John Walter Davies

Effects of Chicory/Perennial Ryegrass Swards Compared with Perennial Ryegrass Swards on the Performance and Carcass Quality of Grazing Beef Steers

An experiment investigated whether the inclusion of chicory (Cichorium intybus) in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne). Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36) were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC) determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

A novel chemical sensor with multiple all-solid-state electrodes and its application in freshwater environmental monitoring

Freshwater quality detection is important for pollution control. Three important components of water quality are pH, ammonia and dissolved H2S and there is an urgent need for a high-precision sensor for simultaneous and continuous measurement. In this study, all-solid-state electrodes of Eh, pH, NH4+ and S2- were manufactured and mounted to a wireless chemical sensor with multiple parameters. Calibration indicated that the pH electrode had a Nernst response with slope of 53.174 mV; the NH4+ electrode had a detection limit of 10-5 mol/L (Nernst response slope of 53.56 mV between 10-1 to 10-4 mol/L). Ag/Ag2S has a detection limit of 10-7 mol/L (Nernst response slope of 28.439 mV). The sensor was cylindrical and small with low power consumption and low storage demand to achieve continuous in-situ monitoring for long periods. The sensor was tested for 10 days in streams at Trawsgoed Dairy farm in Aberystwyth, UK. At the intensively farmed Trawsgoed, the concentration of NH4+ in the stream rose sharply after the application of slurry to adjacent fields. Further, the stream was overhung with extensive vegetation and exhibited changes in pH, which correlated with photosynthetic activity. Measurements of S2- were stable throughout the week. Our data demonstrate the applicability of our multiple electrode sensor.

Stability, fatty acid composition and sensory properties of the M. Longissimus muscle from beef steers grazing either chicory/ryegrass or ryegrass

Research has shown both production and health benefits for the use of chicory (Cichorium intybus) within ruminant diets. Despite this, little was known about the effects of this forage, containing differing fatty acid profiles and secondary plant compounds compared with ryegrass, on beef stability, fatty acid composition or sensory properties. An experiment was conducted to investigate whether the inclusion of chicory in the diet of grazing beef steers would alter these three properties in the M. Longissimus muscle when compared with beef steers grazing perennial ryegrass (Lolium perenne). Triplicate 2 ha plots were established with a chicory (cv. Puna II)/perennial ryegrass mix or a perennial ryegrass control. A core group of 36 Belgian Blue - cross steers were used within a 2-year beef finishing experiment (n=6/replicate plot). In the 2nd grazing year, steers were slaughtered as they reached a target fat class of 3. Muscle pH was checked 2 and 48 h post-slaughter. A section of the hindloin joint containing the M. Longissimus lumborum muscle was removed and a 20 mm-thick steak was cut and muscle samples were taken for analysis of vitamin E and fatty acid analysis. The remaining section of the loin was vacuum packed in modified atmosphere packs and subjected to simulated retail display. A section of the conditioned loin was used for sensory analysis. Data on pH, vitamin E concentration and colour stability in a simulated retail display showed there were no effects of including chicory in the diet of grazing beef steers on meat stability. There were also no differences found in the fatty acid composition or the overall eating quality of the steaks from the two treatments. In conclusion, there were no substantive effects of including chicory in the swards of grazing beef cattle on meat stability, fatty acid composition or sensory properties of the M. Longissimus muscle when compared with beef steers grazing ryegrass-only swards.