Relationship between stress levels of the antepartum cow and her newborn calf

We investigated the relationship of the stress levels of the dam before and after delivery to that of her offspring soon after birth. Eight pregnant cows were penned 7 days before calving. Blood was taken from the jugular vein of cows at ?7, 1, 2 and 3 days from calving. Blood was also taken from newborn calves at 6 h and 1 and 2 days after birth. Concentrations of cortisol and immunoglobulin G in blood and colostrum were examined. Pearson's correlation coefficient showed that the higher the plasma cortisol concentration of a cow before calving, the higher that of its calf after birth (all P < 0.01). In addition, path analysis demonstrated that the direct effect of the plasma cortisol concentration of the dam before calving on the plasma cortisol concentration of her calf after birth was 0.971 (P < 0.01). However, the colostrum cortisol concentration correlated with neither plasma cortisol concentrations of cows before calving nor that of calves after birth. Unlike cortisol, a clear correlation of immunoglobulin G concentrations in plasma and colostrum was not observed between cows and calves. The results indicate stress is transferred from a cow to her newborn calf not by way of the colostrum but through the placenta.     

Influence of selenium administration to dry cows on selected biochemical and immune parameters of their offspring

The study was performed on 16 Holstein‐Friesian calves divided into two groups of eight animals each. The first group was composed of calves whose mothers did not receive selenium supplements (Se0). The second group consisted of calves whose mothers were administered intramuscular injections of a selenium and vitamin E supplement containing 0.5 of sodium selenite/ml and 50 mg of tocopherol acetate/ml in a single dose of 30 ml (Se30) ml, 10 days before the expected parturition date (10 ± 2 days). The calves were fed 2.5 L of the mother's colostrum administered by stomach tube 2 hr after birth and another 2 L 6 hr after birth. Blood from all calves was collected 7 times from external jugular vein (day 0–before colostrum administration and on the 2nd, 3rd, 4th, 7th, 14th and 21st days of life) for analyses of selenium, ceruloplasmin, transferrin, lactoferrin, immunoglobulin G (IgG) concentrations and gamma‐glutamyl transferase (GGT) and lysozyme activity. Selenium concentration was significantly higher in calves whose mothers received selenium supplements than in the offspring of non‐supplemented cows until 72 hr after birth (p ≤ .05). Lysozyme and GGTP activity and IgG concentration were significantly higher in the S30 group during the entire experiment (p ≤ .05). Supplementation of selenium to the mothers did not influence the ceruloplasmin, lactoferrin and transferrin levels in calves. A single injection of a selenium supplement administered to cows during late pregnancy increases selenium levels in calves and enhances passive transfer from the mother to the offspring.     

Colostral and milk insulin-like growth factors and related substances: mammary gland and neonatal (intestinal and systemic) targets

The identification of hormones and regulatory factors in colostrum and milk has led to intensive investigations on their roles in the development and maintenance of the mammary and neonatal tissues. Insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in transgenic mice influence mammary biology gland towards the end of lactation. In the bovine, IGFBP-3 is the major IGFBP in mammary secretions. In addition to binding IGFs, IGFBP-3 also binds to lactoferrin (Lf). Secreted IGFBP-3 re-enters mammary epithelial cells and with the presence of a nuclear localization sequence, IGFBP-3 and Lf enter the nucleus. Nuclear IGFBP-3 affects apoptotic signaling through the retinoic-x-receptors, while Lf affects apoptotic events through unknown mechanisms. Such interactions likely influence mammary development and involution. Furthermore, ingested colostral bioactive factors can exert regulatory functions in neonates. Intestinal receptors for IGFs and insulin are modified by age and/or diet. Feeding IGF-I had no effect, but colostrum extracts had small intestinal effects (stimulation of proliferation and villus size), suggesting that several factors, rather than one single bioactive factor were responsible. Systemic changes of metabolic and endocrine profiles in neonates depend on composition, amounts, time and duration of feeding colostrum. Early postnatal colostrum intake is not only important for the provision and absorption of immunoglobulins. Thus, in neonatal calves the lack of colostrum intake during the first 24h after birth results in a low immunoglobulin G, beta-carotene and Vitamin A status that persists for weeks and plasma patterns of fatty acids, essential amino acids and the glutamine/glutamate ratios are affected. In calves oral administration of IGF-I had no and feeding of colostrum whey extracts had only minor effects on metabolic and endocrine traits. Thus, mammary secretions influence regulatory functions of mammary and neonatal tissues.     

Influence of colostral quality on serum proteins in dairy calves raised in smallholder farms in Thailand

The objective of this study was to analyze the influence of colostral quality on serum proteins in calves. Samples were collected from visited farms in Kasetsart University Veterinary Teaching Hospital at Kamphaeng Saen and Nong Pho Animal Hospital. In total, 35 dairy farms contributed 80 dams and calves’ samples. Colostrum samples from 80 dairy cows and blood samples from their calves were taken to evaluate colostral immunoglobulins (Ig) and immunoglobulin G (IgG), and calf serum protein and IgG. Total colostral Ig, colostral and serum IgG, and serum protein were measured by a colostrometer, single radial immunodiffusion, and refractrometer, respectively. Immunoglobulin G and serum protein concentrations increased in the 1st day after birth, and maximum concentrations were seen in the 2nd day and then decreased in the 7th and 14th days. Average?±?SD total colostral IgG concentrations at calving date and at 1 and 2 days after calving were 93.85?±?33.89, 37.11?±?23.51, and 17.23?±?9.4 mg/mL, respectively. The profile of total Ig and IgG concentrations in colostrum had a similar pattern, with the maximum concentrations obtained in calving date and rapidly decreased thereafter. Low IgG concentrations were seen in the 7th and 14th day after calving. The calves that were fed with high quality colostrum had higher serum protein at 1 day of age, 7.49?±?1.01 g/dL, than calves fed with low quality colostrum, 6.40?±?0.86 g/dL (P?<?0.01). The increase in serum protein after first colostrum feeding of high and low quality colostrum was 1.55?±?1.07 and 0.81?±?0.69 g/dL, respectively (P?=?0.02).     

Effect of colostrum intake on diarrhoea incidence in new-born calves

In a survey which lasted one year and included data of 73 dairy cows with their calves, colostrum immunoglobulin G (IgG) of 22 primiparous cows and serum IgG of their calves were lower than the corresponding IgG levels of 51 multiparous cows and their calves. Serum IgG concentration was not correlated with diarrhoea incidence. Although there were no seasonal differences in the IgG concentration of colostrum and calf serum, neonatal diarrhoea incidence was higher in calves which were born in winter than in calves which were born in summer (P < 0.01). Thus the high diarrhoea incidence in winter was not a consequence of an insufficient IgG transfer to the calves. The 60 calves of the second study were fed colostrum on the first day of life. From the second to the tenth day 28 experimental calves received milk and 0.5 l of surplus colostrum of the first and second milking twice a day, whereas 32 control calves received milk only twice a day. Two of the 28 experimental and 11 of the 32 control calves suffered from diarrhoea during the first ten days of life (P < 0.05). These results show that the ingestion of surplus colostrum in addition to milk after the first day of life protects the new-born calf against infectious diarrhoea.     

Bovine colostrum enriched with lyophilized bovine colostrum stimulates intestinal epithelium renewal of Holstein calves in the first days of life

Consumption of a second meal of colostrum with high quality could contribute to the intestinal epithelium development, especially if there is poor supply of colostrum just after birth. The effect of a second colostrum meal was evaluated on histomorphometry of the intestinal mucosa of newborn Holstein calves fed with high‐ and low‐quality first colostrum. Seventy‐two calves were fed with a first colostrum meal with high (HFM, close to 100 mg/ml) or low (LFM, close to 30 mg/ml) IgG concentration. At 12 hr of life, three treatments of second colostrum feeding were applied to the calves either fed high or low first colostrum: calves fed with low (LOW—close to 30 mg/ml) or high (HIGH—close to 100 mg/ml) IgG concentration; and colostrum enriched with lyophilized bovine colostrum with high IgG concentration (ENRICHED—higher than 120 mg/ml), resulting in six groups. Intestinal samples were collected after 24 and 72 hr of life. In the distal jejunum and ileum, LOW showed higher villus height than ENRICHED (p < .05). In the distal jejunum, greater villus perimeter was observed in the LOW compared to ENRICHED at 24 hr (p < .05). In ileum, LFM showed higher villus perimeter compared to HFM (p < .05). LOW showed the highest villus height‐to‐crypt depth ratio in the medium and distal jejunum and ileum, p < .05. ENRICHED and HFM showed decreased muscle layer thickness in the proximal and distal jejunum respectively (p < .05). The results reveal that the high concentration of total solids, crude protein, IgG and IGF‐I of colostrum with high quality worsened the absorptive area, but may have stimulated the activity of cell division in intestinal crypts. Considering the present results, bovine colostrum enriched with lyophilized bovine colostrum stimulates intestinal epithelium renewal of Holstein calves in the first days of life.     

Serum immunoglobulin G concentrations in calves fed fresh colostrum or a colostrum supplement

This study compared serum immunoglobulin G (IgG) concentrations in calves fed colostrum with those of calves fed a colostrum supplement containing spray-dried serum. Twenty-four Holstein calves were randomly assigned to I of 2 treatment groups (fresh colostrum or colostrum supplement). Each calf was fed 4 L of colostrum (n, = 12) or 4 L of colostrum supplement (n2 = 12) via oroesophageal intubation at 3 hours of age. The concentration of the colostrum supplement fed to calves was twice the manufacturer's recommendation. The median and range values for colostral IgG concentration were 6,430 mg/dL and 1,400-17,000 mg/ dL, respectively. Median serum IgG concentrations at 2 days of age differed significantly (P = .001) between calves receiving fresh colostrum (3,350 mg/dL) and the colostrum supplement (643 mg/dL). Eight percent of calves force fed colostrum had serum IgG concentrations < 1,000 mg/dL, whereas 75% of calves force-fed supplement had IgG concentrations below this threshold. The calculated population relative risks for mortality associated with passive transfer for calves force-fed colostrum and calves force-fed colostrum supplement were 1.09 and 1.90, respectively. Force-fed fresh colostrum is superior to the colostrum supplement studied, but the colostrum supplement has similar efficacy to routine colostrum administration practices.     

Blood and Colostrum/Milk Serum γ‐Glutamyltransferase Activity as a Predictor of Passive Transfer Status in Lambs

The importance of blood and colostrum/milk serum γ‐glutamyl transferase (γ‐GT) enzyme activity was evaluated to assess passive transfer status in healthy lambs. Thirty Akkaraman sheep (3–6 years old) were used which had normal pregnancy period and the same conditions, and the age of the lambs ranged between 0 and 15 days. Blood and colostrum/milk samples were collected from sheep and lambs after birth, before suckling (0) and after on 1st, 3rd, 7th and 15th days. Serum immunoglobulin G (IgG) concentration was determined by the use of Single Radial Immunodiffusion method. Serum γ‐GT activity was measured, using a commercially available kit in blood and colostrum/milk samples. Correlations were carried out between immunoglobulin and γ‐GT levels. Regression models (simple and multiple) were calculated with significant data. Linear correlation was determined between colostrum/milk γ‐GT activity and IgG concentrations and between serum γ‐GT activity and IgG concentrations in lambs on the 0 day. (r: 0.607, P: 0.001), 1st (r: 0.768, P: 0.001) and the 3rd (r: 0.603, P: 0.001) days and on the 1st (r: 0.637, P: 0.001) and 3rd (r: 0.478, P: 0.012) days in the experiment, respectively. Multivariate regression models were developed to estimate sample IgG concentration. Serum and colostrum/milk IgG concentration could be predicted using the formula: lamb serum IgG = 825 + 0.688 (lamb γ‐GT) + 52 (days); colostrum/milk IgG = 832 + 0.505 (colostrum/milk γ‐GT) ? 167 (days). The regression models were moderately accurate in predicting serum IgG concentration (R² = 0.51) and colostrum/milk IgG concentration (R² = 0.55). Test sensitivity and positive predictive values for serum γ‐GT enzyme activity were found to be 96 and 100% and for colostrum/milk γ‐GT enzyme activity were found to be 100 and 68% to prediction IgG concentration. Serum and colostrum/milk γ‐GT activity can be used to assess passive transfer status of lambs. Along with this, regression models used to calculate serum and colostrum/milk γ‐GT activities found to be useful to estimate sample IgG concentration. The use of serum and colostrum/milk γ‐GT enzyme activity was found useful especially after birth on the 0, 1st and 3rd days.     

Effect of addition of soybean trypsin inhibitor to colostrum on immunological status in goat kids

The aim of the study was to evaluate the influence of soybean trypsin inhibitor (TI) on immunoglobulin G (IgG) serum levels and growth in neonatal goat kids. Twenty‐four newborn kids were fed with natural colostrum (group A), and 24 kids received the same colostrum with 1 g of TI per litre (group B). Blood samples were obtained at birth and on days 1, 2 and 4 of life to analyze serum proteins, IgG and haematological parameters. There were no clinical signs of disease and no significant differences in body weight between the groups. Haematological parameters were not affected by treatment. The peak of serum IgG was reached at 24 h of life, but no effects of soybean TI was observed on serum IgG levels. The apparent efficiency of absorption of IgG was similar in both groups (group A 24.5% vs. group B 25.2%, p > 0.05). The addition of TI to colostrum did not change the concentration of serum proteins and their fractions in goat kids. The correlation between serum IgG and γ‐globulin was positive and significant (p < 0.01, r = 0.64) in group A, but not in group B (p > 0.05, r = 0.08), suggesting a negative influence of soybean TI on γ‐globulin absorption. These results show that addition of soybean TI to colostrum did not improve the performance or immunological status in goat kids.     

Colostrum quality,IgG absorption and daily weight gain of calves in small-scale dairy production systems in Southern Vietnam

Dairy production is expanding rapidly in Vietnam, but still, the smallholder farms are most common. The aim of this study was therefore to get improved knowledge about colostrum quality in dairy cows, immunoglobulin G (IgG) absorption, daily weight gain in dairy calves and calf management in small-scale dairy production systems in Southern Vietnam. A field survey was conducted on 40 farms, with two calves on each farm being intensively studied. It was observed that newborn calves were separated from their dams immediately after birth and offered 2–4 L first colostrum within 4 h by bucket feeding. The first colostrum IgG level, fat and protein content were on average 35.6, 4.8 and 21.4%, respectively, and 91% of the cows produced colostrum of good quality (Brix value >22%). The IgG level in serum of calves, measured as Brix value, was on average 9.3%. Colostrum in the samples studied was of quite high quality and on-farm observations showed that colostrum was offered on the first day of calf life, so passive transfer of immunity to the calves was high. In total, 10% of the calves had a Brix value for IgG in serum lower than 8.3%, indicating that those calves had suffered from failure of passive immune transfer (FPT). The daily weight gain of female and male calves was 0.75 and 0.54 kg, respectively. Serum IgG was positively correlated with colostrum protein (P = 0.002). Daily weight gain and diarrhoea was negatively correlated (P = 0.001).     

Use of mammary gland and colostral characteristics for prediction of colostral IgG1 concentration and intramammary infection in Holstein cows.

OBJECTIVE: To determine whether mammary gland or colostral characteristics at calving could be used to predict colostral immunoglobulin G1 (IgG1) concentration or intramammary infection (IMI) and whether leakage of colostrum affects IgG1 concentration. DESIGN: Prospective study. ANIMALS: 113 multiparous Holstein cows. PROCEDURE: Cows were examined within 3 hours of calving, and mammary gland and colostral characteristics, colostral volume, somatic cell count, and concentrations of IgG1, fat, and protein were determined. Bacteriologic culture of mammary secretions was performed approximately 14 and 7 days before calving and at calving. Associations of gland and colostral characteristics with colostral IgG1 concentration, colostral volume, and IMI were examined. RESULTS: Thick or thin colostrum had higher IgG1 concentration than colostrum of intermediate viscosity. Colostrum from mammary glands that were firm had low IgG1 concentration. Colostral IgG1 concentration was weakly correlated with volume. Intramammary infection was likely to be detected if colostrum contained clots or blood or if the California Mastitis Test (CMT) score was > or = 2. Somatic cell count was higher for glands with IMI than for uninfected glands, and CMT score was correlated with cell count. CLINICAL IMPLICATIONS: Mammary gland and colostral characteristics were of little value in predicting IgG1 concentration. Our findings do not support recommendations that first milking colostrum that is thin (watery) or that is from cows producing large volumes not be fed to dairy calves. Colostral characteristics, particularly CMT score, were of value for predicting IMI.     

Absorption of colostral immunoglobulins and its interdependence

Three main factors underlying the immunity state of newborn calves are evaluated. During the absorption of colostral immunoglobulins the immunoprotein profile of a newborn calf is influenced by the following factors (arranged according to importance): volume of the first colostrum taken in, time of the first drinking, and immunoglobulin concentration (IgG and IgM) in colostrum. When given 1.1 or 2.0 litres of colostrum of about the same quality (as to immunity), the calves of the compared groups had significantly different levels of total serum Ig measured 24 hours after birth: 10.7 and 18.6 U ZST (P less than 0.05) and 48 hours after birth: 11.7 and 19.7 U ZST (P less than 0.01). A significant difference in total serum proteins was observed only in the 48th hour post partum (54.4 and 63.6 g per litre; P less than 0.05). At the intake of 1.5 litres of colostrum within two and five hours after birth, with the same total intake of the sum of IgG and IgM in the groups, the calves exhibited, in the 24th hour, total serum Ig levels of 14.4 and 12.4 U ZST (P greater than 0.05) respectively, and 56.0 and 47.9 g per litre (P greater than 0.05) of total serum protein, respectively. With a different concentration of colostral IgG (122.0 or 77.0 g per litre) the statistically significant Ig absorption into blood was adequately different (17.2 and 10.0 U ZST, respectively, P less than 0.05). The differences in the concentration of total serum Ig and total proteins between the 24th and 48th hour after birth were only very small and statistically insignificant. Regression analysis proved a significant relation (P less than 0.01) between the level of total serum Ig 24 and 48 hours after birth and the total amount of IgG and IgM taken in with the first colostrum. The calves coming from primiparae had a lower immunity (P less than 0.01) in comparison with the calves of multiparae. A similar relation in the absorption of colostral Ig was observed when the spontaneously born calves were compared with those born by the Caesarean section (P less than 0.01).     

初乳饲喂次数对娟姗犊牛生产性能的影响

为研究探讨初乳饲喂次数对娟姗犊牛生产性能的影响,试验选取初生重接近的健康娟姗犊牛20 头,随机分为4 组,分别为对照组、试验I组、II组和III组,每组5 头犊牛,试验期为60 天。4 组犊牛出生当日饲喂两次初乳,首次初乳量按照体重的10.0%进行灌服,第2次初乳于出生后6~8 h按照体重的5.0%进行饲喂。4 组犊牛出生当日在产房饲养,2日龄时均转为室外犊牛岛单栏饲养。2日龄后,对照组每天上午06:00和下午16:00时各饲喂常乳1次,2~6日龄每次饲喂1.50 L,7~20日龄每次饲喂1.80 L,21~35日龄每次饲喂2.50 L,36~60日龄每次饲喂3.00 L,自7日龄开始犊牛自由采食颗粒料。试验Ⅰ组、Ⅱ组、Ⅲ组分别继续饲喂初乳至犊牛2日龄、4日龄、6日龄后再饲喂常乳,饲喂时间和饲喂量与对照组一致。结果表明:(1)在饲喂初乳后48 h、72 h、96 h,试验组与对照组犊牛血清免疫球蛋白g(IgG)均差异显著(p<0.05),120 h、144 h、168 h,试验Ⅰ组与对照组比较,犊牛血清IgG含量差异不显著(p>0.05),试验Ⅱ组、Ⅲ组血清IgG含量与对照组相比,差异极显著(p<0.01)。(2)随着初乳饲喂次数的增加,可有效降低犊牛20日龄内腹泻发生率,试验Ⅰ组、Ⅱ组、Ⅲ组较对照组比较犊牛腹泻发生率分别降低9.5%、22.5%、36.5%,治疗犊牛腹泻总成本较对照组分别下降12.0 元、43.2 元、76.8 元,3 组试验组犊牛成活率为100.0%。(3)初乳饲喂次数的增加,使0~60日龄娟姗犊牛平均日增重(ADG)升高,试验组与对照组相比较,日增重均差异极显著(p<0.01),分别增加16.7 g、33.3 g、80.0 g。试验Ⅱ组、Ⅲ组较试验Ⅰ组ADG差异也极显著(p<0.01)。综合考虑,建议娟姗犊牛饲喂初乳至6日龄,可降低犊牛腹泻发生率、减少治疗费用,提高犊牛成活率及ADG。     

Effect of quality of colostrum on health,growth and immunoglobulin G concentration in Holstein calves in a hot environment

The aim of this study was to determine the effect of ingestion of pasteurized and subsequently frozen–thawed pooled colostrum (≥50 mg Ig/mL) with different bacterial counts and immunoglobulin concentration (IgC) on the occurrence of diarrhea and pneumonia in 306 neonatal Holstein calves in a hot environment. Calves were assigned to be fed colostrum with total bacterial counts (TBC) lower or greater than 100 000 colony‐forming units (cfu)/mL, total coliform counts (TCC) greater or lower than 10 000 cfu/mL, and IgC lower or higher than 85 mg Ig/mL. Calves fed colostrum with TBC ≥100 000 cfu/mL were more likely (risk ratio 1.34, confidence interval 1.05–1.71; P < 0.05) to present pneumonia than calves receiving colostrum with lower TBC (incidence 53.2 vs. 39.8%). Calves fed colostrum with high TCC had increased chances of suffering pneumonia (51.4 vs. 42.1%; P < 0.05) than calves fed colostrum with lower TCC. Calves fed colostrum with ≥85 mg Ig/mL tended to present higher daily weight gain (505 ± 113 vs. 484 ± 126 g; P = 0.09). TBC and TCC in colostrum did not influence the incidence rate of diarrhea. It was concluded that under the conditions of the present study, heavy contamination of on‐farm pasteurized frozen–thawed colostrum is seemingly unavoidable and this contamination poses a threat for pneumonia, but not for diarrhea.     

The supply of newborn camel foals (Camelus dromedarius) with immunoglobulin G

A major problem in camel breeding in East Africa is the high mortality rate of young camel calves. The purpose of this research was to examine the quality of camel colostrum and extent of the calves passive immunization by maternal antibodies. In 31 camel birth on a ranch in Kenya, IgG concentrations in the colostrum and in the serum of the calf during the first three days of life were measured. IgG concentration in the serum of the calf reaches a maximum 24 hours after birth. In 39% of the examined calves, this maximum concentration was below 4 g/l. In 61% of the calves, an IgG concentration of more than 4 g/l was reached. No correlation was found between diseased animals and the IgG concentrations in the serum of the calves involved. A minor IgG concentration can be excluded as a reason for calves mortality. The high percentage of insufficient IgG concentration in the serum of the calves therefore must be caused by insufficient intake of colostrum. Future measures in order to decrease calves mortality must therefore try to improve the management of calves, especially the sufficient intake of colostrum.     

白头翁皂苷B4对哺乳期犊牛生长性能和血清指标的影响

本试验旨在研究白头翁皂苷B4对哺乳期犊牛生长性能和血清指标的影响.选取60头新生荷斯坦公犊牛,随机分为4组(每组15头),分别饲喂在代乳粉中添加0(C组)、15(A1组)、30(A2组)和45 mg/d(A3组)白头翁皂苷B4的饲粮.试验期56 d,其中预试期14 d,正试期42 d.每2周空腹称重、测量体尺,每日记录...     

Feeding different amounts of colostrum or only milk replacer modify receptors of intestinal insulin-like growth factors and insulin in neonatal calves

Colostrum intake influences growth and development of the gastrointestinal tract (GIT) in several species and colostral insulin-like growth factors I and II (IGF-I and IGF-II), and insulin are involved in neonatal intestinal tissue growth. We have studied IGF type 1, IGF type 2, and insulin receptors in the intestine of 8-day-old calves fed different amounts of colostrum or only milk replacer. Calves were fed colostrum of the first six milkings on the first 3 days and then milk replacer (GrC(6)) or colostrum only once and then milk replacer (GrC(1)) or they were fed only milk replacer from the beginning, i.e., no colostrum (GrM). Competitive binding studies and ligand blots confirmed the presence of IGF type 1, IGF type 2, and insulin receptors in mucosal cell membranes of duodenum, jejunum, ileum, and colon. The IGF type 1 receptor number in ileum and total intestine in GrC(6) was greater (P<0.05) than in GrC(1) and in GrM, and IGF type 2 receptor number in total intestine was greater (P<0.05) in GrC(6) than in GrM. Insulin binding was best fitted by a model with two binding sites. High affinity insulin receptor numbers in duodenum, ileum, and total intestine were greater (P<0.05) in GrC(6) than in GrM. The data demonstrate that IGF type 1, IGF type 2, and insulin receptors in intestinal mucosa of neonatal calves are influenced by feeding.     

Plasma leptin status in young calves: effects of pre-term birth, age, glucocorticoid status, suckling, and feeding with an automatic feeder or by bucket

Plasma leptin concentrations depend on energy intake and fat stores and are modified by hormones, such as glucocorticoids. We have measured plasma leptin concentrations in pre-term calves (born on day 277 of gestation) during the first week of life, in full-term calves (290 days of gestation), fed similar amounts of nutrients with colostrum or a milk-derived formula, combined with or without dexamethasone treatment (to simulate a high glucocorticoid status), during the first five days of life, and in calves fed with an automatic feeder or by bucket or suckling on dams up to day 28. Leptin concentrations increased (P<0.05) from birth to day 7 in pre-term calves. In full-term calves leptin concentrations were stable from day 1 to day 4 in colostrum-fed animals, but decreased (P<0.05) and were lower (P<0.05) if fed a formula with similar amounts of energy and macronutrients as colostrum. Concentrations increased (P<0.05) from day 1 to day 2 in calves suckling on dams and then remained elevated, but did not change and were lower in calves fed with the automatic feeder or by bucket than in suckling calves. Dexamethasone only slightly elevated leptin concentrations. There was no episodic secretion pattern, and there were no consistent associations of leptin with various metabolites and hormones. In conclusion, plasma leptin in young calves with respect to effects of nutrition (low energy intake) and hormones (glucocorticoids) and in association with metabolic changes behaved differently from what is known in mature cattle.     

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system Part II. Effects on neonatal lymphocytes

It has been established that maternal leukocytes, conditioned by the mammary environment, cross the neonatal gut and circulate in the newborn calf. However, the impact of these cells on the development of neonatal immunity remains to be determined. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal adaptive immunity by examining the expression of surface markers on neonatal lymphocytes. At birth, neonatal calves were fed whole colostrum, or colostrum that had the maternal cells removed (cell-free colostrum), from their respective dams. Peripheral blood samples were collected at regular intervals over the first 4 weeks of life and lymphocytes were evaluated for surface expression of cellular markers. The results of these studies demonstrated that calves receiving whole colostrum had fewer CD11a positive lymphocytes in circulation during the first 2 weeks of life and this marker was expressed at a lower density than calves receiving cell-free colostrum. In addition, calves receiving whole colostrum also had a higher percentage of lymphocytes expressing the activation markers CD25 and CD26 by 7 days after birth. During the first week of life, lymphocytes from calves receiving whole colostrum had a higher density of MHC class I expression on their surfaces than cells from calves receiving cell-free colostrum. In general, these results indicate that transfer of maternal cells with colostrum allows for more rapid development of lymphocytes and maternal cells appeared to enhance their activation.     

Experimental use of gamma globulin preparations and their effect on serum immunoglobulin levels in calves

The saturation effect of a serum and colostrum immunoglobulin preparation on the humoral immunity system of calves was studied during the first days after birth. The positive effect of the preparations depended on the dose and on the immunity level acquired through colostrum. The serum immunoglobulin preparation was used at three doses (1.2 ml, 1.6 ml, 2.2 ml per kg live weight). In the calves suffering from hypogammaglobulinaemia, a significant saturation effect was recorded only at the dose of 2.2 ml per kg live weight. This dose represented an amount greater by up to 79% than the recommended maximum therapeutic dose. The administration of the recommended dose of the colostral immunoglobulin preparation (20 ml per calf) positively influenced the concentration of serum immunoglobulins in 26% of the test calves, but these suffered from hypogammaglobulinaemia. In none of the cases of calves with a normal level of gammaglobulins and calves with diarrhoea was an increase in the concentration of serum immunoglobulins recorded. An increase in the concentration of serum immunoglobulins in the calves after the administration of the above mentioned preparations was so small that it appears impossible to use them in the saturation therapy in calves affected by hypogammaglobulinaemia and agammaglobulinaemia. Some of the mechanisms of the action of gammaglobulin preparations are discussed for the cases where the results of the administration of the preparations were positive.