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1.
The systemic and respiratory local immune response induced by the intradermal administration of a commercial inactivated Mycoplasma hyopneumoniae whole-cell vaccine (Porcilis® MHYO ID ONCE – MSD AH) in comparison with two commercial vaccines administered via the intramuscular route and a negative control (adjuvant only) was investigated. Forty conventional M. hyopneumoniae-free pigs were randomly assigned to four groups (ten animals each): Group A = intradermal administration of the test vaccine by using the needle-less IDAL® vaccinator at a dose of 0.2 ml; Group B = intramuscular administration of a commercially available vaccine (vaccine B); Group C = intramuscular administration of the adjuvant only (2 ml of X-solve adjuvant); Group D = intramuscular administration of a commercially available vaccine (vaccine D). Pigs were vaccinated at 28 days of age. Blood and bronchoalveolar lavage (BAL) fluid samples were collected at vaccination (blood only), 4 and 8 weeks post-vaccination. Serum and BAL fluid were tested for the presence of antibodies by ELISA test. Peripheral blood monomorphonuclear cells (PBMC) were isolated to quantify the number of IFN-γ secreting cells by ELISpot. Moreover, cytokine gene expression from the BAL fluid was performed. Total antibodies against M. hyopneumoniae and specific IgG were detected in serum of intradermally and intramuscularly (vaccine B only) vaccinated pigs at 4 and 8 weeks post-vaccination. M. hyopneumoniae specific IgA were detected in BAL fluid from vaccinated animals (Groups A and B) but not from controls and animals vaccinated with the bacterin D (p < 0.05). Significantly higher gene expression of IL-10 was observed in the BAL fluid at week 8 post-vaccination in the intradermally vaccinated pigs (p < 0.05). The results support that the intradermal administration of an adjuvanted bacterin induces both systemic and mucosal immune responses. Moreover, the intramuscularly administered commercial vaccines each had a different ability to stimulate the immune response both systemically and locally.  相似文献   

2.
Escherichia coli-associated diarrhoea is an important disease adversely affecting the pig industry. This study was conducted to investigate the frequency of virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China. A total of 381 E. coli strains, obtained from 290 faecal samples from pigs on 38 farms, were tested for fimbriae (K88, K99, 987P, F41, F18, F17), non-fimbrial adhesins (AIDA-I, paa, CS31A, eae, saa), enterotoxin (LT-I, LT-II, STa, STb, EAST1), Shiga toxin (Stx1, Stx2, Stx2e), pathogenicity islands (HPI, LEE), α-haemolysin (hlyA), afa8 gene cluster (afaD, afaE) and sepA genes by PCR. Out of the 381 isolates, 206 carried at least one virulence gene. Of the 206 virulence positive isolates, the virulence factor genes detected were EAST1 (n = 120), irp2 (n = 59), paa (n = 50), STb (n = 41), AIDA-I (n = 34), LT-I (n = 23), ler (n = 11), hlyA (n = 9), K88 (n = 8), eae (n = 8), STa (n = 7), sepA (n = 6), F18 (n = 5), afaD (n = 3), afaE (n = 3), K99 (n = 2) and Stx2e (n = 1), with most isolates carrying multiple virulence genes. These results demonstrate that relatively few isolates from the study population express K88, K99, LT-I or STa, but that EAST1 (58%), irp2 (29%), AIDA-I (16.5%), paa (24%) and STb (20%) are frequent virulence factors expressed by E. coli strains isolated from suckling pigs with diarrhoea in China.  相似文献   

3.
The aim of this study was to evaluate the activity of eugenol against the fish pathogen Aeromonas hydrophila and eugenol's effect on hematological and natural immune parameters in silver catfish (Rhamdia quelen). In vitro, eugenol showed weak activity against A. hydrophila, but in vivo, at a subinhibitory concentration (10 mg L?1), it promoted survival in infected silver catfish. Eugenol (50 μg mL?1) reduced the hemolytic activity of A. hydrophila supernatant in vitro in fish erythrocytes. Subjecting catfish to eugenol baths (5 and 10 mg L?1) for five days did not alter the hematological and immunological parameters studied in this work. Based on these results, eugenol can be used to treat or prevent bacterial diseases in fish.  相似文献   

4.
In this study the disposition kinetics and plasma availability of moxifloxacin in Muscovy ducks after single intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administrations of 5 mg kg?1 b.wt. were investigated. The concentrations of moxifloxacin in the plasma were measured using high-performance liquid chromatography (HPLC) with fluorescence detection on samples collected at frequent intervals after drug administration. Following intravenous injection, the decline in plasma drug concentration was bi-exponential with half-lives of (t1/2α) 0.22 ± 0.10 h and (t1/2β) 2.49 ± 0.26 h for distribution and elimination phases, respectively. The volume of distribution at steady-state (Vdss) was 1.02 ± 0.14 l kg?1 and the total body clearance (Cltot) was 0.32 ± 0.11 l kg?1 h?1, respectively. After intramuscular and oral administration of moxifloxacin at the same dose the peak plasma concentrations (Cmax) were 2.38 ± 0.43 and 2.11 ± 0.36 μg ml?1 and were obtained at 1.47 ± 0.26 and 1.83 ± 0.16 h (Tmax), respectively, the elimination half-lives (T1/2el) were 3.14 ± 0.42 and 2.63 ± 0.44 h, respectively, and AUC0–24 were 15.87 ± 2.35 and 14.52 ± 2.37 μg ml?1 h?1, respectively. The systemic bioavailabilities were 96.36 ± 11.54% and 86.79 ± 12.64%, respectively. In vitro plasma protein binding percent was 32%. We concluded that moxifloxacin might be clinically interesting alternative for the treatment of most sensitive bacterial infections in Muscovy ducks.  相似文献   

5.
Experimental evidence suggests that ruminant animals are capable of selecting a nutritionally balanced diet (i.e. a diet appropriate to their metabolic needs) from imbalanced but complementary foods. We tested this hypothesis by offering calves different combinations of the same complementary foods. A 5 × 5 Latin square design was used to assess the effect on diet selection of different combinations (termed as food A and food B) of two complementary foods (alfalfa-grass hay and maize grain) offered in separate feed bunks. In Treatment 1, food A and food B had the same composition, 50.0% hay and 50.0% grain (T50:50). In the rest of the treatments, hay–grain combinations in foods A and B were, respectively: 62.5–37.5% and 37.5–62.5% (T63:37); 75.0–25.0% and 25.0–75.0% (T75:25); 87.5–12.5% and 12.5–87.5% (T88:12); and 100.0–0.0% and 0.0–100.0% (T100:0). Daily intake data were analysed through repeated measures analysis. Crude protein intake was similar across treatments (P = 0.28). An increasing tendency (P = 0.01) in food B intake (the food with more grain content) from T50:50 to T100:0, however, led into a decreasing tendency (P < 0.001) in the protein: energy ratio of the diet across treatments. Grain consumption in treatments T75:25, T88:12 and T100:0 was higher than expected, leading to protein levels in the diet below those required for a balanced diet (predicted vs. observed: 19.38 vs. 16.67, P = 0.004; 20.53 vs. 16.10, P = 0.001; and 20.23 vs. 16.79 g kgMW? 1 d? 1, P = 0.015, for T75:25, T88:12 and T100:0, respectively). Although calves were potentially able to select a balanced diet in all feeding treatments, they failed when offered high grain foods at choice (75% of maize grain or more). Evolved mechanisms to regulate macronutrient intake under natural conditions may fail to adequately operate in artificial environments involving high-energy density foods (e.g. maize grain).  相似文献   

6.
《Veterinary microbiology》2015,175(1):114-122
Mannheimia haemolytica is the primary bacterial agent in the bovine respiratory disease complex. It is thought that M. haemolytica colonizes the tonsillar crypts of cattle as a commensal and subsequently descends into the lungs to cause disease. Many bacterial species persist in the host as biofilms. There is limited information about the ability of M. haemolytica to form biofilms. The aim of this study was to develop an in vitro model for M. haemolytica biofilm formation. We found that M. haemolytica required at least 36 h to form robust biofilms on plastic in vitro when incubated in RPMI-1640 tissue culture medium at 37 °C, with maximal biofilm formation being evident at 48 h. Biofilm formation was inhibited by adding the monosaccharides d(+) galactose and d(+) mannose to the growth medium. Addition of antibodies to the M. haemolytica surface protein OmpA also reduced biofilm formation. Upon evaluating the macromolecules within the biofilm extracellular polymeric substance we found it contained 9.7 μg/cm2 of protein, 0.81 μg/cm2 of total carbohydrate, and 0.47 μg/cm2 of extracellular DNA. Furthermore, proteinase K treatment significantly decreased biofilms (P < 0.05) while α-amylase and micrococcal nuclease decreased biofilms to a lesser extent. M. haemolytica biofilm cells were more resistant than planktonic cells to the antibiotics florfenicol, gentamicin, and tulathromycin. These results provide evidence that M. haemolytica can form biofilms, which could contribute to its ability to persist as a commensal in the bovine upper respiratory tract.  相似文献   

7.
Ivermectin (IVM) resistance of Cooperia spp. in cattle has become an increasing and global problem. The early detection of anthelmintic resistance (AR) is important to propose strategies to slow down the development of resistance and requires sensitive, reliable, economic high-throughput and practical tests. The purpose of the present study was to apply a larval migration inhibition test (LMIT) for evaluating IVM and MOX efficacy against well-characterized field isolates of Cooperia spp. infecting cattle in Brazil. Eight isolates were used for IVM and seven for MOX. The following EC50 values of IVM were observed for the isolates: susceptible, 1.16 ηmol; Nova Alvorada do Sul I, 4.09 ηmol (RF = 3.52); Campo Grande BNA, 3.57 ηmol (RF = 3.07); Campo Grande TBR, 4.09 ηmol (RF = 3,52); Nova Alvorada do Sul II, 2.50 ηmol (RF = 2.15); Bandeirantes, 11.35 ηmol (RF = 9.78); Campo Grande II, 6.03 ηmol (RF = 5.20); and Porto Mortinho, 8.63 ηmol (RF = 7.44). For MOX, the following EC50 values were observed: susceptible, 0.75 ηmol; Campo Grande BNA, 0.93 ηmol (RF = 1.24); Campo Grande TBR, 0.36 ηmol (RF = 0.48); Nova Alvorada do Sul II, 2.57 ηmol (RF = 3.42); Bandeirantes, 1.43 ηmol (RF = 1.90); Campo Grande II, 1.08 ηmol (RF = 1.44); and Porto Mortinho, 0.49 ηmol (RF = 0.65). The LMIT used in the present study can be a useful tool for in vitro evaluation of IVM, but not of MOX. However, such methodology cannot be used in large-scale studies yet. The isolates of Cooperia spp. showed various degrees of resistance to IVM, though remaining susceptible to MOX.  相似文献   

8.
The parasitic ciliate Ichthyophthirius multifiliis infests all species of freshwater fish and can cause severe economic losses in fish breeding. The present study aims to evaluate the antiparasitic activity of the active components from Toddalia asiatica against I. multifiliis. Bioassay-guided fractionation and isolation of compounds with antiparasitic activity were performed on the methanol extract of T. asiatica yielding two bioactive compounds: chelerythrine and chloroxylonine identified by comparing spectral data (NMR and ESI-MS) with literature values. Results from in vitro antiparasitic assays revealed that chelerythrine and chloroxylonine could be 100% effective against I. multifiliis at the concentration of 1.2 mg L?1 and 3.5 mg L?1, with the median effective concentration (EC50) values of 0.55 mg L?1 and 1.90 mg L?1 respectively. In vivo experiments demonstrated that fish treated with chelerythrine and chloroxylonine at the concentrations of 1.8 and 8.0 mg L?1 carried significantly fewer parasites than the control (P < 0.05). The acute toxicity (LC50) of chelerythrine for goldfish was 3.3 mg L?1.  相似文献   

9.
Two experiments were conducted to determine the effects of pre-weaning vitamin E, Se, and Cu supplementation on performance and immune response in stressed calves. In Exp. 1, 71 Hereford x Angus calves were individually creep fed: 1) control supplement (CON), 2) control plus 500 IU vitamin E + 0.3 mg Se/kg DM (E), 3) control plus 10 mg Cu/kg DM (CU), or 4) a combination of E and CU treatments (ECU). In Exp. 2, 80 Hereford (Angus calves were individually creep fed: 1) control supplement (CON), 2) control plus 0.3 mg Se/kg DM (SE), 3) control plus 500 IU vitamin E + 0.3 mg Se/kg DM (LOWE), 4) control plus 1000 IU vitamin E + 0.3 mg Se/kg DM (MEDE), or 5) control plus 1500 IU vitamin E + 0.3 mg Se/kg DM (HIE). Treatments continued for 49 (Exp. 1) or 53 d (Exp. 2) prior to weaning. At weaning all calves were transported to feedlot facilities. In Exp. 1, vitamin E tended (P<0.09) to improve post-weaning ADG and reduce (P<0.06) plasma haptoglobin (Hp), but had no effect on plasma α-tocopherol. Dietary Cu tended to increase (P<0.01) liver Cu stores, and antibody titers to bovine viral diarrhea (BVD) were greater (P<0.04) at weaning in CU and E calves. In Exp. 2, vitamin E tended to increase serum α-tocopherol (P<0.06) and cortisol (P<0.08). Vitamin E and Se supplementation may improve post-weaning performance and decrease plasma Hp concentrations in stressed calves.  相似文献   

10.
The pharmacokinetics of orphenadrine (ORPH) following a single intravenous (i.v.) dose was investigated in six camels (Camelus dormedarius). Orphenadrine was extracted from the plasma using a simple sensitive liquid–liquid extraction method and determined by gas chromatography/mass spectrometry (GC/MS). Following i.v. administration plasma concentrations of ORPH decline bi-exponentially with distribution half-life (t1/2α) of 0.50 ± 0.07 h, elimination half-life (t1/2β) of 3.57 ± 0.55 h, area under the time concentration curve (AUC) of 1.03 ± 0.10 g/h l−1. The volume of distribution at steady state (Vdss) 1.92 ± 0.22 l kg−1, volume of the central compartment of the two compartment pharmacokinetic model (Vc) 0.87 ± 0.09 l kg−1, and total body clearance (ClT) of 0.60 ± 0.09 l/h kg−1. Three orphenadrine metabolites were identified in urine samples of camels. The first metabolite N-desmethyl-orphenadrine resulted from N-dealkylation of ORPH with molecular ion m/z 255. The second N,N-didesmethyl-orphenadrine, resulted from N-didesmethylation with molecular ion m/z 241. The third metabolite, hydroxyl-orphenadrine, resulted from the hydroxylation of ORPH with molecular ion m/z 285. ORPH and its metabolites in camel were extensively eliminated in conjugated form. ORPH remains detectable in camel urine for three days after i.v. administration of a single dose of 350 mg orphenadrine aspartate.  相似文献   

11.
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12.
The objective was to investigate the effect of sea transport on the physiological, behavioural and performance responses of bulls. One-hundred and eleven bulls (mean body weight (standard error of the mean) 429 (5.7 kg)) were randomly assigned to one of three treatments; control (C; n = 54) bulls were housed in 6 pens at Teagasc, Grange Research Centre at a stocking density of (1), 1.7 m2/head (C1.7; 3 pens) and (2), 3.4 m2/head (C3.4; 3 pens) and (3), transported (T) bulls (n = 57) were penned at a space allowance of 1.7 m2/head (6 pens) and allocated to one of five decks on the shipping vessel. C and T bulls were subjected to the same live weight (d −2), blood sampling and rectal temperature (d −1) measurements pre-transport and on d 3, d 6, d 9 and d 11 of the study. T bulls had greater (P < 0.05) live weight gain (+4.4%) compared with C1.7 bulls (−2.0%) and C3.4 (+0.13%)). Time spent lying was greater (P < 0.05) among C1.7 and C3.4 bulls (9.9% and 53.3%, respectively) compared with T bulls (45.8%). Rectal body temperature was not different (P > 0.05) among treatment groups throughout the study. At d 11, neutrophil % was greater (P < 0.05) in transported bulls on decks 1, 2, 4 and 5 compared with C1.7 and C3.4 treatments. Plasma cortisol concentrations were not different (P > 0.05) between control and transported bulls. Plasma creatine kinase (CK) activity was lower (P < 0.05) among C3.4 and T bulls on decks 2, 3, 4 and 5 compared with d 3 values. In conclusion, the welfare of bulls transported by sea on the sea journey was not adversely affected. Housing control bulls at a reduced space allowance (1.7 m2) had a negative effect on live weight gain.  相似文献   

13.
Forage from three sweet potato cultivars (A = TIS-87/0087; B = TIS-8164; C = TIS-2532.OP.1.13 at 30% daily dry matter intake), dried brewers' grains (DBG) and cottonseed meal (CSM) each at 2.5 kg were supplemented to Guinea grass (GG) to form four diets: Diet A = GG + TIS-87/0087; Diet B = GG + TIS-8164; Diet C = GG + TIS-2532.OP.1.13, and Diet D = GG + DBG + CSM (as control). Treatments were assigned as 4 × 4 Latin squares design over 60 days (10-day adaptation and 5-day sampling) using Bunaji and N'Dama cows in early lactation. The 48-h rumen dry matter (DM) degradation ranged (P < 0.01) from 407 g kg? 1 DM for GG to 791 g kg? 1 DM for sweet potato cultivar TIS-87/0087. Bunaji dry matter intake varied (P < 0.05) between 7.1 kg day? 1 in Diet B and 8.9 kg day? 1 in Diet D, but was similar (P > 0.05) among diets for the N'Dama cows. The metabolisable energy (ME) intakes were higher for Diet D although, it recorded the least efficiency of ME utilization for milk production. Milk yields were significantly (P < 0.01) higher in the Bunaji than the N'Dama cows, which is typical of their true breed differences. Total solids, ash, protein, fat, and sugar contents of the milk were similar among diets for both cow breeds, except Bunaji ash contents that ranged (P < 0.05) from 0.77 g 100 g? 1 for Diet B to 0.83 g 100 g? 1 for Diet D. The results suggest that sweet potato forage could be utilized as whole or partial replacement for DBG and CSM to save cost under smallholder farming systems.  相似文献   

14.
In the equine carbohydrate overload model of acute laminitis, disease progression is associated with changes in bacteria found in the cecum. To date, research has focused on changes in specific Gram-positive bacteria in this portion of the intestinal tract. Metagenomic methods are now available making it possible to interrogate microbial communities using animal protocols that sufficiently power a study. In this study, the microbiota in cecal fluid collected from control, non-laminitic horses (n = 8) and from horses with early-stage acute laminitis induced with either oligofructan (n = 6) or cornstarch (n = 6) were profiled. The microbiota were identified based on sequencing the V4 hypervariable region of the 16S rRNA gene. The results of the study show that the relative abundance of Lactobacillus sp. and Streptococcus sp. increased significantly (p < 0.05) following OF and CS infusion. Other significant changes included an increase (p < 0.05) in relative abundance of Veillonella sp. and Serratia sp., two potentially pathogenic, Gram-negative bacteria. Significant decreases in the relative abundance of presumptive normal flora were detected as well. Although changes in cecal microbiota described in this communication are from a pilot study, it is hypothesized that an overgrowth of pathogenic Gram-negative bacteria develops and contributes to enterocolitis, pyrexia and lameness in the carbohydrate overload model of acute laminitis.  相似文献   

15.
《Veterinary parasitology》2015,207(3-4):297-301
A study was designed to compare the efficacy of NexGard® and Bravecto™, 2 recently introduced oral ectoparasiticides containing isoxazolines, against fleas (Ctenocephalides felis) on dogs. Twenty-four healthy dogs, weighing 9.2 kg to 28.6 kg, were included in this parallel group design, randomized, and controlled efficacy study. On Day −1, the 24 dogs were allocated to 3 study groups: untreated control; Nexgard® treated and Bravecto™ treated. The treatments were administered on Days 0, 28 and 56 for Nexgard® (labelled for monthly administration), and once on Day 0 for Bravecto™ (labelled for a 12 week use). Flea infestations were performed weekly with 100 adult unfed C. felis on each dog from Days 42 to 84. Fleas were counted and re-applied at 6 and 12 h post-infestation and removed and counted 24 h post-infestation. The arithmetic mean flea count for the untreated group ranged from 62.9 to 77.6 at 24 h post-infestation, indicating vigorous flea challenges on all assessment days. Both the Nexgard® and Bravecto™ treated groups had statistically significantly (p < 0.05) less fleas compared to the untreated group on all assessment time points and days. Significantly fewer fleas were recorded for NexGard® treated dogs compared to Bravecto™ treated dogs at 6 h post-infestation on Day 56, 63, 70, 77 and 84 and at 12 h post-infestation on Days 70 and 84. No statistically significant (p < 0.05) differences were recorded between the treated groups at 24 h post-infestation. Efficacies recorded 6 h post-infestation for Nexgard® ranged from 62.8% (Day 49) to 97.3% (Day 56), and efficacies ranged from 94.1% (Day 49) to 100% (Days 42, 56, 70 and 84) at 12 h post-infestation. Efficacies recorded for Bravecto™ ranged from 45.1% (Day 84) to 97.8% (Day 42) at 6 h post-infestation, and from 64.7% (Day 84) to 100% (Days 42 and 56) at 12 h post-infestation. Efficacies observed at 24 h were 100% for both products during the study except 99.6% on Day 84 for Bravecto™.  相似文献   

16.
The protective effect of Enterococcus faecium EF55 in chickens challenged with Salmonella enterica serovar Enteritidis phage type 4 (SE PT4) was assessed. The antibacterial effect on the bacterial microflora in the small intestine in relation to white blood cell count, phenotyping of peripheral blood and intestinal lymphocytes, functional activity of lymphocytes and phagocytes and mucin quantitation were investigated. Day-old chicks (85) were randomly divided into four groups. The probiotic group (EF) and Salmonella + probiotic group (EFSE) received E. faecium EF55 (109 CFU – 3 g/group/day) for 21 days. The Salmonella group (SE) and EFSE group were infected with Salmonella Enteritidis (108 CFU in 0.2 ml PBS) in a single dose per os on day four of the experiment. The control group chicks (C) were fed a commercial diet without added bacteria. Supplementation of EF55 in the diet of the chickens in the EFSE group, challenged with S. Enteritidis, caused the density of the intestinal mucin layer to increase significantly in non-specific regions (duodenum and jejunum), but decrease significantly in target regions (caeca) for S. Enteritidis. Probiotic treatment also appeared to result in a significantly higher number of lymphocytes in peripheral blood and a tendency to increase CD3, CD4, CD8, and IgM positive cells 3 days post-infection with S. Enteritidis. The results demonstrated an antibacterial effect and suggested that EF55 had a moderating effect on intestinal mucin production and leukocytic response in the early phase of S. Enteritidis infection.  相似文献   

17.
The performance of rotationally grazed beef suckler cows and their progeny to slaughter on two lowland grassland management systems differing in stocking rate (SR) and fertiliser nitrogen (N) level was compared over eight years. The two Systems were 1) Intensive (INT): SR of 0.56 (bull production) or 0.71 (steer production) ha cow? 1 unit, 211 kg fertiliser N ha? 1, two silage harvests, and 2) Extensive (EXT): SR of 0.69 (bull production) or 0.88 (steer production) ha cow? 1 unit, 97 kg fertiliser N ha? 1 and one staggered silage harvest. A cow unit was defined as a cow plus progeny to slaughter. On the silage harvesting area, the mean application rate for fertiliser N was 110 and 80 kg ha? 1 for first and second harvests, respectively. Herbage dry matter digestibility both pre- and post-grazing was similar (P > 0.05) for the two systems, whereas herbage crude protein concentrations were generally significantly lower for the EXT than the INT system. There was no difference (P > 0.05) between the Systems in cow live weight, body condition score or their changes or in calf live weight gain from birth to weaning. Post-weaning, live weight gain, slaughter weight, carcass weight, kill-out proportion, estimated carcass gain, carcass conformation score or carcass fat score did not differ (P > 0.05) between the systems for heifer, steer or bull progeny. It can be concluded that similar animal performance levels can be expected in an extensive grassland-based suckler calf-to-beef system compatible with the EU, Rural Environmental Protection Scheme as that attained in a more intensive System comprising of both a moderately high SR (~ 1.25 higher) and fertiliser N application (~ 2.1 higher).  相似文献   

18.
《Livestock Science》2006,99(1):39-49
This work proposes an adequate empirical model for the 28-day lactation curve of rabbit does, including fit suitability and biological interpretation. A total of 15,400 test-day milk records were used, corresponding to 550 lactations collected from 134 hybrid New Zealand × Californian rabbit does during five consecutive lactations. To develop this model, five different functions were compared (quadratic, potential, beta-modified, gamma and Gauss models), evaluating their fitting ability to mean and individual lactation curves, and the suitability of their parameters to gather the sources of variation (genetic selection level, type of diet, parity order and gestation overlapping degree) on lactation curve shape. The possible relationship between model parameters and main performance traits was also evaluated. From the results of the present work, it may be concluded that beta-modified equation [Milk yield (g/day) = k × (day/30)a × (1 −  (day/30))b] could be proposed as an alternative to quadratic models for daily milk yield prediction of reproductive rabbit does. When compared to quadratic models, beta-modified model give a slightly better fit to average (R2 = 0.986 vs. 0.985; RMSE = 5.648 vs. 5.813) and individual (Residuals = 21.31 vs. 21.37 g; Mean square prediction error = 883.0 vs. 897.2 g2) lactation curves, especially of those curves showing a lower lactation peak height and a greater persistence of milk yield. However, the most important advantage of the beta-modified model was the greater biological interpretation of its parameters (k regulates the curve height, while a and b regulate the milk yield of ascending and descending period, respectively) and the ability to gather curve changes. This latter aspect is revealed by the relationship of the parameters with main performance traits of lactating does (energy intake, live weight and body reserves mobilisation). Although further research on developing an optimal model is needed, the use of this type of models could provide additional information for a better understanding of the curve shape effect on the performance, body condition and health of reproductive rabbit does.  相似文献   

19.
This study evaluated immune cell populations in pigs following weaning and vaccination for Mycoplasma hyopneumoniae. Piglets (n = 24) were weaned (day 0) at 16 (±1) days of age, and randomly assigned to the vaccination group (n = 16) or control group (n = 8). Complete blood cell counts, flow cytometry and serology were completed for blood samples collected on days 0 (within hours of weaning), 3, 7, 14, 30 and 60. The M. hyopneumoniae S:P ratios (sample optical density: positive control optical density) were negative in the vaccination group until days 30 and 60, when the S:P ratios were 1.3 and 1.0, respectively. Control animals remained serologically negative. The percentage of CD4+ T cells was less (P < 0.01) in control pigs than vaccinated pigs at day 3. In contrast, numbers of CD8+ and CD4+CD8+ T cells were greater (P < 0.01) in control pigs than in vaccinated pigs at days 3 and 7. After day 7, few differences in immune cell types were evident between the groups. Differences in lymphocyte populations could not be solely attributed to vaccination, due at least in part, to the confounding influence of weaning. It was difficult to distinguish the influence of vaccination from the impact of weaning on peripheral immune cell populations.  相似文献   

20.
ObjectiveTo establish if preoperative maropitant significantly reduced intraoperative isoflurane requirements and reduced clinical signs associated with postoperative nausea and vomiting (PONV) in dogs.Study designRandomized clinical trial.AnimalsTwenty-four healthy, client-owned dogs undergoing routine ovariohysterectomy.MethodsPremedication involved acepromazine (0.03 mg kg−1) combined with methadone (0.3 mg kg−1) intramuscularly 45 minutes before anaesthetic induction with intravenous (IV) propofol, dosed to effect. Meloxicam (0.2 mg kg−1) was administered intravenously. Dogs were randomly assigned to administration of saline (group S; 0.1 mL kg−1, n = 12) or maropitant (group M; 1 mg kg−1, n = 12) subcutaneously at time of premedication. Methadone (0.1 mg kg−1 IV) was repeated 4 hours later. Anaesthesia was maintained with isoflurane in oxygen, dosed to effect by an observer unaware of group allocation. The dogs were assessed hourly, starting 1 hour postoperatively, using the short form of the Glasgow Composite Pain Score (GCPS), and for ptyalism and signs attributable to PONV [score from 0 (none) to 3 (severe)] by blinded observers. Owners completed a questionnaire at the postoperative recheck.ResultsOverall mean ± standard deviation end-tidal isoflurane percentage was lower in group M (1.19 ± 0.26%) than group S (1.44 ± 0.23%) (p = 0.022), but was not significantly different between groups at specific noxious events (skin incision, ovarian pedicle clamp application, cervical clamp application, wound closure). Cardiorespiratory variables and postoperative GCPS were not significantly different between groups. Overall, 50% of dogs displayed signs attributable to PONV, with no difference in PONV scores between groups (p = 0.198). No difference in anaesthetic recovery was noted by owners between groups.ConclusionsMaropitant reduced overall intraoperative isoflurane requirements but did not affect the incidence of PONV.Clinical relevanceMaropitant provided no significant benefits to dogs undergoing ovariohysterectomy with this anaesthetic and analgesic protocol, although clinically significant reductions in isoflurane requirements were noted.  相似文献   

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