Absorption Of Colostral Immunoglobulins Research Articles

Difructose Anhydride and Passive Immunity Effects on Passive Immune Transfer and Performance of Feeding Difructose Anhydride to Neonatal Calves.

The objective of this study was to assess the potential effects of supplementing difructose anyhdride III (DFAIII) during the first days of life on the absorption of immunoglobulin G (IgG) and growth performance of calves early in life fed colostrum with a high IgG concentration. Sixty-six healthy new-born Holstein calves were randomly assigned to three treatments consisting of no supplementation (control), supplementation of 12 g/d (DFA12), or 36 g/d (DFA36) of DFAIII during the first 7 d of life via colostrum and milk replacer (MR). Calves were separated from dams at birth and bottle-fed colostrum in two meals, each targeting 2.5 L within the first 18 h of birth. Colostrum had been previously collected from other dams (and preserved frozen) within the first 2 h of calving and had a Brix value ≥32%. Daily consumption of starter concentrate and MR (and colostrum on the first day) were individually monitored. Calves were body weighed using an electronic scale at birth and on a weekly basis thereafter until the end of study at 42 d of age. A sample of colostrum fed to each calf and a blood sample from the jugular vein of the calves were collected at 12 and 24 h of life to determine the IgG concentration. The mean colostrum IgG concentration fed in the current study was 110 ± 33.7 g/L (mean ± SD). No differences in animal performance were found among the treatments. Calves on all treatments consumed the same amount of colostrum with a similar concentration of IgG, and thus the amount of IgG consumed was also similar. Serum IgG concentrations were greater at 24 than at 12 h but did not differ among treatments. However, the apparent efficiency of absorption of colostral immunoglobulins was greater in DFA12 and DFA36 at 12 h of life than in control calves, with no differences observed at 24 h. Even when feeding high-quality colostrum, in terms of IgG concentration, supplementation with difructose anhydride III may pose an additional advantage in promoting the passive transfer of immunoglobulins in neonatal Holstein calves during the first 12 h of life.

Allele mining in gene encoding fc fragment of IgG receptor, transporter, alpha (FCGRT) and association of nucleotide variants with passive transfer of immunity in neonatal buffalo calves.

Neonatal Fc receptors (FcRn) mediate the transcytosis of IgG present in colostrum across absorptive gut epithelium of newborn calves. FcRn receptor is a heterodimer composed of two polypeptides encoded by FCGRT (Fc fragment of IgG Receptor Transporter neonatal) and B2M (Beta 2 microglobulin) genes. Polymorphism in FCGRT gene may have a bearing on absorption of colostral immunoglobulins by neonatal buffalo calves, thereby affecting their immune status and susceptibility to diseases. The primary aim of our study was to mine alleles and single nucleotide polymorphs in the FCGRT gene and determine their association with the levels of IgG in serum of neonatal buffalo calves. On the basis of serum IgG levels estimated by indirect ELISA in 80 newborn calves, 20 calves each with highest and lowest IgG concentration were selected to study polymorphism in the FCGRT gene. The exonic regions of this gene were amplified in nine fragments which were subjected to PCR-SSCP to detect variations followed by the sequencing of variants to locate the SNPs. A total of nine SNPs (7 in introns and 2 in exons) were detected in four polymorphic fragments. Association study based on Odds ratios (ORs) with 95% Confidence Interval (CIs) established that the SNP G40T in fragment 3 has a significant (P < 0.05) bearing on IgG level in serum of neonatal buffalo calves. Genetic variation in FCGRT gene in buffalo calves was found to be associated with their serum IgG levels in neonatal stage which may have implications in calf survival and growth vis-à-vis inadequate transfer of passive immunity.

Absorption of colostral immunoglobulin G by Icelandic dairy calves

Serum samples were taken from 11 Icelandic dairy calves, at birth and 24 hours later, and 11 colostrum samples were taken from their mothers with the concentration of IgG measured by ELISA. The amount of colostrum ingested by each calf was also measured. The results showed that the mean concentration of IgG in cow colostrum at birth was 11.54 mg ml-1. The mean concentration in the serum of calves that had ingested known quantities of colostrum was 8.02 mg ml-1 24 hours postpartum. Both values were lower than described in other cattle breeds. Significant correlation existed between the amount of colostral IgG consumed and serum concentration of IgG in the calves 24 hours postpartum. The mean apparent efficiency of absorption (AEA) was 43%, which is high compared to other studies. Although the study group was small, the results give an indication of the ability of Icelandic calves to absorb colostral IgG.

State of humoral immunity in lactating sows and suckling piglets

The state of humoral immunity in lactating sows and its formation in suckling piglets in the conditions of a pig-breeding complex were studied. In sows after farrow, a high content of total immunoglobulins, the main classes of IgG, IgM and IgA, the concentration of which decreased in a day, followed by an increase in serum as lactation continued was detected in the serum and colostrum. In piglets at birth, the content of total immunoglobulins and the main Ig isotypes was insignificant, and at the age of twenty-four hours, as a result of absorption of colostral immunoglobulins in the small intestine, their amount in the serum was the highest, followed by a decrease in the concentration of IgG and IgA until the end of the suckling period, and IgM - up to day 14 with a further increase in its content, indicating the formation of a primary immune response. It has been detected that the dominant class of immunoglobulins in the serum and colostrum of sows and the serum of piglets is IgG, and in milk - IgA. An increase in the level of medium-dispersed circulating immune complexes (C4%) and their relation to giant (C3%) CICs was revealed, associated with an increase of the antigenic load in sows in the second half of lactation as a result of immunization, in milk - with a decrease in the content of the main classes of immunoglobulins, and in piglets, due to this, with a decrease in passive immunity.

Effect of Parenteral Vaccination of Newborn Holstein Calves against Viral Agents Involved in Bovine Respiratory Disease (BRD)

Background: Newborn calves are born immunosuppressed, hypogammaglobulinemic, immunologically immature, and therefore more vulnerable to many infectious diseases. During pregnancy, the fetal-placental environment is regulated by Th2-type cytokines that neutralize Th1 responses, an important factor for immune defense against viral agents. The ingestion and absorption of colostral immunoglobulins enhance the immunity of the neonate. However, the presence of maternal antibodies might negatively affect the success of parental vaccination in the first two months of life. This study aimed to evaluate the effecacy of parenteral vaccination in newborn calves with high titers of maternal antibodies against respiratory viruses.Materials, Methods &amp; Results: Twenty-eight Holstein calves were allocated to the vaccinated group (VAC, n = 18) or an unvaccinated control group (NVAC, n = 10). The initial vaccination with 5 mL of a commercial vaccine occurred around the 14th day of life (D14) and the booster at D35. Respiratory and diarrhea symptoms were evaluated at D12, D14, D16, D20, D31, D36, D45, D53, and D60. Blood samples were taken for leukogram, haptoglobin, and seroneutralization of BVDV, BoHV-1, BRSV, and BPI3V, at the time of vaccination at D14 (T1), at booster (D35, T2), and 21 days after the booster (D56, T3). Despite the increased prevalence of BRD during the period of the study, no calves from either group exhibited respiratory disease at D12 or D14. In subsequent assessments, the frequency of BRD increased over time in the VAC group until it reached a maximum prevalence of 38.9% (7/18) at D31. In the NVAC group, the maximum prevalence observed was 40% at D45 and D60. A comparison of the frequencies for BRD cases showed a statistical trend at D36 (P = 0.07), with a higher prevalence for the NVAC group (30%) in relation to the VAC group (5.6%). For the NVAC group, a greater number of total leukocytes was observed at T3 (P = 0.038) and granulocytes (trend) at T2 (P = 0.066). Time analysis demonstrated a decrease in haptoglobin concentration in both groups (NVAC, P = 0.005 and VAC, P = 0.006), with a reduction in the values at T1 and T3 (NVAC = 0.005 and VAC = 0.024). Antibody titers were similar between groups for BVDV, BoHV-1, and BRSV. Higher titers for BPI3V were observed for the VAC group at D56 (P = 0.045).Discussion: The early-onset BRD was present in both groups between 30 and 60 days of age, based on the higher prevalence observed. These data reinforce the importance of early immunization programmes before infection. Factors such as management practices and facilities may have also contributed to the higher prevalence of BRD. The increased number of leukocytes and neutrophils at T2 (D35) and T3 (D56) in the NVAC group points to a stronger inflammatory response to various types of potential challenges. The inflammatory leukocyte profile explains the higher haptoglobin values observed in the NVAC group at T2 (D35). The similarity of titers of antibodies against BVDV, BoHV-1, and BRSV between groups may indicate that vaccinating the calves at 14 days of age did not induce a humoral immune response to these viruses, likely due to interference from the maternal antibodies. Early vaccination prevented a drop in specific viral antibodies and promoted partial protection for vaccinated calves around 14 days of age, with a decrease in the intensity of the inflammatory response at the peak of the disease and a higher concentration of antibodies against BPI3V after the booster.

Birth delivery method affects expression of immune genes in lung and jejunum tissue of neonatal beef calves

BackgroundCaesarean section is a routine veterinary obstetrical procedure employed to alleviate dystocia in cattle. However, CS, particularly before the onset of labour, is known to negatively affect neonatal respiration and metabolic adaptation in humans, though there is little published information for cattle. The aim of this study was to investigate the effect of elective caesarean section (ECS) or normal trans-vaginal (TV) delivery, on lung and jejunal gene expression profiles of neonatal calves.ResultsPaternal half-sib Angus calves (gestation length 278 + 1.8 d) were delivered either transvaginally (TV; n = 8) or by elective caesarean section (ECS; n = 9) and immediately euthanized. Lung and jejunum epithelial tissue was isolated and snap frozen. Total RNA was extracted using Trizol reagent and reverse transcribed to generate cDNA. For lung tissue, primers were designed to target genes involved in immunity, surfactant production, cellular detoxification, membrane transport and mucin production. Primers for jejunum tissue were chosen to target mucin production, immunoglobulin uptake, cortisol reaction and membrane trafficking. Quantitative real-time PCR reactions were performed and data were statistically analysed using mixed models ANOVA. In lung tissue the expression of five genes were affected (p < 0.05) by delivery method. Four of these genes were present at lower (LAP, CYP1A1, SCN11α and SCN11β) and one (MUC5AC) at higher abundance in ECS compared with TV calves. In jejunal tissue, expression of TNFα, Il-1β and 1 l-6 was higher in ECS compared with TV calves.ConclusionsThis novel study shows that ECS delivery affects the expression of key genes involved in the efficiency of the pulmonary liquid to air transition at birth, and may lead to an increased inflammatory response in jejunal tissue, which could compromise colostral immunoglobulin absorption. These findings are important to our understanding of the viability and management of neonatal calves born through ECS.

Health and performance of calves fed fresh colostrum from their dams compared to those fed stored colostrum from non-dams

The objective of this study was to assess the preweaning performance, health, and survival of calves fed fresh colostrum from their dams compared to calves receiving colostrum that was not from their dams, and had been stored frozen or refrigerated. A total of 182 Holstein heifer calves born during July and August 2010 at a north-central Florida dairy farm were included. Explanatory variables included colostrum source, adjusted colostrum score, total estimated IgG intake, time to colostrum feeding, and calf-serum total protein determination as a measure of colostral immunoglobulin absorption. Control variables comprised birth weight and dam parity number. Average daily weight gain (ADG) was not affected by colostrum source. Number of disease events was the only variable showing a significant negative association with ADG (P=0.001), but there was a tendency to significance for lower-birth weight to be associated with a higher number of disease events; P=0.08. Source of colostrum did not affect the number of disease events or the total number of days on treatment. Similarly, no significant association with calf mortality was found for colostrum source. Time to event analyses did not indicate any significant association between morbidity and mortality and any of the explanatory variables, including colostrum source. We concluded that colostrum source was not significantly associated with performance, health, and survival in this population of dairy calves.

Duração da imunidade passiva para lentivírus de pequenos ruminantes em cordeiros

In order to evaluate the passive immunity against small ruminant lentiviruses (SRLV) in lambs, this study was conducted from two experimental groups. The first one (G1) was established by nine lambs subjected to artificial feeding of colostrum of goats positive for SRLV. The second one (G2) was the control group, consisting of ten lambs subjected to suckling of colostrum from their negative mothers. Blood samples were obtained before the first feeding, after 24 hours of birth and at 7, 15, 30, 50, 70, 90 and 120 days of age. The concentrations of total serum protein (TSP), albumin (ALB), globulin (GLOB) and immunoglobulin G (IgG) were determined and antibodies to SRLV were surveyed from the techniques of agar gel immunodiffusion (AGID), enzyme linked immunosorbent assay (Elisa) and immunoblotting (IB). In both groups, the lowest averages of TSP, GLOB and IgG were observed at birth and the highest averages were observed at 24 hours of life, due to absorption of colostral immunoglobulins. For G1, transfer of immunity could also be detected by immunodiagnostic tests. At birth, the animals were seronegative. After 24 hours, all animals were positive in three serological tests. Negative results began to be observed after 15 days of age by the AGID test. As for Elisa testing, all animals remained reagent until 50 days old. Only IB was able to detect anti-SRLV at 70 days. Regarding G2, all animals tested negative in AGID and IB, from birth until 120 days of age. However, false-positive results were observed until day 15 in Elisa, due to nonspecific reactions. These data are consistent with the sensitivity and specificity of serological tests and show that starting at 90 days of age, colostral antibodies to SRLV are no longer detected in the serum of lambs.

Evaluation of serum immunoglobulin G concentrations in dairy calves by use of an automated turbidimetric immunoassay

Administration of colostrum to newborn calves is recognized as an important component of dairy calf health maintenance because colostral immunoglobulin absorption is required to establish passive immunity. Despite the importance of a good colostrum management program, over one-third of dairy operations still depend on the calf nursing the dam as the only method for colostrum delivery, and 19.2% of calves are estimated to have failure of transfer of passive immunity. Multiple assays have been described to assess serum immunoglobulin G (lgG) concentrations in calves; however, none are ideal for routine use on farms. The purpose of this study was to evaluate the reliability of a new commercially available automated turbidimetric immunoassay and portable analyzer for measuring serum IgG concentrations in dairy calves.

Effect of single oroesophageal feeding of 3 L versus 4 L of colostrum on absorption of colostral IgG in Holstein bull calves

Ingestion and absorption of colostral immunoglobulins is essential for survival of dairy calves. The hypothesis put forward in this study was that large colostral volumes (4L) reduce absorption of colostral immunoglobulin by reducing apparent efficiency of absorption of immunoglobulins compared to smaller colostral volumes (3L), when colostrum is fed once by oroesophageal tubing. The objective of this study was to evaluate the effect of colostral volume on apparent efficiency of absorption (AEA) of colostral immunoglobulin G (IgG) when calves are fed 3L compared to 4L of colostrum. Twenty-eight, age-matched Holstein bull calves aged between 2 and 8h were randomly assigned to receive 3L or 4L of colostrum with similar colostral IgG concentration, once, by oroesophageal tubing. Serum IgG concentration at 48h of age and AEA of IgG were compared between the two groups. The results of the study showed that there was no difference in the serum IgG concentrations at 48h of age or AEA of IgG between the groups (P>0.05). The results of this study suggest that dairy producers can save colostrum by feeding 3L of colostrum when calves are fed once by oroesophageal tubing. There seems to be no added practical benefit in feeding 4L of colostrum compared to 3L when colostrum is fed once. Studies with larger sample sizes are required to compare mortalities up to weaning between groups of dairy calves fed 3L compared to 4L of colostrum.

Contribution to knowledge of colostral immunoglobulin absorption in intensively bred calves

A whole series of factors affect the degree of absorption of colostral immunolobulins. One of the most important factors is the time of feeding of newborn calves with colostrums in the first hours following birth. The objective of these investigations was to determine the effect of immunoglobulin concentration in colostrum on the process of immunoglobulin absorption during the first day of life of calves. A farm of Holstein-Friesian cows was selected for these investigations. The examinations covered 35 cows. For the examination of total immunoglobulin concentration, colostrum was taken two hours after calving. The immunoglobulin concentration was determined using the method of paper electrophoresis and RID-partigen immunodiffusion plates (INEP, Zemun). The amount of immunoglobulin in blood serum of calves was determined using the method of the zinc sulphate turbidity test (ZST). The average concentration of immunoglobulin in colostrum two hours after calving was 65.95?15.80 g/l. The biggest reached average concentration of immunoglobulin in blood serum of calves was determined following the absorption of immunoglobulin during the first day, and it amounted to 27.18?10.2 g/l, which presents 1.91? 0.72 g/kg of the body mass of calves. The straight-line linear equation is _ =0.595+0.25xi. The correlation coefficient between taken and resorbed immunoglobulins amounts to r=0.80. It can be concluded on the grounds of the obtained results that the amount of immunoglobulin in colostrum in the first drinking is of primary importance for the health status of the calves and that resorption is increased by 0.25 grams with every gram of immunoglobulin taken with colostrum.

Colostral immunoglobulins absorption in Canchim and Nelore calves

The efficiency of absorption of colostral immunoglobulins was evaluated in five Canchim and seven Nelore calves. They received colostrum pools with concentration of 70.20 ± 6.14 mg/mL through esofageal feeder at 2, 12, 24 and 36 hours after birth. The immunoglobulins concentrations of the pools were estimated through specific gravity and measured by radial immunodifusion. In the blood collection at birth and during the first 70 days of life, the total protein was assayed by biuret method and the immunoglobulins were assayed by radial immunodifusion. Data were analysed as a randomized split-plot statistical model. The highest concentrations of serum immunoglobulins and total protein were observed at 24 hours of age. No significant differences (P&gt;0.5484) were observed for immunoglobulins concentration at 24 hours, with concentrations of 28.80 ± 7.24 mg/mL for Canchim and 27.32 ± 9.54 mg/mL for Nelore. The efficiency for immunoglobulins absorption was not significantly different (P&gt;0.8715) between breeds, 64.04 ± 7.74% for Canchim and 62.30 ± 6.93% for Nelore. The lack of statistical significance persisted until the fourtieth day of life, period of maternal immunoglobulin predominance in the calves blood circulation. In the following period, from 40 to 70 days of age, phase of establishment of the endogenous production of immunoglobulin, differences in the IgG concentrations between the two groups were detected refflecting a possible breed effect difference. The process of colostral IgG absorption by the newborn calves was not affected by breed. The differences between breeds in the calves serum IgG were related to the phase of endogenous production of antibodies.

Serum levels of insulin like growth factor-l and total protein in newborn calves offered different amounts of colostrums

The aim of this investigation was to determine the concentrations of insulin like growth factor-I (IGF-I) and total protein in blood serum from calves consuming different amounts of colostrum during the first 32 h of postnatal life, as well as at 7 days old. The experiment involved two groups of calves. The first group was offered the standard amount of colostrum while the second group received half the recommended amount. At birth serum concentration of IGF-I was in the range from 5 to 13 nmol/L. Compared to the initial level there was a marked decrease of mean IGF-I concentration in both groups of calves at 2 h after the first intake of colostrum. Thereafter, the level gradually increased until 20 h of age, more markedly in the group which received the full ration of colostrum. The highest mean IGF-I concentrations were recorded at 20 h in both groups (11.81 nmol/L for group one and 8.96 nmol/L for group two), and were significantly higher than values recorded 2h after the first intake of colostrum. Two hours after the third intake of colostrum, serum concentration of IGF-I dropped in both groups, compared with the value recorded at 20 h. During the time period from 4hto32h after birth, the calves that received the standard amount of colostrum had a significantly higher mean concentration of serum IGF-I than the calves which received an insufficient amount. Calves were born with serum concentrations of total proteins, which were lower than those found for adult animals. Serum protein concentrations in the calves that consumed normal amounts of colostrum increased more rapidly than in the calves that received insufficient amounts of colostrum. Presumably, total protein concentrations increased as a consequence of colostral immunoglobulin absorption. Thus our results indicate that the amounts of colostrum received during the first 32 h of postnatal life had strong effects on the serum concentrations of IGF-I and total proteins. The differences in IGF-I concentrations between the two groups of calves may have been a consequence of greater colostral IGF-I absorption and/or the result of greater absorption of other colostral components, which stimulate endogenous synthesis of this bioactive substance in the tissues of neonatal calves.

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.

Operation-management factors associated with early-postnatal mortality of US foals

Of 7320 equine foals reported born alive during 1997 on 1043 operations that had equids on 1 January 1997, and that participated in the United States National Animal Health Monitoring System (NAHMS) Equine 1998 Study, 120 foals were reported to have died (by either euthanasia or natural causes) within the first 2 days of a live birth. The weighted estimate was 1.7% mortality (standard error=0.5) within the first 2 days of live birth for all foals born on operations in the 28 states included in the study. A multivariable logistic-regression model revealed that foals born in the southern region were more likely to have been reported to have died within the first 2 days of live birth than in the western region. In addition, the following operation-level factors were associated with increased odds of a foal dying within the first 2 days of live birth: not routinely testing newborn foals for adequate absorption of colostral immunoglobulins during the first 2 days of life; adding new resident equids to the operation during 1997; having non-resident equids stay on the operation for 1–30 days during 1997; never requiring an official health certificate (for operations that had non-resident equids stay on the operation for 1–30 days); using something other than straw or hay as the predominant bedding type; and feeding equids a vitamin-mineral supplement/premix with forage and/or grain.

Associations between passive immunity and morbidity and mortality in dairy heifers in Florida, USA

A prospective cohort study was undertaken to determine calf-level factors that affected calf health status between birth and 6 months of age. A convenience sample of approximately 3300 female Holstein calves born in 1991 on two large Florida dairy farms was used for the study. Data collected on each calf at birth included farm of origin, weight, height at the pelvis, birth date, and serum total protein (a measure of colostral immunoglobulin absorption). Birth season was dichotomized into summer and winter using meteorological data collected by University of Florida Agricultural Research Stations. Health data including date of initial treatment and number of treatments were collected for the diseases diarrhea, omphalitis, septicemia and pneumonia. All calves were followed for 6 months. Cumulative incidences of mortality and occurrence of diarrhea, omphalitis, septicemia and pneumonia were 0.12, 0.35, 0.11, 0.24 and 0.21, respectively. Serum total protein (TP) was a significant risk factor for mortality. The association of TP and mortality was quadratic and showed a dramatic decrease in mortality as TP increased from 4.0 to 5.0 g/dl, a small improvement from 5.0 to 6.0 g/dl and virtually no improvement in mortality rates as TP increased over 6.0 g/dl. The hazard mortality ratio was constant from birth to six months, indicating that the increased risk of mortality associated with low levels of TP was evident through six months of age. No interactions between TP, farm, season, or birth weight were found in these analyses. Serum total protein concentration was a significant risk factor for the occurrences, age of onset and severity of septicemia and pneumonia. The association between TP and septicemia was linear and an interaction with birth season was found. The association between TP and pneumonia was quadratic, and in contrast to the TP-and-septicemia relationship, the morbidity hazard ratio for pneumonia was not constant over the time measured; that is, colostral immunity protected the calf from developing pneumonia early in life, but this effect disappeared as the calf got older. Total protein was not a significant risk factor for diarrhea or omphalitis.

Calf and disease factors affecting growth in female holstein calves in Florida, USA

A prospective cohort study was undertaken to determine calf-level factors that affect performance (growth) between birth and 14 months of age in a convenience sample of approximately 3300 female Holstein calves born in 1991 on two large Florida dairy farms. Data collected on each calf at birth included farm of origin, birth date, weight, height at the pelvis, and serum total protein (a measure of colostral immunoglobulin absorption). Birth season was dichotomized into summer and winter using meteorological data collected by University of Florida Agricultural Research Stations. Data collected at approximately 6 and 14 months of age included age, weight, height at the pelvis, and height at the withers. Growth in weight and stature (height) was calculated for each growth period; growth period 1 (GP1) = birth to 6 months, and growth period 2 (GP2) = 6 to 14 months. Health data collected included date of initial treatment and number of treatments for the diseases diarrhea, omphalitis, septicemia, pneumonia and keratoconjunctivitis. After adjusting for disease occurrence, passive transfer of colostral immunoglobulins had no significant effect on body weight gain or pelvic height growth. Season of birth and occurrence of diarrhea, septicemia and respiratory disease were significant variables decreasing heifer growth (height and weight) in GP1. These variables plus farm, birth weight and exact age when ‘6 month’ data were collected explained 20% and 31% of the variation in body weight gain and pelvic height growth, respectively, in GP1. The number of days treated for pneumonia before 6 months of age significantly decreased average daily weight gain in GP2 ( P < 0.025), but did not affect stature growth. Treatment for pneumonia after 6 months of age did not significantly affect weight or height gain after age 6 months. Neither omphalitis nor keratoconjunctivitis explained variability in growth in either of the growth periods.

Pulmonary histopathologic findings, acid-base status, and absorption of colostral immunoglobulins in newborn calves

Summary A study was conducted to investigate whether aspiration of amniotic fluid is associated with a deleterious effect on absorption of colostral immunoglobulins or on blood gas and acid-base values of healthy newborn calves. Fourteen calves purchased from commercial sources were transported to a research facility immediately after birth and fed colostrum with known concentrations of immunoglobulins. Blood samples for gas analyses were collected within 5 hours of birth, 24 hours later, and prior to euthanasia. Between 3 and 5 days of age, calves were euthanatized by an overdose of barbiturates. Eleven calves had evidence of bronchoaspiration of amniotic fluid, as determined by presence of meconium, squamous epithelium, or keratin in histologic sections of fixed lung or by cytologic analysis of bronchoalveolar lavage fluid. Blood gas tensions and pH were within reference ranges in 11 of 14 calves. Aspiration of amniotic fluid could not be linked to any specific changes in blood gas tensions, add-base status, or absorption of colostral immunoglobulins. Presence of keratin and meconium in the lungs often was accompanied by mild exudative alveolitis and focal atelectasis. It was concluded that aspiration of small amounts of amniotic fluid with or without meconium is common in calves and is not associated with hypoxemia, respiratory acidosis, or failure of passive transfer.

Colostrum

Despite increasing awareness of the importance of passive immunity in calves to reduce disease prevalence, morbidity from calfhood diseases, days to first illness, sick days, days of viral shedding, viremia, growth and productivity(l-6), 20 to 30% of neonates will be hypo- or agammaglobulinemic. Failure of passive transfer of maternal immunoglobulins (FPT) occurs when there is a problem with 1 or more of the 3 phases of passive transfer: formation of colostrum with a high concentration of immunoglobulin, ingestion of an adequate volume of colostrum by the calf in a timely fashion, or efficient absorption of colostral immunoglobulin. Some calves with FPT are healthy and productive neonates, which is a reflection of the importance of other factors including environmental conditions, management practices, pathogen load, pathogen virulence, and nutrition of the calf in addition to acquisition of passive immunity. There is general acceptance that failure of passive transfer exists when calves between 36 and 48 hours of age have serum immunoglobulin concentrations less than 1000 mg/di. Individual calf problems can occur when its serum immunoglobulin concentration is below 1000 mg/di; herd problems occur with increased prevalence of scours and respiratory disease occur when large numbers of calves have FPT.

Decreased colostral immunoglobulin absorption in calves with postnatal respiratory acidosis

Summary The effect of postnatal acid-base status on the absorption of colostral immunoglobulins by calves was examined in 2 field studies. In study 1, blood pH at 2 and 4 hours after birth was related to serum IgG1 concentration 12 hours after colostrum feeding (P &lt; 0.05). Decreased IgG1 absorption from colostrum was associated with respiratory, rather than metabolic, acidosis, because blood PCO2 at 2 and 4 hours after birth was negatively related to IgG1 absorption (P &lt; 0.05), whereas serum bicarbonate concentration was not significantly related to IgG1 absorption. Acidosis was frequently observed in the 30 calves of study 1. At birth, all calves had venous PCO2 value ≥ 60 mm of Hg, 20 of the calves had blood pH &lt; 7.20, and 8 of the calves had blood bicarbonate concentration &lt; 24 mEq/L. Blood pH values were considerably improved by 4 hours after birth; only 7 calves had blood pH values &lt; 7.20. Calves lacking risk factors for acidosis were examined in study 2, and blood pH values at 4 hours after birth ranged from 7.25 to 7.39. Blood pH was unrelated to IgG1 absorption in the calves of study 2. However, blood PCO2 was again found to be negatively related to colostral IgG1 absorption (P &lt; 0.005). Results indicate that postnatal respiratory acidosis in calves can adversely affect colostral immunoglobulin absorption, despite adequate colostrum intake early in the absorptive period.