate intestinal morbidity caused by Cryptosporidium.

Short communication: Serum immunoglobulin G and total protein concentrations in dairy calves fed a colostrum-replacement product

Neonatal calf health is largely dependent on the ingestion and absorption of maternally derived antibodies via colostrum administration. The objective of this study was to evaluate the efficacy of a commercially available plasma-derived colostrum-replacement (CR) product as compared with bovine colostrum. Holstein calves were removed from the dam immediately after birth and randomly allocated to 1 of 3 groups. Group 1 calves (n=22) were fed 1 package of the CR product; group 2 calves (n=22) were fed 2 packages of the CR product; and group 3 calves (n=22) were fed 3L of bovine colostrum. Blood samples were collected from all calves 24h after colostrum or CR feeding and analyzed for serum IgG and total protein concentrations. Calves fed bovine colostrum had significantly higher serum IgG and total protein concentration than calves in either group fed the CR product. Group 1 calves (1 package of CR product) had a significantly higher incidence of failure of transfer of passive immunity than calves in groups 2 or 3. The results of this study indicated that 2 packages of this CR product achieved adequate IgG concentrations in calves. However, calves fed 1 package of this CR product consistently had failure of transfer of passive immunity.

An evaluation of Brix refractometry instruments for measurement of colostrum quality in dairy cattle

Acquisition of high quality colostrum is an important factor influencing neonatal calf health. Many methods have been used to assess the Ig concentration of colostrum; however, improved, validated evaluation tools are needed. The aims of this study were to evaluate both optical and digital Brix refractometer instruments for the measurement of Ig concentration of colostrum as compared with the gold standard radial immunodiffusion assay laboratory assessment and to determine the correlation between Ig measurements taken from fresh and frozen colostrum samples for both Brix refractometer instruments. This research was completed using 288 colostrum samples from 3 different farms. It was concluded that the optical and digital Brix refractometers were highly correlated for both fresh and frozen samples (r=0.98 and r=0.97, respectively). Correlation between both refractometer instruments for fresh and frozen samples and the gold standard radial immunodiffusion assay were determined to be very similar, with a correlation coefficient between 0.71 and 0.74. Both instruments exhibited excellent test characteristics, indicating an appropriate cut-off point of 22% Brix score for the identification of good quality colostrum.

Dairy farming in Kars district, Turkey: III. Neonatal calf health

The study was designed to determine the health status of neonatal calves on dairy farms in Kars district. It involved retrospective questioning (2001 calving season) and prospective follow up (2002 calving season). The localities and farms were selected from a list using a 2-stage stratified random sampling method. Farms were weekly visited by authors during the 2002 calving season for clinical problems. A total of 624 calves, born on 45 farms from 7 different localities, were followed up in the 2002 calving season. On the same farms data were collected regarding 582 neonatal calves in the 2001 calving season by questionnaire. The overall morbidity in 2002 and 2001 was 51.1% and 36.3%, respectively. The morbidity of diarrhoea, omphalitis, pneumonia, premature birth, omphalitis-enteritis complex, and pneumonia-enteritis complex were 24.4%, 13%, 3.4%, 2.4%, 2.4%, and 1% in 2002, and 17.4%, 1.4%, 6.2%, 0%, 2.7%, and 6% in the 2001 calving season, respectively. Clinical problems of trauma, umbilical hernia, complicated hernia, and an unknown reason were also diagnosed at low proportion. The overall mortality determined in 2001 and 2002 was 10.5% and 6.7%, respectively. The most common causes of mortality were diarrhoea (2.2%), premature birth (2.1%), and trauma (0.8%) in 2002 while diarrhoea (7.7%), pneumonia (0.7%), and Foot and Mouth Disease (1.4%) were most common in 2001. Additionally, deaths due to pneumonia, omphalitis, congenital deformation, and an unknown reason were also experienced. Age distribution of cases revealed that diarrhoea and omphalitis were common in the first 2 weeks of life while pneumonia was more frequent in the 4th week of neonatal life. A positive association between group size and disease existence was determined. Of the cases examined, 12.9% (12/93) had the failure of passive transfer while all controls had adequate colostrums (0/45). The study revealed that a considerable proportion of calves suffer from at least 1 clinical problem during neonatal life and around 1 in tenth die, resulting in detrimental effects on farm profitability.

Feasibility of the Concept of Orally Administered Electronic Boluses for Identification of Cattle

The European Community Directive 92/102 requires all member countries to be able to operate a national identity scheme for cattle, sheep, pigs and goats with brief details kept in a central register. An identification device must be accurate, dependable and tamperproof. At the same time, it has to safeguard the welfare of the animal. The present study was performed to examine the effects of electronic boluses for animal identification on the health of neonatal calves. Electronic boluses for animal identification (electronic bolus, NEDAP AGRI, Groenlo, the Netherlands) were administered into the ruminoreticular compartment of 5 neonatal calves aged from 3 to 5 days with a bodyweight from 36 to 42 kg, which were purchased from a local dealer. An applicator was used which allowed insertion of the boluses directly into the reticulorumen. In order to examine possible effects of these boluses on the health of the calves, the animals were closely monitored during a period of 3 months by a) general clinical examination and b) analyses of various blood parameters at regular intervals. Five additional calves, which received no bolus, served as controls. Once weekly the following blood parameters were determined: PCV, RBC, WBC and differentials, serum total protein and protein pattern, urea, Na, K and Cl. No diseases occurred that were directly related to the presence of the bolus in the gastrointestinal tract (e.g. esophageal obstruction, obstruction of the pylorus) during a period of 3 months. The number of episodes of diarrhea or bronchopneumonia in the group fitted with boluses did not differ from untreated controls. Results of laboratory analyses revealed no statistically significant differences in the group fitted with boluses compared to controls. Weight gains in calves with boluses did not differ from controls. X-rays taken at the end of the trial showed that all boluses were sited in the reticulum of the calves. When the boluses were read at an age of 12 months, all boluses were detected. In a second trial, 4 female calves born at the department itself received a bolus transponder at 3 days of age. These animals were monitored by clinical examination once weekly until an age of one year. These calves did not show any disease symptoms and no boluses were lost within one year. Based on findings in 9 calves, which were closely monitored, there was no evidence for bolus associated effects on the general health. Under the precaution that no force is used the applicator specifically developed for intraruminal administration of boluses is suitable for use.

Effect of pasteurization at 76 and 63 degrees C on the absorption of colostral IgG in calves.

The timely ingestion and absorption of colostral immunoglobulin is a critical determinant of neonatal calf health. Calves are born without appreciable concentrations of the serum immunoglobulins needed to protect against pathogenic bacteria, viruses and protozoa (Tyler &amp; Parish, 1995). The beneficial effect of passive transfer of colostral immunoglobulin also extends beyond the neonatal period and persists into juvenile and adult life (Robison et al. 1988; Tyler et al. 1998; DeNise et al. 1989). Calves with failure of passive transfer, defined as serum protein &lt; 50 g/l or serum IgG &lt; 10 g/l, have increased mortality risks that persist until 10 weeks of age (Tyler et al. 1998).Several diseases are potentially spread by the ingestion of colostrum, including bovine leukosis and Johne's disease (Perrin &amp; Polack, 1988; Streeter et al. 1995). In one study 22% of latently infected cows were demonstrated to shed Mycobacterium paratuberculosis in their colostrum (Streeter et al. 1995). Optimal programmes to prevent and eradicate these diseases generally include the provision that calves are given colostrum derived from cows of known negative disease status. Pasteurization or heat treatment of colostrum may provide a mechanism whereby calves are provided with protection against neonatal disease without creating undue potential for infection by chronic, economically relevant diseases.Attempts to heat disinfect colostrum are common in goat herds (MacKenzie et al. 1987). Pasteurization has been demonstrated to be effective against the caprine arthritis–encephalomyelitis virus (Adams et al. 1983; MacKenzie et al. 1987). Although Myco. paratuberculosis appears to resist pasteurization, this form of processing has been demonstrated to decrease the likelihood of positive colostral cultures for Myco. paratuberculosis under experimental conditions (Meylan et al. 1996). Sterilizing the milk and colostrum given to calves is a logical and reasonable strategy to prevent transmission of infectious microorganisms. The potential disadvantage of heat treating colostrum is that the immunoglobulins in colostrum may become denatured (Smith &amp; Sherman, 1994). Pasteurization causes only a slight decrease in the colostral concentration of IgG in cattle (Meylan et al. 1996); however, the biological behaviour of these pasteurized immunoglobulins has not been critically examined. Therefore, we cannot be completely confident that immunoglobulin absorption, persistence in serum and biological activity are unchanged by this processing.The goal of this study was to determine the effect of pasteurization at 76 and 63 °C on the absorption of IgG from colostrum. Should these procedures decrease immunoglobulin absorption, the use of pasteurization in disease eradication programmes would require increased efforts to optimize the passive transfer of immunoglobulin.

Effect of a commercially available nonspecific immunomodulating biologic product on health of neonatal calves

Objective To determine whether treatment with a commercially available nonspecific immunomodulating biologic product would alter the clinical course of disease in neonatal calves. Design Systematically randomized, controlled cohort study. Animals 200 Holstein bull calves 1 to 5 days old. Procedure Assessments were performed that included evaluation of fecal consistency, attitude, appetite, and hydration status. Calves with abnormal results were enrolled in the study. Calves were systematically assigned to control or treatment groups (100 calves/group). Calves in the treatment group were given a single IV injection of the biologic product at the time of enrollment, whereas control calves were not given the product. Calves were assessed daily for 5 days to evaluate fecal consistency, attitude, appetite, hydration status, and rectal temperature. Assessments were made without knowledge of group assignment. Results Treatment with the immunomodulating product was not associated with a decrease in the number of calves that had moderate or severe departures from clinically normal conditions for attitude, appetite, or hydration on days 1 though 5, compared with control calves. Fecal consistency scores were significantly greater for treated calves on days 1 (P = 0.03) and 5 (P = 0.02), compared with scores for control calves. Clinical Implications Administration of the nonspecific immunomodulating biologic product did not significantly affect outcome of clinical disease for calves in the treated group, compared with calves in the control group. On the basis of results of this study, we cannot recommend use of the nonspecific immunomodulating biologic product for the treatment of undifferentiated diarrheal disease in neonatal calves. (J Am Vet Med Assoc 1998;213:1308-1311)

The effect of colostral immunoglobulin supplement on the passive immunity, growth and health of neonatal calves

Neonatal dairy calves were randomly allotted to three colostrum feeding regimens with increasing intakes of immunoglobulins (Ig) on the first day of life. The control group was fed one litre of pooled colostrum (Ig intake 19.5 g). In two experimental groups, the pooled colostrum was supplemented with 0.5 or 1.5 litres of commercial Ig-concentrate, giving a total Ig intake of 52.7 and 119.0 g, respectively. Serum IgG, IgM and IgA levels increased linearly (p &lt; 0.001) on day 2 post partum with the increasing Ig intake. The calculated mean Ig-absorption rate was 61% and decreased linearly for IgM (p = 0.051) and IgG (p = 0.078) with increasing Ig intake. At the highest Ig intake, serum IgG remained above 10 g/l during 30 days post partum. In the experimental groups, serum IgM and IgA decreased sharply during the first week of life and were relatively constant thereafter. In the control group, however, there was an increase in serum IgM after one week post partum, perhaps due to the in situ production of Ig. With the increasing Ig intake there was a small and non-significant tendency for better live weight gain (p = 0.286) and a lower incidence of diarrhoea (p = 0.421) during the first four weeks of life. It is concluded that the Ig-product tested is well absorbed during 24 hours post partum and it can be used either as a supplement to maternal colostrum when its quality is poor, or as a substitute when colostrum is not available.