Infectious bovine keratoconjunctivitis: subconjunctival administration of a Moraxella bovis pilus preparation enhances immunogenicity

To compare the immune response elicited by 3 routes of vaccination, 36 calves were randomly allotted to 4 groups of 9 calves each. Group I was vaccinated subconjunctivally only. Group II was vaccinated concomitantly, both subconjunctivally and in the dewlap. Group III was vaccinated in the dewlap only. Group IV was not vaccinated and served as a virulence control for the Moraxella bovis culture. Calves in groups I, II, and III were given 2 inoculations with 14 days between inoculations. Twenty-one days after the last inoculation, the ventral conjunctival sac of all calves was instilled with cells of a virulent M bovis strain. After challenge exposure, all vaccinated calves (groups I, II, and III) had evidence of enhanced resistance, compared with the nonvaccinated calves. The highest to lowest gradients of immune responsiveness were: Group I greater than or equal to group II greater than group III greater than group IV. When immune criteria, such as the percentage of diseased eyes, the mean duration of infection, the severity of corneal lesions, and the serologic response were compared, groups I and II were significantly (P less than 0.05) more resistant to challenge exposure than were groups III and IV. Group III was significantly (P less than 0.05) different from group IV in severity of lesions and in serologic response. Also, the mean duration of infection was shorter, and the percentage of diseased eyes was less in group III than in group IV (P greater than 0.10). Group I was more resistant than was group II (P less than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Electronic measurement of erythrocyte volume and volume heterogeneity in horses during erythrocyte regeneration associated with experimental anemias

Anemia was induced in three groups of horses by moderate or severe acute hemorrhage, or by acetyl phenylhydrazine-induced hemolysis (Groups I, II, and III, respectively). Serial hemograms were done on a multichannel automated blood cell counter with histogram capability. Changes in hematocrit, mean cell volume, erythrocyte number, red cell distribution width (RDW), and standard deviation of erythrocyte volume were examined over time. Significant increases in mean cell volume were first detectable by days 17, 20, and 14 and reached maximum by days 43, 41, and 29, in Groups I, II, and III, respectively (P less than 0.05). Increased mean cell volume was interpreted as reflecting accelerated erythrocyte regeneration; however, not all horses with accelerated regeneration had changes in mean cell volume. Estimated erythrocyte production rate correlated poorly with hematocrit nadir and change in mean cell volume (r = 0.37 and r = 0.36, respectively, P greater than 0.05). In some horses effective regeneration occurs without development of macrocytosis. Mean cell volume remained increased after other parameters returned to control values, suggesting that mean cell volume values may provide retrospective evidence of altered erythrocyte turnover. Anisocytosis as indicated by significant increases in the standard deviation was greatest during the early part of the regenerative response, reaching maximum values on days 30, 28, and 21 in Groups I, II, and III, respectively, and began to decrease as homogeneous repopulation with macrocytes occurred. Red cell distribution width increased significantly only in severe hemorrhage and hemolysis groups, reaching mean maximum values of 24.3 on day 20 and of 26.4 on day 21 in Groups II and III, respectively (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Physeal Fractures in the Horse II. Management and Outcome

Seventy physeal fractures in horses were initially managed by euthanasia (18), stall confinement (25), application of a cast (7), or internal fixation (20). Of the 52 physeal fractures initially managed with stall confinement, a cast, or internal fixation, 23 (44%) healed and 13 (25%) of these horses became sound. The number of horses less than 4.5 months of age with pressure physeal fractures that became sound was significantly higher (p < 0.05) than the number of horses greater than 4.5 months of age. The number of horses with functional, pain-free limbs (sound horses) or functional limbs (lame horses) was not significantly different (p > 0.05) for Salter-Harris Type I, II, III, or IV pressure physeal fractures; however, critical examination for growth disturbances was not performed. The number of horses with pressure or traction physeal fractures of less than 5 days duration prior to presentation that healed or became sound was not significantly different (p > 0.05) when compared with those horses with fractures of greater than or equal to 5 days duration.     

Muscle fibre type composition in untrained and endurance-trained Andalusian and Arab horses

Muscle biopsies were taken from the middle gluteal muscle of 68 stallions (52 Andalusian [AN] and 16 Arab [AR]) ranging from six to 12 years of age. Seventeen AN horses and eight AR horses were untrained, while the remainder underwent active endurance training for 6 months. Fifteen AN horses were moderately endurance-trained while the other 20 AN horses and eight AR horses were strongly endurance-trained. Percentages of type I and type II fibres were similar in all groups (P greater than 0.05). The group of horses with the hardest training had a higher percentage of type IIA fibres (AN P less than 0.01; AR P less than 0.02) and a lower percentage of type IIB fibres (P less than 0.05 for AN and AR) than the untrained horses. All trained horses had a higher percentage of type IIB oxidative fibres and a lower percentage of type IIB non-oxidative fibres than the untrained horses (P less than 0.01 for both). These results suggest that the proportions of type I and type II fibres are highly stable within a given breed, but the stimulus of training facilitates changes both in contractile properties and, particularly, in the oxidative capacity of type II subgroups.     

Use of intravenous flecainide in horses with naturally-occurring atrial fibrillation

REASONS FOR PERFORMING STUDY: It has been reported that i.v. flecainide has a high efficacy for the treatment of experimentally-induced acute atrial fibrillation (AF) in horses and that its use is associated with minimal toxic side effects. OBJECTIVES: The objectives were to study the efficacy of i.v. flecainide as a treatment for atrial fibrillation in horses with naturally-occurring AF. METHODS: Ten horses with naturally-occurring AF were treated with 2 mg/kg bwt flecainide i.v. at a rate of 0.2 mg/kg bwt/min. In 3 horses, the infusion was continued at 0.05-0.10 mg/kg bwt/min until a total dose of 3.0 mg/kg bwt had been administered. Heart rate, QRS duration and average interval between fibrillation waves were measured before, during and following flecainide infusion. If conversion to normal sinus rhythm was not achieved, horses were treated with quinidine sulphate per os at a dose of 22 mg/kg bwt given every 2 h. RESULTS: None of the horses with chronic AF (n = 9) converted to sinus rhythm with flecainide i.v. The only horse treated successfully had acute AF of 12 days' duration. The QRS duration and fibrillation cycle length increased significantly (P = 0.006 and 0.002, respectively) during and following flecainide infusion. Heart rate did not increase significantly over time however, 3 horses developed heart rates in excess of 100 beats/min. Two horses developed a potentially dangerous ventricular dysrhythmia during the first 15 mins of treatment. Quinidine sulphate given per os restored sinus rhythm in 8 out of 9 horses, with minimal adverse effects. CONCLUSIONS: Although flecainide might be efficacious in cases of acute AF, it was not possible to restore sinus rhythm in horses with naturally-occurring chronic AF at the dosages used in this study. In 2 horses, 2.0 mg/kg bwt flecainide was associated with potentially dangerous dysrhythmias. POTENTIAL CLINICAL RELEVANCE: Intravenous administration of 2 mg/kg bwt flecainide is unlikely to convert chronic AF in horses and could induce dangerous dysrhythmias.     

Antithrombin III activity in horses with large colon torsion

A chromogenic peptide substrate assay was used to determine serially plasma antithrombin III (AT III) activity in 4 groups of horses. Group I consisted of healthy, mature horses in which AT III activity was determined twice daily for 7 consecutive days. Groups 2 and 3 contained healthy horses in which AT III activity was monitored for 7 days after controlled, but varying, conditions of general anesthesia and surgery (median celiotomy). Group 4 was made up of patients with a presurgical diagnosis of colonic torsion. In healthy awake horses (group I), there was no difference in AT III values over time. Postoperative AT III activity in the halothane-anesthetized horses (group 2) and in the sham-operated horses (group 3) was not significantly (P = 0.05) different from base-line values at any time. A significant decrease (P = 0.05) in AT III activity was observed on postoperative days 1 through 3 in the group of horses with large colon torsion, but returned to preoperative values by day 4 after surgery in the horses that survived. In those horses that did not survive, AT III activity remained below base-line values for the duration of observation. Seemingly, plasma AT III activity in horses was not significantly affected by halothane anesthesia or surgery. Serial evaluation of AT III activity may be useful for predicting survival in horses with large colon torsion.     

Aromatic-dependent Salmonella dublin as a parenteral modified live vaccine for calves

A virulent Salmonella dublin isolate was made histidine-requiring (his-) to allow recognition. The his- derivative, SL1367 (still calf-virulent), was then given by transduction and mutation, a transposon-generated non-reverting aromatic biosynthesis (aro) defect; this defect caused loss of virulence for the mouse. The his- aro- derivative strain, SL1438, was effective as a live vaccine in mice. Twenty male Holstein calves were divided into 4 groups. Groups I, II, and III were vaccinated IM at 2 weeks and at 3 weeks of age with aromatic-dependent (aro-) S dublin strain SL1438. Groups I and III received freshly prepared vaccine and group II received lyophilized vaccine. Serious adverse reactions to the vaccination were not seen. After vaccination, the mean maximum increase in rectal temperature was 1.8 C in group I and III calves and 0.6 C in group II calves. Fewer group II calves developed diarrhea (1 of 5) or positive blood cultures (0 of 5) after vaccination compared with group I and III calves (6 of 10 and 5 of 10, respectively). Postvaccination diarrhea was mild and of short duration. Group IV was comprised of 5 nonvaccinated calves. At 5 weeks of age, all calves were challenge exposed orally. Group I, II, and IV calves were challenge exposed with 10(11) virulent S dublin SL1367. Group III was challenge exposed with 10(11) virulent S typhimurium UCD 108-11. Subsequently, fever and diarrhea (lasting 1 to 3 days), but no deaths, were observed in the vaccinated calves. Four of the 5 nonvaccinated (group IV) calves died (P less than 0.001) within 8 days after challenge exposure. Aro- S dublin SL 1438 did not cause serious adverse effects and provided protection against oral challenge exposure with either virulent S dublin or S typhimurium.     

Rhodococcus (Corynebacterium) equi: bactericidal capacity of neutrophils from neonatal and adult horses

The capacity of hematogenous polymorphonuclear neutrophilic leukocytes (PMNL) to kill Rhodococcus equi was compared in horses of various ages. A radioisotope bactericidal assay was used to determine the capacity of PMNL to kill R equi. Assays were conducted on PMNL from horses in 3 groups: group I, 13 foals with a mean age of 3.3 days; group II, 10 group-I foals at a mean age of 35.7 days; and group III, adult dams of group-I foals. Bacteria were obtained from the lungs of a foal with R equi pneumonia and opsonized with fresh adult equine serum that contained R equi specific antibody. The mean peak percentage of R equi killed by PMNL was 78.9 for group I, 90.1 for group II, and 87.9 for group III. There was no significant difference (P greater than 0.05) among groups; however, 15% of foals in group I (2 foals) had a mean peak percentage of 30.5 killed, which was significantly (P less than 0.05) lower than the percentage for other foals in group I. The results of our investigation indicated that the capacity of PMNL to kill opsonized R equi is similar in neonatal, young, and adult horses. However, some neonatal foals have a substantially lower capacity to kill R equi, which may be an important factor in the pathogenesis of R equi infections.     

Treatment of Atrial Fibrillation in Horses: New Perspectives

Forty-one horses were treated for atrial fibrillation (AF) with 22 mg/kg quinidine sulfate via nasogastric tube every 2 hours until conversion to sinus rhythm, a cumulative dose of 88 to 132 mg/kg had been administered in 2-hour increments, or the horse had adverse or toxic effects from the drug. Treatment intervals were prolonged to every 6 hours if conversion had not occurred. Digoxin was administered before treatment if the horse had a fractional shortening ≤ 27% (3 horses), was prone to tachycardia (resting heart rate ≥ 60 beats/min) (1 horse), or had a previous history of sustained tachycardia of over 100 beats/min during prior conversion (3 horses). Digoxin was administered during day 1 of quinidine sulfate treatment if the horse developed a sustained tachycardia of over 100 beats/min during treatment (11 horses) or on day 2 if conversion had not occurred (7 horses). Plasma quinidine concentrations within 1 hour of conversion of AF to sinus rhythm ranged from 1.7 to 7.5 μg/mL (mean, 4.05± 1.6) and ranged from 1.7 to 4.7 μg/mL in 97% of horses. Most horses (92%) with plasma quinidine concentrations > 5 μg/mL exhibited an adverse or toxic effect of quinidine sulfate (clinical or electrocardiographic). There was no statistical association between plasma quinidine concentrations and sustained tachycardia (> 100 beats/min), diarrhea, or colic. Ataxia and upper respiratory tract stridor were significantly associated with plasma quinidine concentrations. In most instances (98%) conversion did not occur while toxic or adverse effects of quinidine sulfate were present or when plasma quinidine concentrations were > 5 μg/mL.     

Effect of beta-tricalcium phosphate in surgically created subchondral bone defects in male horses

beta-Tricalcium phosphate (TCP) was evaluated as a synthetic bone grafting material in horses. Sixteen horses were randomly assigned to 4 groups of 4 horses. In each horse, an 11-mm by 10-mm circular defect with a smooth margin was created surgically in the weight-bearing surface of both third metacarpal bones (McIII) and the left third metatarsal bone. The defect in the left McIII was filled with TCP, the defect in the right McIII was filled with a mixture of 50% autogenous cancellous bone (ACB) and 50% TCP, and the defect in the left third metatarsal bone was not filled to serve as a control. Nuclear imaging and radiographic evaluation of surgical sites were performed at postsurgical week (PSW) 4 and 13 in group-I horses and at PSW 26, 39, and 52 in groups-II, -III, and -IV horses, respectively. Horses in groups I, II, III, and IV were euthanatized at PSW 13, 26, 39, and 52, respectively, and specimens were harvested for histologic evaluation. Results were compared among treatment methods, as well as among time intervals. The greatest activity at defect sites was seen in group-I horses at PSW 4. Activity counts in limbs of group-I horses at PSW 13 and counts in limbs of group-II horses at PSW 26 were not significantly (P less than or equal to 0.05) different. Activity counts in groups-III and -IV horses at PSW 39 and 52, respectively, were less than those in groups I and II. However, there was no significant difference in activity counts between limbs implanted with TCP or ACB:TCP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rhodococcus equi foal pneumonia: protective effects of immune plasma in experimentally infected foals

The immunoprophylactic capacity of specific immune plasma was evaluated in pony foals infected experimentally with Rhodococcus equi. Immune plasma, produced by repeated parenteral administration of viable R. equi to adult horses, was harvested and frozen. Group I (six control foals) and Group II (six principal foals) received lactated Ringers solution and immune plasma respectively at three and five days of age. R. equi were aerosolised into a caudal lung lobe of all foals at seven days of age. Clinical signs, haematological alterations, immune responses, thoracic radiographs and technetium99m pulmonary perfusion scans were monitored. All foals were destroyed and complete post mortem examinations performed. All foals developed pneumonia as evidenced by clinical, radiographic and perfusion alterations, but the survival rate of principal foals was significantly (P less than 0.01) greater than that of control foals. Five control foals developed terminal disease, whereas all principal foals recovered. There was no significant (P greater than 0.05) difference in temperature response, or peripheral blood leucocyte, neutrophil or fibrinogen concentrations between groups. ELISA values for R. equi antibody were significantly (P less than 0.001) greater in principal foals following treatment, but there was no significant (P greater than 0.05) difference in IgG or IgM concentrations between groups. Results of the haemolysis inhibition assay indicated that equi factor neutralising antibodies were transferred by immune plasma to the principal foals. Post mortem examinations of five control foals destroyed at approximately three weeks post infection because of terminal disease, revealed severe pyogranulomatous pneumonia. One control and all principal foals were either free of lesions or had resolving lesions and/or minimal scar formation at three months post infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of procaine in adverse reactions to procaine penicillin in horses

Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penicillin preparations to 50 degrees C for 1 day led to a significant (P less than 0.01) increase in the amount of soluble procaine. Heating to 50 degrees C for 7 days also produced a significant (P less than 0.02) increase. Soluble procaine tended to return to baseline concentrations when veterinary procaine penicillin preparations were heated to 50 degrees C for 2 days then stored for 7 days at room temperature. Administration of procaine HCl intravenously (IV) at 2, 5, and 10 mg/kg produced behavioural, locomotor and vascular reactions, which were clinically similar to those reported in adverse reactions to procaine penicillin. The more severe reactions occurred at higher doses, although different horses responded variably at the same dose. Some adverse reactions lead to recumbency but none were fatal. The blood procaine concentrations 1 min after IV administration averaged 19.0 +/- 12.6 and 25.3 +/- 16 micrograms/ml at 2.5 mg/kg and 5 mg/kg, respectively. Ten min after administration, blood procaine concentrations were significantly higher (P less than 0.001) in the 5 mg/kg group than in the 2.5 mg/kg group. Intramuscular (IM) procaine HCl at 5 mg/kg produced significantly lower (P less than 0.001) blood concentrations than similar IV doses, and, in contrast to the IV doses, the amount of procaine in the blood was significantly higher 5 and 10 min after administration than it was after 1 min. Mild excitatory reactions in 4/5 horses were noted 5 to 10 min after IM administration. Administration of diazepam 20 s before procaine HCl prevented the excitatory adverse reaction in 2/2 horses, but administration after the procaine did not influence the outcome.     

外源性金属硫蛋白对奶牛泌乳性能的影响

选取24头经产泌乳中国荷斯坦牛,随机等分为Ⅰ、Ⅱ、Ⅲ、Ⅳ 4组,分别每头静脉注射经生理盐水溶解的Zn-MT 0（对照）、5.0、10.0和15.0mg,以探讨外源性金属硫蛋白（MT）对奶牛泌乳性能的影响。结果表明,Ⅱ组、Ⅲ组和IV组的4%标准乳产量均显著（P〈0.05）高于对照组;各试验组奶中MT含量显著（P〈0.05或P〈0.01）高于对照组;各组间的乳脂率虽无显著差异（P〉0.05）,但也呈现出试验组高于对照组的趋势。说明MT是一种能够有效调控奶牛泌乳性能的生理活性物质和高效抗氧化剂。     

Effects of an adapted intravenous amiodarone treatment protocol in horses with atrial fibrillation

REASON FOR PERFORMING STUDY: Good results have been obtained with a human amiodarone (AD) i.v. protocol in horses with chronic atrial fibrillation (AF) and a pharmacokinetic study is required for a specific i.v. amiodarone treatment protocol for horses. OBJECTIVES: To study the efficacy of this pharmacokinetic based i.v. AD protocol in horses with chronic AF. METHODS: Six horses with chronic AF were treated with an adapted AD infusion protocol. The protocol consisted of 2 phases with a loading dose followed by a maintenance infusion. In the first phase, horses received an infusion of 6.52 mg AD/kg bwt/h for 1 h followed by 1.1 mg/kg bwt/h for 47 h. In the second phase, horses received a second loading dose of 3.74 mg AD/kg bwt/h for 1 h followed by 1.31 mg/kg bwt/h for 47 h. Clinical signs were monitored, a surface ECG and an intra-atrial electrogram were recorded. AD treatment was discontinued when conversion or any side effects were observed. RESULTS: Three of the 6 horses cardioverted successfully without side effects. The other 3 horses did not convert and showed adverse effects, including diarrhoea. In the latter, there were no important circulatory problems, but the diarrhoea continued for 10-14 days. The third horse had to be subjected to euthanasia because a concomitant Salmonella infection worsened the clinical signs. CONCLUSION: The applied treatment protocol based upon pharmacokinetic data achieved clinically relevant concentrations of AD and desethylamiodarone. POTENTIAL RELEVANCE: Intravenous AD has the potential to be an alternative pharmacological treatment for AF in horses, although AD may lead to adverse drug effects, particularly with cumulative dosing.     

Changes to oxfendazole chiral kinetics and anthelmintic efficacy induced by piperonyl butoxide in horses

REASONS FOR PERFORMING THE STUDY: The study of novel pharmacological strategies to control parasitism in horses is required since many parasite species have developed resistance to anthelmintic drugs. OBJECTIVES: To evaluate the effects of piperonyl butoxide (PB) (a metabolic inhibitor) on the plasma availability and enantiomeric behaviour of oxfendazole (OFZ) given orally to horses, and to compare the clinical efficacy of OFZ given either alone or co-administered with PB in naturally parasitised horses. METHODS: Fifteen naturally parasitised crossbred male ponies were allocated into 3 groups (n = 5) and treated orally as follows: Group I (control) received distilled water as placebo; Group II was dosed with OFZ (10 mg/kg bwt); and Group III was treated with OFZ (10 mg/kg bwt) co-administered with PB (63 mg/kg bwt). Jugular blood samples were obtained over 120 h post treatment. Three weeks after treatments, all experimental horses were subjected to euthanasia. RESULTS: The observed maximum plasma concentration (Cmax) and area under the concentration vs. time curve (AUC) values for OFZ increased 3- and 5-fold, respectively, in the presence of PB. The plasma concentration profiles of fenbendazole (FBZ), a metabolite generated from OFZ, were significantly lower after the treatment with OFZ alone (AUC = 0.8 microg x h/ml) compared to those obtained after the OFZ + PB treatment (AUC = 2.7 microg x h/ml). The enhanced pharmacokinetic profiles correlated with increased anthelmintic efficacy. The combination OFZ + PB showed 100% efficacy against mature nematode parasites. The efficacy against cyathostome L3 larvae increased from 94% (Group II) to 98.7% (Group III). Consistently, the number of L4 larvae recovered from OFZ + PB treated horses (Group III) (n = 146) was significantly lower (P<0.05) than that recovered from Group II (n = 1397). CONCLUSIONS: The use of PB as a metabolic inhibitor may be useful to enhance OFZ activity against mature and migrating larvae of different parasite species in horses. POTENTIAL RELEVANCE: Metabolic inhibitors may be used to enhance the activity of benzimidazole anthelmintics and extend the effective lifespan of benzimidazole drugs in the face of increasing resistance.     

Influence of dietary calcium on lead poisoning in mallard ducks (Anas platyrynchos)

Forty-five mallard ducks were allotted into 3 dietary groups. Group I was fed pelleted calcium-supplemented corn; group II was fed a pelleted commercial duck ration; and group III was fed cracked corn. Ten ducks of each group were given four No. 4 lead shot via an esophageal tube, and 5 ducks of each dietary group were kept as pair-fed controls. Anorexia and weight loss were most severe in the treated group III ducks. Group III had a maximum reduction in food consumption of 87% followed by a slight improvement in appetite; they lost 35% of their initial body weight. Group I treated ducks had a reduction in food consumption of 64% that eventually returned to the quantities consumed at the start of the experiment; group I ducks lost 18% of their initial body weight. Group II treated ducks maintained healthy appetites during the experiment and had a weight gain of 2% of their initial body weight. The number of ducks that became moribund and were euthanatized differed significantly among the treated groups with 100% of group III, 50% of group I, and 0% of group II treated ducks becoming moribund. All 3 groups of treated ducks had increased protoporphyrin IX concentrations compared with controls. Groups I and III lead-treated ducks had significant (P less than 0.05) reductions in erythrocyte counts, PCV, hemoglobin concentrations, and mean corpuscular hemoglobin concentrations as compared with controls. Group II had reduced hemoglobin concentration and mean corpuscular hemoglobin concentration compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of repeated administration of hCG on follicular and luteal characteristics and serum progesterone concentrations in eCG-superovulated Sanjabi ewes

The objective of this study was to evaluate if treatment of equine chorionic gonadotrophin (eCG)-superovulated Sanjabi ewes with repeated administration of human chorionic gonadotropin (hCG) would increase the number of normal corpus luteum (CL) and serum progesterone concentrations and decrease the number of persistent follicles. The superovulated ewes were divided into four groups on day 0 (day of sponge removal); the ewes were treated by an intramuscular administration of 500?IU hCG on day 0 (Group I: n?=?10), on days 0 and 1 (Group II: n?=?10), or on days 0, 1, and 2 (Group III: n?=?10) and no treatment for control group (n?=?10). Blood samples were collected on days 0, 1, 2, 5, and 8 (day of slaughter), and serum progesterone concentrations were determined. According to progesterone concentrations, 50 (4/8) and 0?% of the ewes underwent premature luteal regression in the control group and the hCG groups, respectively. There were more CLs in Group III than in Group II and the control group. Ewes treated with hCG had a greater number of normal-looking CL. CL diameter was significantly greater in Group II and Group III than other groups. Total CL weight was significantly (P?<?0.05) higher in Group III than in Group I and the control group. Number of persistent follicle and persistent follicle diameter were lower in control group compared to the other groups. Eight days after sponge removal, serum progesterone concentration was significantly higher in Group III than in Group I and the control group. The present results indicate that repeated administration of hCG supported CL formation, increased serum progesterone concentration, and prevented premature luteal regression in eCG-superovulated Sanjabi ewes.     

Role of oxytocin and/or PGF2 alpha on breeding efficiency in buffaloes

A study was conducted on 40 buffalo-cows, assigned randomly, immediately after calving into three groups: group I (n = 10) injected with saline and taken as control; group II (n = 15) received 25 mg PGF2 alpha/animal (Lutalyse); group III (n = 15) received 25 mg PGF2 alpha + 25 i.u. oxytocin/animal (Syntocinon), single i.m. dose. Oxytocin and/or PGF2 alpha significantly (P less than 0.01) shortened the interval from calving to first service (38.33 and 31.53 days for groups II and III respectively, versus 91.60 days for controls). The treatment reduced the service period (38.29 and 35.87 days for groups II and III respectively, versus 45.40 days for controls). Concomitantly a significant (P less than 0.01) decrease in the open-days post partum was achieved (76.62 and 67.40 days for groups II and III respectively, versus 137.00 days for controls). In addition, the treated buffaloes needed significantly (P less than 0.01) fewer services per conception (1.67 and 1.20 S/C for groups II and III respectively) than the untreated ones (2.70 S/C), besides a substantial improvement (P less than 0.01) in their conception rate either at 60 or 85 days post partum. Significantly improved (P less than 0.05) results were obtained in the oxytocin and PGF2 alpha treated animals, than in those receiving PGF2 alpha alone for all the previous parameters, except for the service period. Buffaloes therefore seemed to respond better to such treatment than dairy cows.     

复合异位酸对山羊小肠氨基酸流通量和表观消化率的影响

试验研究了日粮添加复合异位酸对山羊小肠氨基酸流通量和表观消化率的影响。采用3×3拉丁方试验设计,选用3头安装有永久性瘤胃瘘管、十二指肠近端瘘管和回肠远端瘘管、平均体重为(25.4±0.75)kg的健康麻城黑山羊为试验动物。I组为空白对照,饲喂基础日粮。II组、III组分别饲喂含0.3%和0.6%复合异位酸(钠盐形式)的试验日粮。采用Co-EDTA标记法测定小肠氨基酸流通量和表观消化率。结果显示:III组缬氨酸和异亮氨酸十二指肠流通量极显著高于对照组(P0.01),亮氨酸和必需氨基酸显著高于对照组(P0.05);缬氨酸和丙氨酸的小肠表观消化率显著高于对照组(P0.05)。II组缬氨酸和异亮氨酸十二指肠流通量显著高于对照组(P0.05)。III组异亮氨酸十二指肠流通量显著高于II组(P0.05)。