Energy requirements of young female cattle. 6. Energy requirements

Results taken from 6 experiments with young female cattle comprising 477 metabolism periods served the derivation of the animals energy requirement in the development range greater than 125 kg live weight according to the factorial method. The energy requirement per kg LW0.75 and day, calculated from metabolism data, was independent of the stage of development and the intensity of feeding. It averaged 455 +/- 66 kJ metabolizable energy/kg LW0.75.d and 250 +/- 37 kJ NEFcattle/kg LW0.75.d respectively. The partial energy requirement for live weight gain, expressed in net energy fat, was equivalent to the energy content of the live weight gain. Energy retention and thus energy requirement per kg live weight gain increased with the live weight and reached a maximum of 26 MJ. Energy retention per kg live weight gain largely depended on the intensity of feeding and the stage of gravidity. Restrictive energy supply and progressing gravidity decreased energy content in the weight gain. The influences mentioned were taken into consideration on the derivation of the partial requirement for live weight gain. Equations were developed for the estimation of the energy requirement of young female cattle, which can be applied to both gravid and non-gravid cattle.     

Energy balance and body condition influence luteal function in Holstein heifers

A factorial experiment was conducted to determine influence of energy balance (EB) and body condition (BC) on luteal function in heifers. Heifers with moderate (MBC) or fat (FBC) BC were fed individually to sustain positive EB (PEB) or to cause negative EB (NEB). Intake of feed was measured daily and body weight weekly. Progesterone was quantified daily in serum for 3.5 estrous cycles. On days 9, 10, or 11 after fourth estrus, blood was sampled every 15 min for 12 hr to quantify luteinizing hormone (LH), growth hormone (GH), insulin and non-esterified fatty acids (NEFA). The next day, luteal cells were incubated and proportions of small to large cells were determined. After fourth estrus, area of progesterone profiles in serum for 10 days postestrus was reduced in all heifers relative to MBC-PEB heifers. But, luteal weight from FBC-PEB and MBC-NEB heifers was less than MBC-PEB heifers and FBC-NEB heifers were intermediate. Secretion of progesterone in vitro was increased by LH for PEB but not NEB heifers. MBC-NEB heifers had increased ratios of small to large luteal cells. Independent of BC, NEB decreased concentrations of insulin and increased GH and NEFA. Secretion of progesterone was not associated with LH, GH or insulin, but was correlated negatively with NEFA. We conclude that reduced concentrations of progesterone in serum of FBC-PEB and MBC-NEB heifers is due to impaired luteal development. But, reduced concentrations of progesterone in serum of NEB heifers is due also to reduced basal (MBC) and LH-induced (MBC and FBC) secretion of progesterone by luteal cells. Body condition at onset of NEB may determine when effects of NEB on progesterone are detected.     

Familial chondrodysplasia in Holstein calves.

After the release of a report from France on the occurrence of malformed calves genetically related to a Holstein sire, a study was performed to characterize the defect. Danish breeders were encouraged to submit defective progeny of the sire for laboratory examination. Four cases were submitted, whereas a fifth case was only reported. Lesions in affected calves were analogous, with disproportionate growth retardation characterized by fascial dysplasia and shortening of the vertebral column and the abaxial skeleton. Endochondral osteogenesis was disturbed with disorganization of epiphyseal plate chondrocytes, a lesion consistent with generalized chondrodysplasia. Based on morphology, the defect was grouped as a "Dexter bulldog type". A genetic etiology was suspected as cases occurred in a familial pattern. Genealogical evaluation revealed several common ancestors belonging to widely used breeding lines of US Holstein, but because of the extensive use of these sires, their presence in the pedigrees of affected calves might be accidental. Further studies are needed to determine the mode of inheritance.     

Brachyspina syndrome in two Holstein calves

Brachyspina syndrome, a rare lethal skeletal malformation, is described in two Italian Holstein calves. Both calves were stillborn and had shortened trunks with long legs. Radiography demonstrated several abnormalities of the cervical and thoracolumbar vertebral column. Visceral malformations involving the heart, kidney, genital tract and gastrointestinal system were also found. Both calves were traced back to the same sire and an inherited basis was strongly suspected.     

Maternal body condition during late-pregnancy is associated with in utero development and neonatal growth of Holstein calves

Background: Nutritional management in the dry period can alter body condition score(BCS) in dairy cows, a subjective measure of body fat. As such, differences in BCS during late-pregnancy not only mirror nutrient utilization by fat depots, but also can play important roles on the metabolic and hormonal environment. We investigated the association between cow BCS during late-pregnancy on developmental parameters and blood variables of neonatal calves. Forty-nine multiparous Holstein cows were retrospectively divided by prepartal BCS into normal BCS ≤3.25(NormBCS; 3.02 ± 0.17, n = 30) or high BCS ≥3.75(HighBCS; 3.83 ± 0.15, n = 19) groups.Plasma samples were collected from cows at-10 d relative to parturition. Body weight, hip and wither height, hip width and body length were measured at birth and weekly through weaning(42 d of age) and until 9 weeks of age. Calf blood samples were collected from the jugular vein at birth(before receiving colostrum, 0 d), 24 h after first colostrum and at 7, 21, 42 and 50 d of age. The data were subjected to ANOVA using the mixed procedure of SAS. The statistical model included day, BCS, and their interactions.Results: Dry matter intake(kg/d or % of body weight) during the last 4 weeks of pregnancy was lower(P ≤ 0.06) in HighBCS cows. Plasma concentrations of fatty acids, ceruloplasmin, and nitric oxide were greater overall(P 0.05) at d-10 prior to calving in HighBCS cows, and they tended(P = 0.08) to have greater concentrations of reactive oxygen metabolites. Birth body weight was lower(P = 0.03) in calves born to dams with HighBCS. In addition,plasma concentrations of fatty acids, albumin and urea(P 0.05) were greater in those calves. Although calves born to cows with HighBCS maintained a lower postnatal body weight(P = 0.04), hip and wither height, hip width, and body length, there was no difference(P 0.05) in daily starter intake and average daily gain due to maternal BCS.Conclusions: Overall, results highlight an association between BCS during late-gestation on in utero calf development and postnatal growth. A high maternal BCS during late-gestation was associated with lower calf body weights, which could be due to lower maternal intakes and a state of inflammation and metabolic stress.     

Disposition and bioavailability of neomycin in Holstein calves

Pedersoli, W.M., Ravis, W.R., Jackson, J., Shaikh, B. Disposition and bioavailability of neomycin in Holstein calves. J. vet. Pharmacol. Therap. 17 , 5–11.
The disposition and absorption kinetics of neomycin were studied in healthy ruminating dairy calves ( n -6), approximately 3-months-old. The calves were treated with single intravenous (i.v.) (12 mg/kg), intramuscular (i.m.) (24mg/kg), oral (p.o.) (96 mg/kg) and repeated p.o. (96 mg/kg, b.i.d., 15½ days) doses of neomycin. A 3-week rest period was allowed between treatments A and B and B and C Baseline and serial venous blood samples were collected from each calf plasma concentrations of neomycin were determined by a high performance liquid chromatography procedure. The resulting data were evaluated by using compartmental pharmacokinetic models and nonlinear least squares regression analysis. The mean of some selected parameters were t ½λ3 7.48 ± 2.02 h, Cl_t= 0.25 ± 0.04 L/h/kg, V _d(ss)= 1.17 ± 0.23 L/kg, and MRT = 4.63 ± 0.87 h for the i.v. data and t _½= 11.5 ± 3.8 h, MRT _abs= 0.960 ± 1.001 h, F = 127 ± 35.2%, and Cl_t/F = 0.199 ± 0.047 L/h/kg for the i.m. data, respectively. Only one calf absorbed neomycin to any significant degree (F = 0.0042) after a single p.o. dose. Selected mean parameters determined after repeated oral dosing were: F = 0.45 ± 0.45%, C_max= 0.26 ± 0.37 g/ml, and t_max= 2.6 ± 2.9 h. Terminal half-lives determined for the i.v. and i.m. treatments were considerably longer than those reported previously in the literature.     

Cardiac isoenzymes in healthy Holstein calves and calves with experimentally induced endotoxemia

This paper describes a controlled study designed to establish normal values for cardiac troponins I and T (cTnI and cTnT) and CK-MB mass in healthy newborn Holstein calves, and to compare values for cTnI, cTnT, CK-MB and total creatine kinase (CK) with age-matched calves experiencing experimentally induced endotoxemia. Nineteen healthy Holstein bull calves, 48 to 72 h of age were used. Baseline cTnI, cTnT, CK-MB and total CK measurements were obtained from control (n = 9) and experimental (n = 10) calves. Controls then received physiological saline and experimental calves received endotoxin (O55:B5 Escherichia coli LPS) intravenously after which cardiac biomarkers and total CK were measured at 3 h, 6 h, 12 h, and 24 h post-initiation of infusion. Measured values were analyzed and compared using analysis of variance (ANOVA) by repeated measure design, with statistical significance set at P < 0.05. The cardiac biomarker cTnT was not detected in any calf at any time point, and CK-MB was only detected in 5 of 95 samples. The cTnI was significantly increased compared to baseline and controls, 3 h post lipopolysaccharide (LPS) infusion. Total CK was significantly increased in LPS administered calves at 18 and 24 h post infusion. The mean, standard deviation, and range for cTnI in healthy controls were 0.023 ng/mL (s = 0.01), and 0.01 to 0.05 ng/mL, respectively. In conclusion, LPS administration was associated with rapid and significant increases in cTnI but CK-MB and cTnT were not detected in the plasma of healthy calves. Total CK values increased significantly following LPS administration. Biochemical evidence of myocardial injury occurs within 3 h following LPS administration to neonatal Holstein calves.     

Cardiovascular effects of sevoflurane in Holstein calves

Objective The purpose of this study was to determine the cardiovascular effects of sevoflurane in calves. Study design Prospective experimental study. Animals Six, healthy, 8–12‐week‐old Holstein calves weighing 80 ± 4.5 (mean ± SEM) kg were studied. Methods Anesthesia was induced by face‐mask administration of 7% sevoflurane in O₂. Calves tracheae were intubated, placed in right lateral recumbency, and maintained with 3.7% end‐tidal concentration sevoflurane for 30 minutes to allow catheterization of the auricular artery and placement of a Swan‐Ganz thermodilution catheter into the pulmonary artery. After instrumentation, administration of sevoflurane was temporarily discontinued until mean arterial pressure was > 100 mm Hg. Baseline values were recorded and the vaporizer output increased to administer 3.7% end‐tidal sevoflurane concentration. Ventilation was controlled to maintain normocapnia. The following were recorded at 5, 10, 15, 30 and 45 minutes after collection of baseline data and expressed as the mean value (± SEM): direct systolic, diastolic, and mean arterial blood pressures; cardiac output; mean pulmonary arterial pressure; pulmonary arterial occlusion pressure, heart rate; and pulmonary arterial temperature. Cardiac index and systemic and pulmonary vascular resistance values were calculated using standard formulae. Arterial blood gases were analyzed at baseline, and at 15 and 45 minutes. Differences from baseline values were determined using one‐way analysis of variance for repeated measures with post‐hoc differences between mean values identified using Dunnet's test (p < 0.05). Results Mean time from beginning sevoflurane administration to intubation of the trachea was 224 ± 9 seconds. The mean end‐tidal sevoflurane concentration at baseline was 0.7 (± 0.11)%. Sevoflurane anesthesia was associated with decreased arterial blood pressure at all sampling times. Mean arterial blood pressure decreased from a baseline value of 112 ± 7 mm Hg to a minimum value of 88 ± 4 mm Hg at 5 minutes. Compared with baseline, arterial pH was decreased at 15 minutes. Pulmonary arterial blood temperature was decreased at 15, 30 and 45 minutes. Arterial CO₂ tension increased from a baseline value of 43 ± 3 to 54 ± 4 mm Hg (5.7 ± 0.4 to 7.2 ± 0.3 kPa) at 15 minutes. Mean pulmonary arterial pressure was increased at 30 and 45 minutes. Pulmonary arterial occlusion pressure increased from a baseline value of 18 ± 2 to 23 ± 2 mm Hg at 45 minutes. There were no significant changes in other measured variables. All calves recovered from anesthesia uneventfully. Conclusion We conclude that sevoflurane for induction and maintenance of anesthesia was effective and reliable in these calves and that neither hypotension nor decreased cardiac output was a clinical concern. Clinical relevance Use of sevoflurane for mask induction and maintenance of anesthesia in young calves is a suitable alternative to injectable and other inhalant anesthetics.     

哺乳犊牛的消化特点与蛋白质需要

本文从犊牛的消化生理特点出发,综述了犊牛出生后的生理特征及蛋白质、必需氨基酸的需要量,并对代乳品中蛋白质原料进行了论述。     

Effect of cellooligosaccharide or synbiotic feeding on growth performance,fecal condition and hormone concentrations in Holstein calves

We investigated the effect of cellooligosaccharide (CE) or a combination of dextran and Lactobacillus casei ssp. casei strain JCM1134^T (synbiotic; SB) feeding on growth performance, fecal condition and hormone concentrations in Holstein calves. Fifty‐two female Holstein calves were randomly assigned to three treatment groups: CE feeding group (n = 16), SB feeding group (n = 18), and control group (n = 18). Body weight at 90 days of age, as well as daily body weight gain (DG) and feed efficiency after weaning to 90 days of age were greater (P < 0.05) in the CE feeding group than in the control group. The total fecal score tended to be lower (P < 0.1) in the SB feeding group than in the control group. Plasma insulin concentration was higher (P < 0.05) in the CE feeding group than in the control group at 90 days of age. Our results indicate that CE feeding improved DG and feed efficiency in calves. On the other hand, there was less effect on growth performance and fecal Escherichia coli counts in calves fed SB.     

Experimental Babesia bovis infection in Holstein calves

One intact and two splenectomized Holstein calves were infected intravenously with a Mexican strain of Babesia bovis and killed following the onset of severe clinical disease. A light and electron microscopic study was conducted on selected tissues to examine the relationship between parasitized erythrocytes and microvascular endothelial cells. The pattern and degree of specific organ sequestration of parasitized erythrocytes was assessed and correlated to lesions. Red blood cells infected with Babesia bovis exhibited stellate membrane protrusions. This morphological change appeared to mediate erythrocyte sequestration in the microvascular and capillary beds of the brain, kidney, and adrenal gland by an as yet unknown mechanism(s).     

Energy requirements of young female cattle. 5. Energy intake and energy expenditure

From 6 experiments dealing with the development of young female cattle, partly from calf to calving, 660 metabolism periods were evaluated as to energy intake, live weight gain (LWG) and energy expenditure. Growth intensity was deliberately regulated through energy intake. In the experiment with the highest growth rate the average LWG was greater than 850 g/animal and day and in the experiment with the lowest growth rate at about 550 g/animal and day. Energy expenditure increased from 15 MJ net energy fatcattle/kg LWG at a live weight of 50 kg to 50-80 MJ NEFcattle/kg LWG in clear dependence on growth intensity. Comparative examinations of energy intake and energy requirement, estimated with equations forming the basis of recommendations for the energy supply of young female cattle in the framework of the GDR system of feed evaluation, lead to the conclusion that a new concept of identifying the energy requirement of young female cattle has to be developed.     

Bovine neonatal pancytopenia in German Holstein calves

Profiles of blood cell counts were evaluated for 15 calves from three different farms. These calves showed petechia in the mucous membranes and in the skin and prolonged secondary bleeding after puncture. The clinical course of the disease could be observed in eleven calves. With exception of one case, the blood cell counts indicated a severe anaemia, leukocytopenia and thrombocytopenia. Out of these 15 calves, six calves survived and the other nine calves died or had to be euthanized due to the severity of the disease. Necropsy of these nine calves revealed petechia in the skin, subcutis, muscles, in inner organs and all serous membranes. Pathohistological examination showed a depletion of the bone marrow and lymphatic tissue in eight calves. These findings confirmed the diagnosis of bovine neonatal pancytopenia (BNP) for eight of these nine calves. Bluetongue virus serotype 8 was tested negatively using PCR. Bovine virus diarrhoea virus (BVDV) was negatively tested using immunofluorescence and cell culture and salmonella species were negatively tested in seven dissected calves. A cluster of toxins was negatively tested in one of the dissected calves. All 15 calves had high antibody titres for BVDV. The BVDV-antibody titres from twelve dams with affected calves were positive in six cases and not detectable in the other six cases. In three of the six dams with not detectable BVDV-antibody titres, calves were fed with colostrum of a further dam with high BVDV-antibody titres. In the further three dams without detectable BVDV-antibody titres, we could not ascertain which colostrum has been fed to the calves. BVDV-specific antigen could not be detected in any of the samples from the calves and dams tested. Using the activity of the gamma-glutamyl-transferase, we assumed a sufficient supply with colostrum for the examined calves.The cause for the occurrence of these BNP cases was due to bone marrow depletion.The reason for the bone marrow depletion remained unclear. However, it was obvious that the BNP described here is highly likely caused by colostrum from cows with positive BVDV-antibody titres.     

Familial occurrence of diprosopus in German Holstein calves

Diprosopus was diagnosed in six German Holstein calves born on different dairy farms. The degree of facial duplication varied from a partial doubling of the nostrils and upper jaw to complete duplication of the face with formation of two mouths, four eyes and four ears. Further calves descending from the same parents or dams and calves from the same farms were not affected. A joint pedigree was ascertained for the calves with diprosopus. Furthermore, a previously reported case of diprosopus could be traced back to the same ancestors of this pedigree. Consequently, we detected the first time a familial accumulation of diprosopus. Since the ancestors showed no signs of diprosopus and the frequency of diprosopus in German Holsteins is presumably low, an oligogenic inheritance is likely. Recessive genes or a combination of recessive and dominant genes may cause this anomaly.     

Dexamethasone-induced exophthalmos in a group of Holstein calves

Six Holstein calves were evaluated for progressive exophthalmos. The affected calves were receiving daily injections of dexamethasone (30 microg/kg subcutaneously twice daily) as part of a metabolic study. The control calves did not exhibit exophthalmos. The ocular examinations were normal except for the exophthalmos, which ranged from mild to marked in severity. Upon postmortem examination, marked deposition of retrobulbar adipose tissue was noted in the affected calves. Dexamethasone administration appears to increase deposition of retrobulbar adipose tissue resulting in a progressive exophthalmos.     

Variation in cardiac markers and electrocardiographic alterations in young calves naturally infected with bovine tropical theileriosis

The present study was designed to assess the deleterious effects of bovine tropical theileriosis on the cardiovascular system and the consequent myocardial involvement in young calves. Myocardial effects in parasitic diseases are often neglected. Hemolytic anemia, associated secondary hypoxia, and vasculitis are cardinal features of bovine theileriosis. In the present study, electrocardiogram (ECG) alongside serum cardiac troponin I (cTnI) and creatinine phosphokinase-myocardial band (CPK-MB) concentrations were analyzed in infected, treated, and control groups of young calves. Non-significant alterations were noticed in ECG. However, certain signs like sinus tachycardia, first-degree AV block, atrial premature complex, left atrial hypertrophy, and right atrial hypertrophy were found on consistent basis in infected calves. A significant increase in the serum concentration levels of cTnI and CPK-MB was noticed in infected calves followed by significant fall in both these biomarkers post treatment. cTnI and CPK-MB can definitely be used as myocardial markers in theileriosis-affected animals.     

Myelopathy in Holstein x Gir calves in Brazil

This case report contains clinical and pathologic features of a degenerative myelopathy in Holstein X Gir crossbred calves in Brazil. The bilateral and symmetrical spinal cord white matter lesions were interpreted as a primary axonopathy that may be of the dying-back type.