BACKGROUND: Heat treatment of colostrum has been suggested as a control measure to eliminate or reduce the transfer of colostrum-borne pathogens to dairy calves.Objectives: The aims of this study were to determine the effects of on-farm heat treatment of bovine colostrum on colostral bacterial counts and IgG concentration and evaluation of passive transfer of immunity in neonatal dairy calves. Methods: Ninety-six L of first milking colostrum was collected from Holstein cows and pooled to create a uniform batch. Twenty-four calves were enrolled in 4 treatment groups before suckling occurred and fed raw colostrum (n=6), heat-treated colostrum at 60 ºC for 30 min (n=6), heat-treated colostrum at 60 ºC for 60 min (n=6) and heat-treated colostrum at 60 ºC for 90 min (n=6). Colostrum samples were collected before and after heat treatment and cultured for total bacterial count and analyzed for total IgG concentration. For the first and second feeding 2 L of colostrum was bottle fed by 2 and 12 h of age respectively. Serum samples were collected from calves at 0 h (precolostrum) and 6, 24, 48, 72 h (postcolostrum) and analyzed for serum total protein and IgG concentrations. Results: Heat treatment of colostrum at 60 ºC for 30 and 60 min reduced total bacterial count, yet maintained colostrul IgG concentration compared to the control. There was no difference between treatment groups when examining serum total protein and IgG concentrations, but apparent efficiency of IgG absorption was significantly greater at 6 h in calves that were fed heat-treated colostrum compared to calves fed raw colostrum. ConclusionS: There was no effect of on-farm batch heat treatment of colostrum at 60 ºC till 90 min on serum concentration of IgG.

BACKGROUND: The immunity and health of newborn calf are related to immunoglobulins uptake from colostrum where treatment of colostrum may improve the uptake. Objectives: The purpose of this study was to investigate the effect of controlled heat-treating of colostrum and antibiotic addition on immunoglobulins absorption, performance and health parameters of calf. Methods: The colostrum pool was prepared from multiparous dams and was frozen after the treatments. Colostrum was fed immediately after the birth three times a day for 2 days. Twelve newborn Holstein calves were divided into three treatment groups including 1) raw colostrum (control), 2) heat-treated colostrum, and 3) colostrum with oxytetracyclin in a completely randomized design. Blood samples were obtained in days 0, 7, 14, 21 and 28 via jugular vein. Health score and fecal point were determined daily. Results: Results showed that heat-treating of colostrum increased immunoglobulins uptake and their apparent efficiency of absorption (p<0.01), where a 24% increase in blood immunoglobulins concentrations and a 15% in their apparent efficiency of absorption were observed by heating the colostrum compared with control group and a lower increase was observed compared with antibiotic group. No significant differences were observed in weight gain, weaning time and weight as well as the amount and time of beginning starter intake among groups. Feed conversion ratio did not affected by the treatments. There were no significant differences in blood cells counts among groups. Calves fecal point was not affected by the treatments but health score was increased by using heat-treated colostrum where scour incidence was reduced (p<0.05). Conclusions: Results of the study showed that controlled heat-treating of colostrum is an effective and practical method to improve immunoglobulins absorption and reduce scour incidence in calf.

We examined the effect of infusion of lipopolysaccharide (LPS) on serum tumor necrosis factor alpha (TNF alpha) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (CF) and colostrum-deprived (CD) foals. Eleven CF and 8 CD neonatal foals were given a bolus IV infusion of Escherichia coli 055:B5 lipopolysaccharide (0.5 microgram/kg of body weight) in sterile saline (0.9% NaCl) solution. Four CF and 2 CD foals were given saline solution alone. Serum IgG concentration and serum anti-LPS IGG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum TNF alpha concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as TNF alpha by immunoprecipitation with caprine antisera raised against the 15 NH2-terminal amino acids of human TNF alpha. Tumor necrosis factor alpha was not detected in any preinfusion serum samples nor in any samples from foals given saline solution alone. Serum TNF alpha concentration increased in all LPS-infused foals and peaked between 60 and 90 minutes after infusion. Serum TNF alpha concentrations, expressed as mean percentage of peak serum TNF alpha concentration, persisted longer in CD foals given LPS than in CF foals given LPS. All LPS-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the CF and CD foals given LPS were not significantly different at any time. Serum TNF alpha concentrations were correlated with depression index scores in both LPS-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in CF foals given LPS. Mean rectal temperature in CD foals given LPS was significantly less than that for CF foals given LPS 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after.

Failure to obtain passive transfer of immunity via colostrum can be detrimental to the health and survival of a young pup. It has been stated that pups that do not receive colostrum in the first 2 days after birth, be given adult dog serum as a source of protective immunoglobulins. Twenty-five Beagle pups were obtained by cesarean section from 6 Beagle bitches. The pups were allotted to 3 groups at birth. Group 1 was a control group and was allowed to suckle colostrum. Group-2 pups received 22 ml of pooled adult dog serum/kg of body weight (10 ml/lb) SC at birth. Group-3 pups were given 22 ml of pooled adult dog serum/kg by stomach tube at birth. Pups from groups 2 and 3 were separated from the bitch for 48 hours to prevent colostral antibody absorption and were fed a commercially available milk replacer by stomach tube. After 48 hours, all pups were returned to the bitch until they were weaned at 6 weeks of age. Blood samples were collected from all of the pups at birth and on days 1, 2, 7, 14, 21, 28, and 35. The concentration of IgA, IgG, and IgM in serum was determined by radial immunodiffusion and compared by use of a one-way analysis of variance. The control pups had significantly higher serum concentrations of IgA and IgG, than the pups in groups 2 and 3 on days 1 and 2 and 2 and 7, respectively. Group-2 pups had significantly higher serum IgM concentrations on day 1 than either group 1- or group-3 pups.

The changes in serum total protein and immunoglobulin levels, and BVD, IBR and PI-3 viral neutralizing antibody titers in colostrum-conferred Korean native calves during the first 12 weeks postpartum were studied. The mean concentration of total protein, total immunoglobulin, IgG, IgM and IgA in sera of 9 calves at birth were 3.8 +- 0.5g/dl, 0.27 +- 0.15mg/ml, 0.06 +- 0.08mg/ml, 0.21 +- 0.11mg/ml, and extremely low concentration, respectively. Serum total protein level reached a maximum at 20 hours after birth, total immunoglobulin, IgG and IgM levels at 24 hours, and IgA level at 28 hours, respectively. Serum IgA level reached a minimum at 4 weeks old, IgM level at 5 weeks, total immunoglobulin level at 8 weeks, and IgG level at 10 weeks, respectively. After then those levels had begun to increase, but total protein level was still decreasing at 12 weeks old. The half-lives of IgG, IgM, and IgA were 21.1 days, 4.0 days, and 2.6 days respectively. In 10 Korean native cows immediately after parturition, serum neutralizing antibody titers specific to BVD, IBR and PI-3 virus were 8.7 +- 1.5 log2, 5.7 +-1.2 log2, and 6.8 +- 1.0 log2, respectively. And colostral neutralizing antibody titers against BVD, IBR, and PI-3 virus were 10.1 +- 1.4 log2, 6.8 +- 1.3 log2, and 7.8 +- 1.7 log2, respectively. Before suckling the colostrum, SN antibody titers against BVD, IBR, and PI-3 virus were undetectable from all of 9 Korean native calves. Nevertheless SN antibody titer against BVD virus reached a maximum level (9.2 +- 0.6 log2) at 24 hours after birth, that against IBR virus (6.1 +- 1.0 log2) at 20 hours after birth, and that against PI-3 virus (6.8 +- 0.9 log2) at 32 hours after birth, respectively. In 12 weeks old calves, the SN antibodies against BVD and IBR virus were still decreasing, but that against PI-3 virus reached a minimum at 10 weeks, and increased after 12 weeks of age. The half-lives of SN antibodies against BVD, PI-3 and IBR, virus were 16.0 days, 22.6 days, and 25.5 days, respectively.

The somatic cell count (SCC) is a screening test for the evaluation of intramammary infection; however, changes in mammary secretion during colostrogenesis can promote a physiological increase in the SCC, potentially reducing its reliability in the diagnosis of mastitis. Therefore, the aim of this study was to evaluate bovine colostrum SCC as an indicative parameter of breast infection in Holstein periparturient cows. A total of 80 samples were harvested from the first milking colostrum of 20 cows and were subjected to manual SCC and bacteriological examination. Bacterial growth was present in 36.62% of the crops; coagulase-negative Staphylococcus (CNS) was the predominant microorganism (76.92%). The median SCC in infected cows (1.8 × 106 cells/mL) was significantly higher than in uninfected cows (0.9 × 106 cells/mL) (p = 0.0451). The sensitivity (100–15%), specificity (100–2.2%), and false positive (100–2.2%) of the SCC decreased gradually when thresholds of 0.2–10.0 × 106 cells/mL were adopted. In contrast, the proportion of false negatives (0–84.6%) revealed an opposite trend. The threshold of greatest concordance between SCC and bacteriological examination was 10.0 × 106 cells/mL; however, the sensitivity rates (15.4%), specificity (2.2%), and false positive (2.2%) were very low. Based on these results, we conclude that SCCs increased prior to the infectious processes of the mammary gland, particularly in the CNS group. However, physiological changes caused by colostrogenesis resulted in poor concordance between the SCC and bacteriological examination of the colostrum.