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The use of hormonal protocols in puberty induction and synchronization of oestrus has lead to an increase in the efficiency of replacement gilts. The aim of this study was to evaluate different doses of porcine LH in precocious puberty induction and oestrus synchronization in a homogeneous group of gilts. Sixty-seven homogeneous prepubertal gilts (Camborough 22) at 137 +/- 4 days of age and 87 +/- 7 kg were treated with three different hormonal protocols: T1--600 UI of equine chorionic gonadotrophin (eCG; Novormon) and after a 72-h period 5 mg of LH (Lutropin); T2--600 UI of eCG and a 72-h period 2.5 mg of LH; T3--600 UI of eCG and a 72-h period 1.25 mg of LH. The ovaries were examined at slaughter, on day 6 after the hormonal treatment. There were no statistical differences (p > 0.05) between the different LH doses in the percentage of the detected oestrus (T1 = 42.85%; T2 = 60.87%, T3 = 52.18%), oestrus duration (T1 = 41.44 +/- 16.30 h; T2 = 48.57 +/- 16.29 h, T3 = 39.33 +/- 11.42 h), number of corpora lutea (T1 = 9.61 +/- 5.43; T2 = 9.86 +/- 3.32, T3 = 8.13 +/- 5.52) and percentage of animals presenting ovarian cystic degeneration (T1 = 33.33%; T2 = 39.13%, T3 = 39.13%). The T2 (2.5 mg of LH) presented the lowest dispersion (p < 0.05) of the LH-ovulation interval (T1 = 37.17 +/- 4.07 h; T2 = 38.26 +/- 2.84 h; T3 = 36.25 +/- 5.69 h). The LH dose reduction to 2.50 and 1.25 mg presented equal results with the recommended dose of 5.0 mg, and could be used in the precocious induction of oestrus in gilts. The 2.5-mg LH dose showed the lowest dispersion of ovulation and it can be used in fixed-time artificial insemination programmes.  相似文献   
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The purpose of this study was to determine the cardiovascular effects of 2.0% end‐tidal isoflurane in dogs administered dexmedetomidine (DEX). Using a randomized crossover design and allowing at least 2 weeks between treatments 12 adult hound dogs of either sex weighing 22 ± 1.7 SD kg were anesthetized by face mask administration of either sevoflurane or isoflurane to facilitate instrumentation prior to administration of treatment drugs. Dogs were intubated and instrumented to enable measurement of heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, mean pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), and cardiac output (CO) via thermodilution using 5 mL of 5% dextrose, and recording the average of three replicate measurements. Cardiac index (CI) and systemic (SVR) and pulmonary vascular resistances were calculated. Following completion of instrumentation, dogs were allowed to recover for 40 minutes. After collection of baseline data, dogs were administered one of four treatments at T‐10 minutes prior to injection of DEX (500? g M–2 IM): 1) saline (SAL); 2) atropine [ATR, 0.02 (n = 6) or 0.04 (n = 6) mg kg–1 IM]; 3) ISO (2.0% end tidal concentration); or 4) ISO + ATR. Cardiovascular data were collected at T‐20 and T‐5 minutes prior to administration of DEX, and at 5, 10 , 20, 30, 40, and 60 min following DEX. Data were analyzed using anova for repeated measures with post‐hoc differences between means identified using Bonferroni's method (p < 0.05). Differences in ATR dose were not found to be significant and thus results for ATR dose groups were pooled. Administration of SAL (dexmedetomidine alone) was associated with decreases in HR and CO and increases in SAP, MAP, DAP, CVP, and SVR. Administration of ATR was associated with an increase in HR and CO compared with SAL. Administration of ISO was associated with an increase in HR and a decrease in SVR, MAP and CVP compared with SAL. Administration of ISO + ATR was associated with effects similar to that of ISO or ATR alone. We conclude that administration of ISO reduces the increase in SVR associated with administration of DEX and does not adversely affect CO.  相似文献   
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