Colostrum Treatment Research Articles

Effect of colostrum treated by heat on immunological parameters in newborn lambs

Seventeen newborn lambs were fed with untreated colostrum (group A) and 18 lambs were fed with colostrum treated by heat (56 °C, 30 min) (group B). Blood samples were obtained at seven time points from day 0 to 38 of life. Clinical status and body weight were recorded and serum protein fractions and IgG levels were determined in blood. Phagocytosis of neutrophils from the lambs and opsonic capacity of their serum were examined using a flow cytometry method. As an indicator of in vivo cellular immunity, reactions to intradermal injection of phytohemagglutinin (PHA) were examined at 8 and 16 days of age. There were no clinical signs of disease and no significant differences in body weight between groups. Lambs from group B had lower total protein initially and lower γ-globulin and IgG levels until day 32 compared to lambs from group A ( P < 0.01). Heat treatment of colostrum had no significant effect on serum opsonic capacity or phagocytosis by neutrophils and these functions increased with age. However, responses to PHA in lambs from group B were lower ( P < 0.01) than group A at day 8 of life, but not at day 16, suggesting that cellular immunity was affected by the treatment of colostrum. These results showed that colostrum treated by heat impaired cellular and IgG levels in lambs, but not phagocytic function. However, these changes did not affect the health or performance of the lambs.

Effect of a bovine colostrum whey supplementation on growth performance, faecal Escherichia coli population and systemic immune response of piglets at weaning

This study examined the effect of a bovine colostrum whey supplementation on growth performance, feed intake, faecal Escherichiacoli population and systemic immune response of piglets at weaning. A total of 96 piglets weaned at 26 ± 2 days of age were assigned for 4 weeks to one of the two treatments: (1) the control (commercial diet with bovine milk whey powder) and (2) the colostrum (commercial diet with freeze-dried bovine colostrum whey) treatments. The two supplements were incorporated in the diet at a level of 20 g/kg during the first 2 weeks after weaning and lowered to a level of 10 g/kg for the next 2 weeks. BW and feed intake were measured weekly. Faecal E. coli counts were determined weekly on specific culture media. Blood samples were collected weekly and submitted to a cell counter analyser for their main components (red and white blood cells, platelets) and flow cytometry was used to determine the lymphocyte population (B, T, Th and Tc). Finally, total seric immunoglobulin (IgM, IgG and IgA) concentrations were determined by the ELISA method. During the first week of the trial, the piglets from the colostrum treatment had improved average daily gain (170 g/day v. 81 g/day, P < 0.001), average daily feed intake (346 g/day v. 256 g/day, P = 0.03) and feed efficiency (BW gain/feed intake) (0.48 v. 0.31, P = 0.04). The pigs fed the colostrum treatment had also a 25% increase in circulating IgA (P = 0.03) compared with the control treatment the first week. It is concluded that a distribution of bovine colostrum whey (20 g/kg diet) during the first week post-weaning induces a systemic IgA response and has a beneficial action on growth performances and feed efficiency.

Effects of Feeding Heat-Treated Colostrum on Passive Transfer of Immune and Nutritional Parameters in Neonatal Dairy Calves

The first objective of this study was to describe the effect of on-farm heat treatment of colostrum on colostral bacteria counts and IgG concentrations. The second objective was to describe the effect of feeding heat-treated (vs. raw) colostrum on passive transfer of colostral immune and nutritional parameters in neonatal calves. Pooled batches of colostrum were mixed and divided equally: one half was fed raw whereas the other half was fed after heat treatment at 60°C for 60min using a commercial on-farm batch pasteurizer. Colostrum samples were cultured for total bacteria count and total coliform count and analyzed for total IgG concentration. Forty-nine Holstein calves were fed either raw colostrum (n = 24) or heat-treated colostrums (n = 25) within 1 to 2h after birth. Serum samples collected from calves at 0h (precolostrum) and 24h (postcolostrum) were assayed for serum total protein; IgG, IgA, and IgM concentrations; peripheral total leukocyte counts; neutrophil counts; lymphocyte counts; lymphocyte phenotypes; vitamin A, vitamin E, cholesterol, and β-carotene concentrations. Serum samples collected from 2- to 5-d-old calves were tested for immunoglobulin function via a bovine viral diarrhea virus type I serum neutralization titer and for neutrophil bacterial opsonization activity. On-farm batch heat treatment of colostrum at 60°C for 60min resulted in lower colostrum bacteria concentrations while maintaining colostral IgG concentration. Calves fed heat-treated colostrum had significantly greater serum total protein and IgG concentrations at 24h, plus greater apparent efficiency of IgG absorption (total protein = 6.3 mg/dL; IgG = 22.3 mg/mL; apparent efficiency of absorption = 35.6%) compared with calves fed raw colostrum (TP = 5.9 mg/dL; IgG = 18.1 mg/mL; apparent efficiency of absorption = 26.1%). There was no effect of treatment on serum concentrations of IgA, IgM, vitamin A, vitamin E, cholesterol, β-carotene or vitamin E:cholesterol ratio, or on serum bovine viral diarrhea virus type I serum neutralization titers. There was no difference between treatment groups when examining calf plasma total leukocyte counts, neutrophil counts, lymphocyte counts, or neutrophil opsonization activity. However, the latter results were considered inconclusive.

Passive Transfer of Immunoglobulin G and Preweaning Health in Holstein Calves Fed a Commercial Colostrum Replacer

The objective of this study was to describe passive transfer of IgG and preweaning health in newborn calves fed a commercially available plasma-derived colostrum replacement (CR) product or maternal colostrum (MC). Twelve commercial Holstein dairy farms enrolled singleton newborn heifer calves to be fed fresh MC (n=239 calves) or one dose of CR containing 125g of Ig (n=218 calves) as the first colostrum feeding. For 7 of these farms that routinely provided a second feeding of 1.9L of MC to their calves 8 to 12h after the first colostrum feeding, calves assigned to the CR treatment group were offered a second feeding consisting of 1.9L of commercial milk replacer supplemented with one dose of a commercially available plasma-derived colostrum supplement, containing 45g of Ig per dose, 8 to 12h after the first colostrum feeding. A blood sample was collected from all calves between 1 to 8 d of age for serum IgG and total protein (TP) determination, and records of all treatment and mortality events were collected until weaning. Serum IgG and TP concentrations were significantly higher in calves fed MC (IgG=14.8±7.0mg/mL; TP=5.5±0.7g/dL) compared with calves fed CR (IgG=5.8±3.2mg/mL; TP=4.6±0.5g/dL). The proportion of calves with failure of passive transfer (serum IgG <10.0mg/mL) was 28.0 and 93.1% in the MC and CR treatment groups, respectively. Though a trend was present, the proportion of calves treated for illness was not statistically different for calves fed MC (51.9%) vs. CR (59.6%). Total number of days treated per calf (MC=1.7; CR=2.0), treatment costs per calf (MC=$10.84; CR=$11.88), and proportion of calves dying (MC=10.0%; CR=12.4%) was not different between the 2 colostrum treatment groups. The mean serum total protein concentration predictive of successful passive transfer (serum IgG=10mg/mL) was 5.0g/dL in calves fed MC or CR. Long-term follow-up of these calves (to maturity) is ongoing to describe the effects of feeding CR on longevity, productivity, risk for Johne's disease, and economics.

Effect of a mixture of micronutrients, but not of bovine colostrum concentrate, on immune function parameters in healthy volunteers: a randomized placebo-controlled study

BackgroundSupplementation of nutritional deficiencies helps to improve immune function and resistance to infections in malnourished subjects. However, the suggested benefits of dietary supplementation for immune function in healthy well nourished subjects is less clear. Among the food constituents frequently associated with beneficial effects on immune function are micronutrients such as vitamin C, vitamin E, β-carotene and zinc, and colostrum. This study was designed to investigate the effects these ingredients on immune function markers in healthy volunteers.MethodsIn a double-blind, randomized, parallel, 2*2, placebo-controlled intervention study one hundred thirty-eight healthy volunteers aged 40–80 y (average 57 ± 10 y) received one of the following treatments: (1) bovine colostrum concentrate 1.2 g/d (equivalent to ~500 mg/d immunoglobulins), (2) micronutrient mix of 288 mg vitamin E, 375 mg vitamin C, 12 mg β-carotene and 15 mg zinc/day, (3) combination of colostrum and micronutrient mix, or (4) placebo. Several immune function parameters were assessed after 6 and 10 weeks. Data were analyzed by analysis of variance. Groups were combined to test micronutrient treatment versus no micronutrient treatment, and colostrum treatment versus no colostrum treatment.ResultsOverall, consumption of the micronutrient mix significantly enhanced delayed-type hypersensitivity (DTH) responses (p < 0.05). Adjusted covariance analysis showed a positive association between DTH and age. Separate analysis of younger and older age groups indicated that it was the older population that benefited from micronutrient consumption. The other immune function parameters including responses to systemic tetanus and oral typhoid vaccination, phagocytosis, oxidative burst, lymphocyte proliferation and lymphocyte subset distribution were neither affected by the consumption of micronutrients nor by the consumption of bovine colostrum concentrate.ConclusionConsumption of bovine colostrum had no effect on any of the immune parameters assessed. The micronutrient mix enhanced cellular immunity as measured by DTH, with an increased effect by incremental age, but did not affect any of the other immune parameters measured. Although correlations between decreased DTH and enhanced risk of certain infection have been reported, it remains unclear whether and enhanced DTH response actually improves immune defense. The present data suggests that improvement of immune parameters in a population with a generally good immune and nutritional status is limited and that improvement of immune function in this population may be difficult.

Heat Treatment of Bovine Colostrum. I: Effects of Temperature on Viscosity and Immunoglobulin G Level

The objective of this study was to identify the critical temperature, at or below which heat-treatment of bovine colostrum would produce no significant changes in viscosity, IgG concentration, or Ig activity. Results of preliminary work, using a Rapid Visco Analyzer (RVA) to heat 50-mL aliquots from 6 unique batches of bovine colostrum at 59, 60, 61, 62, and 63°C, suggested that colostrum could be heated to 60°C for up to 120min without changing viscosity or IgG concentration. This finding was confirmed by heating 50-mL aliquots from 30 unique batches of colostrum in an RVA for 120min at 60 and 63°C. Heating colostrum to 63°C resulted in an estimated 34% decrease in IgG concentration and 33% increase in viscosity. However, there was no difference in IgG concentration between preheat-treated (73.4±26.5 mg/mL) and post-heat-treated (74.5±24.3 mg/mL) samples after heating colostrum to 60°C in an RVA for 120min. Similarly, viscosity was unaffected after heating colostrum to 60°C in an RVA for 120min. High quality colostrum (≥73.0 mg/mL) suffered greater losses of IgG and greater viscosity changes when heated to 63°C than did moderate quality colostrum (<73.0 mg/mL). However, the effects of colostrum quality were minor if high quality colostrum was only heated to 60°C. The results of a bovine viral diarrhea serum neutralization assay suggested that antibody activity was unchanged after heating colostrum to either 60 or 63°C. However, these results were interpreted as being inconclusive due to a high proportion of missing results because of the congealing of many samples after heat treatment. The results of this study indicate that 50-mL volumes of bovine colostrum can be heat treated at 60°C for up to 120min in an RVA without affecting IgG concentration or viscosity.

The Suppressive Effect of Bovine Colostrum Combined with Antibiotics on Renal Inflammation

Purpose: Bovine colostrum contains three times more immunoglobulin than human colostrums does. We investigated the effectiveness of administering Bovine colostrum combined with antibiotics in an animal model of ascending pyelonephritis. Materials and Methods: Thirty female Sprague-Dawley rats were divided into 5 groups: the normal group, the non-treated control group, the Bovine colostrum administered group, the antibiotic treatment group and the combined administration of antibiotics and Bovine colostrums group. After anesthetizing, an inoculum of 1x10 colony forming units per ml of Escherichia coli (E. coli, ATCC 25922 strain) was instilled into the bladder through the urethra and the urethra was occluded for 4 hours. We began treatment with ciprofloxacin (15mg/kg, for 5 days, intramuscularly) alone or Bovine colostrum (6ml/kg, for 5 days, orally) alone or with combination treatment 72 hours after inoculation. The rats were sacrificed 4 weeks after infection. Both kidneys were examined pathologically. We carried bacterial culture examinations of the urine and the kidney tissue. Results: As the results of examining the cultures of the urine and kidney tissues, no bacteria were cultivated in the antibiotics treatment group and the combined treatment group. 66.7% of the control group and 33.3% of the bovine colostrum treatment group had positive urine cultures and 66.7% of the control group and 41.7% of the bovine colostrum treatment group showed a positive reaction on the kidney tissue culture. The severity of pyelonephritis, as noted on the pathological examination, was highest in the control group. The combined treatment group had the lowest degree of infection among all the groups. Conclusions: The administration of bovine colostrum in combination with antibiotics can significantly reduce the inflammation associated with ascending pyelonephritis. (Korean J Urol 2006;47:1111-1116) ꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏ

Preparation of serocolostrum by membrane microfiltration

Treatment of bovine, equine and caprine colostrum by membrane microfiltration with a pore size of 0.1 µm was studied in order to obtain a specific separation of whey colostrum components. These components are most interesting for imparting passive immunity and positive physiological action to newborn mammals. From the carrying out of 80 kg batches of colostrum, the microfiltra- tion equipment used allowed the recovery of at least 80% of the IgG and other minor whey proteins in the microfiltrate. This liquid, named serocolostrum, is crystal clear, free of blood and somatic cells as well as fat globules and casein micelles, and it has a high hygienic and bacteriological qua- lity (less than 10 CFU·mL -1 ). Specific concentration of the serocolostrum IgG proteins by high molecular weight cut-off (MWCO: 100 kg·mol -1 ) membrane ultrafiltration was also studied in order to obtain purified IgG products suitable for preliminary animal trials. Purity (IgG/TS) as high as 90% was obtained. The use of a lower MWCO UF membrane (8 kg·mol-1) allowed concentra- tions of growth factors (TGF-β and IGF-1) but the observed separation did not agree with the data of the literature, i.e. a binding of IGF-1 with a 45 kg·mol -1 protein.

Photodynamic inactivation of an RNA enveloped virus in goat colostrum

The primary objective of this study was to determine if a RNA enveloped virus can be inactivated in goat colostrum using methylene blue (MB) and 1 h of illumination (photodynamic inactivation (PI)). The effects of illumination on the virucidal properties of MB were studied in translucent media as well as colostrum. Concentrations of MB evaluated were 10, 1.0, 0.1 and 0.01 μM. Bovine viral diarrhea virus (BVDV) was used as a model for caprine arthritis-encephalitis virus (CAEV). Virus, immunoglobulin, bacterial and coliform levels were determined before and after treatments. In transparent media, concentrations of MB >0.1 μM inactivated virus regardless of time, with or without light exposure. Sixty minutes of light treatment significantly reduced viral levels in samples containing 0.01 μM MB as compared to dark treatment. In colostrum, light treatment significantly inactivated virus in samples containing 1.0 and 10 μM MB. Concentrations of immunoglobulin were not adversely affected, and total bacterial and coliform counts increased. We concluded that PI of a RNA enveloped virus appears to be achievable in goat colostrum without lowering immunoglobulin concentrations, or creating a hazardous degree of bacterial and coliform proliferation.The clinical relevance of this experiment is that PI has the potential to inactivate CAEV in goat colostrum, thus providing the goat industry an alternative to heat treatment of colostrum. However, further refinement of this technique is warranted.

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.

Successful Hyperimmune Bovine Colostrum Treatment of Savanna Monitors (Varanus exanthematicus) Infected with Cryptosporidium sp.

Successful Hyperimmune Bovine Colostrum Treatment of Savanna Monitors (Varanus exanthematicus) Infected with Cryptosporidium sp.

The provision of supplementary colostrum to newborn lambs: effects on post-natal lamb and ewe behaviour

In sheep, as in many other species, the first hours following the birth of young are characterised by behavioural interactions between the mother and her young which cause the ewe and lamb to become bonded to each other, particularly within 2–4 h of birth. The aim of this study was to determine whether the provision of supplementary colostrum affected early mother–young behaviour. Eighteen pregnant twin-bearing Scottish Blackface hill ewes were used. At parturition, one lamb from each twin pair received 25 ml/kg birth weight artificial colostrum (treatment group) while the other did not receive artificial colostrum (control group). Lambs and ewes were observed during four consecutive periods of 30 min immediately after birth. During these observation periods, ewes and lambs were undisturbed and lambs were allowed to suck. Results showed that (i) during the first 30-min period, lambs which received supplementary colostrum were less active than their siblings which did not receive supplementary colostrum (resting time 22.3 (±1.10) min vs. 18.6 (±1.43) min for treatment and control lambs, respectively; p=0.05); (ii) during the first 30-min period lambs which received supplementary colostrum were licked for less time than their siblings (14.8 (±2.13) vs. 20.6 (±1.22) min for treatment and control lambs, respectively; p<0.05); (iii) at the end of the observation period, lambs from the treatment group had higher rectal temperatures than control lambs (39.8 (±0.09) °C vs. 39.4 (±0.08) °C, for treatment and control lambs, respectively; p<0.01). It is concluded that, although the provision of supplementary colostrum may reduce the risk of hypothermia, it may also have a deleterious effect on early ewe–lamb interactions.

Therapeutic efficacy of hyperimmune bovine colostrum treatment against clinical and subclinical Cryptosporidium serpentis infections in captive snakes

Therapy based on the protective passive immunity of Hyperimmune Bovine Colostrum (HBC) (raised against Cryptosporidium parvum in dairy cows immunized during gestation) was tested for heterologous efficacy in subclinical and clinical infections of 12 captive snakes with C. serpentis. Six gastric HBC treatments of 1% snake weight at 1-week intervals each, have histologically cleared C. serpentis in three subclinically infected snakes, and regressed gastric histopathological changes in one of these snakes. In all snakes, each subsequent HBC treatment significantly decreased the number of oocysts recovered in gastric lavage eluants ( P<0.03). The treatments induced oocyst-negative gastric eluants and stools in all snakes, and improved clinical signs of infection. Clinically infected snakes displayed severe histopathological changes in the gastric region; however, the numbers of developmental stages of C. serpentis were moderate. Considering the severity of pathology, much lower than expected pathogen numbers were observed, and it is believed that clinically infected snakes did not have enough time to repair tissue damage that had occurred over the years of infection. As the HBC treatment was safe and highly efficacious, it is recommended to gastrically administer the HBC therapeutically to snakes that are clinically or subclinically infected with C. serpentis. Hyperimmune bovine colostrum can also be used in snake supportive therapy or prophylaxis.

Effect of treatment with formaldehyde and formic acid on immunoglobulin content of stored bovine colostrum

Colostrum was collected from the first postpartum milking of German Black Pied cows. Four independent pools of colostrum were made and the following preservation methods replicated in each pool, viz. formaldehyde treatment, 0.1% (F1) and 0.05% (F2); formic acid treatment, 0.5% (FA1) and 0.1% (FA2) and an untreated control (NF). All the colostrum batches were stored at an average incubation temperature of 28°C in 200-ml plastic bottles. Samples were collected from every batch on Day 0 (before incubation) and subsequently after every week for 4 weeks. All the samples collected were analysed for immunoglobulin (IgG1, IgG2, IgA and IgM) content of the whey fraction using the single radial immunodiffusion (SRID) method. pH was measured using a glass electrode pH meter.Formaldehyde treatment of colostrum maintained almost constant immunoglobulin levels under the conditions of this experiment. There were significant drops in the mean IgG1 (P < 0.0001) and IgM (P < 0.005) contents in the control (NF) and the formic acid treated (FA1 and FA2) colostrum. The levels of IgA and IgG2 remained fairly constant for all treatments and there was no observable trend with storage duration. The pH of formaldehyde treated colostrum remained above 4.8 for the 4 weeks of storage whereas that of the untreated control colostrum dropped to below pH 4.8 in the first 3 days and remained stable to the 4th week. This work has shown that inclusion of formaldehyde at levels as low as 0.05% (wt/vol.) preserves immunoglobulins of colostrum stored at high ambient temperature. The use of formic acid was not beneficial for preservation of colostral immunoglobulins. Thus colostrum preserved with formaldehyde may be of good feeding value for newborn calves whereas that preserved with formic acid may be useful only for older calves.

Evaluation of colostrum and whey-derived gammaglobulins for prevention of cryptosporidiosis in artificially infected neonatal calves

Thirty colostrum-deprived Friesian male calves were used to study the effect of colostrum and whey-derived gammaglobulins on the clinical events and oocyst-excretion pattern following artificial infection with a fresh, field-sourced strain of Cryptosporidium parvum. The calves were raised naive and free from contact with C. parvum from birth until infection at either 10 or 17 days of age. The two age groups comprised three sub-groups that were each given a single treatment of colostrum, whey-derived gammaglobulins or whole milk (controls) at 5 hours after birth. Blood samples taken both before and 48 hours after this dosing showed the mean serum gamma globulin concentrations changed from almost zero in all calves to 462,279 and 29 mg/dl for the colostrum, whey-derived gammaglobulin and whole milk sub-groups respectively. The results showed that a majority of calves shed Cryptosporidium oocysts within 7 days of oral infection but that no diarrhoea or other clinical signs were associated with this. However, when the level of C. parvum faecal shedding was graded, the results showed a trend towards a higher level of oocyst shedding and over a longer period of time in the control calves deprived of any passive immunity than in the two groups given either colostrum or whey-derived gammaglobulins.

Enhancement of Resistance to Cryptosporidium parvum by Pooled Bovine Colostrum during Murine Retroviral Infection

The therapeutic efficacy of pooled bovine colostrum for the control of cryptosporidiosis was investigated during murine acquired immunodeficiency syndrome in female C57Bl/6 mice. Mice were infected with LP-BM5 murine leukemia retrovirus for four months and then inoculated with Cryptosporidium parvum oocysts. Persistent cryptosporidiosis was established in all retrovirus immunosuppressed mice, while control mice were refractory to infection. Parasite colonization of intestinal villi was significantly (P < 0.05) reduced in immunosuppressed animals that received dietary supplemental pooled bovine colostrum compared with to those that did not receive colostrum treatment. Similarly, shedding of oocysts in the feces of immunosuppressed animals that received dietary pooled bovine colostrum was significantly (P < 0.05) reduced compared with those that did not at 26 days post-parasite challenge. Since the nonimmune bovine colostrum contained no anti-Cryptosporidium antibodies, this suggests that passively transferred antibodies alone are unlikely to have provided the improved resistance shown in this study.

Possible effect of altered management practices on seroprevalence of bovine leukemia virus in heifers of a dairy herd with history of high prevalence of infection

Summary A bovine leukemia virus (blv) control program was instituted at a high-prevalence, purebred Holstein dairy. The specific control program required single use of needles and obstetrical sleeves, disinfection of tattoo equipment before use, dehorning by use of electrical burning devices, replacement of whole milk feeding with high-quality milk replacer, and heat treatment of colostrum before feeding. The effect of the program was estimated by comparing the pre- (1987) and postintervention (1989) prevalences of blv-agar gel immunodiffusion titers within particular heifer age cohorts (0 to 90, 91 to 180, 181 to 360 days, and 361 days to parturition). Random serologic testing was conducted quarterly within each cohort, but was analyzed on a combined yearly basis. Seroprevalence of blv decreased in all age cohorts &gt; 180 days old, with significant decreases in the 361 days to parturition (P = 0.003) and the combined 181 days to parturition cohorts (P = 0.0004). Prevalence within the latter cohort decreased from 0.44 in 1987 to 0.17 in 1989. These results were obtained without either culling or segregation of blv-agar gel immunodiffusion-positive cattle.

Effects of immune colostrum and orally administered antisporozoite monoclonal antibodies on the outcome of Cryptosporidium parvum infections in neonatal mice.

A neonatal BALB/c mouse model of cryptosporidiosis was used to examine the potential passive transfer of immunity via immune colostrum and oral treatment with anticryptosporidial monoclonal antibodies. Neonates suckled by dams that recovered from Cryptosporidium parvum infections were equally susceptible to infection as their control counterparts suckled by naive dams. Parasite loads among the control and immune colostrum-fed mice were indistinguishable. Neonates receiving orally administered antisporozoite monoclonal antibodies were equally susceptible to infections compared with the control and immune colostrum-fed mice. Parasite loads among the mice receiving daily oral treatment with monoclonal antibody mixtures exhibited significantly lower parasite loads compared with the control mice (P less than 0.05).

Further Characterization of Human Colostral Antioxidants: Identification of an Ascorbate-Like Element as an Antioxidant Component and Demonstration of Antioxidant Heterogeneity

Human colostrum manifests antioxidant properties, being capable of spontaneous reduction of cytochrome c, depletion of polymorphonuclear leukocyte-produced H2O2 and protection of epithelial cells from PMN-mediated detachment. These activities can be electrophoretically concentrated at either 3.5 kD or 50 kD dialysis membranes at mildly alkaline pH. They are progressively lost under increasingly alkaline conditions. They are resistant to 1-mM N-ethylmaleimide. Examination of a series of antioxidant compounds showed that ascorbate manifests several characteristics of colostrum, being able to reduce cytochrome c and deplete H2O2 but not altering PMN-mediated HEp2 cell detachment. Addition of ascorbate oxidase to colostrum decreased its cytochrome c-reducing activity by more than 85%, decreased its H2O2-depleting activity by nearly 50%, but did not alter its ability to protect HEp2 cells, all suggesting heterogeneity of colostral antioxidant activities. Treatment of colostrum with an enzymatic system (xanthine + xanthine oxidase) known to destroy ascorbate's cytochrome c-reducing activity yielded paradoxical results, decreasing colostral cytochrome c reduction in a dose-related manner, while increasing its H2O2-depleting activity. These studies demonstrate that a colostral component similar to ascorbate, a known antioxidant compound is responsible for the majority of colostral cytochrome c-reducing activity, for about half of its H2O2-depleting activity, and little, if any, of its protective effect on HEp2 cells. Thus colostral antioxidant activity is heterogeneous.

Assessing Herd Performance in Relation to Replacement Rearing

Replacement rearing involves most of the general herd health and production control programs instituted for the milking herd, i.e., nutrition, reproduction, disease control (vaccinations), ventilation, calving management, parasite control and even mastitis prevention, as well as more specific management areas such as colostrum management, pinkeye prevention and treatment of calf related diseases.