The number and proportion of CTX-M positive Escherichia coli organisms were determined in feces from cattle, chickens, and pigs in the United Kingdom to provide a better understanding of the risk of ...the dissemination of extended-spectrum β-lactamase (ESBL) bacteria to humans from food animal sources. Samples of bovine (n = 35) and swine (n = 20) feces were collected from farms, and chicken cecal contents (n = 32) were collected from abattoirs. There was wide variation in the number of CTX-M-positive E. coli organisms detected; the median (range) CFU/g were 100 (100 × 10(6) to 1 × 10(6)), 5,350 (100 × 10(6) to 3.1 × 10(6)), and 2,800 (100 × 10(5) to 4.7 × 10(5)) for cattle, chickens, and pigs, respectively. The percentages of E. coli isolates that were CTX-M positive also varied widely; median (range) values were 0.013% (0.001 to 1%) for cattle, 0.0197% (0.00001 to 28.18%) for chickens, and 0.121% (0.0002 to 5.88%) for pigs. The proportion of animals designated high-density shedders (≥1 × 10(4) CFU/g) of CTX-M E. coli was 3/35, 15/32, and 8/20 for cattle, chickens, and pigs, respectively. We postulate that high levels of CTX-M E. coli in feces facilitate the dissemination of bla(CTX-M) genes during the rearing of animals for food, and that the absolute numbers of CTX-M bacteria should be given greater consideration in epidemiological studies when assessing the risks of food-borne transmission.
The aim of this study was to assess the effects of commonly used anaesthetics alfaxalone and propofol on salivary and urinary cortisol in healthy cats. Fifteen male castrated research-purposed cats ...received randomly intravenous continuous rate infusions of 8 mg/kg/h of alfaxalone, 12 mg/kg/h of propofol and 2 ml/kg/h of Lactated Ringer's solution for 30 min, with intervals of 6 days between treatments. Saliva samples were collected for 24 h before each infusion and for 24 h from the start of each infusion. Urine was collected as single pooled samples over each 24 h period. Mean integrated saliva cortisol responses in cats treated with alfaxalone were greater than responses of cats treated with propofol (P = 0.034) and controls (P = 0.017). Integrated responses in cats treated with propofol did not differ from controls. The mean urinary cortisol/creatinine ratio (UCCR) was higher on the day of treatment than the day before treatment in cats treated with alfaxalone (P < 0.0001) and in cats treated with propofol (P = 0.0168) and did not differ between days in cats treated with lactated Ringer's solution. The mean UCCR was higher in cats treated with alfaxalone than in cats treated with lactated Ringer's solution (P = 0.0020) on the day of treatment. Mean total urinary cortisol over 24 h was greater in cats treated with alfaxalone than controls (P = 0.0267). In conclusion, alfaxalone increased short-term salivary and urinary cortisol concentrations in healthy cats as compared to propofol and a control group of non-anesthetised cats.
•Alfaxalone can increase urinary and salivary cortisol in cats.•Propofol and alfaxalone have different effects on the HPA axis in cats.•Cortisol can be accurately measured in small volumes of saliva using ELISA.•Marked individual differences in urinary and salivary cortisol in cats.
Abstract Recently, we demonstrated that brain neuropeptide Y (NPY) mRNA expression was increased in heat exposed chicks. However, the functions of brain NPY during heat stress are unknown. This study ...was conducted to investigate whether centrally administered NPY affects food intake, rectal temperature, monoamines, stress hormones and plasma metabolites in chicks under high ambient temperatures (HT). Five or six-day-old chicks were centrally injected with 0, 188 or 375 pmol of NPY and exposed to either HT (35 ± 1 °C) or a control thermoneutral temperature (CT; 30 ± 1 °C) for 3 h whilst fed or fasted. NPY increased food intake under both CT and HT. NPY reduced rectal temperature 1 and 2 h after central administration under CT, but not under HT. Interestingly, NPY decreased brain serotonin and norepinephrine concentrations in fed chicks, but increased concentrations of brain dopamine and its metabolites in fasted and fed chicks, respectively. Plasma epinephrine was decreased by NPY in fed chicks, but plasma concentrations of norepinephrine and epinephrine were increased significantly by NPY in fasted-heat exposed chicks. Furthermore, NPY significantly reduced plasma corticosterone concentrations in fasted chicks. Plasma glucose and triacylglycerol were increased by NPY in fed chicks, but triacylglycerol declined in fasted NPY-injected chicks. In conclusion, brain NPY may attenuate the reduction of food intake during heat stress and the increased brain NPY might be a potential regulator of the monoamines and corticosterone to modulate stress response in heat-exposed chicks.
Pure-bred embryos were transferred within and reciprocally between large (Suffolk) and small (Cheviot) breeds of sheep to establish 4 treatment groups: SinS (Suffolk embryos in Suffolk dams), SinC ...(Suffolk embryos in Cheviot dams), CinS (Cheviot embryos in Suffolk dams), and CinC (Cheviot embryos in Cheviot dams). The recipient ewes carried single fetuses to term. The maternal plasma concentrations of ovine placental lactogen (oPL), progesterone, IGF-1, FFA, and glucose were measured on d 50, 90, 120, and 140 of pregnancy. Birth weight, body dimensions, and placental characteristics of lambs were recorded at birth. There was a recipient ewe breed x lamb breed x time interaction for the concentration of oPL (P = 0.03), but no such interaction was observed for progesterone (P = 0.42), IGF-1 (P = 0.57), glucose (P = 0.36), or FFA (P = 0.72). There were no differences in oPL (P = 0.28) and progesterone (P = 0.34) concentrations between SinC and SinS ewes. The concentrations of FFA on d 140 (P = 0.008), and those of glucose on d 50 (P = 0.02) and 120 (P = 0.01), were greater in SinC ewes than in SinS ewes. The ewes in CinS had less FFA concentration (P = 0.002) at all time points than CinC ewes. The concentrations of IGF-1 on d 90 were greater (P = 0.004) in CinS ewes than CinC ewes, but did not differ (P = 0.16) on d 50, 120, and 140. The concentrations of glucose on d 50 (P = 0.001), 90 (P = 0.03), and 140 (P = 0.03) were less in CinS ewes compared with CinC ewes. The birth weight of SinC lambs (5.04 ± 0.20 kg) was lighter (P = 0.001) than SinS lambs (5.94 ± 0.19 kg), and body dimensions of SinC lambs were smaller (P = 0.01) than SinS lambs. Neither birth weight nor the body dimensions of CinS lambs differed (P = 0.24) from CinC lambs. Cotyledon number was reduced (P = 0.04) in the CinS (57.5 ± 6.3) compared with the SinS group (74.2 ± 5.9), whereas mean cotyledon weight in CinS (2.42 ± 0.20 g) was greater (P = 0.02) than SinS (1.74 ± 0.21 g). It was concluded that the large genotype lambs were lighter and smaller when born to small genotype dams; however, the birth weight or body dimensions of small genotype lambs did not differ when born to large genotype dams. This study suggests that plasma oPL, progesterone, IGF-1, FFA, and glucose concentrations at different times throughout pregnancy reflect the regulatory effect of the uterine environment on the development of the fetus.
Several studies have shown that both quiescent and proliferating somatic donor cells can be fully reprogrammed after nuclear transfer (NT) and result in viable offspring. So far, however, no ...comparative study has conclusively demonstrated the relative importance of donor cell cycle stage on nuclear cloning efficiency. Here, we compare two different types of bovine fetal fibroblasts (BFFs) that were synchronized in G
0, G
1, and different phases within G
1. We show that for non-transgenic (non-TG) fibroblasts, serum starvation into G
0 results in a significantly higher percentage of viable calves at term than synchronization in early G
1 or late G
1. For transgenic fibroblasts, however, cells selected in G
1 show significantly higher development to calves at term and higher post-natal survival to weaning than cells in G
0. This suggests that it may be necessary to coordinate donor cell type and cell cycle stage to maximize overall cloning efficiency.
Insulin-like growth factors (IGFs) play an important role in regulating normal physiology, and may be involved in the control of reproduction. The aim of this study was to define the relationship ...between IGF-I concentrations and reproductive performance over the breeding and non-breeding seasons in lines of New Zealand Romney rams that had been selected for low and high blood serum IGF-I concentration. Yearling rams from two selection lines (13 from the high line and 19 from the low line) were examined in July (winter), September (autumn) and November (summer) 2006 and March (spring) 2007. Scrotal circumference including the inguinal skin was recorded. Semen was collected by electroejaculation on 4 occasions over a 12-month period. Semen was evaluated according to standard procedures (volume, motility, density and morphology). Samples were collected from four animals from each group for measurements of mRNA for IGF-I and the IGF type 1 receptor (IGF 1R) in the testis, and IGF-I, IGF 1R and the insulin receptor (IR) in the liver. Blood samples were collected via jugular venipuncture for the measurement of IGF-I, insulin and testosterone. The incidences of morphologically abnormal sperm cells, the scrotal circumference and sperm motility were higher in the breeding than in non-breeding season. Seasonal changes were found in the percentage of abnormal sperm, scrotal circumference, sperm motility and sperm density, but there were no differences between lines in any reproductive parameters. IGF-I mRNA levels were higher in the high than the low line in the liver but not in the testis, whereas the opposite was found for levels of IGF 1R mRNA. mRNA levels for the insulin receptor in the liver were higher in the high line. Plasma testosterone concentrations did not differ between lines, whereas the concentrations of IGF-I and insulin were higher in the high line. The results suggest that IGF-I may be locally produced in the liver and the testis, and that selection for high IGF-I may not be associated with improved reproductive performance in rams.
Recent research has revealed a neuroendocrine connection between the skeleton and metabolism. Exercise alters both bone modeling and energy balance and may be useful in further developing our ...understanding of this complex interplay. However, research in this field requires an animal model of exercise that does not cause a physiological stress response in the exercised subjects. In this study, we develop a model of short-term voluntary exercise in the female rat that causes bone modeling without causing stress. Rats were randomly assigned to one of three age-matched groups: control, tower climbing, and squat exercise (rising to an erect bipedal stance). Exercise for 21 days resulted in bone modeling as assessed by peripheral quantitative computed tomography. Fecal corticosterone output was used to assess physiological stress at three time points during the study (preexercise, early exercise, and late in the exercise period). There were no differences in fecal corticosterone levels between groups or time points. This model of voluntary exercise in the rat will be useful for future studies of the influence of exercise on the relationship between skeletal and metabolic health and may be appropriate for investigation of the developmental origins of those effects.
Most of New Zealand's herpetofauna species are threatened and in decline. Yet, little is known about their basic physiology and endocrinology. This study examined plasma corticosterone (CORT) ...concentrations in a threatened endemic New Zealand reptile, the Duvaucel's gecko, in relation to season, sex, body temperature, body condition and female reproductive condition (pregnant versus non-pregnant). In addition, seasonal plasma CORT concentrations were compared between captive geckos from a breeding facility and a wild population to determine whether concentrations of CORT were chronically elevated in captive lizards. Plasma CORT concentrations showed significant seasonal variation, but were not related to sex, body temperature, body condition or female reproductive condition. Geckos, which successfully bred in captivity each year, did not exhibit chronically elevated plasma CORT levels but showed an elevation of plasma CORT concentrations in summer compared with wild geckos. Information on basal CORT concentrations in species of conservation concern can be beneficial for improving their management and can aid in identifying and evaluating stress-related changes in hormone patterns of individuals and chronic stress, which is particularly relevant for threatened species breeding programs.
The objectives of this study were to characterise reproductive and metabolic endocrinology parameters in Romney rams from lines selected since 1986, for high or low circulating IGF-1 concentrations. ...Seasonal changes were recorded in the patterns of IGF-1, insulin and the response of serum testosterone to hCG administration. Serum testosterone concentrations, adjusted for covariance with IGF-1 concentrations, were higher in both strains (
P
<
0.05) in the autumn (March), compared to other times of year. The response of serum testosterone to hCG increased (
P
<
0.01) between mid-winter (July) and the following autumn. Serum testosterone concentrations were higher (
P
<
0.05) in high, compared to low-IGF rams in July and September (spring), but not in March (autumn). The serum IGF-1 concentrations were higher (
P
<
0.01) throughout the entire experiment in the high- versus the low-IGF rams, although the concentrations in the high-IGF rams declined between July and March. Insulin concentrations were also higher in the high-IGF line. The difference between the two lines was greatest in July, but not significant in March. Samples of liver and testes tissue were collected from 4 animals in each line for the polymerase chain reaction (PCR) determinations of mRNA expression for IGF-1, Type 1 IGF receptor (IGF-1R) and IGF-binding proteins (IGFBP's). Genes for IGF-1, IGF-1R and the IGFBP-2, -3, -4, -5 and -6 were expressed in the testis. Expression of IGF-1R and IGFBP-3 in the testis and that of IGF-1 in the liver, was greater in the high- than the low-IGF line rams. These studies suggest circulating concentrations IGF-1 to be associated with basal, but not gonadotrophin-stimulated steroidogenesis. The differences in IGF-1 status between lines are modulated by the differential expression of mRNA for IGF-1R and the IGFBP's and by differences between lines in the negative feedback of IGF-1.
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