Pharmacological characterization of muscarinic receptors in the contractions of isolated bronchi in the horse

We investigated the effects of nonselective muscarinic antagonist (atropine) and of selective muscarinic subtype 1 (M₁), 2 (M₂), 3 (M₃) antagonists (VU0255035, methoctramine, pFHHSiD, respectively) on the contractions evoked by electrical field stimulation (EFS) or by exogenous ACh in isolated horse bronchial muscle. Atropine completely inhibited neurogenic contractions in a concentration‐dependent fashion, whereas selective muscarinic antagonists induced relevant modifications only at the highest concentration tested. Experiments with selective muscarinic antagonists in combination showed that only the simultaneous blockade of M₁/M₃ or M₂/M₃ receptors was able to induce a nearly complete suppression of contractions. The contractions induced by exogenous ACh were competitively antagonized only by atropine (pA₂ = 9.01 ± 0.05). M₃ selective antagonist, up to 10⁻⁶ m , caused a moderate concentration‐dependent rightward shift of ACh curve (pA₂ = 7.96 ± 0.10). These data show that M₃ muscarinic receptors possess a central role in mediating cholinergic contraction of horse bronchi, while M₁ and M₂ receptors seem to have a cooperative role. Selective muscarinic antagonists seem unlikely to be useful against bronchoconstriction associated with airway diseases in horses. Conversely, compounds with selectivity for both M₁ and M₃ receptors could be as effective as traditional anticholinergics and induce fewer cardiac side effects.     

Muscarinic Receptors in Equine Airways

The distribution of muscarinic receptors in equine airways was investigated using autoradiography. Frozen sections of tissue from six different levels in the bronchial tree, from the trachea to the distal bronchioles, were incubated in vitro with 1.5 nmol/L of the muscarinic receptor antagonist 1-[N-methyl-³H]scopolamine methyl chloride (³H-NMS). In addition, the subtype pattern of muscarinic receptors was investigated in equine tracheal smooth muscle using radioligand binding with methoctramine, tripinamide, 4-DAMP-methiodide and pirenzipine as competitors against the binding of 1.3 nmol/L ³H-NMS. The autoradiograms showed specific labelling indicating a high density of muscarinic receptors in smooth-muscle tissue in all levels of the airway tree investigated. Besides muscle tissue, subepithelial glands were the only structures specifically labelled. The dominating subtypes in tracheal smooth muscle investigated with radioligand binding studies were found to be M₂ and M₄, as both methoctramine (pK _d = 8.5) and tripinamide (pK _d = 8.6 and 6.7 for two different sites) showed high affinity. The density of the M₃-muscarinic receptor subtype was low, but this subtype could be detected with statistical significance when methoctramine was used as the competitor against ³H-NMS binding.     

Muscarinic receptor subtypes in equine tracheal smooth muscle

Selective muscarinic receptor antagonists were used to identify muscarinic receptor subtypes in equine trachealis strips. The M₁ receptor antagonist pirenzepine (10^–7 mol/L to 3 × 10^–5 mol/L) and the M₃ receptor antagonist 4-diphenylacetoxy-N-methylpiperidine (4-DAMP, 10^–9 mol/L to 3 × 10^–7 mol/L³) dose dependently inhibited the contractile responses to electrical field stimulation (EFS) and exogenous acetylcholine (ACh). Schild plots yielded a pA₂ value for pirenzepine vs ACh of 6.75 ± 0.09, which is consistent with the affinity for M₂ or M₃ receptors, and a pA₂ value for 4-DAMP vs ACh of 8.47 ± 0.09, which is in agreement with the affinity for M₃ receptors. The M₂ receptor antagonist gallamine (10^–5 mol/L and 10^–4 mol/L) did not affect the response of trachealis to exogenous ACh and low-frequency EFS (0.1–2 Hz) but decreased the responses to high-frequency EFS (4–16 Hz). These results suggest that the muscarinic receptors mediating contractions induced by ACh in equine tracheal smooth muscle are of the M₃ subtype. The lack of an increase in the response to EFS following gallamine suggests that functional prejunctional inhibitory M₂ receptors are not present on the cholinergic nerves innervating equine tracheal smooth muscle.     

Muscarinic receptor subtypes, β-adrenoceptors and cAMP in the tracheal smooth muscle of conventional and double-muscled calves

The total muscarinic (M₁ + M₂ + M₃) and -adrenergic receptors in the tracheal smooth muscle of conventional and double-muscled calves were identified and characterized with the non-specific antagonists [³H]quinuclidinyl benzilate ([³H]QNB) and [³H]dihydroalprenolol ([³H]DHA) respectively.Although the quantity of -adrenoceptors in double-muscled calves was 25% lower (p<0.05) than in conventional calves (B _max=327±89 fmol/mg protein), adenylate cyclase assays indicated that the basal adenylate cyclase activity and the (–)-isopropylnoradrenaline (ISO)- and sodium fluoride (NaF)-stimulated values were not significantly different between these calves. However, the density of muscarinic receptors in double-muscled calves was 40% higher (p<0.01) than in conventional calves (B _max=2955±625 fmol/mg protein). Subtypes of muscarinic receptors were studied with [³H]telenzepine (M₁-receptors), [³H]AF-DX 384 (M₂-receptors) and [³H]4DAMP (M₁ and M₃-receptors). It was found that in both double-muscled and conventional calves about 40% of the receptors were of the M₃-subtype, the remaining 60% being M₂-receptors.From these results, it is suggested that inflammation of the respiratory tract in double-muscled calves may be complicated by an imbalance between the cholinergic bronchoconstrictor and the -adrenergic bronchodilator components of the autonomic nervous system.     

Concentrations of platelet α2-adrenoceptors,lymphocyte muscarinic receptors,and blood monoamines in dogs (Canis familiaris) affected by canine cognitive dysfunction syndrome

Canine cognitive dysfunction syndrome (CDS) is a neurodegenerative disorder of aged dogs characterized by a progressive decline in cognitive function. In humans and laboratory animals, a variety of neurotransmitter abnormalities have been described in patients affected by age-related dementia. Specifically, the regulatory role of the catecholaminergic, serotonergic, and cholinergic systems has been outlined. The aim of the present study was to measure blood monoamine levels, platelet α₂-adrenergic receptors, and lymphocyte muscarinic receptors in healthy adult and aged dogs and in dogs affected by canine cognitive dysfunction. Based on clinical and behavioral examination, 40 dogs were divided into 3 groups: healthy adults (n = 14), aged dogs (n = 17), and aged dogs affected by canine cognitive dysfunction (n = 9). A significant reduction in plasma levels of norepinephrine and dopamine was observed both in aged dogs (0.16 ± 0.02 ng/mL, P < 0.01; 0.11 ± 02 ng/mL, P < 0.01, respectively) and in CDS dogs (0.14 ± 0.03 ng/mL, P < 0.05; 0.10 ± 00.005 ng/mL, P < 0.01, respectively) compared with adults (0.29 ± 0.04 ng/mL and 0.15 ± 0.02 ng/mL, respectively). No significant differences were observed among groups for α₂-adrenergic receptor concentrations. Canine lymphocytes express 2 distinct classes of muscarinic receptors, characterized by high (HA) and low affinity (LA) for [³H]-N-methyl-scopolamine. A significant age-dependent decrease in HA muscarinic receptors was observed. However, no differences were found between aged dogs (87.65 ± 11.08 sites/cell × 10²) and in CDS dogs (90.17 ± 6.75 sites/cell × 10² ) for HA muscarinic receptor concentrations. As far as LA muscarinic receptors are concerned, CDS dogs showed a significant increase (393.48 ± 63 sites/cell × 10²; P < 0.05) with respect to healthy adult dogs (188.84 ± 16.50 sites/cell × 10²). Our results suggest that the reduction in HA muscarinic receptor-binding sites could be representative of the physiological aging process, whereas the increase in lymphocyte LA muscarinic receptor levels could be related to the cognitive decline.     

Pharmacokinetics of Tilmicosin (Provitil Powder and Pulmotil Liquid AC) Oral Formulations in Chickens

A bioavailability and pharmacokinetics study of powder and liquid tilmicosin formulations was carried out in 18 healthy chickens according to a single-dose, two-period, two-sequence, crossover randomized design. The two formulations were Provitil and Pulmotil AC. Both drugs were administered to each chicken after an overnight fast on two treatment days separated by a 2-week washout period. A modified rapid and sensitive HPLC method was used for determination of tilmicosin concentrations in chicken plasma. Various pharmacokinetic parameters including area under plasma concentration–time curve (AUC₀₋₇₂), maximum plasma concentration (C _max), time to peak concentration (t _max), elimination half-life (t _1/2β), elimination rate (k _el), clearance (Cl_B), mean residence time (MRT) and volume of distribution (V _d,area) were determined for both formulations. The average means of AUC₀₋₇₂ for Provitil and Pulmotil AC were very close (24.24 ± 3.86, 21.82 ± 3.14 (μg.h)/ml, respectively), with no significant differences based on ANOVA. The relative bioavailability of Provitil as compared to Pulmotil AC was 111%. In addition, there were no significant differences in the C _max (2.09 ± 0.37, 2.12 ± 0.40 μg/ml), t _max (3.99 ± 0.84, 5.82 ± 1.04 h), t _1/2β (47.4 ± 9.32, 45.0 ± 5.73 h), k _el (0.021 ± 0.0037, 0.022 ± 0.0038 h⁻¹), Cl_B (19.73 ± 3.73, 21.37 ± 4.54 ml/(min/kg)), MRT (71.20 ± 12.87, 67.15 ± 9.01 h) and V _d,area (1024.8 ± 87.5, 1009.8 ± 79.5 ml/kg) between Pulmotil AC and Provitil, respectively. In conclusion, tilmicosin was rapidly absorbed and slowly eliminated after oral administration of single dose of tilmicosin aqueous and powder formulations. Provitil and Pulmotil AC can be used as interchangeable therapeutic agents.     

Estimates of phenotypic and genetic parameters for birth weight of Brown Swiss calves in Turkey using an animal model

A study was conducted to assess the influence of genetic and environmental factors on Brown Swiss calf birth weight, and to estimate variance components, genetic parameters, and breeding values. Data were collected on 1,761 Brown Swiss calves born from 1990 to 2005 in the Konuklar State Farm in Turkey. Mean birth weight for all calves was 39.3 ± 0.09 kg. Least squares mean birth weights for male and female Brown Swiss calves were 40.3 ± 0.02 and 39.0 ± 0.02 kg, respectively. Variance components, genetic parameters, and breeding values for birth weight in Brown Swiss calves were estimated by restricted error maximum likelihood (REML)–best linear unbiased prediction(BLUP) procedures using an MTDFREML (multiple trait derivative free restricted maximum likelihood) program employing an animal model. Direct heritability (h _d²), maternal heritability (h _m²), total heritability (h _T²), r _am and c _am estimates were 0.12, 0.09, 0.23, −0.58, and −0.06, respectively. The estimated maternal permanent environmental variance expressed as a proportion of the phenotypic variance (c ²) was 0.05. Breeding values were estimated for the trait and used to evaluate genetic trends across the time period investigated. The genetic trend linear regression was not different from zero. No genetic trend for birth weight was expected, since there had been no direct selection pressure on the trait. Absence of a trend confirms that there was no change due to selection pressure on correlated traits. Genetic and environmental parameter estimates were similar to literature values indicating that effective selection methods used in more developed improvement programs would be effective in Turkey as well.     

Sweet potato and Green panic as sole fodder for stall-fed lactating White Fulani cows and growing calves

Three sweet potato varieties (TIS-87/0087; TIS-8164; TIS-2532.OP.1.13) and Green panic (Panicum maximum) were evaluated for forage quality in a completely randomized design (CRD) using 12 sole-fed lactating White Fulani cows for 21 days, and 12 growing White Fulani and White Fulani x Brown Swiss calves for 77 days. Dry matter intake of cows ranged (p < 0.05) between 131 g/W_kg ^0.734 in TIS-87/0087 and 152 g/W_kg ^0.734 in TIS-8164. Daily milk yields increased (p < 0.05) in TIS-87/0087 (2%) and TIS-8164 (5%), but decreased in TIS-2532.OP.1.13 (5%) and Green panic (19%). Mean (±SEM) milk total solids (13.16 ± 0.05 g/100 g), ash (0.78 ± 0.01 g/100 g), protein (3.79 ± 0.07 g/100 g), fat (3.98 ± 0.06 g/100 g), and lactose (4.62 ± 0.14 g/100 g) were significantly different (p < 0.05) among treatments. The White Fulani x Brown Swiss calves recorded about 10, 25 and 29% higher birthweight, milk intake and bodyweight gains respectively, but about 3% lower dry matter intake than the purebred White Fulani calves. The rumen degradation rates were similar (p > 0.05), while the rest rumen dry matter degradation characteristics were lowest (p < 0.05) for Green panic. Sweet potato forage could be used as sole feed or supplement for dry-season Green panic.     

EFFECT OF VENTILATION TECHNIQUE AND AIRWAY DIAMETER ON BRONCHIAL LUMEN TO PULMONARY ARTERY DIAMETER RATIOS IN CLINICALLY NORMAL BEAGLE DOGS

In dogs, a mean broncho‐arterial ratio of 1.45 ± 0.21 has been previously defined as normal. These values were obtained in dogs under general inhalational anesthesia using a single breath‐hold technique. The purpose of the study was to determine whether ventilation technique and bronchial diameter have an effect on broncho‐arterial ratios. Four healthy Beagle dogs were scanned twice, each time with positive‐pressure inspiration and end expiration. For each ventilation technique, broncho‐arterial ratios were grouped into those obtained from small or large bronchi using the median diameter of the bronchi as the cutoff value. Mean broncho‐arterial ratios obtained using positive‐pressure inspiration (1.24 ± 0.23) were statistically greater than those obtained at end expiration (1.11 ± 0.20) P = 0.005. There was a strong positive correlation between bronchial diameter and broncho‐arterial ratios for both ventilation techniques (positive‐pressure inspiration r_s = .786, P < 0.0005 and end expiration r_s = .709, P < 0.0005). Mean broncho‐arterial ratio for the large bronchi obtained applying positive‐pressure inspiration was 1.39 cm ± 0.20 and during end expiration was 1.22 cm ± 0.20. Mean broncho‐arterial ratio for the small bronchi obtained during positive‐pressure inspiration was 1.08 cm ± 0.13 and during end expiration was 1.01 cm ± 0.13. There was a statistically significant difference between these groups (F = 248.60, P = 0.005). Findings indicated that reference values obtained using positive‐pressure inspiration or from the larger bronchi may not be applicable to dogs scanned during end expiration or to the smaller bronchi.     

Prevalence and biology of goat warble fly infestation by <Emphasis Type="Italic">Przhevalskiana silenus</Emphasis> in Jammu province,India

Examination of 3,960 goats brought from six districts of Jammu province and slaughtered at Jammu abattoir from July 2005 to June 2006 revealed 47.22% prevalence of larval stages of warble fly (Przhevalskiana silenus Brauer, 1858) in goats. Highest prevalence was recorded in Udhampur (56.44%) and lowest in Doda district (13.49%). Classification of the study area into four zones based on height (meters above sea level), viz., zone I (300–325 m asl), zone II (325–800 m asl), zone III (800–1,500 m asl), and zone IV (>1,500 m asl), revealed significant (p < 0.01) difference in infestation among animals of zone II (71.68%), zone III (40.12%), and zone IV (22.41%). However, animals of zone I did not reveal any infestation. Statistical analysis in relation to age showed significant (p < 0.01) difference among different age groups, i.e., <1 year (2.81%), 1–3 years (51.17%), and >3 years (43.16%). Breed-wise analysis also showed significantly (p < 0.01) higher infestation rate among Bakerwali (51.51%) goats as compared to Beetal (42.59%). But no significant difference was recorded among male (47.81%) and female (46.82%) animals. The overall mean larva count (L1, L2, and L3) was observed to be 14.72 ± 0.34, ranging from 4 to 72. It was significantly (p < 0.05) higher in animals of zone II (22.20 ± 0.21) as compared to goats of zones III (14.21 ± 0.41) and IV (7.73 ± 0.90). Age-wise analysis of mean larva count also showed significant (P < 0.05) difference between animals of 1–3 years (16.25 ± 0.37) and >3 years of age (13.18 ± 0.40). Mean larvae count in relation to sex and breed did not reveal any significant difference. First-instar larvae (L₁) were recorded from May to mid-September, second larval stage (L₂) from mid-September to mid-December, and third-stage larvae (L₃) from mid-December to February. However, No larvae were recorded from March to April, which is suggestive of pupation period in this region. Thus, it is concluded that adult fly is active in April to June. The results further confirmed that internal life cycle of P. silenus is subcutaneous and no migration of larvae occurs. This is the first report from India, based on slaughter house study on the prevalence and biology of goat warble fly infestation. It will help in devising suitable prophylactic and eradication program to check the economic losses rendered by adult fly.     

Effect of supplementation with corn oil on postpartum ovarian activity,pregnancy rate,and serum concentration of progesterone and lipid metabolites in F<Subscript>1</Subscript> (<Emphasis Type="Italic">Bos taurus</Emphasis> × <Emphasis Type="Italic">Bos indicus</Emphasis>) cows

The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy rate, progesterone (P₄), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in blood of F₁ (Bos taurus × Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously. All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination, evaluating simultaneously ovarian activity. P₄ and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P₄ and CHO was higher for OG with respect to CG (2.52 ± 0.65 vs 1.88 ± 0.62 ng/ml and 117.79 ± 11.57 vs 85.71 ± 12.11 mg/dl, respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone and cholesterol in grazing B. taurus × B. indicus cows with low body condition score showing postpartum anoestrus.     

Effect of supplementation of dietary protected lipids on intake and nutrient utilization in Deccani lambs

Four complete isonitrogenous (crude protein 13%) rations with 0 (T₁), 5 (T₂), 10 (T₃) and 15 (T₄) per cent calcium soap from red palm oil (protected fat) were formulated and evaluated using four Deccani lambs (19.32 ± 0.82 kg) in a completely randomized design at the end of a growth trial. The average daily dry matter intake (% body weight or g/kg W^0.75 per day) in lambs fed ration T₄ was significantly (p < 0.05) lower than in those fed rations T₁, T₂, and T₃. There was no significant difference in the digestibility of proximate principles and cell-wall constituents except for ether extract (EE) and cellulose. EE digestibility was significantly (p < 0.05) higher by 15.71, 14.65 and 11.56 percentage units, respectively in lambs fed rations T₂, T₃ and T₄ as compared to those fed ration T₁. Ration T₄ had significantly (p < 0.05) lower cellulose digestibility than rations T₁, T₂ and T₃. Nitrogen and phosphorous balances (g/day) were not significantly (p > 0.05) different among the four rations. Calcium balance (g/day) was higher by 0.65, 1.39 and 1.40, respectively, in lambs fed rations T₂ (p > 0.05) and T₃ and T₄ (p < 0.05) in comparison to those fed ration T₁. Digestible crude protein and total digestible nutrients content (g/kg DM) of rations were not significantly (p > 0.05) different among the four rations. It is concluded that calcium soap from red palm oil can be supplemented up to 10% level as a concentrated energy source in the rations of Deccani lambs without any adverse effect on dry matter intake and cellulose digestibility.     

Effect of supplementation of indigenous browse tree pods on weight gain and carcass parameters of Abergelle rams

The objective of the study was to evaluate the effect of supplementation of indigenous browse tree pods on nutrient intake, digestibility, weight gain, and carcass parameters of local Abergelle rams fed grass hay as a basal diet. This experiment was conducted at the Abergelle Agricultural Research Center farm in Tigray region, northern Ethiopia. Experimental rams were grouped according to their initial body weight (17.4?±?0.95 kg) in a randomized complete block design into three treatments and six replications. Treatments consisted of feeding grass hay free of choice supplemented with pods of either Acacia tortilis (T₁), Faidherbia albida (T₂), or Dichrostachys cinerea (T₃) fed at the rate of 10 g kg^?1 body weight daily. The crude protein (CP) contents of the supplemental feeds in T₁, T₂, and T₃ were 167, 156, and 135 g kg^?1 dry matter (DM), respectively. The CP intake was significantly higher (P?<?0.05) in T₁ and T₂ than that in T₃. No statistical difference (P?>?0.05) was observed in the digestibilities of DM and CP. Final body weight, average daily gain, slaughter weight (SW), hot carcass weight, and ribeye area were not significantly different (P?>?0.05) among the treatments. However, dressing percentage based on SW in T₁ and T₂ was significantly higher (P?<?0.05) than that in T₃. Therefore, from this research, it can be concluded that though the weight gains and carcass weights of experimental rams were not as such remarkable among the treatments, efficient utilization of locally available and cheap browse tree pods as alternative protein supplements to Abergelle sheep during the dry season could be important to small holder farmers.

     

Lung microdialysis study of florfenicol in pigs after single intramuscular administration

For most bacterial lung infections, the concentration of unbound antimicrobial agent in lung interstitial fluid has been considered as the gold standard for estimating the antibacterial efficacy. In this study, the pharmacokinetics of florfenicol (FF) in porcine lung interstitial fluid was investigated after single intramuscular administration at two different doses (20 and 50 mg/kg). Twelve pigs underwent thoracotomy under general anesthesia. Then, the CMA/30 probe was implanted into the lung and perfused at 1 μL/min. The microdialysis (MD) samples were collected on a preset schedule and analyzed by high‐performance liquid chromatography (HPLC). Noncompartmental pharmacokinetic analysis was performed. FF exhibited rapid distribution and slow elimination in porcine lung interstitial fluid. The main pharmacokinetic parameters at 20 and 50 mg/kg were 4.88 ± 0.54 and 10.36 ± 2.52 μg/mL for the maximum concentration (C_max), 3.25 ± 0.32 and 3.50 ± 0.27 h for the time to C_max (T_max), 9.47 ± 6.84 and 7.75 ± 3.23 h for the half‐life (t_1/2), 0.10 ± 0.06 and 0.10 ± 0.04 1/h for the terminal elimination rate constant (λ_z), 13.85 ± 7.97 and 11.42 ± 2.79 h for the mean residence time (MRT), 37.77 ± 8.13 and 71.15 ± 16.99 h·μg/mL for the area under the curve from time 0 to 18.25 h (AUC_0–18.25), and 51.18 ± 20.11 and 88.78 ± 27.58 h·μg/mL for the area under the curve from time 0 to infinity (AUC_0–∞), respectively.     

Feed intake,digestibility and body weight change in Farta sheep fed hay supplemented with rice bran and/or noug seed (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>) meal

The study was conducted to determine the effect of supplementation with rice bran (RB) and /or noug seed (Guizotia abyssinica) meal (NSM) on feed intake, digestibility, and body weight (BW) change in hay based feeding of Farta sheep. Twenty five yearling Farta rams with a mean initial BW of 19.23 ± 0.28 kg were used in randomized complete block design arranged into five blocks of five animals. The five dietary treatments that consisted of hay alone (T₁), hay + RB (T₂), hay + mixture of RB and NSM at a ratio of 1:2 (T₃), hay + mixture of RB and NSM at a ratio of 2:1 (T₄) and hay + NSM (T₅) were randomly assigned to each sheep within a block. The supplements were daily offered at 300 g dry matter (DM) head⁻¹ in two equal parts at 800 and 1600 h. Supplementation improved the total DM and acid detergent fiber (ADF) intake (P < 0.05), organic matter (OM) intake (P < 0.01), crude protein (CP) intake (P < 0.001). The apparent digestibility of DM in T₅ was higher (P < 0.05) than in T₁ and T₂ and that of T₄ was also higher (P < 0.05) than in T₁. The apparent digestibility of CP in T₅ and T₄ were higher (P < 0.001) than in T₁ and T₂ and that of T₃ and T₂ were also higher (P < 0.001) than for T₁. The BW gain of experimental sheep was improved (P < 0.01) by supplementation with NSC (T₅) and/or its mixtures with RB (T₃ and T₄). The results of the study showed that supplementation with either of both mixtures of NSM and RB at 43% of total DM intake promoted better feed intake, digestibility and BW gain in Farta sheep.     

Effect of supplementation of mustard oil cake on intake,digestibility and microbial protein synthesis of cattle in a straw-based diet in Bangladesh

The objective of this study was to analyse the effects of different levels of rumen-degradable protein (RDP) on intake, digestibility and microbial protein synthesis by supplementing mustard oil cake (MOC) on rice straw-based diet of cattle (Bos indicus) in Bangladesh. A 4 × 4 Latin square design was applied. Four diets having constant energy (7.0 MJ/kg of dry matter (DM)) with varying levels of RDP (M ₀ = 4.1 g/MJ (control), M ₁ = 6.3 g/MJ, M ₂ = 8.3 g/MJ and M ₃ = 12.4 g/MJ of metabolizable energy (ME)) were received by each animal for a period of 28 days. A metabolism trial was conducted for 7 days. Results indicate that with increasing levels of RDP, crude protein (CP) and RDP intake increased significantly (P < 0.01). The significant (P < 0.01) increase in digestibility values are obtained for DM, organic matter, CP and digestible organic matter in the rumen. The digestibility of neutral detergent fibre and acid detergent fibre was also increased significantly (P < 0.05). The total nitrogen (N), ammonia-N and total volatile fatty acids increase significantly (P < 0.01) while the rumen pH increased from M ₀ to M ₂ and decreased thereafter. The efficiency microbial N intake increased significantly (P < 0.01) but showed a curvilinear response with higher RDP level (12.40 g/RDP/MJ ME). This study concludes that supplementation of RDP from MOC enhances the intake, digestibility and microbial protein synthesis which ultimately increases utilization of low-quality feed resources that can be used for developing cost-effective feeding systems on a straw-based diet in tropical regions.     

Trade-off expression of melatonin receptor subtypes (Mel1a and Mel1b) and androgen receptor in lung of a tropical bird,Perdicula asiatica

The role of circulatory steroid hormone along with melatonin in lung of any seasonally breeding bird has never been explored so far. This could be interesting because steroid hormones are immunosuppressive while melatonin is immunostimulatory in nature. In our present study, we report the effect of exogenous melatonin and testosterone on expression of melatonin receptor subtypes (Mel_1a and Mel_1b) and androgen receptor in lung of a tropical bird Perdicula asiatica. Birds were collected from vicinity of Varanasi and acclimatized in laboratory with sufficient food and water. The birds were treated with melatonin and testosterone at dose of 25 µg/100 g B.wt./day and 1 mg/100 g B.wt./day, respectively, for 28 days. At the end of the experiment, the birds were sacrificed and lung tissue and blood sample were collected for immunohistochemistry, Western blot analysis and hormonal assay. Testosterone treatment increased circulatory testosterone and upregulated expression of androgen receptors whereas downregulated expression of melatonin receptor subtypes Mel_1a and Mel_1b. Melatonin administration increased peripheral melatonin and upregulated expression of melatonin receptor subtypes Mel_1a and Mel_1b while downregulated androgen receptor. Thus, our results suggest that a trade-off relationship between melatonin and testosterone exists in regulation of their receptors in lung of Perdicula asiatica.     

Relationship of age to body weight,scrotal circumference,testicular ultrasonograms,and semen quality in Sahiwal bulls

The objective of the present study was to determine the relationship of age to body weight (BW), scrotal circumference (SC), number of pixels of testicular ultrasonograms (NP), and semen quality in Sahiwal bulls. The study was based on 128 Sahiwal bulls of different age groups (from 0 to >100 months of age). Bulls were evaluated for SC, BW, and NP. Semen was evaluated once a week for five consecutive weeks from regularly collected donor bulls (n = 86) ranging in age from 25–30 to >100 months. Ejaculate volume, sperm motility, sperm concentration, sperm morphology, percent live sperms, sperm plasma membrane integrity, and normal acrosome were compared among different age groups. Mean SC and BW increased (P < 0.05) in a curvilinear manner from birth to >100 months of age. Mean NP of testicular ultrasonograms increased (P < 0.05) from 0 to 24 months and then plateaued until >100 months of age. Body weight, SC, and NP were positively correlated with age from birth until >100 months (r = 0.91, 0.87, and 0.40, respectively). Ejaculate volume (5.7 ± 0.2 vs. 4.6 ± 0.09 ml) and sperm concentration (1,281.6 ± 17.7 vs. 1,115.8 ± 55.9 × 10⁶/ml) increased (P < 0.05) in mature bulls compared to younger ones. However, motility (68.6 ± 0.3%), plasma membrane integrity (50.8 ± 1.0%), and normal acrosome (74.8 ± 0.5%) remained insignificant due to age. In six of eight age groups studied, morphological abnormalities were well within the range (18.1 ± 0.3%). In conclusion, the BW, SC, and NP of testicular ultrasonograms, ejaculate volume, and concentration increased with age. Moreover, semen quality is fairly independent of age except volume and concentration in Sahiwal bulls.     

Effect of food on the pharmacokinetics of oral cefuroxime axetil in dogs

Cefuroxime axetil pharmacokinetic profile was investigated in 12 Beagle dogs after single intravenous and oral administration of tablets or suspension at a dose of 20 mg/kg, under both fasting and fed conditions. A three-period, three-treatment crossover study (IV, PO under fasting and fed condition) was applied. Blood samples were withdrawn at predetermined times over a 12-hr period. Cefuroxime plasma concentrations were determined by HPLC. Data were analyzed by compartmental analysis. No statistically significant differences were observed between formulations and feeding conditions on PK parameters. Independently of the feeding condition, absorption of cefuroxime axetil after tablet administration was low and erratic. The drug has been quantified in plasma in 3 out of 6 and 5 out of 6 dogs in the fasted and fed groups. For this formulation, the bioavailability (F), peak plasma concentration (C_max), and area under the concentration–time curve (AUC) of cefuroxime axetil were significantly enhanced (p < .05) by the concomitant ingestion of food (32.97 ± 13.47–14.08 ± 7.79%, 6.30 ± 2.62–2.74 ± 0.66 µg/ml, and 15.75 ± 3.98–7.82 ± 2.76 µg.hr/ml for F, C_max, and AUC in fed and fasted dogs, respectively), while for cefuroxime axetil suspension, feeding conditions affected only the rate of absorption, as reflected by the significantly shorter absorption half-life (T_½(a)) and time to peak concentration (T_max) (0.55 ± 0.27–1.15 ± 0.19 hr and 1.21 ± 0.22–1.70 ± 0.30 for T_½(a) and T_max in fed and fasted dogs, respectively). For cefuroxime axetil tablets, T > MIC (≤1 µg/ml) was <2 hr in fasted and ≈4 hr in fed animals, and for cefuroxime axetil suspension, T > MIC (≤1 µg/ml) was ≈5 hr and for T >MIC (≤4 µg/ml) was ≈2.5 hr for fasted and fed dogs, respectively. Cefuroxime axetil as a suspension formulation seems to be a better option than tablets. However, its short permanence in plasma could reduce its clinical usefulness in dogs.     

Plasma Concentrations,Pharmacokinetics and Urinary Excretion of Gatifloxacin after Single Intravenous Injection in Buffalo Calves

The pharmacokinetics and urinary excretion of gatifloxacin were investigated after a single intravenous injection of 4 mg/kg body weight in buffalo calves. The therapeutic plasma drug concentration was maintained for up to 12 h. Gatifloxacin rapidly distributed from blood to tissue compartments, which was evident from the high values of the distribution rate constant, α₁ (11.1 ± 1.06 h⁻¹) and the rate constant of transfer of drug from central to peripheral compartment, k ₁₂ (6.29 ± 0.46 h⁻¹). The area under the plasma drug concentration–time curve and apparent volume of distribution were 17.1 ± 0.63 (μg.h)/ml and 3.56 ± 0.95 L/kg, respectively. The elimination half-life (t _{1/2 β}), total body clearance (Cl_B) and the ratio of drug present in tissues and plasma (T/P) were 10.4 ± 2.47 h, 235.1 ± 8.47 ml/(kg.h) and 10.1 ± 2.25, respectively. About 19.7% of the administered drug was excreted in urine within 24 h. A satisfactory intravenous dosage regimen for gatifloxacin in buffalo calves would be 5.3 mg/kg at 24 h intervals. Abbreviations for pharmacokinetic parameters are given in the footnote of Table I