Protection of newborn calves against fatal multisystemic infectious bovine rhinotracheitis by feeding colostrum from vaccinated cows.

To determine whether consumption of colostrum with high levels of serum neutralizing antibody to bovine herpesvirus 1 would protect neonatal calves from the frequently fatal multisystemic form of infectious bovine rhinotracheitis, Holstein calves were fed for 48 h after birth with either pooled colostrum from seropositive vaccinated cows or colostrum from seronegative unvaccinated cows. The serum neutralizing antibody achieved in the former calves was between 64 and 256 and the titer in the latter calves was below 8. At 48 h of age the calves were challenged by aerosolization with bovine herpesvirus 1. All five seronegative calves died or were euthanized in a moribund state between days 5 and 7 of the trial, whereas all five seropositive animals remained healthy throughout the study. Twice daily clinical examination revealed significantly lower scores in the seronegative group from 60 h postinfection. Relative lung weights were greater in the seronegative group, associated with a severe acute necrotizing bronchiolitis with fibrin exudation. The seronegative group of calves also demonstrated an acute necrotizing rumenitis, pharyngitis, glossitis, esophagitis, laryngitis and tracheitis. The seropositive animals had only small areas of subacute necrotizing fibrinopurulent rhinitis. Bovine herpesvirus 1 virus was isolated from all nasal passages of all calves but isolation of virus in the seronegative calves was made from the trachea (5/5), lung (4/5), bronchial lymph nodes (4/5), spleen (4/5), thymus (3/5), liver (2/5), rumen (2/5) and brain (1/5).(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum enzyme changes in newborn calves fed colostrum

In 10 newborn Holstein calves, which were initially bottle-fed on pooled colostrum, there were transient increases in several serum enzymes. Within a few hours, the mean serum gamma-glutamyl transferase (gammaGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), acid phosphatase (ACP), and lactate dehydrogenase (LDH) activities increased 62.5, 2.4, 2.0, 1.8 and 1.3 fold, respectively. In two other calves given initial feeds of enzyme-free pasteurized milk, there were similar increases in serum enzymes, except serum gammaGT. Correct interpretation of serum enzyme activities in newborn calves must take into account the normal increases which occur after feeding colostrum. Serum gammaGT was the only enzyme to increase markedly as a result of its absorption from colostrum. The other serum enzymes are presumably released from the tissues of the calf. The increased activities of serum CK observed in some newborn calves probably resulted from trauma during birth or increased muscular activity after birth.     

Diarrhoea in dairy calves reduced by feeding colostrum from cows vaccinated with rotavirus

Forty-two dairy calves remained with their dams for two days after birth, and then were removed to a calf rearing shed. Calves were allocated to three groups for the next 14 days, and received twice daily either whole milk, whole milk with a 10 per cent supplement of pooled normal bovine colostrum or whole milk with 10 per cent supplement of colostrum from cows vaccinated with rotavirus. A natural outbreak of diarrhoea occurred, affecting 28 of the 42 calves. Feeding immune colostrum delayed the onset of diarrhoea, and reduced its incidence, duration and severity. Live weight gains were consequently improved. The group fed normal colostrum had diarrhoea intermediate in severity between that of control calves and those fed immune colostrum. The aetiology of the diarrhoea was complex, with calves excreting rotavirus, enteropathogenic Escherichia coli and cryptosporidia.     

Comparison of three methods of feeding colostrum to dairy calves

Absorption of colostral immunoglobulins by Holstein calves was studied in 3 herds in which 3 methods of colostrum feeding were used. Failure of passive transfer, as determined by calf serum immunoglobulin G1 (IgG1) concentration less than 10 mg/ml at 48 hours of age, was diagnosed in 61.4% of calves from a dairy in which calves were nursed by their dams, 19.3% of calves from a dairy using nipple-bottle feeding, and 10.8% of calves from a dairy using tube feeding. The management factor determined to have the greatest influence on the probability of failure of passive transfer in the herds using artificial methods of colostrum feeding (bottle feeding or tube feeding) was the volume of colostrum fed as it affected the amount of IgG1 received by the calf. In dairies that used artificial feeding methods, failure of passive transfer was infrequent in calves fed greater than or equal to 100 g IgG1 in the first colostrum feeding. In the dairy that allowed calves to suckle, prevalence of failure of passive transfer was greater than 50% even among calves nursed by cows with above-average colostral IgG1 concentration. Analysis of the effect of other management factors on calf immunoglobulin absorption revealed small negative effects associated with the use of previously frozen colostrum and the use of colostrum from cows with long nonlactating intervals.     

Evaluation of methods for dehydration of bovine colostrum for total replacement of normal colostrum in calves

Different methods for the dry preservation of colostrum to be used as a total replacement for bovine colostrum were evaluated. Pooled colostrum from the first and second postpartum milkings from multiparous dairy cows containing immunoglobulin in excess of 40 g/L was freeze-dried, microwave vacuum evaporated, and spray-dried. Spray-drying produced a dried colostrum in which immunoglobulin quantity and function were preserved and was the most cost-effective. Other dehydration methods, although effectively conserving immunoglobulins, were too slow and costly to be used to produce a bovine colostrum replacer. Newborn, colostrum-deprived, dairy calves fed spray-dried colostrum containing 126 grams of immunoglobulin reconstituted in three liters of water as their sole source of immunoglobulin achieved normal mean serum immunoglobulin concentrations. Spray-dried colostrum with high concentrations of immunoglobulin may be produced economically and used as an effective and convenient colostrum replacer in newborn calves.     

牦牛初乳对新生犊牛血液生化组成的影响

初乳是哺乳动物分娩后最初几天的乳腺分泌物。大量研究表明,初乳不仅为新生幼仔提供必要的常规营养成分,如蛋白质、矿物质、维生素等,而且提供免疫保护和代谢信息[1]。由于牛、羊等反刍动物的胎盘无法通过免疫球蛋白,因此,新生犊牛须借助初乳获得被动免疫[2]。牦牛是我国青藏高     

Control of diarrhoea and death in home-bred dairy calves by bucket feeding pooled colostrum.

The feeding of colostrum to newborn calves from a bucket was found to be more effective in ensuring immune globulin uptake than leaving cow and calf together for two days post partum. A marked seasonal variation in the immune globulin status of calves, which could not readily be explained by management factors, was noted during two consecutive seasons.     

新生犊牛的生理特点及饲养管理措施

新生犊牛由于组织器官发育不完善,胃肠消化功能弱,体温调节能力差,抵抗力免疫力低下,代谢旺盛生长发育快等生理特点,若管理不善,极易造成犊牛免疫力低,死亡率高等不良后果,因此科学化、精细化的饲养管理非常重要。本文通过对新生犊牛生理特点的分析,介绍了新生犊牛饲养管理关键技术,为培育健康状况良好,有生长潜力的牛群提供借鉴。     

Dexamethasone and colostrum feeding affect hepatic gluconeogenic enzymes differently in neonatal calves

Plasma glucose concentrations in neonates are influenced by colostrum feeding and by glucocorticoids. We have tested whether a high-glucocorticoid status after birth, as well as colostrum feeding, influences glucose metabolism in association with changes of hepatic expression and activities of gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) and pyruvate carboxylase (PC; EC 6.4.1.1) in neonatal calves. Calves (n = 14 per group) were fed either colostrum or a milk-based formula with nutrient and energy contents similar to colostrum. Half the calves in each feeding group were treated with dexamethasone (DEXA; 30 microg/[kg BW x d]). Pre- and postprandial blood samples were taken on d 1, 2, 4, and 5 and liver samples were collected on d 5 of life. Dexamethasone treatment increased (P < or = 0.05) plasma concentrations of glucose, insulin, and glucagon more in colostrum-fed than in formula-fed calves but increased (P < or = 0.05) urea concentrations and decreased (P < or = 0.05) concentrations of NEFA, ACTH, and cortisol independent of colostrum vs. formula feeding. Colostrum feeding increased (P < 0.05) plasma glucose, but decreased (P < 0.05) plasma urea concentrations. Glucagon-to-insulin ratios in DEXA-treated and colostrum-fed calves were decreased (P < 0.05). Dexamethasone treatment decreased hepatic mRNA levels and activities of PC (P < 0.001 and P < 0.10) and activities of PEPCK (P < 0.001) but increased (P < 0.001) the glycogen content. Colostrum feeding increased (P < 0.05) mitochondrial PEPCK mRNA levels and PEPCK activities in calves not treated with DEXA but decreased (P < 0.1) amounts of PC mRNA. In conclusion, increased plasma glucose concentrations after DEXA treatment were not associated with a stimulation of hepatic gluconeogenic enzyme activities; however, colostrum feeding probably raised plasma glucose concentrations because of increased hepatic gluconeogenic activities.     

Evaluation of the transfer of immunoglobulin from colostrum anaerobic fermentation (colostrum silage) to newborn calves

Colostrum silage is an anaerobic fermentation methodology of excess farm colostrum used to conserve and provide as milk replacement for calves. The present study aimed to evaluate the levels of immunoglobulins present in bovine colostrum silage and its absorption by newborn calves. The concentration of immunoglobulins was determined in fresh colostrum and colostrum silage stored for 12 months. The absorption of immunoglobulins by calves was assessed immediately after birth and 24 h after colostrum silage intake. The immunoglobulin levels were evaluated by ELISA. The results highlighted that colostrum silage kept similar levels of immunoglobulins as the ones in colostrum in natura, and can be transferred to newborn calves with similar amounts to calves fed with colostrum in natura. It is concluded that colostrum silage keeps viable immunoglobulins, and is able to transfer passive immunity to newborn calves.     

Relationships between acid-base balance, serum composition and colostrum absorption in newborn calves

Twenty-seven newborn Holstein bull calves were bottle-fed 2 litres of pooled colostrum which had been stored at -20 degrees C. Blood gas analysis before feeding showed a partially compensated respiratory acidosis in most of the calves, although they all appeared to be clinically normal. Mean venous blood pH was 7.346, carbon dioxide tension (PCO2) was 57.5 mmHg (7.6 kPa), bicarbonate was 30.6 mmol/l and base excess was 3.82 mmol/l. Mean serum IgG1 increased to 8.1 g/l after feeding colostrum. Several significant positive correlations were observed between post-absorptive serum protein, IgG1, IgM, gamma-glutamyltransferase (gamma GT) and D-xylose. Calves with either low serum albumin, high serum CK or low serum gamma GT before feeding tended to have less absorption of colostral protein. It was concluded that reduced absorption of IgG1 from colostrum is associated with hypercapnia in apparently healthy newborn calves.