Heat-treatment of bovine colostrum. II: effects of heating duration on pathogen viability and immunoglobulin G

Batches (30-L) of first-milking bovine colostrum, inoculated with Mycoplasma bovis (10⁸ cfu/mL), Listeria monocytogenes (10⁶ cfu/mL), Escherichia coli O157:H7 (10⁶ cfu/mL), Salmonella enteritidis (10⁶ cfu/mL), and Mycobacterium avium subsp. paratuberculosis (Map; 10³ cfu/mL), were heat-treated at 60°C for 120 min in a commercial on-farm batch pasteurizer system. Duplicate 50-mL subsamples of colostrum were collected at 15-min intervals throughout the heat-treatment process for the purpose of bacterial culture and for measurement of IgG concentration (mg/mL) and antibody activity [log₂(bovine viral diarrhea virus type 1 serum neutralization titer)]. Four replicate batches of colostrum were run for each of the 5 pathogens studied. There was no effect of heating moderate- to high-quality colostrum at 60°C for at least 120 min on mean IgG concentration (pre = 60.5 mg/mL; post = 59.1 mg/mL). Similarly, there was no effect of heat-treatment on the mean log₂ bovine viral diarrhea virus type 1 serum neutralization titer (pre = 12.3; post = 12.0). Viable M. bovis, L. monocytogenes, E. coli O157:H7, and S. enteritidis added to colostrum could not be detected after the colostrum was heat-treated at 60°C for 30 min. Average bacteria counts showed that Map was not detected when batches were heated at 60°C for 60 min. Although the authors believe that heat-treating colostrum at 60°C for 60 min should be sufficient to eliminate Map from colostrum in most situations, further research is needed to determine whether these findings may be replicated, given that variability was observed in Map culture results.     

Effect of heat treatment of bovine colostrum on bacterial counts, viscosity, and immunoglobulin G concentration

A study was conducted to identify the optimal temperature and time at which heat treatment of bovine colostrum would least change viscosity and IgG concentrations yet reduce bacterial count. First-milking colostrum with >50 g of immunoglobulins/L (measured by colostrometer) was collected from 30 Holstein cows. Aliquots of colostrum were heated for 0, 30, 60, or 90 min at 57, 60, or 63°C in a water bath. Samples were examined for viscosity, IgG₁, and IgG₂ concentrations, standard plate count, coagulase-negative staphylococci, environmental streptococci, coliform, gram-negative noncoliform, Streptococcus agalactiae, and Staphylococcus aureus counts. All heat treatments reduced counts of all bacteria groups measured compared with untreated colostrum samples. Heat treatment at ≥60°C denatured IgG₁ compared with untreated colostrum; however, colostral IgG₂ levels were not reduced when temperature was held at 60°C for <60 min. Viscosity was not affected when temperature was held at 60°C for <60 min. In this study, heat treatment of bovine colostrum at 60°C for 30 or 60 min reduced bacterial count, slightly reduced IgG concentration, and did not affect viscosity.     

AOT-异辛烷反胶束萃取技术分离牛初乳IgG的研究

在一个琥珀酸二(2-乙基己基)酯磺酸钠(AOT)-异辛烷反胶束体系中，研究了水相pH值、离子强度和有机相表面活性剂AOT浓度等因素对牛初乳乳清蛋白中IgG分离效果的影响。结果表明，在以下两组优化条件：①pH值为7．668，[Na^ ]浓度为0．270mol／L，[AOT]浓度为0．088mol／L；②pH值为6524，[Na^ ]浓度为0．205mol／L，[AOT]浓度为0．175mol／L，水相IgG的残留率或纯度分别达到最大值，分别为90．23％和98．35％．RID分析表明，反胶束萃取过程对原牛初乳乳清IgG的免疫反应活性基本无影响。     

Evaluation of the effects of ultraviolet light on bacterial contaminants inoculated into whole milk and colostrum,and on colostrum immunoglobulin G

Raw milk and colostrum can harbor dangerous microorganisms that can pose serious health risks for animals and humans. According to the USDA, more than 58% of calves in the United States are fed unpasteurized milk. The aim of this study was to evaluate the effect of UV light on reduction of bacteria in milk and colostrum, and on colostrum IgG. A pilot-scale UV light continuous (UVC) flow-through unit (45 J/cm²) was used to treat milk and colostrum. Colostrum and sterile whole milk were inoculated with Listeria innocua, Mycobacterium smegmatis, Salmonella serovar Typhimurium, Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Acinetobacter baumannii before being treated with UVC. During UVC treatment, samples were collected at 5 time points and bacteria were enumerated using selective media. The effect of UVC on IgG was evaluated using raw colostrum from a nearby dairy farm without the addition of bacteria. For each colostrum batch, samples were collected at several different time points and IgG was measured using ELISA. The UVC treatment of milk resulted in a significant final count (log cfu/mL) reduction of Listeria monocytogenes (3.2 ± 0.3 log cfu/mL reduction), Salmonella spp. (3.7 ± 0.2 log cfu/mL reduction), Escherichia coli (2.8 ± 0.2 log cfu/mL reduction), Staph. aureus (3.4 ± 0.3 log cfu/mL reduction), Streptococcus spp. (3.4 ± 0.4 log cfu/mL reduction), and A. baumannii (2.8 ± 0.2 log cfu/mL reduction). The UVC treatment of milk did not result in a significant final count (log cfu/mL) reduction for M. smegmatis (1.8 ± 0.5 log cfu/mL reduction). The UVC treatment of colostrum was significantly associated with a final reduction of bacterial count (log cfu/mL) of Listeria spp. (1.4 ± 0.3 log cfu/mL reduction), Salmonella spp. (1.0 ± 0.2 log cfu/mL reduction), and Acinetobacter spp. (1.1 ± 0.3 log cfu/mL reduction), but not of E. coli (0.5 ± 0.3 log cfu/mL reduction), Strep. agalactiae (0.8 ± 0.2 log cfu/mL reduction), and Staph. aureus (0.4 ± 0.2 log cfu/mL reduction). The UVC treatment of colostrum significantly decreased the IgG concentration, with an observed final mean IgG reduction of approximately 50%. Development of new methods to reduce bacterial contaminants in colostrum must take into consideration the barriers imposed by its opacity and organic components, and account for the incidental damage to IgG caused by manipulating colostrum.     

Impact of irradiation and immunoglobulin G concentration on absorption of protein and immunoglobulin G in calves fed colostrum replacer

The objective of this study was first to evaluate whether irradiation treatment of a commercial colostrum replacer (CR) affected acquisition of passive immunity. If the irradiation treatment negatively affected the acquisition of passive immunity, the second objective was to evaluate whether an increased total IgG mass, in a single feeding of CR derived from bovine serum fractions, could compensate for this effect. Acquisition of passive immunity was assessed by 24-h serum IgG levels, serum protein levels, apparent efficiency of absorption (AEA) of IgG, and the ability to prevent failure of passive transfer (FPT) in day-old dairy calves fed a single feeding of CR. Single-dose packs of CR were sent to a commercial irradiation facility for electron-beam irradiation at 3 to 7 kGy (low irradiation) or 15 to 20 kGy (high irradiation). Fifty-six Holstein, Jersey, or crossbred calves were randomly assigned to 1 of 5 treatments: 1) 130 g of IgG (460 g of CR), no irradiation; 2) 130 g of IgG (460 g of CR), low irradiation; 3) 160 g of IgG (518 g of CR), low irradiation; 4) 190 g of IgG (575.4 g of CR), low irradiation; and 5) 130 g of IgG (460 g of CR), high irradiation. All CR were reconstituted in water and mixed in a household blender to a constant solids concentration of 18.7%. Increasing doses of irradiation (130 g of Ig with no, low, or high irradiation) resulted in a linear decrease in 24-h serum IgG and AEA of IgG, and increased the percentage of calves with FPT. Increasing the IgG mass in the CR (130, 160, and 190 g of Ig with low irradiation) resulted in a linear increase in 24-h serum IgG and serum total protein levels, and a linear decrease in AEA of IgG. There was no effect of increasing the mass of IgG fed on the percentage of calves with FPT. The correlation between serum IgG and serum total protein at 24 h was positive; however, at 24 h the irradiation treatments reduced the serum IgG-to-serum total protein ratio. In this study, CR isolated from bovine serum, providing 130 g of IgG in the first feeding and receiving either no irradiation or a low irradiation treatment, was sufficient to prevent FPT in calves.     

Heat treatment of colostrum increases immunoglobulin G absorption efficiency in high-, medium-, and low-quality colostrum

Previous studies with heat-treated colostrum fed to neonatal calves have consistently used average-quality colostrum. Studies have not compared colostrum across a range of immunoglobulin levels. This study was conducted to investigate IgG absorption in neonatal dairy calves using colostrum of various qualities. Colostrum from the Pennsylvania State University dairy was collected over 2 yr and sorted into high, medium, and low quality based on colostrometer measurement. Colostrum within each category was pooled to create 3 unique, uniform batches. Half of each batch was frozen to be fed without heat treatment. The second half of each batch was heat treated at 60°C for 30 min. This process was conducted in September 2011, and repeated in June 2012. Colostrum treatments were analyzed for standard plate count, coliforms, noncoliform gram-negative bacteria, and total IgG concentration. Plasma samples were collected from 145 calves 48 h after birth and analyzed for IgG₁, IgG₂, total protein, and hematocrit. Colostrum quality (high, medium, or low), treatment (unheated or heat treated), and their interactions were analyzed as fixed effects, with year included as a random effect. Heat treatment significantly reduced all types of bacteria and IgG concentration. Plasma IgG concentration at 48 h increased linearly with the concentration of IgG in the colostrum that was consumed. Heat treatment of colostrum increased plasma IgG concentration by 18.4% and apparent efficiency of absorption by 21.0%. Results of this study suggest that heat treatment of colostrum containing approximately 50 to 100 mg IgG/mL increases absorption of IgG from colostrum.     

Effect of on-farm commercial batch pasteurization of colostrum on colostrum and serum immunoglobulin concentrations in dairy calves

The objectives were to describe the effect of on-farm commercial batch pasteurization on immunoglobulin (IgG) concentrations and the fluid and feeding characteristics of colostrum and to compare serum IgG concentrations in calves fed fresh versus pasteurized colostrum. Newborn calves (123) were systematically allocated to dietary treatments of either fresh or pasteurized colostrum at both the first and second colostrum feedings. The IgG concentrations were measured for batches of colostrum fed fresh and in pre and postpasteurized samples for batches of colostrum fed after being pasteurized and in calf serum. Pasteurization reduced colostrum IgG concentration, with the percentage reduction averaging 58.5 and 23.6% for 95-L and 57-L batches, respectively. Pasteurizing high quality colostrum in 57-L (vs. 95-L) batches resulted in higher IgG concentrations in the end product. Pasteurization of 57-L batches produced colostrum of normal or only mildly thickened consistency that could be fed to calves. Serum IgG concentrations were higher for calves fed fresh colostrum and for calves with a shorter time interval (< or = 6 h) between first and second colostrum feedings. After controlling for the time interval between feedings, serum IgG concentrations were significantly higher for 40 calves fed unpasteurized (19.1 mg/ml) vs. 55 calves fed pasteurized colostrum (9.7 mg/ml) for calves fed 2 L at first feeding. By contrast, there was no difference in serum IgG concentrations between 8 calves fed unpasteurized (16.1 mg/ml) and 20 calves fed pasteurized colostrum (13.5 mg/ml) after calves were fed 4 L at the first feeding. While the latter results suggest that pasteurizing colostrum may work for producers with excellent colostrum management, these results are preliminary and should be interpreted with caution, given the fewer number of calves and batches of colostrum involved with this second comparison.     

Evaluation of factors associated with immunoglobulin G,fat, protein,and lactose concentrations in bovine colostrum and colostrum management practices in grassland-based dairy systems in Northern Ireland

The objectives of this study were to investigate colostrum feeding practices and colostrum quality on commercial grassland-based dairy farms, and to identify factors associated with colostrum quality that could help inform the development of colostrum management protocols. Over 1 yr, background information associated with dairy calvings and colostrum management practices were recorded on 21 commercial dairy farms. Colostrum samples (n = 1,239) were analyzed for fat, protein, lactose, and IgG concentration. A subset was analyzed for somatic cell count and total viable bacteria count. Factors associated with nutritional and IgG concentrations were determined using both univariate and multivariate models. This study found that 51% of calves were administered their first feed of colostrum via esophageal tube, and the majority of calves (80%) were fed >2 L of colostrum at their first feed (mean = 2.9 L, SD = 0.79), at a mean time of 3.2 h (SD 4.36) after birth, but this ranged across farms. The mean colostral fat, protein, and lactose percentages and IgG concentrations were 6.4%, 14%, 2.7%, and 55 mg/mL, respectively. The mean somatic cell count and total viable count were 6.3 log₁₀ and 6.1 log₁₀, respectively. Overall, 44% of colostrum samples contained <50 mg/mL IgG, and almost 81% were in excess of industry guidelines (<100,000 cfu/mL) for bacterial contamination. In the multivariate model, IgG concentration was associated with parity and time from parturition to colostrum collection. The nutritional properties of colostrum were associated with parity, prepartum vaccination, season of calving, and dry cow nutrition. The large variation in colostrum quality found in the current study highlights the importance of routine colostrum testing, and now that factors associated with lower-quality colostrum on grassland-based dairy farms have been identified, producers and advisers are better informed and able to develop risk-based colostrum management protocols.     

Short communication: Fractional milking distribution of immunoglobulin G and other constituents in colostrum

The provision of quality colostrum with a high concentration of immunoglobulins is critical for newborn calf health. Because first colostrum may be low in overall concentration to effectively reduce the risk of newborn infections, we tested equivalent milking fractions of colostrum for possible IgG differences. The objective of this study was to determine if the fractional composition of colostrum changes during the course of milking with a focus on immunoglobulins. Twenty-four Holstein and Simmental cows were milked (first colostrum) within 4 h after calving. The colostrum of 1 gland per animal was assembled into 4 percentage fractions over the course of milking: 0 to 25%, 25 to 50%, 50 to 75%, and 75 to 100%. The IgG concentration among the various fractions did not change in any significant pattern. Concentration of protein, casein, lactose and somatic cell count remained the same or exhibited only minor changes during the course of fractional milking colostrum. We determined that no benefit exists in feeding any particular fraction of colostrum to the newborn.     

Selenium addition to colostrum increases immunoglobulin G absorption by newborn calves

The objective of this study was to show a new function of Se in IgG absorption from colostrum by newborn calves. The same amount and quality of colostrum with or without Se addition was fed to paired calves (n = 60) 4 times at <2, 12, 24, and 36 h after birth, respectively. Four-time feeding of colostrum containing 1.0 ppm Se significantly increased IgG amount in the blood plasma of calves 24 h after birth; however, its effect was small (about 20% increase). Although the addition of 3.0 ppm Se once at the first colostrum feeding was more effective on IgG absorption, its significant effect was a 42% increase on average. The increased IgG concentration of blood plasma continued for about 2 wk. It is known that the absorption of colostrum IgG is mediated by intestinal pinocytosis, which continues for only 24 h after birth. The addition of Se to colostrum might directly activate this physiological pinocytosis of intestinal epithelial cells because of the rapidity of the reaction. This effect is not nutritional but rather pharmacological. Supplemented Se also resulted in its increased concentration in blood plasma. Selenium is an essential mineral for animals; however, newborn calves are always deficient in Se at birth. Application of this method in calves would also provide an immediate supply of Se and might contribute to the development of the immune system of calves. This study showed that Se supplementation to colostrum increased IgG amount and Se concentration in blood plasma in newborn calves.     

牛初乳巴氏杀菌工艺的优化研究

热处理是牛初乳加工中必不可少的工艺过程.通过对热处理强度对初乳中IgG保留率、微生物数量以及营养成分损失的影响进行研究,并对巴式杀菌工艺进行优化,得出以下结果:杀菌温度为60℃和63℃,加热时间超过30 min可以将微生物数量降低到安全数量.IgG的保留率随加热温度的升高而降低,随加热时间的延长而降低.加热温度对美拉德反应、脂肪氧化和蛋白质水解反应的影响均显著.通过优化得出,杀菌温度60℃和加热时间30 min,可以既保证微生物安全,同时最大保留IgG的浓度和营养成分损失较低.     

牛初乳营养成分与其免疫球蛋白活性保持技术研究进展

牛初乳由高浓度的生物活性成分组成,具有调节肠道菌群、促进机体生长发育、增强人体免疫力的作用,是一种十分重要的功能性食品原料。免疫球蛋白是牛初乳中最重要的活性成分,但其在加工过程中损失较大。免疫球蛋白活性保持技术能够保护其免于热、酸和碱等不良环境的影响,进而提升牛初乳综合利用价值。文章综述了牛初乳的营养成分和牛初乳中免疫球蛋白主要活性保持技术的研究进展,并对其未来研究前景进行了展望。     

Short communication: evaluation of a color method for testing immunoglobulin G concentration in goat colostrum

Colostrum samples (n = 1084) of first and second milking from Majorera goats were taken. The immunoglobulin (Ig) G concentrations estimated by measurement of the color of goat colostrum and by the radial immunodiffusion technique were compared. Least squares analysis of the relationship between the color measurement method and IgG concentration resulted in a significant linear relationship. Using 20 mg of IgG/ mL of colostrum as the cut-off point for colostrum selection, the sensitivity, specificity, and negative predictive value of the color method as a test of IgG concentration in goat colostrum were 93.03, 71.43, and 78.12%, respectively.     

The effect of colostrum storage conditions on dairy heifer calf serum immunoglobulin G concentration and preweaning health and growth rate

The objective of the present study was to compare serum IgG concentration, weight gain, and health characteristics in Irish spring-born dairy calves fed colostrum stored using a range of conditions. Immediately after birth, 75 dairy heifer calves were assigned to 1 of 5 experimental colostrum treatments: (1) fresh pasteurized colostrum, fed immediately after pasteurization; (2) fresh colostrum, fed immediately after collection but not pasteurized; (3) colostrum stored unpasteurized at 4°C in a temperature-controlled unit for 2 d before being fed to calves; (4) colostrum stored unpasteurized at 13°C in a temperature-controlled unit for 2 d before being fed to calves; and (5) colostrum stored unpasteurized at 22°C in a temperature-controlled unit for 2 d before being fed to calves. All colostrum had IgG concentrations >50 g/L and was fed to calves promptly after birth. Blood samples were obtained from calves via the jugular vein at 0 h (before colostrum feeding) and at 24 h of age to determine the rate of passive transfer of IgG; individual calf live-weights were recorded to monitor weight gain (kg/d) from birth to weaning. Colostrum stored in warmer conditions (i.e., 22°C) had >42 times more bacteria present and a pH that was 0.85 units lower and resulted in a serum IgG concentration that was almost 2 times lower compared with colostrum that was pasteurized, untreated, or stored at 4°C for 2 d. Colostrum stored at 4°C for 2 d had more bacteria present than pasteurized and fresh colostrum but did not result in reduced calf serum IgG concentrations. Average daily weight gain from birth to weaning did not differ among treatments. Even if colostrum has sufficient IgG (>50 g/L) but cannot be fed to calves when freshly collected, storage at ≤4°C for 2 d is advisable to ensure adequate passive transfer when it is consumed by the calf.     

Short communication: Addition of varying amounts of sodium bicarbonate to colostrum replacer: effects on immunoglobulin G absorption and serum bicarbonate in neonatal calves

Fifty-two dairy calves were blocked by birth date and, within each block, randomly assigned to 1 of 4 treatments to investigate the effects of incremental levels of sodium bicarbonate (NaHCO₃) on IgG metabolism. Treatments were (1) colostrum replacer (CR) + 0 g of NaHCO₃ (control); (2) CR + 15 g of NaHCO₃; (3) CR + 30 g of NaHCO₃; or (4) CR + 45 g of NaHCO₃. Calves were fed colostrum replacer (>200 g of IgG) in one feeding within 45 min of birth (0 h) and 2 L of milk replacer at 12, 24, 36, and 48 h. Only calves born in calving pens from multiparous cows with no dystocia were used in this study. Blood samples were taken at 0, 6, 12, 24, and 48 h postpartum, and serum was analyzed for IgG using radial immunoassay and bicarbonate using spectrophotometry. Feeding increasing levels of sodium bicarbonate had negative linear effects on IgG concentration, IgG apparent efficiency of absorption, and IgG area under the curve, primarily due to the effect of the highest dose of NaHCO₃ (45 g). Sodium bicarbonate treatments had no effect on serum bicarbonate concentration. However, area under the curve of serum bicarbonate increased linearly with the amount of NaHCO₃ fed.     

Effect of different heating times of high-, medium-, and low-quality colostrum on immunoglobulin G absorption in dairy calves

The objective of this study was to determine the effect of different durations of heat treatment on passive transfer of IgG from high-, medium- and low-quality colostrum. Colostrum was collected from The Pennsylvania State University dairy herd and divided by quality (high, medium, or low) based on colostrometer measurements. Colostrum was pooled by quality to create 3 unique batches. Each batch was further divided in thirds as follows: frozen to be fed without heat treatment, heated at 60°C for 30 min, or heated at 60°C for 60 min. Colostrum samples from each treatment were collected and analyzed for standard plate count, gram-negative noncoliforms, coliforms, and total IgG concentration. Serum samples were collected from 108 Holstein calves before feeding colostrum and 24 h after birth. Blood samples were analyzed for total protein, total IgG, and hematocrit. Colostrum quality (high, medium, or low), heat treatment (unheated, 60°C for 30 min or, 60°C for 60 min), and their interaction were analyzed as fixed effects, with calf sex included as a random block effect. Colostrum IgG was different between quality groups (92.5, 59.4, and 48.1 mg/mL of IgG). Heating colostrum reduced IgG concentration compared with the control by 9% when heated for 30 min and by 12% when heated for 60 min. Colostrum heated for 60 min had a lower standard plate count than colostrum heated for 30 min or not heated (1.8, 2.0, and 3.6 log cfu/mL, respectively). Serum IgG concentration at 24 h increased as colostrum quality increased (18.0, 22.2, and 24.8 mg/mL) and tended to increase as heat treatment time increased (19.7, 20.3, and 25.0 mg/mL of IgG). Apparent efficiency of IgG absorption was greater in calves that received medium-quality colostrum compared with calves fed high-quality colostrum (38.1 and 25.0%, respectively). These results suggest an upper limit may exist to the amount of IgG absorption in a given time period and that medium- or high-quality colostrum yields similar blood IgG concentration given the same volume of intake.     

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 125 g of Ig (n = 218 calves) as the first colostrum feeding. For 7 of these farms that routinely provided a second feeding of 1.9 L of MC to their calves 8 to 12 h after the first colostrum feeding, calves assigned to the CR treatment group were offered a second feeding consisting of 1.9 L of commercial milk replacer supplemented with one dose of a commercially available plasma-derived colostrum supplement, containing 45 g of Ig per dose, 8 to 12 h 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 ± 7.0 mg/mL; TP = 5.5 ± 0.7 g/dL) compared with calves fed CR (IgG = 5.8 ± 3.2 mg/mL; TP = 4.6 ± 0.5 g/dL). The proportion of calves with failure of passive transfer (serum IgG <10.0 mg/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 = 10 mg/mL) was 5.0 g/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 feeding colostrum at different volumes and subsequent number of transition milk feeds on the serum immunoglobulin G concentration and health status of dairy calves

Transfer of sufficient IgG to the newborn calf via colostrum is vital to provide it with adequate immunological protection and resistance to disease. The objectives of the present study were to compare serum IgG concentration and health parameters of calves (1) fed different volumes of colostrum [7, 8.5, or 10% of body weight (BW)] within 2 h of birth and (2) given 0, 2, or 4 subsequent feedings of transition milk (i.e., milkings 2 to 6 postcalving). Ninety-nine dairy calves were fed 7, 8.5, or 10% of BW in colostrum within 2 h of birth and given 0, 2, or 4 subsequent feedings of transition milk. The concentration of IgG in the serum of calves was measured at 24, 48, 72, and 642 h of age by an ELISA. The apparent efficiency of absorption for IgG was determined. Health scores were assigned to calves twice per week and all episodes of disease were recorded. The effect of experimental treatment on calf serum IgG concentration differed by the age of the calf. Calves fed 8.5% of BW in colostrum had a greater mean serum IgG concentration than calves fed 7 or 10% of BW at 24, 48, and 72 h of age. At 642 h of age, serum IgG concentrations of calves fed 8.5% of BW (24.2 g/L) and calves fed 10% of BW (21.6 g/L) did not differ, although the serum IgG concentration of calves fed 8.5% of BW was still greater than that of calves fed 7% of BW (20.7 g/L). No difference in serum IgG concentration existed between calves fed 7% of BW and those fed 10% of BW at any age. No significant effect of number of subsequent feedings of transition milk on calf serum IgG concentration was detected. The apparent efficiency of absorption of calves fed 8.5% of BW in colostrum (38%) was greater than calves fed 7% of BW in colostrum (26%) and tended to be greater than in calves fed 10% of BW (29%). Calves fed further feedings of transition milk after the initial feeding of colostrum had a lower odds (0.62; 95% confidence interval: 0.41 to 0.93) of being assigned a worse eye/ear score (i.e., a more copious ocular discharge or pronounced ear droop) and a lower odds (0.5; 95% confidence interval: 0.32 to 0.79) of being assigned a worse nasal score (i.e., a more copious and purulent nasal discharge) during the study period relative to calves that received no further feedings of transition milk. In conclusion, calves fed 8.5% of BW in colostrum within 2 h of birth achieved a greater concentration of IgG in serum in the first 3 d of life than calves fed either 7 or 10% of BW. Feeding calves transition milk subsequently reduced their odds of being assigned a worse eye/ear and nasal score.     

Short communication: Addition of milk replacer to colostrum whey: effect on immunoglobulin G passive transfer in Majorera kids

Forty-two Majorera kids (21 males and 21 females) were assigned to 3 groups, a colostrum group (C), a colostrum whey group (CW), and a colostrum whey plus milk replacer group (CWMR). All kids were fed twice on the first day and received 4 g of IgG/kg of body weight. No differences were found in serum IgG among the different treatments. Kid serum IgG concentrations on d 2 were 14.57, 17.25, and 13.32 mg/mL in the C, CW, and CWMR group, respectively. Labor time per animal was higher in the C and CW treatments than in the CWMR group (24.2 ± 2.3, 20.9 ± 3.4, and 16.1 ± 1.5 min, respectively). This new management system may decrease labor costs during the colostrum feeding period.     

Effects of lyophilized colostrum and different colostrum feeding regimens on passive transfer of immunoglobulin g in Majorera goat kids

Three experiments were conducted including 180 Majorera kids. In the first experiment, the effect of use of lyophilized colostrum vs. frozen colostrum on immunoglobulin G (IgG) blood serum concentration was evaluated. Kids (n = 40) received the same management and IgG mass [3368 mg/kg of body weight (BW)] during the colostrum feeding period. The IgG in blood serum of kids from the lyophilized colostrum group was greater than that for kids that received frozen colostrum. The second experiment evaluated the effect of total IgG ingested by kids (n = 60) on IgG in blood serum during the colostrum feeding period. Three groups of animals received 3368, 1684, and 842 mg of IgG/kg of BW in 4 feedings for 2 d [high IgG concentration (H-IgG), medium IgG concentration (M-IgG), and low-IgG concentration (L-IgG), respectively]. The IgG blood serum in the kids that received H-IgG was greater than in the other 2 treatment groups, and no statistical differences were found for IgG in blood serum of kids that received either M-IgG or L-IgG. The third experiment evaluated the effect of timing of lyophilized colostrum meals on IgG blood serum concentration. Four groups of kids (n = 80) were used. Two groups received 1684 mg of IgG/kg of BW (higher level-1 d and higher level-2 d) and the other 2 groups received 842 mg of IgG/kg of BW (lower level-1 d and lower level-2 d). Two groups received 2 feedings in 1 d, and the other 2 groups received 4 feedings over a 2-d period, as denoted. Higher level-1 d kids had greater IgG blood serum concentration than the higher level-2 d kids, and no statistical differences were found between lower level-1 d and lower level-2 d kids.