Tropical Animal Health and Production - Natural compounds from medicinal plants provide safe and sustainable alternatives to synthetic anthelmintics. In this study, we assessed in vitro and in vivo... 相似文献
AIMS: To explore and validate the utility of rumen endoscopy for collection of rumen papillae for gene expression measurement.
METHODS: Four adult Coopworth ewes were fasted for either 4 or 24 hours. Animals were sedated, placed in a dorsally recumbent position at 45 degrees with the head upright, and an endoscope inserted via a tube inserted into the mouth. Biopsies of rumen papillae were taken from the ventral surface of the rumen atrium under visual guidance. Two biopsies were collected from one of the animals that had been fasted for 4 hours, and three from one of the animals that had been fasted for 24 hours. Video of the rumen atrium and reticulum was also collected. The animals recovered uneventfully. Biopsies were subsequently used for extraction and sequencing of mRNA.
RESULTS: The ventral surface of the rumen atrium was accessible after 4 hours off pasture, but a larger region was accessible after 24 hours of fasting. Sedation allowed access for endoscope use for around 5 to 10 minutes after which increased saliva flow was noted. Rumen papillae biopsies were easily collected, with samples from a variety of sites collected in the ~10 minute time window. High quality RNA was obtained for stranded mRNA sequencing. Of the resulting reads, 69–70% mapped uniquely to version 3.1 of the ovine genome, and 48–49% to a known gene. The rumen mRNA profiles were consistent with a previously reported study.
CONCLUSIONS: This method for obtaining rumenal tissue was found to be rapid and resulted in no apparent short or long term effects on the animal. High quality RNA was successfully extracted and amplified from the rumen papillae biopsies, indicating that this technique could be used for future gene expression studies. The use of rumen endoscopy could be extended to collection of a variety of rumen and reticulum anatomical measurements and deposition and retrieval of small sensors from the rumen. Rumen endoscopy offers an attractive and cost effective approach to repeated rumen biopsies compared with serial slaughter or use of cannulated animals. 相似文献
The Massachusetts Acid Rain Monitoring project surveyed 80.5% of the state's 5294 named water bodies between 1983 and 1985. PH and acid neutralizing capacity (ANC) were measured monthly the first 14 mo and semi-annually afterwards. Sample collection and analysis were performed by volunteers. The majority of surface waters in Massachusetts were found to be sensitive to possible long term acidification, with 63% exhibiting ANC less than 200 μeq L?1 and 22% with ANC less than 40 μeq L?1. Seasonal patterns in ANC were observed, the median ANC being 384 μeq L?1 in summer/fall and 134 μeq L?1 in winter/spring. Geographical differences were also found across the state: the streams and lakes with lowest pH and ANC were located in the southeastern and north-central parts of the state, while the most alkaline surface waters were found in the western-most part of the state, which is the only area of the state with significant limestone deposits. 相似文献
Thirty-five male Afshari lambs (3.5 months old), with an average weight of 35 kg were randomly assigned to one of five experimental
treatments relating to optimal replacement level of rice bran in lamb finishing diets. The lambs were fed a milled concentrate
(3 mm screen) diet supplemented with 15% (DM basis) chopped (5 cm length) lucerne hay and chopped (5 cm length) maize silage
or wet (80% moisture) sugar beet pulp. Barley grain in the lambs’ diets was replaced by rice bran at either 0, 15, 30, 45
or 60% of the concentrate mixture on a dry matter basis. Results show that lambs fed 45 and 60% rice bran treatments weighed
significantly less than those fed with 15 and 30% and control group (P < 0.05). Average daily gain in lambs fed with concentrate
mixtures containing 45 and 60% rice bran were 33 and 47% lower than control, respectively (P < 0.05). Lambs that received
diets containing 45 and 60% rice bran, had lower feed intake (P < 0.05) than other groups. Using rice bran in the finishing
diet had no significant effect on dressing percentage, tail percentage, abdominal fat and visceral organ weights. These results
suggest that barley can be replaced with rice bran up to 30% in the finishing diets of lambs without any adverse effect on
lamb performance. 相似文献
In contrast to conventional inbreeding that takes up to seven generations to develop inbred lines, the doubled haploid (DH) technology allows production of inbred lines in two generations. The objectives of the present study were to: (a) evaluate testcross performance of 45 doubled haploid lines under drought stress and non-stress conditions (b) estimate heritabilities for grain yield and other traits and (c) to assess the genetic distance and relationship among the DH lines using 163,080 SNPs generated using genotyping-by-sequencing (GBS). The 45 hybrid and five checks were evaluated using a 10 × 5 alpha lattice in six drought stress and nine well-watered environments in Kenya, Uganda, and Tanzania. Differences in trait means between the drought stress and well-watered conditions were significant for all measured traits except for anthesis date. Genetic variances for grain yield, grain moisture, plant height and ear height were high under well-watered environments while genetic variance for anthesis date, root lodging and stalk lodging were high under drought stress environments. Combined analyses across drought stress and well-watered environments showed that ten top hybrids produced 1.6–2.2 t/ha grain yield under well-watered condition and 1–1.4 t/ha under drought stress condition higher than the mean of the commercial checks. Genetic distance between pairwise comparisons of the 38 of the 45 DH lines ranged from 0.07 to 0.48, and the overall average distance was 0.36. Both cluster and principal coordinate analysis using the genetic distance matrix calculated from 163,080 SNPs showed two major groups and the patterns of group was in agreement with their pedigree. Thirteen (13) of the best hybrids are currently in National Performance Trials testing, an important step towards commercialization in Kenya, Tanzania and Uganda. 相似文献
Three groups of 1/2 Simmental X 1/4 Brahman X 1/4 Hereford bull calves were used during two different years to study effects of zeranol on sexual development. At 154 d of age, half the calves were implanted with 36 mg zeranol and half, not implanted, served as controls. Implanted calves were reimplanted at 90-d intervals throughout the trial (9 mo) each year. Trial 1 was conducted with 24 calves and Trial 2 was conducted the following year with 10 bulls. Twenty-four days after weaning (200 d of age) and at 28-d intervals thereafter, bulls in drylot in Trial 1 were weighted, scrotal circumference (SC) was measured and an ejaculate of semen was collected by electroejaculation to determine puberty. At these times, bulls were given 200 micrograms of GnRH i.m. and blood was collected at 0, 1, 2, 3, 4 and 5 h after GnRH. Serum concentrations of LH and testosterone (TEST) were determined. At slaughter, testis weight, length and circumference and pubertal status were recorded. Bulls implanted with zeranol had smaller SC than control bulls during the entire 9-mo period (P less than .0001). More control bulls reached puberty than did implanted bulls (82.4 vs 23.5%, respectively; P less than .001). Control bulls had larger testis measurements at slaughter (P less than .0001). Implants did not alter total weight gain or ADG (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Endoscopy was undertaken to examine the gastroduodenal mucosa of 24 healthy dogs after seven days and again after 28 days of oral non-steroidal anti-inflammatory drug (NSAID) administration. The dogs were divided into four groups. One group received ketoprofen (1 mg/kg every 24 hours), one group carprofen (2 mg/kg every 12 hours for seven days followed by 2 mg/kg every 24 hours), a third group meloxicam suspension (0·2 mg/kg every 24 hours), and the last group gelatin (one capsule every 24 hours). Serum biochemical and complete blood count parameters did not change significantly after NSAID administration. Gastroduodenal lesions were observed in 17 dogs, but in all cases these were mild to moderate. The dogs receiving gelatin or carprofen showed the fewest and the least severe lesions, although there was no statistically significant difference between the three test drugs and the control group (P 0–05). None of the dogs showed any clinical signs related to the gastrointestinal lesions. 相似文献
Two cases are reported, illustrating the antemortem diagnosis of systemic amyloidosis in Siamese cats. A cat presenting with inappetence and depression was diagnosed as having systemic amyloidosis with spontaneous haemorrhage from the liver. In another cat from the same breeding cattery, chronic renal failure due to systemic amyloidosis was an incidental finding. Little treatment was possible in either case and both were later euthanased. The two cats had similar renal and hepatic pathology but different signs of disease. 相似文献
Effective use of hydrogen peroxide as a chemical sterilant in mushroom production and selection of cultivable mushroom strains for tropical conditions require knowledge of the genetic diversity in the tolerance of the strains to hydrogen peroxide and to high temperatures. Therefore, three experiments were conducted to examine the sensitivity of Pleurotus mycelium to temperature and hydrogen peroxide. In Experiment 1, eight Pleurotus strains, which included two Pleurotus sajor-caju strains, three Pleurotus ostreatus strains, Pleurotus salmoneo stramineus, Pleurotus cornicopae and Pleurotus eryngii were cultured aseptically on agar at 25, 30 and or 35 °C. In Experiment 2, the eight strains were cultured aseptically on agar at six hydrogen peroxide concentrations (0–0.1%, v/v) at 27 °C. In Experiment 3, P. sajor-caju strain 1, a fast growing strain, was cultured non-asceptically at six hydrogen peroxide concentrations (0–0.1%, v/v) at 27 °C. In Experiment 1, mycelial growth was maximal at 25–30 °C, whereas a temperature of 35 °C was detrimental to mycelial growth except in one strain. At the highest temperature tested (35 °C), the relative mycelial growth rate (% of maximum) ranged from 6 to 91%, indicating marked differences in tolerance of the strains to high temperature. In Experiment 2, the mycelial growth rate in all strains increased when hydrogen peroxide was increased from 0 to 0.001% (v/v), and then decreased with further increments in hydrogen peroxide concentration. The strains differed markedly in sensitivity to hydrogen peroxide. The hydrogen peroxide concentration associated with 50% reduction in maximum mycelial growth rate due to toxicity (EC50) ranged from 0.009 to 0.045% (v/v). It was noted that P. sajor-caju strain 1 which was the most tolerant strain to high temperature was also the most tolerant to high hydrogen peroxide concentration. In Experiment 3, involving non-aseptic culture of P. sajor-caju strain 1, bacterial growth was observed at concentrations ≤0.016%, whilst the upper hydrogen peroxide concentration limit for fungal growth was 0.025% (v/v). The highest hydrogen peroxide concentrations 0.016% (v/v) and 0.025% (v/v) in which bacteria and fungi, respectively, were observed to grow were within the concentration range 0.009–0.028% (v/v) that was found in Experiment 2 to cause a 50% reduction in mycelia growth in six of the eight Pleurotus strains tested. Use of hydrogen peroxide as a chemical sterilant in conjunction with strains highly tolerant of its toxicity offers a very cheap method of producing spawn as well as the mushrooms, and opens up opportunities for poor rural people. 相似文献