Colostral transfer of gamma glutamyl transferase in lambs

Serum gamma glutamyl transferase (GGT) levels in blood samples taken from normal lambs which had suckled colostrum were found to be up to 140 times normal adult levels. These high serum levels declined rapidly reaching a stable level approximately 60% higher than normal adult values by 24 days of age. Newborn lambs which had not yet consumed colostrum had GGT levels which would be considered normal in adult sheep. The GGT concentration in ewes' colostrum was up to 470 times normal serum levels. There was a significant positive correlation between serum GGT and gamma globulin levels in blood samples taken from lambs within 24 hours of birth.

Lambs' serum alkaline phosphatase (AP) and serum glutamate oxaloacetate transaminase (SGOT) levels also rose concurrently with the absorption of colostral gamma globulin, with the day 1 AP values being significantly correlated with the serum gamma globulin levels. Serum AP levels declined gradually but were still well above normal adult levels at 45 days of age while SGOT levels returned to normal adult levels by two to three days after birth.

It is concluded therefore that, as previously shown in calves, lambs acquire high levels of serum GGT activity from their mothers' colostrum in proportion to the amount of gamma globulin absorbed and also show a concurrent rise in serum AP activity. However the rise in SGOT levels at this time has not been observed in calves.     

Colostral transfer of gamma glutamyl transferase in lambs

Serum gamma glutamyl transferase (GGT) levels in blood samples taken from normal lambs which had suckled colostrum were found to be up to 140 times normal adult levels. These high serum levels declined rapidly reaching a stable level approximately 60% higher than normal adult values by 24 days of age. Newborn lambs which had not yet consumed colostrum had GGT levels which would be considered normal in adult sheep. The GGT concentration in ewes' colostrum was up to 470 times normal serum levels. There was a significant positive correlation between serum GGT and gamma globulin levels in blood samples taken from lambs within 24 hours of birth. Lambs' serum alkaline phosphatase (AP) and serum glutamate oxaloacetate transaminase (SGOT) levels also rose concurrently with the absorption of colostral gamma globulin, with the day 1 AP values being significantly correlated with the serum gamma globulin levels. Serum AP levels declined gradually but were still well above normal adult levels at 45 days of age while SGOT levels returned to normal adult levels by two to three days after birth. It is concluded therefore that, as previously shown in calves, lambs acquire high levels of serum GGT activity from their mothers' colostrum in proportion to the amount of gamma globulin absorbed and also show a concurrent rise in serum AP activity. However the rise in SGOT levels at this time has not been observed in calves.     

Occurrence of Blood Cells and Serum Proteins in Bovine Fetuses and Calves

Hematological values of peripheral blood were determined for bovine fetuses and calves of various ages. Erythrocyte values increased through gestation. Fetuses 100 days or older had total values within the ranges of those reported for normal adult cattle. Mature erythrocytes were not observed in embryos and only a few were observed in fetuses 40 days of age. Fetuses 250 days or older had only a few rubricytes (<10/100 WBC). Leukocytes were first identified in the peripheral blood of a 45-day old fetus. Absolute leukocyte values increased through gestation and reached maximum values shortly before parturition. Granulocytes were first observed at 130 days of gestation and reached maximum values near parturition.

Total serum protein and gamma-globulin concentrations of colostrum-deprived calves were similar to serum protein and gammaglobulin concentrations of fetuses older than 265 days and were lower than values for the colostrum-fed calves. The immunoelectrophoretic pattern of 59-day old fetuses, the earliest age at which serum samples were obtained, demonstrated albumin, an α1 globulin and a β globulin, possibly transferrin. Additional α and β globulins appeared in the older fetuses and by 175 days of gestation serum electophoretic patterns of the fetuses were similar to patterns normally found with adult bovine serum except for the absence of the gammaglobulins in fetal serum. Immunoglobulin M was detected in 39 of 95 fetal serum samples by radial diffusion and in 13 of 95 samples by immunoelectrophoresis. Immunoglobulin G was detected in ten of 95 fetal serum samples by radial diffusion and in six of 95 samples by immunoelectrophoresis.

     

Studies on Diarrhea in Neonatal Calves III. Acid-base and Serum Electrolyte Values in Normal Calves from Birth to Ten Days of Age

A detailed clinical examination was conducted and blood samples were collected from a total of 151 normal calves as soon as possible after birth and at two to three day intervals until the calves were ten days old.

The mean venous pH values for calves from birth to ten days of age was 7.38 ± 0.05.

The mean serum sodium, potassium, magnesium, inorganic phosphate, calcium and chloride ion concentrations in normal calves from birth to ten days of age were 148 ± 13, 5.4 ± 0.8, 2.1 ± 0.4, 4.3 ± 0.8, 5.6 ± 0.5, 95 ±5, mEq/litre respectively. The mean serum osmolality in normal calves from birth to ten days of age was 280 ± 12 mOsm/litre.

     

Colostral transfer of gamma glutamyl transpeptidase in calves

Serum gamma glutamyl transpeptidase (GGT) levels in blood samples taken from normal calves which bad suckled colostrum were much higher than those found in healthy adult cattle. Levels of over 60 times the normal adult level were observed. These high levels of GGT took approximately 5 weeks to decline to adult values. Calves which appeared to have not received or absorbed colostrum had GGT levels which would be considered normal in adult cattle. A calf with serum gamma globulin levels which indicated an intermediate amount of colostrum absorption had a level of GGT which was intermediate between that expected for normal adult cattle and that found in calves which had more fully absorbed colostrum. The mean GGT level observed in colostrum from 6 newly-calved cows was over 800 times the mean serum GGT level of the same 6 cows. It therefore appears most likely that GGT is concurrently absorbed with colostrum by calves and this gives rise to the very high levels seen in normal calves.

Calves with very high levels of serum GGT also had raised levels of alkaline phosphatase (AP) which slowly declined but never reached normal adult levels within the 53-day period of observation.

It therefore appears that high levels of both GGT and AP are achieved by calves at the time of colostrum absorption and it is concluded that clinical interpretation of serum GGT and AP levels in young calves is closely dependent upon parallel knowledge of their serum gamma globulin levels.     

Hypernatremia in Calves

Hypernatremia (sodium chloride intoxication) is described in two calves due to presumed mixing errors of oral electrolyte solutions while undergoing therapy for neonatal diarrhea. The experimental induction of hypernatremia in two clinically normal calves is also reported. Physical findings in diarrheic calves included depression, weakness, dehydration, and diarrhea. Serum sodium concentrations were found to be 171.6 mEq/l and 208.0 mEq/l, respectively. Treatment with intravenous fluids was attempted in both cases, but one calf died after 6 hours and the other calf died after 2 days and exhibited periodic convulsions before death. Experimental induction with oral administration of 1 l of electrolyte concentrate, which contained approximately 2750 mEq sodium revealed that the normal calves would willingly consume the solution as mixed with milk and develop clinical signs of hypernatremia within 6 hours of administration. Serum sodium concentrations of 176.0 and 179.8 were found in the experimental calves and coincided with the onset of overt depression and weakness, at which time they were euthanatized. Cerebrospinal fluid electrolyte analysis paralleled the serum electrolyte alterations.     

Changes in serum protein electrophoresis profiles and acute phase proteins in calves with diarrhea

Calf diarrhea leads to substantial economic losses in the livestock industry worldwide due to medical treatment costs, retarded growth performance, and even death. The objective of this study was to investigate changes in serum protein profiles and acute phase proteins in calves with diarrhea and identify the association between these changes and diarrhea. A total of 185 Korean beef calves were used and divided into 3 groups by age: 1 to 10 days (n = 46), 11 to 20 days (n = 65), and 21 to 30 days (n = 74). Blood and fecal samples were collected from each calf. Serum concentrations of total protein, protein fractions (albumin, α1-globulin, α2-globulin, β-globulin, and γ-globulin), haptoglobin (Hp), and serum amyloid A (SAA) were analyzed. Compared to calves without diarrhea, calves with diarrhea had significantly lower albumin concentrations at 11 to 20 days and 21 to 30 days of age (P = 0.017 and P = 0.000, respectively) and significantly higher α1-globulin fractions at 21 to 30 days of age (P = 0.01). Interestingly, α2-globulin fractions were significantly higher in diarrheic calves in all age groups, whereas γ-globulin fractions were significantly lower in calves with diarrhea aged 1 to 10 days, compared with normal animals. In calves with diarrhea, the concentration of Hp was significantly higher, whereas SAA levels were not different between normal and diarrheic calves. In addition, a positive correlation was found between α2-globulin and Hp (P = 0.0004). Taken together, these results provide useful information about the use of serum protein profiles and Hp as prognostic and diagnostic markers for animal health status.     

Evaluation of the Total Carbon Dioxide Apparatus and pH Meter for the Determination of Acid-Base Status in Diarrheic and Healthy Calves

Three simple tests of acid-base status were evaluated for field use. Blood samples were collected from 20 diarrheic and 24 healthy calves less than six weeks of age. One sample was collected anaerobically and immediately analyzed on a blood gas analyzer. The other samples were used for measurement of blood and serum pH using a pH meter and pH paper, and for serum total carbon dioxide (TCO₂) using a TCO₂ apparatus. The TCO₂ apparatus gave the best results and would be useful in the field. TCO₂ apparatus measurements had a high correlation, r=0.91, with blood gas analyzer blood bicarbonate values. Healthy calves have a serum TCO₂ content of 30 mmol/L and bicarbonate requirements for correcting metabolic acidosis in diarrheic calves can be calculated:

Bicarbonate required (mmol) = (30-TCO₂) × Body Weight × 0.6 This can be converted to grams of sodium bicarbonate by dividing by 12.

     

Determination of lactose and xylose malabsorption in preruminant diarrheic calves.

In preliminary studies feeding the poorly absorbed carbohydrate sorbitol at 2.3 g/kg body weight as an indication of maximal fermentative capacity failed to produce the expected large increase in breath hydrogen excretion but did produce a transient diarrhea in five out of six control calves. Twelve healthy control and eighteen diarrheic calves were fed lactose or D-xylose on consecutive days at 1.15 g/kg body weight and a concentration of 46 g/L. Breath and blood samples were collected at 1 h intervals from 0 to 7 h. After administration of lactose, there was a significant increase in breath hydrogen excretion in diarrheic versus control calves. The increase in plasma glucose concentrations was delayed in diarrheic calves but the area under the absorption curve was similar in control and diarrheic calves. After administration of D-xylose, breath hydrogen excretion did not increase significantly but plasma D-xylose concentrations were significantly reduced in diarrheic calves. The pathogens commonly isolated from the feces were Cryptosporidium species, rotavirus and coronavirus. The number of pathogens and the severity of the calves' acid-base deficit were not related to the severity of carbohydrate malabsorption. Decreased absorption of lactose and D-xylose may be the result of intestinal villous atrophy caused by viral or parasite infection. It was concluded that carbohydrate malabsorption rather than a specific lactose maldigestion is a significant problem in diarrheic calves. Diarrheic calves appear to digest and absorb lactose when fed in small amounts.     

Prediction of Serum IgG1 Concentration in Holstein Calves Using Serum Gamma Glutamyltransferase Activity

We examined the relationship between serum gamma glutamyltransferase (GGT) activity and serum gamma immunoglobulin G (IgG1) concentration in Holstein calves. Blood samples were collected from calves aged 1 to 3 days. A follow-up sample was obtained from each calf 2, 7, or 15 days after the initial sampling. Serum GGT activity and lgG1 concentration were measured. Regression models were used to predict lgG1 concentration as a function of age and serum GGT activity measured 2, 7, or 15 days later.
Serum GGT activity and calf age at the time of the second sample were directly related to serum IgG1 concentration in the initial sample in calves aged 3 to 17 days ( r = .54) and in calves aged 3 to 10 days ( r = .63). Models were used to estimate the serum GGT activity equivalent to a serum IgG1 concentration of 1,000 mg/dL. One-day-old calves should have serum GGT activities > 200 IU/L. Four-day-old calves should have serum GGT activities > 100 IU/L. One-week-old calves should have serum GGT activities > 75 IU/L. Calves with serum GGT activities < 50 IU/L should be classified as having failure of passive transfer.     

Changes in the blood biochemical and haematological profile of neonatal calves with age

Fourteen calves were used to investigate the changes from birth to 83 days of age in the concentrations of serum albumin, alkaline phosphatase, beta-hydroxybutyrate, plasma cortisol, serum creatine kinase, creatinine, iron, plasma fibrinogen, serum gamma-glutamyl transferase, plasma glucose, haptoglobin, serum non-esterified fatty acids, total protein, transferrin, triglycerides, urea and gamma globulin; the haematological variables measured were: basophils, eosinophils, haematocrit, haemoglobin, lymphocytes, mean cell haemoglobin, mean cell haemoglobin concentration, mean cell volume, monocytes, band neutrophils, neutrophils, platelets, red blood cells and white blood cells. The changes are presented as a series of graphs and the values are discussed in relation to the published reference ranges for adult cattle. Two populations of calves were identified which gave rise to a bimodal distribution for some of the variables. Differences in haematocrit, haemoglobin and red blood cell counts were apparent at birth, with raised values for these measurements being associated with an increased white blood cell and neutrophil count between three and 27 days of age.     

复合特异性卵黄抗体对18～28日龄犊牛生长、腹泻和免疫力的影响

本文旨在饲粮中添加复合特异性卵黄抗体(Ig Y)探究其对18~28日龄犊牛生长、腹泻和免疫力的影响。选取初生中国荷斯坦公犊牛20头,10日龄之前饲喂鲜奶,之后随机分为2组,对照(CON)组饲喂基础饲粮;试验(IGY)组在基础饲粮中日添加45 mg/kg BW的复合特异性Ig Y。预试期为犊牛11~17日龄,期间进行代乳品过渡,正试期为18~28日龄。分别于犊牛18和28日龄晨饲前称重,每天记录犊牛采食量并进行粪便评分。试验结束当天(28日龄)晨饲前颈静脉采血,测定血清中总抗氧化能力(T-AOC)和碱性磷酸酶(AKP)活性以及免疫球蛋白、一氧化氮(NO)、溶菌酶(LZM)浓度。结果表明:饲粮添加复合特异性Ig Y虽然对犊牛平均日增重和料重比无显著影响(P0.05),却有助于降低犊牛的粪便评分和腹泻率,作用显著(P0.05);IGY组较CON组极显著提高了犊牛血清中免疫球蛋白G(Ig G)、免疫球蛋白M(Ig M)和免疫球蛋白A(Ig A)的浓度(P0.01),分别提高7.19%、5.71%和8.50%;IGY组T-AOC极显著高于CON组(P0.01),而NO浓度却显著低于CON组(P0.05);IGY组血清LZM浓度极显著低于CON组(P0.01),复合特异性Ig Y对血清AKP活性却无显著影响(P0.05)。结果提示,饲粮中添加复合特异性Ig Y通过提高犊牛免疫球蛋白浓度和抗氧化能力以及发挥Ig Y本身抗原抗体反应,增强犊牛免疫能力和抵抗外界应激能力,降低了腹泻率,促进了犊牛健康。     

Anion gap correlates with serum D- and DL-lactate concentration in diarrheic neonatal calves

The objective of this study was to investigate the relationship between serum D- and L-lactate concentrations, and anion gap (AG) in neonatal calves. The association of AG with lactic acidosis in diarrheic calves has only been investigated by measurement of L-lactate in calves with experimentally induced diarrhea. D-lactate has recently been reported to be present in high concentrations in the serum of some diarrheic neonatal calves. The contribution of this acid to AG is not reported. The relationship between AG and L- and D-lactate concentrations was examined in 24 healthy calves and 52 calves with naturally occurring infectious diarrhea with metabolic acidosis. AG was calculated as [Na+ + K+] - [Cl- + HCO3-]. D- and L-lactate were quantified using high-performance liquid chromatography. There was no correlation between L-lactate and AG, contrary to previous reports in the literature. Moderate correlations between D-lactate concentration and AG (r = .74, P < .0001), and between DL-lactate and AG (r = .77), P < .0001) were detected. No differences existed due to the age or sex of the calf. This study indicates that AG provides information on the nature of acidosis in the diarrheic, neonatal calf and reinforces the importance of investigating clinical, in addition to experimental, populations.     

饲粮中添加牛至精油和莫能菌素对荷斯坦犊牛血清生化指标、消化酶活性及瘤胃微生物区系的影响

旨在研究牛至精油（oregano essential oil,OEO）与莫能菌素（monensin,MON）对荷斯坦犊牛血清生化指标、消化酶活性以及瘤胃微生物区系的影响。本试验前期阶段选用了体重相近（（41.31±2.23）kg）,体况良好的荷斯坦初生犊牛80头,随机分为4组,每组20头,采用单栏饲养。对照组饲喂全脂牛乳和颗粒饲料,其他3个试验组在饲喂全脂牛乳和颗粒饲料的基础上分别添加4 g·kg^-1牛至精油、3.6 g·kg^-1莫能菌素和7.6 g·kg^-1牛至精油和莫能菌素的混合物,饲喂至56、70日龄时,从每组中选取6头体重相近的公犊,颈静脉采血测定血清指标,并通过口腔导管的形式采集犊牛的瘤胃液,检测消化酶活性以及瘤胃微生物区系。结果表明：1）添加牛至精油显著提高了56日龄犊牛血清中TP、SOD、GSH和GSH-Px的浓度（P ≤ 0.05）;莫能菌素对56、70日龄犊牛BUN浓度有降低的趋势（P<0.10）。2）牛至精油显著降低了56、70日龄犊牛瘤胃中产琥珀酸丝状杆菌的数量（P<0.05）,显著提高了白色瘤胃球菌的数量（P ≤ 0.05）;莫能菌素显著降低了56、70日龄犊牛瘤胃中原虫的数量（P ≤ 0.05）,并有降低白色瘤胃球菌数量的趋势（P<0.10）,在56日龄时,莫能菌素有降低犊牛瘤胃中黄色瘤胃球菌数量的趋势（P<0.10）;牛至精油和莫能菌素对56、70日龄犊牛瘤胃中溶纤维丁酸弧菌有显著的交互作用（P ≤ 0.05）;在56日龄时,牛至精油和莫能菌素对栖瘤胃普雷沃氏菌有交互作用的趋势（P<0.10）,而在70日龄时则呈显著的交互作用（P ≤ 0.05）。3）牛至精油和莫能菌素对56、70日龄犊牛瘤胃中胃蛋白酶浓度有显著的交互作用（P ≤ 0.05）。综上所述,饲粮中添加牛至精油可提高犊牛的免疫力和抗氧化能力。莫能菌素在抑制瘤胃内原虫数量上强于牛至精油,牛至精油对提高主要蛋白质降解菌数量的作用效果优于莫能菌素。总之,牛至精油可改善犊牛的健康状况以及调控瘤胃微生物区系,牛至精油作为天然植物抗生素可替代犊牛期预防性治疗的其他类抗生素生长促进剂。     

The significance of bredavirus as a diarrhea agent in calf herds in Lower Saxony]

The objective of this investigation was to determine the distribution of Bredavirus in cattle herds in Lower Saxony and to evaluate its significance as potential cause of diarrhea in calves. Fecal samples and paired blood samples of 119 diarrheic and 46 healthy calves up to two months of age were collected from herds where diarrhea of calves was a problem. Fecal samples were examined for Breda-, rota- and coronavirus by solid phase immune electron microscopy and by ELISA, for K99-positive E. coli and salmonella by microbiological methods, and for cryptosporidia in smears. Antibody titers against Bredavirus, total serum protein and serum gamma globulin content were evaluated in the blood samples. Bredavirus was found in fecal samples from 5% (n = 6) of diarrheic calves which came from four different herds, but not in healthy calves. Rotavirus (31.9%), coronavirus (18.5%) and cryptosporidia (29.9%) were detected more frequently in fecal samples than Bredavirus. In this investigation rotavirus, coronavirus and cryptosporidia were present in addition in all herds where Bredavirus was found. In contrast to the low percentage of fecal samples containing Bredavirus, antibody titers in 75% of calves confirmed the high prevalence of Bredavirus infection in the cattle population of Lower Saxony.     

Prevalence and serum protein values of strangles (Streptococcus equi) affected mules at Remount Depot,Sargodha (Pakistan)

The prevalence of Streptococcus equi serovar equi (S.equi) in nasal discharge and pus samples from sub‐mandibular lymph nodes in mules at the Remount Depot, Sargodha was examined and total serum proteins, serum albumin, serum globulin and fibrinogen measured. A total of 250 nasal swabs and pus samples were collected from mules and examined microbiologically: 99 (39.6%) were positive for S. equi. A higher occurrence of S. equi was recorded in foals as compared to adults. The concentrations of total serum protein, serum globulin and fibrinogen were significantly increased (P<0.05), while the concentration of serum albumin significantly decreased (P<0.05) in strangles‐affected mules. It was concluded that increased total serum proteins, serum globulin and fibrinogen along with decreased serum albumin were important indicators of infection by S. equi in mules.     

Effects of surgery on the acute phase response in clinically normal and diseased horses

The serum concentrations of serum amyloid A, haptoglobin and fibrinogen were measured in a group of horses before and at intervals after elective and non-elective surgery, and in a control group of normal horses. There was a significant, rapid and repeatable increase in the concentration of serum amyloid A in response to both elective and non-elective surgery. In the control horses its serum concentration was within the normal range, from 0 to 0.2 microg/ml. Twenty-four hours after elective surgery its mean peak concentration was 16.4 microg/ml, and after non-elective surgery it was 27.3 microg/ml. In contrast, the serum concentrations of haptoglobin and fibrinogen increased more slowly after surgery and had not decreased by 72 hours after surgery.     

Serum IgG Concentrations after Intravenous Serum Transfusion in a Randomized Clinical Trial in Dairy Calves with Inadequate Transfer of Colostral Immunoglobulins

Background: Plasma transfusions have been used clinically in the management of neonates with failure of passive transfer. No studies have evaluated the effect of IV serum transfusions on serum IgG concentrations in dairy calves with inadequate transfer of passive immunity.
Hypothesis: A commercially available serum product will increase serum immunoglobulin concentration in calves with inadequate transfer of colostral immunoglobulins.
Animals: Thirty-two Jersey and Jersey-Holstein cross calves with inadequate colostral transfer of immunoglobulins (serum total protein <5.0 g/L).
Methods: Thirty-two calves were randomly assigned to either control (n = 15) or treated (n = 17) groups. Treated calves received 0.5 L of a pooled serum product IV. Serum IgG concentrations before and after serum transfusion were determined by radial immunodiffusion.
Results: Serum protein concentrations increased from time 0 to 72 hours in both control and transfused calves and the difference was significant between the control and treatment groups ( P < .001). Mean pre- and posttreatment serum IgG concentrations in control and transfused calves did not differ significantly. Median serum IgG concentrations decreased from 0 to 72 hours by 70 mg/dL in control calves and increased over the same time interval in transfused calves by 210 mg/dL. The difference was significant between groups ( P < .001). The percentage of calves that had failure of immunoglobulin transfer 72 hours after serum transfusion was 82.4%.
Conclusions and Clinical Importance: Serum administration at the dosage reported did not provide adequate serum IgG concentrations in neonatal calves with inadequate transfer of colostral immunoglobulins.     

Serum concentrations of tumor necrosis factor-alpha in neonatal calves with presumed septicemia

This study was performed to determine the concentrations of tumor necrosis factor (TNF) in the serum of neonatal calves with presumed sepsis and determine the correlation between serum concentrations of TNF and the severity and outcome of disease. Thirty-five sick calves < 30 days old that suffered from enteritis, respiratory disease, or both were considered suitable for inclusion in this study by satisfying clinical and laboratory criteria suggestive of septicemia. At admission, blood samples were collected from all calves to determine the prevalence of high concentrations of TNF. The clinical course and outcome of disease then were recorded. Of the 35 calves with presumed sepsis, 10 had high serum TNF concentrations. Scleral injection, weak or absent suckling reflex, sternal or lateral recumbency, unresponsive or comatose state, and death rate of calves with high serum TNF concentration were greater than those values for calves without high serum TNF concentration. Calves with high serum TNF concentration had significantly lower mean IgG (P < .001), globulin (P < .0001), and calcium (P < .0001) concentrations; greater serum creatinine concentrations (P < .0001); and > or = 2+ toxic changes in neutrophils than did calves without high serum TNF concentrations. Mean values for packed cell volume, band neutrophil count, and venous Pco2 were significantly (P < .007) higher in the group of calves with high serum TNF concentration. Results of this study indicate that serum TNF concentration is correlated with clinical criteria of sepsis in neonatal calves. A close association was apparent between disease severity and serum TNF concentrations in this group of calves with presumed septicemia.     

营养条件对荷斯坦公犊生长发育及血液中激素水平的影响

选择同期出生的48头中国荷斯坦公犊,在其1月龄时随机分为4组,Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别采用全乳、全乳+精料、代乳粉(料)和精料(对照组)进行饲养,研究不同日粮饲喂犊牛对其生长发育的影响。结果表明:Ⅰ组的体重在2～6月龄时均显著高于Ⅲ、Ⅳ组(P<0.05);尽管Ⅲ组的体重和日增重在2月龄时显著低于另3组(P<0.05),但到6月龄时,其日增重达到1.35kg/d,且与Ⅰ组无显著差异(P>0.05)并明显高于Ⅳ组(P<0.05)。说明代乳料饲喂的犊牛在后期的生长能够接近全乳饲喂的水平。4组间体长指数和髋胸指数在分组饲养后的开始几个月里存在显著性差异(P<0.05)。体重、日增重以及多数体尺指标均与T3和GH浓度呈显著(P<0.05)或极显著(P<0.01)相关,T4和INS浓度仅与体斜长、体长指数和髋胸指数呈显著(P<0.05)相关,且日增重仅与T3浓度有极显著相关(P<0.01)。Ⅰ组犊牛的血清中T3浓度在2～6月龄时均显著高于Ⅳ组(P<0.05),且除6月龄以外,其余各月龄时均显著高于Ⅲ组(P<0.05)。说明血清中T3浓度可能是能反映并监控荷斯坦犊牛生长发育和营养情况的重要指标。