A comparison of serum vitamin A and vitamin E concentrations in shelter, feral, and pet cats

Upper respiratory infection (URI) is an important cause of morbidity and mortality in shelter cats. Malnutrition, specifically vitamin A deficiency, has been associated with respiratory tract infections in humans in developing countries. The purpose of this study was to determine whether feral cats and cats in shelters have lower serum vitamin A concentrations than pet cats, because it was surmised that a vitamin A deficiency may predispose these cats to develop URI. This was a cross-sectional study in which serum retinol, α-tocopherol, γ-tocopherol and beta carotene concentrations were measured from 48 shelter cats, 56 feral cats, and 42 pet cats, using HPLC. Retinol, α-tocopherol, and γ-tocopherol concentrations were found to be significantly lower in the shelter and feral cat populations than in pet cats (p ≤ 0.0001). There was no evidence of an effect of sex or neuter status on vitamin concentrations. Sick feral cats had a higher beta carotene level than did healthy feral cats. Within shelter and feral populations, no other effect of health status was found. The lower mean serum retinol and tocopherol concentrations in the feral and shelter cat groups could be due to oxidative or other forms of stress, the amount of vitamin consumed, or combinations of these. Further studies are needed to determine whether supplementation of fat-soluble vitamins improves the health status of feral or shelter cats.     

Early Pregnancy Diagnosis by Serum Progesterone and Ultrasound in Sheep Carrying Somatic Cell Nuclear Transfer-Derived Pregnancies

Early pregnancy diagnosis and monitoring play an important role following embryo transfer in sheep. The aims of the current study were to investigate (i) the pattern of serum progesterone profiles in sheep carrying somatic cell nuclear transfer (SCNT)‐derived (clone) pregnancies, and (ii) the frequency of pregnancy loss during development following SCNT embryo transfer. Sheep SCNT embryos were made using standard nuclear transfer techniques. Day 7 embryos were surgically transferred to oestrus‐synchronized recipients (n = 27). As a control, normal fertile ewes (n = 12) were bred by natural breeding. Serum was collected from all the ewes on the day of estrus (day 0 sample), 7 days post‐estrus (day 7 sample) and 19 days post‐estrus (day 19 sample) and every 10 days thereafter until lambing or pregnancy loss occurred. Serum progesterone (P4) was assessed using enzyme immunoassay. Pregnancy was confirmed by ultrasound scanning on day 35 of pregnancy followed by subsequent scanning every 10 days. In control ewes, pregnancy rate on day 35 was 83.3% (10/12), whereas in the ewes that received SCNT embryos, it was 22.2% (6/27; p < 0.05). The day 45 pregnancy rate in the control ewes was 83.3%, whereas in the SCNT embryo recipients it was 11.0% (p < 0.05). Hormone analysis revealed that SCNT embryo recipients exhibited a significantly lower P4 profiles at different time points in pregnancy compared to controls (p < 0.05). This study highlights the use of serum progesterone in combination with ultrasound for the investigation of embryo loss and crucial times during development of normal and SCNT embryos in sheep. Further, the serum P4 levels directly reflect the degree of placental development in these two groups.     

Antimicrobial susceptibility patterns of Haemophilus parasuis from pigs in the United Kingdom and Spain

A total of 30 British and 30 Spanish Haemophilus parasuis isolates were tested for their susceptibility to 19 of the antimicrobials currently used in swine practice with a broth microdilution method in order to know the emergence of resistance against these compounds in this porcine pathogen. All the British isolates were susceptible to penicillin, ceftiofur, erythromycin, tilmicosin, enrofloxacin, and florfenicol, and most of them were susceptible to the remaining antimicrobials (the highest resistance rate found was of 20% to neomycin). In contrast, all the Spanish isolates were susceptible exclusively to florfenicol, and high proportions of resistance were encountered for penicillin, ampicillin, oxytetracycline, erythromycin, tilmicosin, tiamulin and trimethoprim+sulphamethoxazole; in addition, a bimodal or multimodal distribution, or tailing of Spanish isolates over the MIC range was observed for clindamycin, sulphonamides and tylosine tartrate, suggesting the development of acquired resistance. In addition, several multiresistance patterns were found among the Spanish isolates, 23.3% of them being resistant to at least eight antimicrobials, the same rate as that encountered for those being susceptible to all antimicrobials tested. This study showed that in general British H. parasuis isolates are susceptible to antimicrobial agents routinely used for treatment of porcine respiratory diseases; however, the Spanish isolates need a more continuous surveillance of their susceptibility patterns.     

The distribution of Phratora vulgatissima (Coleoptera: Chrysomelidae) on cultivated willows in Britain and Ireland

Insect samples were collected from the canopy of 24 willow short rotation coppice (SRC) sites on farmland in Britain and Ireland in 1995. The blue willow beetle Phratora (= Phyllodecta) vulgatissima (L.) (Coleoptera: Chrysomelidae), previously identified as the main defoliating pest of this crop, was recorded from 13 of these at varying levels of abundance. Data describing aspects of the environment at each site were also collected. These data were used to create potential explanatory variables for a regression analysis of beetle abundance. This analysis indicated that P. vulgatissima were most likely to occur and were more abundant at older willow sites on clay soils and at sites that bad certain free-living willow species growing nearby. Within sites, most willow clones sampled contained P. vulgatissima, although two, Salix burjatica‘Germany’ (‘Aquatica Gigantea’) and Salix mollissima‘Q83’ (Salix triandra × Salix viminalis), were avoided. Chrysomelid pest avoidance and clonal resistance could form part of an integrated pest management strategy for SRC crops.     

Feeding-induced increases in insulin do not suppress secretion of growth hormone

Secretion of growth hormone (GH) is reduced for several hours after feeding when access to feed is restricted to a 2-hr period each day. We hypothesized that increased secretion of insulin after feeding inhibits release of GH from the anterior pituitary gland. Our objectives were to determine whether: 1) alloxan prevents concentrations of insulin from increasing after feeding steers; 2) concentrations of GH remain high after feeding alloxan-treated steers; and 3) GH-releasing hormone (GHRH) stimulates greater release of GH in alloxan-treated, than in control, steers after feeding. Steers were injected iv with either saline (control) or with alloxan (110 mg/kg) (n = 4 per group). Concentrations of insulin were not different (P = 0.61) between control and alloxan-treated steers before feeding (87.5 +/- 33.6 pmol/l). However, alloxan prevented insulin from increasing (P < 0.001) after feeding (131.8 pmol/1) compared with control steers (442.0 pmol/l) (pooled SEM = 47.5). Overall, GH was higher (P < 0.05) in alloxan-treated (6.4 ng/ml) than in control steers (3.7 ng/ml) (pooled SEM = 0.7), but GH decreased (P < 0.001) after feeding in both groups. Iv injection of GHRH stimulated release of GH 1 hr before, but not when injected 1 hr after feeding (P < 0.001). In addition, net areas under the GH curve were not significantly different between control and alloxan-treated groups. We conclude that increased concentrations of insulin after feeding do not mediate feeding-induced suppression of GH secretion in steers.     

Factors affecting toxicity of ferulate towards the cyanobacterium Oscillatoria cf chalybea

The objectives of this study were to determine the effect of ferulate and its analogs, and factors which may affect the toxicity of ferulate to Oscillatoria cf chalybea, the cyanobacterium presumed to cause musty flavor in farm-raised catfish. Rapid bioassays utilizing 96-well and six-well cell culture plates were used to monitor the toxicity of ferulate analogs and potential ferulate stability factors toward O cf chalybea. The additions of low concentrations of the oxidizing compound sodium carbonate peroxyhydrate with ferulate did not help control O cf. chalybea. Of three forms of ferulate tested, trans-ferulate was most toxic towards O cf chalybea. Light enhanced the toxicity of ferulate, indicating that weather conditions and the time of day could influence the success of ferulate applications to fish ponds to control O cf chalybea. Ferulate was less toxic to O cf chalybea in six-well culture plates than in 96-well plates, indicating that higher concentrations of ferulate should be used in field trials, due to possible reduction of ferulate toxicity towards O cf chalybea in large, aquatic environments (ie fish ponds). These studies provided fundamental information on potential ferulate toxicity towards O cf chalybea to be considered before conducting field trials (ferulate applications to fish ponds). © 1999 Society of Chemical Industry